v3.25.4
Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Mar. 05, 2026
Jun. 30, 2025
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2025    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Entity Registrant Name SYNLOGIC, INC.    
Entity Central Index Key 0001527599    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company true    
Entity Common Stock, Shares Outstanding   11,698,919  
Entity Public Float     $ 4.4
Entity File Number 001-37566    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 26-1824804    
Entity Interactive Data Current Yes    
Entity Address, Address Line One PO Box    
Entity Address, Address Line Two 30    
Entity Address, City or Town Winchester    
Entity Address, State or Province MA    
Entity Address, Postal Zip Code 01890    
City Area Code 617    
Local Phone Number 659-2802    
Document Annual Report true    
Document Transition Report false    
Auditor Firm ID 185