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          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfNotesPayable" xlink:label="us-gaap_RepaymentsOfNotesPayable"/>
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          <link:loc xlink:type="locator" xlink:href="guts-20260331.xsd#guts_ChangeOfControlMember" xlink:label="guts_ChangeOfControlMember"/>
          <link:loc xlink:type="locator" xlink:href="guts-20260331.xsd#guts_RejuvaDirectProgramExpensesMember" xlink:label="guts_RejuvaDirectProgramExpensesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber"/>
          <link:loc xlink:type="locator" xlink:href="guts-20260331.xsd#guts_NonCashOperatingLeaseExpense" xlink:label="guts_NonCashOperatingLeaseExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="guts-20260331.xsd#guts_WarrantLiabilitiesPolicyTextBlock" xlink:label="guts_WarrantLiabilitiesPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="guts-20260331.xsd#guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCosts" xlink:label="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="guts-20260331.xsd#guts_LossOrMaterialCostsRelatedToIndemnificationObligation" xlink:label="guts_LossOrMaterialCostsRelatedToIndemnificationObligation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="us-gaap_AccruedProfessionalFeesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="us-gaap_ScheduleOfStockByClassTable"/>
          <link:loc xlink:type="locator" xlink:href="guts-20260331.xsd#guts_NonCashInterestExpense" xlink:label="guts_NonCashInterestExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany"/>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value of warrant liability.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value of Warrant Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Incorporation, State or Country Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2030</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Increase (Decrease) in Accounts Payable, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accounts Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClassOfWarrantsOrRightsCancelled_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrants Or Rights Cancelled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClassOfWarrantsOrRightsCancelled_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Class Of Warrants Or Rights Cancelled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClassOfWarrantsOrRightsCancelled_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of warrants or rights cancelled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Long-Term Debt Instruments [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Notes Payable, Long-Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCurrentReportingStatus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Current Reporting Status</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromWarrantExercises_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Warrant Exercises</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromWarrantExercises_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercises of common stock warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromWarrantExercises_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from common stock warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesEConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series E convertible preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesEConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series E Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesEConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series E Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Expenses [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating expenses:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 2 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 2</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredTaxAssetsCapitalizedPatentAndTrademarkCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Capitalized patent and trademark costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredTaxAssetsCapitalizedPatentAndTrademarkCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax assets, capitalized patent and trademark costs.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and Contingencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Research and Development, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development tax credits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock, par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible preferred stock, original issuance price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product and Service [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Period Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total future minimum lease payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Interest Rate, Stated Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate upon amendments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityShellCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Shell Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock, shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending Balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning Balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible preferred shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractualObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Obligation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractualObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities related to obligation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Accrued Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertibleDebtMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Debt [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertibleDebtMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022 Convertible Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Fair value of warrants issued in connection with the reissuance of 2022 Convertible Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cash and Cash Equivalents, at Carrying Value, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and cash equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Cash and/or certain permitted cash equivalent investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common stock exchanged</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquityValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Temporary equity value conversion of convertible securities.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquityValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity Value Conversion Of Convertible Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquityValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of convertible preferred stock into common stock upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquityValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Conversion of convertible preferred stock into common stock upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash, long-term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average grant-date fair value, granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Expiration Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant expiration period.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant expiration period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Purchase Price of Common Stock, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise price per share of stock options as percentage of fair market value of common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFilerCategory_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Filer Category</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyFourEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand and twenty four employee stock purchase plan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyFourEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand And Twenty Four Employee Stock Purchase Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyFourEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024 Employee Stock Purchase Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities and stockholders' equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Three</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2029</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increases recorded to income tax provision</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExerciseOfPre-FundedWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of pre-funded warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExerciseOfPre-FundedWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exercise of pre-funded warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExerciseOfPre-FundedWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exerciseofprefundedwarrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FirstTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">First tranche.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FirstTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">First Tranche [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FirstTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">First Tranche</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesFConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series F convertible preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesFConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series F Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesFConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series F Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentDateOfFirstRequiredPayment1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Date of First Required Payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentDateOfFirstRequiredPayment1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">First principal payment date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Valuation Allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Valuation allowance at beginning of year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Valuation allowance at end of year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Federal statutory income tax rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Effective income tax rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Remainder of Fiscal Year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026 (Remaining)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentIncomeInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest income, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentIncomeInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment Income, Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Jurisdiction [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforwards not subject to expiration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ReclassificationOfDeferredOfferingCostsToAdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reclassification of deferred offering costs to additional paid-in capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ReclassificationOfDeferredOfferingCostsToAdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reclassification of deferred offering costs to additional paid-in capital.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ReclassificationOfDeferredOfferingCostsToAdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reclassification of deferred offering costs to additional paid-in capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheBWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tranche B Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheBWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tranche B warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheBWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tranche B Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndNineteenNoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">2019 Note.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndNineteenNoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand and Nineteen Note [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndNineteenNoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2019 Note</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockAmountConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Conversion of Stock, Amount Converted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockAmountConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of convertible preferred stock into common stock upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Significant Accounting Policies [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Significant Accounting Policies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable and Accrued Liabilities, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Shares, Grant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Basic, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net income (loss) per share, basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ResearchAndDevelopmentTaxCreditCarryforwardsExpirationYear_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Research and development tax credit carryforwards expiration year.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ResearchAndDevelopmentTaxCreditCarryforwardsExpirationYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Tax Credit Carryforwards Expiration Year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ResearchAndDevelopmentTaxCreditCarryforwardsExpirationYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development tax credit carryforwards expiration year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Adjustments to reconcile net income (loss) to net cash used in operating activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Rollforward of Fair Value of Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertibleLongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Notes Payable, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertibleLongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022 Convertible Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertibleLongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Outstanding principal amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes payable, long-term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DomesticCountryMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Domestic Tax Jurisdiction [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DomesticCountryMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Federal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Attributable to Parent [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Stockholders' equity:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders' equity:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Fair Value of Warrant Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntitySmallBusiness_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Small Business</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Retained Earnings (Accumulated Deficit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings (Accumulated Deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accumulated deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NatureOfOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nature of Operations [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NatureOfOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Nature of the Business</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforward, subject to expiration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from exercise of stock options</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrivateFinancingRoundMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Private financing round.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrivateFinancingRoundMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Private Financing Round [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrivateFinancingRoundMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Private Financing Round</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of stock, price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of stock, combined offering price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant liabilities.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_UnderwritingAgreementWithBofASecuritiesIncAndEvercoreGroupLLCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Underwriting Agreement with BofA Securities, Inc. and Evercore Group L.L.C [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_UnderwritingAgreementWithBofASecuritiesIncAndEvercoreGroupLLCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Underwriting Agreement with BofA Securities, Inc. and Evercore Group L.L.C.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_UnderwritingAgreementWithBofASecuritiesIncAndEvercoreGroupLLCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Underwriting Agreement with BofA Securities, Inc. and Evercore Group L.L.C</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-Based Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisConversionInToCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value measurement with unobservable inputs reconciliation recurring basis conversion in to common stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisConversionInToCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Conversion In To Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisConversionInToCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion into common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeasesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Leases [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amendment Flag</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ThirdTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Third tranche.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ThirdTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Third Tranche [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ThirdTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Third Tranche</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product and Service [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Date from which Warrants or Rights Exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants exercisable date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesC1ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series C-1 Convertible Preferred Stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesC1ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series C-1 Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesC1ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series C-1 Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Number of Securities Called by Warrants or Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants to purchase common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Issuance of shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities, convertible preferred stock and stockholders' equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Postal Zip Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used in operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Operating Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment reporting, CODM, profit (loss) measure, how used, description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due After Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted Average Exercise Price, Grant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Three</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2029</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Amount Capitalized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExerciseOfCommonStockWarrantsShares_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exercise of common stock warrants shares.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExerciseOfCommonStockWarrantsShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exercise of Common Stock Warrants Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExerciseOfCommonStockWarrantsShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of common stock warrants (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Interest Rate, Effective Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Address Line One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndElevenStockIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand and eleven stock incentive plan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndElevenStockIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand And Eleven Stock Incentive Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndElevenStockIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">2011 Stock Incentive Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Carrying value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Carrying Amount, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock (Series A, B, C-1, C-2, D, E and F), $0.00001 par value; no shares authorized and no shares issued or outstanding at September 30, 2024; 78,112,639 shares authorized and 77,994,156 shares issued and outstanding at December 31, 2023; aggregate liquidation preference of $0 and $379,081 at September 30, 2024 and December 31, 2023, respectively</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Supplemental Cash Flow Information [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Supplemental disclosure of cash flow information:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Right-of-Use Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use lease assets, operating</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred tax assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockUnderEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Under Employee Stock Purchase Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockUnderEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock under employee stock purchase plan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockUnderEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock Under Employee Stock Purchase Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentType_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Type</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfRevenueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfRevenueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost of Revenue [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Central Index Key</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrimeRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prime Rate [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrimeRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Wall Street Journal Prime Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClaimsOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Claims outstanding.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClaimsOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Claims outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net increase (decrease) in cash, cash equivalents and restricted cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Adjustment of Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of warrant liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Estimated fair value of warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Change in fair value of warrant liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Decrease in fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OfferingClosingDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Offering closing date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OfferingClosingDate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Offering closing date.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockTrancheAAndTrancheBWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common stock, Tranche A and Tranche B warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockTrancheAAndTrancheBWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock, Tranche A and Tranche B warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockTrancheAAndTrancheBWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock, Tranche A and Tranche W warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockTrancheAAndTrancheBWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common Stock, Tranche A and Tranche B Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common stock, Par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance of Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Tranche One [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tranche One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SharesWithHeldForExercisePriceOfPreFundedWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares withheld for exercise price of pre funded warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SharesWithHeldForExercisePriceOfPreFundedWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Shares with held for exercise price of pre funded warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_RevitaDirectProgramExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revita Direct Program Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_RevitaDirectProgramExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revita Direct Program Expenses [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_RevitaDirectProgramExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Revita direct program expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AccruedPersonnelExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Personnel Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AccruedPersonnelExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued personnel expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AccruedPersonnelExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payroll and payroll-related expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesAConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series A convertible preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesAConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series A Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesAConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PaymentForOperatingLeasesWithinOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payment for operating leases within operating activities.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PaymentForOperatingLeasesWithinOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payment for operating leases within operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PaymentForOperatingLeasesWithinOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payment for operating leases within operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of common stock options (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Number of Shares, Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Fiscal Year End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Long-Term Debt Instruments [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentQuarterlyReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Quarterly Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, State or Province</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of convertible preferred stock into common stock upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Conversion of Convertible Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Preferred Stock, Shares Outstanding, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Preferred Stock, Shares Outstanding, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Capital Shares Reserved for Future Issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares available for future grant under the 2024 Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Conversion of Stock, Shares Converted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares converted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Share-Based Compensation Expense Related to Its Stock Options and Restricted Stock Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Stock Options Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of common stock options</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued Expenses and Other Current Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Net Deferred Tax Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfParticipantsInPivotalCohort_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Participants in Pivotal Cohort</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfParticipantsInPivotalCohort_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of participants in pivotal cohort</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfParticipantsInPivotalCohort_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">It refers to the participants in the Pivotal Cohort.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Event</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_MinimumRequiredBidPriceAmountPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum required bid price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_MinimumRequiredBidPriceAmountPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum Required Bid Price Amount Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_MinimumRequiredBidPriceAmountPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Minimum required bid price amount per share.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PlanEffectiveDate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Plan effective date.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PlanEffectiveDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Effective Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PlanEffectiveDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan effective date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Tax Credit Carryforwards, Research</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development tax credit carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other long-term assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Basis of Presentation and Significant Accounting Policies [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basis of Presentation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StateAndLocalJurisdictionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">State and Local Jurisdiction [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StateAndLocalJurisdictionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesLongTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant liabilities long term.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesLongTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Liabilities Long term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesLongTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant liabilities, long-term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Value, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, $0.00001 par value; 10,000,000 shares authorized at March 31, 2026 and December 31, 2025; no shares issued and outstanding at March 31, 2026 and December 31, 2025</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Selling, General and Administrative Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Selling, General and Administrative Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Selling, general and administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Maturity Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maturity date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable and Other Accrued Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses and other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accrued expenses and other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 3 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 3</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Fair Value Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionOriginalDebtInterestRateOfDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion, Original Debt, Interest Rate of Debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionOriginalDebtInterestRateOfDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest accrued on the unpaid principal balance, Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning Balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending Balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accounts Receivable, after Allowance for Credit Loss, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable, after Allowance for Credit Loss, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PlanAdoptionDate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Plan adoption date.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PlanAdoptionDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Adoption Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PlanAdoptionDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan adoption date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DebtInstrumentPeriodicPaymentPercentageOfPrincipal_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument periodic payment percentage of principal.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DebtInstrumentPeriodicPaymentPercentageOfPrincipal_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Periodic Payment Percentage of Principal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DebtInstrumentPeriodicPaymentPercentageOfPrincipal_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Periodic payment percentage of principal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and contingencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Leases [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_HarithRajagopalanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Harith Rajagopalan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_HarithRajagopalanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Harith Rajagopalan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_HarithRajagopalanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Harith Rajagopalan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Basis Spread on Variable Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate margin</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityReverseStockSplit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders' Equity, Reverse Stock Split</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityReverseStockSplit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reverse stock split, description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquitySharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Temporary equity shares conversion of convertible securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquitySharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity Shares Conversion Of Convertible Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquitySharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of convertible preferred stock into common stock upon initial public offering (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TemporaryEquitySharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Conversion of convertible preferred stock into common stock upon initial public offering (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioForecastMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Forecast [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioForecastMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Scenario Forecast</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfComplianceDays_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Compliance Days</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfComplianceDays_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of compliance days.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfComplianceDays_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of compliance days</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FinanceLeaseLiabilityToBePaidAfterYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FinanceLeaseLiabilityToBePaidAfterYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, after Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FinanceLeaseLiabilityToBePaidAfterYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantAverageTradingPriceThresholdConsecutiveTradingDays_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Average Trading Price Threshold Consecutive Trading Days</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantAverageTradingPriceThresholdConsecutiveTradingDays_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant average trading price threshold consecutive trading days.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantAverageTradingPriceThresholdConsecutiveTradingDays_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant average trading price threshold consecutive trading days</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ReclassificationOfWarrantLiabilityToEquityUponInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reclassification of warrant liability to equity upon initial public offering.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ReclassificationOfWarrantLiabilityToEquityUponInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reclassification Of Warrant Liability To Equity Upon Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ReclassificationOfWarrantLiabilityToEquityUponInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reclassification of warrant liability to equity upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Capital Expenditures Incurred but Not yet Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchases of property and equipment included in accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net income (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandFourteenWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Fourteen Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandFourteenWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Fourteen Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandFourteenWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2014 Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationAllocationAndClassificationInFinancialStatementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Recognized Amount [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted Average Number of Shares Outstanding, Basic, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average number of common shares outstanding, basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheAWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tranche A Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheAWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tranche A warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheAWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tranche A Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_StatementScenarioAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scenario [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PeriodOfOptionGrantedToUnderwriters_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Period of option granted to Underwriters</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PeriodOfOptionGrantedToUnderwriters_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Period of option granted to Underwriters.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PeriodOfOptionGrantedToUnderwriters_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Period of option granted to Underwriters</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingExpenseInformationUsedByCodmDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting, Expense Information Used by CODM, Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingExpenseInformationUsedByCodmDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment reporting, expense information used by CODM, description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonIPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-IPO.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonIPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non I P O [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonIPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-IPO</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Effective Income Tax Rate Reconciliation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesLeasingArrangements_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use lease assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesLeasingArrangements_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Right-of-use lease assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesLeasingArrangements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Leasing Arrangements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowanceAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Allowance [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance of Private Placement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of private placement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsNetAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Net [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsNetAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Subsequent Event</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Events [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Interest Rate Terms</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate terms</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Variable Rate [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsInProcessResearchAndDevelopment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capitalized research and development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsInProcessResearchAndDevelopment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Asset, In-Process Research and Development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total stockholders' equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueAdjustmentOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value adjustment of notes payable.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueAdjustmentOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Adjustment Of Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueAdjustmentOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueAdjustmentOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Change in fair value of notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Stockholders' Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionOriginalDebtDueDateOfDebtDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion, Original Debt, Due Date of Debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionOriginalDebtDueDateOfDebtDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Original maturity date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantAverageTradingPriceThresholdPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant average trading price threshold per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantAverageTradingPriceThresholdPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Average Trading Price Threshold Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantAverageTradingPriceThresholdPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant average trading price threshold per share.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementsInterTransfersBetweenLevels_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of transfers of financial instruments classified as an asset or liability between level 1, level 2, and level 3 of the fair value hierarchy.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementsInterTransfersBetweenLevels_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurements Inter Transfers Between Levels</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementsInterTransfersBetweenLevels_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transfers between level 1, level 2 and level 3</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UseOfEstimates_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Use of Estimates, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UseOfEstimates_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Use of Estimates</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine2_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Address Line Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Disclosures [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Measurements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DebtInterestRatePaidInKind_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt interest rate paid in kind.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DebtInterestRatePaidInKind_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Interest Rate Paid In Kind</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DebtInterestRatePaidInKind_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate paid in kind</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductInformationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product Information [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsNoteDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants and Rights Note Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsNoteDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant Liabilities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other long-term assets and liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesDConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series D convertible preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesDConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series D Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesDConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series D Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Noncash Investing and Financing Items [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash investing and financing activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseAndOtherAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Expense and Other Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseAndOtherAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid expenses and other current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Partial repayment of notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reclassification of warrant liability to equity upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issued fully vested warrant to purchase convertible preferred stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Warrant purchase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredChargesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Charges, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredChargesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Public Offering Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableToBankNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable to Bank, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableToBankNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023 Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, City or Town</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrefundedWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prefunded Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrefundedWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prefunded warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrefundedWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pre-funded Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number of Reportable Segments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of reportable segment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AccruedResearchAndDevelopmentServicesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Research And Development Services Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AccruedResearchAndDevelopmentServicesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued research and development services current.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AccruedResearchAndDevelopmentServicesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_SecurityExchangeName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Security Exchange Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredOfferingCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Offering Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredOfferingCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPaymentOfInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value measurement with unobservable inputs reconciliation recurring basis liability payment of interest.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPaymentOfInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Payment Of Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPaymentOfInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payment of interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Decrease in fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value measurement with unobservable inputs reconciliation recurring basis liability decrease.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Decrease</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Inventory, Net, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventory</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Cash, cash equivalents and restricted cash at beginning of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Cash, cash equivalents and restricted cash at end of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestPaidNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Paid, Excluding Capitalized Interest, Operating Activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestPaidNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant liabilities.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Liabilities [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Exercise Price of Warrants or Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Exercise price of warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentPeriodEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Period End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrefundWarrantExchangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prefund Warrant Exchange [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrefundWarrantExchangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prefund warrant exchange.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PrefundWarrantExchangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prefund Warrant Exchange</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfParticipantsInMidpointCohort_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of participants in midpoint cohort</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfParticipantsInMidpointCohort_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Participants in Midpoint Cohort</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfParticipantsInMidpointCohort_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">It refers to the participants in the Midpoint Cohort.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Financial Position [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Security, Excluded EPS Calculation [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PercentageOfInitialPublicOfferingPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of initial public offering per share.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PercentageOfInitialPublicOfferingPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage of initial public offering per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PercentageOfInitialPublicOfferingPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of initial public offering per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsOutstandingMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants and Rights Outstanding, Maturity Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsOutstandingMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants maturity date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClassOfWarrantsOrRightsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of warrants or rights exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClassOfWarrantsOrRightsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrants Or Rights Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ClassOfWarrantsOrRightsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Class Of Warrants Or Rights Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2028</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Variable Rate [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted Average Number of Shares Outstanding, Diluted, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average number of common shares outstanding, diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SecondTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Second tranche.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SecondTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Second Tranche [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SecondTrancheMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Second Tranche</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity File Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AugustTwentyTwentyFivePublicOfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">August 2025 Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AugustTwentyTwentyFivePublicOfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">August Twenty Twenty Five Public Offering [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AugustTwentyTwentyFivePublicOfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">August twenty twenty five public offering.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CoverAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cover [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationReturnToProvision_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective income tax rate reconciliation return to provision.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationReturnToProvision_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Return To Provision</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationReturnToProvision_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Return to provision</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SummaryOfValuationAllowanceTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Summary of Valuation Allowance [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SummaryOfValuationAllowanceTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Valuation Allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scenario [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number of Operating Segments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of operating segment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Segment Information</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer, Including Assessed Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Liquidation Preference</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock, liquidation preference</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Liquidation preference</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PercentageOfCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of common stock shares outstanding.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PercentageOfCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage of Common Stock Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PercentageOfCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of common stock shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermDebtTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Debt, Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Convertible, Conversion Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion price considered</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfProductInformationTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nature of Operation, Product Information, Concentration of Risk [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AfterAmendmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">After amendments.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AfterAmendmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">After Amendments [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AfterAmendmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">After Amendments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermDebtTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Debt, Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">New Accounting Pronouncements, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recently Adopted/Issued Accounting Pronouncements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Conversion of Convertible Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible notes converted into common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Conversion of convertible preferred stock into common stock upon initial public offering (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Depreciation, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecognized tax benefits, interest, or penalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Common Stock, Shares, Outstanding, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Common Stock, Shares, Outstanding, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value measurement with unobservable inputs reconciliation recurring basis liability increase.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Increase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increase in fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Obligation, Fiscal Year Maturity [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Future Minimum Lease Payments for Operating and Finance Leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Transition Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Additional Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net deferred tax assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total operating expenses</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total research and development expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total research and development expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and development expenses</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A, B, C-1, C-2, D, E and F Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Cash Flows [Abstract]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock in initial public offering, net of underwriting discounts, commissions and offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Stock issued during period, aggregate offering price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Fair Value Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-deductible stock compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Preferred and Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Income (Loss) Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ConvertiblePreferredStockDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Convertible preferred stock disclosure.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ConvertiblePreferredStockDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Preferred Stock Disclosure [Text[Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ConvertiblePreferredStockDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeptemberTwoThousandTwentyThreeWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">September Two Thousand Twenty Three Warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeptemberTwoThousandTwentyThreeWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">September Two Thousand Twenty Three Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeptemberTwoThousandTwentyThreeWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">September 2023 Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net income (loss) and comprehensive income (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Segment net income (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Increase (Decrease) in Inventories, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Inventories</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Inventory</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_BeginningSeptember302026Member_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Beginning September 30, 2026.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_BeginningSeptember302026Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Beginning September 30, 2026 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_BeginningSeptember302026Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Beginning September 30, 2026</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_August2025OfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">August 2025 Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_August2025OfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">August 2025 Offering [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_August2025OfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">August 2025 Offering.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IndirectExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Indirect Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IndirectExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Indirect expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IndirectExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Indirect expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentCovenantCompliance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Covenant Compliance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentCovenantCompliance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial covenants, Compliance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxContingencyLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Contingency [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockConvertibleSharesIssuable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Convertible, Shares Issuable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockConvertibleSharesIssuable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock converted to warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ProceedsFromIssuanceOfCommonStockNet_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from issuance of common stock net.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ProceedsFromIssuanceOfCommonStockNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Issuance Of Common Stock Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ProceedsFromIssuanceOfCommonStockNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of common stock net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ProceedsFromIssuanceOfCommonStockNet_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net proceeds from issuance of common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected dividend yield</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Risk-free interest rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Prepaid Expense and Other Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Prepaid expenses and other current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Year Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investing activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accounts Payable, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and Development Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Research and Development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionOriginalDebtIssuanceDateOfDebtDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion, Original Debt, Issuance Date of Debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionOriginalDebtIssuanceDateOfDebtDayMonthAndYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issued date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComponentsOfDeferredTaxAssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Components of Deferred Tax Assets [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionConvertedInstrumentAmount1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion, Converted Instrument, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionConvertedInstrumentAmount1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of 2022 Convertible Notes into common stock upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockFromRestrictedStockUnitsVesting_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of common stock from restricted stock units vesting.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockFromRestrictedStockUnitsVesting_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance Of Common Stock From Restricted Stock Units Vesting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockFromRestrictedStockUnitsVesting_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock from restricted stock units vesting (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheBWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tranche B Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheBWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tranche B Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheBWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tranche B warrant.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IpoClosingDate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">IPO closing date.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IpoClosingDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">IPO Closing Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IpoClosingDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">IPO closing date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Stock Options Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from exercise of stock options</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Disclosures [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant liabilities current.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Liabilities Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant liabilities, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OnAndPriorToSeptember302024Member_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">On and prior to September 30, 2024.</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExaminationDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax examination, description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TimothyKiefferMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Timothy Kieffer [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TimothyKiefferMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Timothy Kieffer.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TimothyKiefferMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Timothy Kieffer</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used in investing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredOfferingCostsIncludedInAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred offering costs included in accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredOfferingCostsIncludedInAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred offering costs included in accrued expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredOfferingCostsIncludedInAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred offering costs included in accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Title of 12(b) Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesNetAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Net [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesNetAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Money Market Funds [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Money Market Funds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock, shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible preferred shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OperatingLossCarryforwardsExpirationYear_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Operating loss carryforwards expiration year.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OperatingLossCarryforwardsExpirationYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards Expiration Year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OperatingLossCarryforwardsExpirationYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforward expiration year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeEnd1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Maturity Date Range, End</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentMaturityDateRangeEnd1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Extended maturity date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026 (Remaining)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other long-term liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reconciliation of Revenue from Segments to Consolidated [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in operating assets and liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant exercised.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Recurring and Nonrecurring [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Unrecognized Tax Benefits, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Unrecognized Tax Benefits, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecognized tax position</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid-in Capital [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional Paid-in Capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses and other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Frequency [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trading Symbol</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and Equipment, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OpenTaxYear_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Open Tax Year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OpenTaxYear_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax return open year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ProceedsFromIssuanceOfWarrantsYetToReceive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Issuance Of Warrants Yet To Receive</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ProceedsFromIssuanceOfWarrantsYetToReceive_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds From Issuance Of Warrants Yet To Receive</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ProceedsFromIssuanceOfWarrantsYetToReceive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of warrants yet to receive</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredTaxAssetsAccruedExpensesAndOther_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred tax assets, accrued expenses and other.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredTaxAssetsAccruedExpensesAndOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued expenses and other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financing activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected term of stock option</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Weighted average expected term (in years)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Expected term (in years)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Recurring [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value on Recurring Basis</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityExTransitionPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Ex Transition Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total future minimum lease payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueAdjustmentOfNotesPayableNoncash_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value adjustment of notes payable noncash.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueAdjustmentOfNotesPayableNoncash_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Adjustment of Notes Payable Noncash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueAdjustmentOfNotesPayableNoncash_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of notes payable, non-cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCostsValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock in connection with at-the-market offering, net of issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCostsValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance of Common Stock in Connection with At-the-market Offering, Net of Issuance Costs Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCostsValue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of common stock in connection with at-the-market offering, net of issuance costs value.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Components [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AugustTwoThousandTwentyFiveWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">August Two Thousand Twenty Five Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AugustTwoThousandTwentyFiveWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">August two thousand twenty five warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AugustTwoThousandTwentyFiveWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">August 2025 Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyFourIncentiveAwardPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand and twenty four incentive award plan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyFourIncentiveAwardPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand And Twenty Four Incentive Award Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyFourIncentiveAwardPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024 Incentive Award Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total other income (expense), net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other income, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total other income, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Component [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reconciliation of Revenue from Segments to Consolidated [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfRevenueFromSegmentsToConsolidatedTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Reconciliation of Reported Operating Expenses to Net Loss Under the Significant Expenses Principle</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfStockDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock Disclosures [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">IPO [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">IPO</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesNonCurrentFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant liabilities, non-current fair value disclosure.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesNonCurrentFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant liabilities, non-current fair value disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesNonCurrentFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant liabilities, long-term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Employee Stock Purchase Plans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock under employee stock purchase plan (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes payable, long-term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Notes payable, long-term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Outstanding principal balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maximum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueWarrantsReclassifiedToEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value warrants reclassified to equity.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueWarrantsReclassifiedToEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Warrants Reclassified To Equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueWarrantsReclassifiedToEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reclassification to equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Value, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, $0.00001 par value; 300,000,000 shares authorized as of March 31, 2026 and December 31, 2025; 158,648,963 and 153,372,044 shares issued and outstanding at March 31, 2026 and December 31, 2025, respectively</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Principal Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Principal payments on finance lease obligations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants and Rights Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Immediately exercisable warrants amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OutstandingRestrictedStockUnitsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding Restricted Stock Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OutstandingRestrictedStockUnitsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Outstanding restricted stock units.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OutstandingRestrictedStockUnitsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Outstanding restricted stock units [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxContingencyTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Contingency [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Tax Assets, Operating Loss Carryforwards, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Operating Loss Carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net operating loss carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FirstAmendmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">First amendment.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FirstAmendmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">First Amendment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FirstAmendmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">First Amendment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State income taxes, net of federal benefit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueOfWarrantLiabilitiesRecognizedInConnectionWithPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Of Warrant Liabilities Recognized In Connection With Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueOfWarrantLiabilitiesRecognizedInConnectionWithPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value of warrant liabilities recognized in connection with public offering.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_FairValueOfWarrantLiabilitiesRecognizedInConnectionWithPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value of warrant liabilities recognized in connection with August 2025 public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentCovenantDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Covenant Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentCovenantDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial covenants, Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OutstandingStockOptionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Outstanding stock options.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OutstandingStockOptionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Outstanding stock options [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_OutstandingStockOptionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding Stock Options</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected volatility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityRegistrantName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Registrant Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantsAndRightsOutstandingPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrants and rights outstanding per share.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantsAndRightsOutstandingPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants And Rights Outstanding Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantsAndRightsOutstandingPerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value of Series B convertible preferred stock per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesCurrentFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant liabilities, current fair value disclosure.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesCurrentFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant liabilities, current fair value disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesCurrentFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant liabilities, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Nonoperating Income (Expense), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Other expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NatureOfBusinessAndOrganizationDetailsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Nature of business and organization details.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NatureOfBusinessAndOrganizationDetailsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nature of Business and Organization Details [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Additional Paid in Capital, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid in Capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional paid-in capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Conversion of Stock, Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock issuable upon conversion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Events [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_S3RegistrationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">S-3 Registration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_S3RegistrationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">S 3 Registration [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_S3RegistrationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">S 3 Registration.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Income Tax Expense (Benefit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax benefits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Frequency [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_UnderwritingAgreementWithLadenburgThalmannCoIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Underwriting Agreement with Ladenburg Thalmann &amp; Co. Inc.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_UnderwritingAgreementWithLadenburgThalmannCoIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Underwriting Agreement with Ladenburg Thalmann &amp; Co. Inc. [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_UnderwritingAgreementWithLadenburgThalmannCoIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Underwriting Agreement with Ladenburg Thalmann &amp; Co. Inc.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_UnderwritingAgreementWithLadenburgThalmannCoIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Underwriting Agreement with Ladenburg</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance of Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of common stock under employee stock purchase plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from issuance of common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Fair Value of Warrant Determined Using Black Scholes Valuation Model</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Common Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesBConvertiblePreferredStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series B convertible preferred stock warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesBConvertiblePreferredStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series B Convertible Preferred Stock warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesBConvertiblePreferredStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series B Convertible Preferred Stock Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Payments to Acquire Property, Plant, and Equipment, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfCommonStockReservedForIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of common stock reserved for issuance.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfCommonStockReservedForIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number of Common Stock Reserved For Issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfCommonStockReservedForIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of common stock reserved for issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesC2ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series C-2 convertible preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesC2ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series C-2 Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesC2ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series C-2 Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-Based Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Selling, General and Administrative Expenses [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Selling, General and Administrative Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Selling, General and Administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of stock, number of shares issued in transaction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of stock, number of shares issued in transaction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Issuance of common stock in initial public offering, net of underwriting discounts, commissions and offering costs (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number of shares sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock, shares authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible preferred shares authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Diluted, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net income (loss) per share, diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationPermanentDifferences_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective income tax rate reconciliation permanent differences.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationPermanentDifferences_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Permanent Differences</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationPermanentDifferences_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Permanent differences</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Percent [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_September2025OfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">September 2025 Offering [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_September2025OfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">September 2025 Offering.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_September2025OfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">September 2025 Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">City Area Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredTaxAssetsLeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Tax Assets, Lease Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredTaxAssetsLeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Lease Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_DeferredTaxAssetsLeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AtTheMarketOfferingATMMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">At The Market Offering ("ATM") [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AtTheMarketOfferingATMMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">At The Market Offering ("ATM").</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AtTheMarketOfferingATMMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">At-The-Market Offering ("ATM")</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_AtTheMarketOfferingATMMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">At-The-Market Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyThreeNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">2023 Notes.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyThreeNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand And Twenty Three Notes [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TwoThousandAndTwentyThreeNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023 Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common stock warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_CommonStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Face Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Principal amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Principal amount of convertible notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line of Credit Facility, Maximum Borrowing Capacity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum borrowing capacity under loan and security agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NatureOfBusinessAndOrganizationDetailsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Nature of business and organization details.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NatureOfBusinessAndOrganizationDetailsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nature of Business and Organization Details [LIne items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PersonnelRelatedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Personnel-related expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PersonnelRelatedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Personnel Related Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_PersonnelRelatedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Personnel related expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock under employee stock purchase plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Employee Stock Purchase Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders' Equity Note, Stock Split, Conversion Ratio</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reverse stock split conversion ratio</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Property and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Right-of-Use Asset Obtained in Exchange for Finance Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance lease right-of-use asset obtained in exchange for lease liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeptemberTwentyTwentyFiveOfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">September 2025 Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeptemberTwentyTwentyFiveOfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">September Twenty Twenty Five Offering [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeptemberTwentyTwentyFiveOfferingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">September twenty twenty five offering.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_JayCaplanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Jay Caplan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_JayCaplanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Jay Caplan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_JayCaplanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Jay Caplan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Share-Based Payment Arrangement, Noncash Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Noncash Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheAWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tranche A Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheAWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tranche A Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_TrancheAWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tranche A warrant.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_JulyTwoThousandTwentyThreeWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">July two thousand twenty three warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_JulyTwoThousandTwentyThreeWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">July Two Thousand Twenty Three Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_JulyTwoThousandTwentyThreeWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">July 2023 Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesBConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series B convertible preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesBConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series B Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_SeriesBConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series B Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities, long-term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 1 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 1</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfStockLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash provided by financing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense) [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other income (expense), net:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExitFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exit fee percentage.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExitFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exit Fee Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ExitFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exit fee percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Securities That Could Potentially Dilute Basic Net Income (Loss) Per Share in Future Were Not Included in Computation of Diluted Income (Loss) Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Jurisdiction [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Interactive Data Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationChangeInFairValueOfConvertibleNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective income tax rate reconciliation change in fair value of convertible notes payable.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationChangeInFairValueOfConvertibleNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Change In Fair Value Of Convertible Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_EffectiveIncomeTaxRateReconciliationChangeInFairValueOfConvertibleNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of convertible notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating activities:</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfTradingDays_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of trading days</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NumberOfTradingDays_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of trading days.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Tax Identification Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Fair value of common stock per share</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Repayment of notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount paid off</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ChangeOfControlMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Change of control.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ChangeOfControlMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change of Control [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_ChangeOfControlMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change of Control</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_RejuvaDirectProgramExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Rejuva Direct Program Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_RejuvaDirectProgramExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Rejuva Direct Program Expenses [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_RejuvaDirectProgramExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Rejuva direct program expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Proceeds from Issuance or Sale of Equity, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance or Sale of Equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from equity financing or series of financings</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from follow-on offering, net of underwriting discounts and commissions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Local Phone Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonCashOperatingLeaseExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-cash operating lease expense.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonCashOperatingLeaseExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non-cash operating lease expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonCashOperatingLeaseExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash interest expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2028</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Issuance of common stock in connection with at-the-market offering/initial public offering net of issuance or offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Liabilities Policy Text Block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant liabilities.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_WarrantLiabilitiesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock in connection with at-the-market offering, net of issuance costs (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance of Common Stock in Connection with At-the-market Offering, Net of Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of common stock in connection with at-the-market offering, net of issuance costs.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Policies [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2030</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfStockDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_LossOrMaterialCostsRelatedToIndemnificationObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Loss or material costs related to indemnification obligation.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_LossOrMaterialCostsRelatedToIndemnificationObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Loss or material costs related to indemnification obligation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Professional Fees, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Professional fees and consulting services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Accrued Expenses and Other Current Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfStockByClassTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock, Class of Stock [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonCashInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Cash Interest Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonCashInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash interest expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="guts_NonCashInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non cash interest expense.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Emerging Growth Company</link:label>
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          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityIncorporationStateCountryCode" xlink:to="dei_EntityIncorporationStateCountryCode_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_lbl"/>
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          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="guts_ClassOfWarrantsOrRightsCancelled" xlink:to="guts_ClassOfWarrantsOrRightsCancelled_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:to="us-gaap_ScheduleOfDebtInstrumentsTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl"/>
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          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_EquityAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCurrentReportingStatus" xlink:to="dei_EntityCurrentReportingStatus_lbl"/>
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          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="guts_DeferredTaxAssetsCapitalizedPatentAndTrademarkCosts" xlink:to="guts_DeferredTaxAssetsCapitalizedPatentAndTrademarkCosts_lbl"/>
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          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany_lbl"/>
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  <xsd:element id="guts_FirstAmendmentMember" name="FirstAmendmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_ClassOfWarrantsOrRightsCancelled" name="ClassOfWarrantsOrRightsCancelled" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_NumberOfParticipantsInPivotalCohort" name="NumberOfParticipantsInPivotalCohort" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_August2025OfferingMember" name="August2025OfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_September2025OfferingMember" name="September2025OfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_TrancheAWarrantMember" name="TrancheAWarrantMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_SeriesC1ConvertiblePreferredStockMember" name="SeriesC1ConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_SeptemberTwoThousandTwentyThreeWarrantsMember" name="SeptemberTwoThousandTwentyThreeWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_ThirdTrancheMember" name="ThirdTrancheMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_SharesWithHeldForExercisePriceOfPreFundedWarrants" name="SharesWithHeldForExercisePriceOfPreFundedWarrants" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_SeriesEConvertiblePreferredStockMember" name="SeriesEConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_TemporaryEquityValueConversionOfConvertibleSecurities" name="TemporaryEquityValueConversionOfConvertibleSecurities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_TrancheAWarrantsMember" name="TrancheAWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_SeriesFConvertiblePreferredStockMember" name="SeriesFConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_IndirectExpenses" name="IndirectExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIncrease" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIncrease" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_TwoThousandAndElevenStockIncentivePlanMember" name="TwoThousandAndElevenStockIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_FinanceLeaseLiabilityToBePaidAfterYearFour" name="FinanceLeaseLiabilityToBePaidAfterYearFour" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_NumberOfTradingDays" name="NumberOfTradingDays" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_BeginningSeptember302026Member" name="BeginningSeptember302026Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_PrefundWarrantExchangeMember" name="PrefundWarrantExchangeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_WarrantExercised" name="WarrantExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_WarrantLiabilitiesTextBlock" name="WarrantLiabilitiesTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_WarrantLiabilitiesCurrentFairValueDisclosure" name="WarrantLiabilitiesCurrentFairValueDisclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_LossOrMaterialCostsRelatedToIndemnificationObligation" name="LossOrMaterialCostsRelatedToIndemnificationObligation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_ResearchAndDevelopmentTaxCreditCarryforwardsExpirationYear" name="ResearchAndDevelopmentTaxCreditCarryforwardsExpirationYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_RevitaDirectProgramExpensesMember" name="RevitaDirectProgramExpensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_TemporaryEquitySharesConversionOfConvertibleSecurities" name="TemporaryEquitySharesConversionOfConvertibleSecurities" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisConversionInToCommonStock" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisConversionInToCommonStock" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_PrivateFinancingRoundMember" name="PrivateFinancingRoundMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_ProceedsFromIssuanceOfWarrantsYetToReceive" name="ProceedsFromIssuanceOfWarrantsYetToReceive" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_OutstandingRestrictedStockUnitsMember" name="OutstandingRestrictedStockUnitsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_IpoClosingDate" name="IpoClosingDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_DeferredOfferingCostsIncludedInAccruedExpenses" name="DeferredOfferingCostsIncludedInAccruedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_ExitFeePercentage" name="ExitFeePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_PlanEffectiveDate" name="PlanEffectiveDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_CommonStockUnderEmployeeStockPurchasePlanMember" name="CommonStockUnderEmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_NumberOfCommonStockReservedForIssuance" name="NumberOfCommonStockReservedForIssuance" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_FairValueOfWarrantLiabilitiesRecognizedInConnectionWithPublicOffering" name="FairValueOfWarrantLiabilitiesRecognizedInConnectionWithPublicOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_WarrantLiabilitiesLongTerm" name="WarrantLiabilitiesLongTerm" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_TrancheBWarrantsMember" name="TrancheBWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_DebtInstrumentPeriodicPaymentPercentageOfPrincipal" name="DebtInstrumentPeriodicPaymentPercentageOfPrincipal" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_SeriesAConvertiblePreferredStockMember" name="SeriesAConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour" name="LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_JayCaplanMember" name="JayCaplanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_ReclassificationOfWarrantLiabilityToEquityUponInitialPublicOffering" name="ReclassificationOfWarrantLiabilityToEquityUponInitialPublicOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_UnderwritingAgreementWithLadenburgThalmannCoIncMember" name="UnderwritingAgreementWithLadenburgThalmannCoIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_IssuanceOfCommonStockFromRestrictedStockUnitsVesting" name="IssuanceOfCommonStockFromRestrictedStockUnitsVesting" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_PlanAdoptionDate" name="PlanAdoptionDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_NumberOfParticipantsInMidpointCohort" name="NumberOfParticipantsInMidpointCohort" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_CommonStockTrancheAAndTrancheBWarrantsMember" name="CommonStockTrancheAAndTrancheBWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_WarrantLiabilities" name="WarrantLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_ReclassificationOfDeferredOfferingCostsToAdditionalPaidInCapital" name="ReclassificationOfDeferredOfferingCostsToAdditionalPaidInCapital" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_TwoThousandAndTwentyFourEmployeeStockPurchasePlanMember" name="TwoThousandAndTwentyFourEmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_NatureOfBusinessAndOrganizationDetailsTable" name="NatureOfBusinessAndOrganizationDetailsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCosts" name="IssuanceOfCommonStockInConnectionWithAt-The-MarketOfferingNetOfIssuanceCosts" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_S3RegistrationMember" name="S3RegistrationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_OfferingClosingDate" name="OfferingClosingDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_EffectiveIncomeTaxRateReconciliationPermanentDifferences" name="EffectiveIncomeTaxRateReconciliationPermanentDifferences" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_TwoThousandFourteenWarrantMember" name="TwoThousandFourteenWarrantMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_EffectiveIncomeTaxRateReconciliationChangeInFairValueOfConvertibleNotesPayable" name="EffectiveIncomeTaxRateReconciliationChangeInFairValueOfConvertibleNotesPayable" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_FirstTrancheMember" name="FirstTrancheMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_OperatingLossCarryforwardsExpirationYear" name="OperatingLossCarryforwardsExpirationYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_DeferredTaxAssetsAccruedExpensesAndOther" name="DeferredTaxAssetsAccruedExpensesAndOther" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_TwoThousandAndNineteenNoteMember" name="TwoThousandAndNineteenNoteMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_WarrantLiabilitiesNonCurrentFairValueDisclosure" name="WarrantLiabilitiesNonCurrentFairValueDisclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_WarrantLiabilitiesPolicyTextBlock" name="WarrantLiabilitiesPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_AccruedResearchAndDevelopmentServicesCurrent" name="AccruedResearchAndDevelopmentServicesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_WarrantAverageTradingPriceThresholdPerShare" name="WarrantAverageTradingPriceThresholdPerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_AccruedPersonnelExpenses" name="AccruedPersonnelExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_CommonStockWarrantsMember" name="CommonStockWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_SeriesC2ConvertiblePreferredStockMember" name="SeriesC2ConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_AugustTwentyTwentyFivePublicOfferingMember" name="AugustTwentyTwentyFivePublicOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_SeriesDConvertiblePreferredStockMember" name="SeriesDConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_ExerciseOfCommonStockWarrantsShares" name="ExerciseOfCommonStockWarrantsShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_NumberOfComplianceDays" name="NumberOfComplianceDays" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_OnAndPriorToSeptember302024Member" name="OnAndPriorToSeptember302024Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_ConvertiblePreferredStockDisclosureTextBlock" name="ConvertiblePreferredStockDisclosureTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_EffectiveIncomeTaxRateReconciliationReturnToProvision" name="EffectiveIncomeTaxRateReconciliationReturnToProvision" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_FairValueAdjustmentOfNotesPayable" name="FairValueAdjustmentOfNotesPayable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_SeriesBConvertiblePreferredStockWarrantsMember" name="SeriesBConvertiblePreferredStockWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_PaymentForOperatingLeasesWithinOperatingActivities" name="PaymentForOperatingLeasesWithinOperatingActivities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_SeptemberTwentyTwentyFiveOfferingMember" name="SeptemberTwentyTwentyFiveOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_PercentageOfCommonStockSharesOutstanding" name="PercentageOfCommonStockSharesOutstanding" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_PersonnelRelatedExpenses" name="PersonnelRelatedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_AfterAmendmentsMember" name="AfterAmendmentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_AtTheMarketOfferingATMMember" name="AtTheMarketOfferingATMMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_SeriesBConvertiblePreferredStockMember" name="SeriesBConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_FairValueAdjustmentOfNotesPayableNoncash" name="FairValueAdjustmentOfNotesPayableNoncash" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_JulyTwoThousandTwentyThreeWarrantsMember" name="JulyTwoThousandTwentyThreeWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_WarrantAverageTradingPriceThresholdConsecutiveTradingDays" name="WarrantAverageTradingPriceThresholdConsecutiveTradingDays" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="guts_WarrantsAndRightsOutstandingPerShare" name="WarrantsAndRightsOutstandingPerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="guts_ChangeOfControlMember" name="ChangeOfControlMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_OutstandingStockOptionsMember" name="OutstandingStockOptionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_AugustTwoThousandTwentyFiveWarrantsMember" name="AugustTwoThousandTwentyFiveWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_RejuvaDirectProgramExpensesMember" name="RejuvaDirectProgramExpensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_WarrantLiabilitiesCurrent" name="WarrantLiabilitiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="guts_DeferredTaxAssetsCapitalizedPatentAndTrademarkCosts" name="DeferredTaxAssetsCapitalizedPatentAndTrademarkCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_NonCashInterestExpense" name="NonCashInterestExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_ProceedsFromIssuanceOfCommonStockNet" name="ProceedsFromIssuanceOfCommonStockNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_HarithRajagopalanMember" name="HarithRajagopalanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="guts_NonCashOperatingLeaseExpense" name="NonCashOperatingLeaseExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDecrease" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDecrease" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="guts_MinimumRequiredBidPriceAmountPerShare" name="MinimumRequiredBidPriceAmountPerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
</xsd:schema>
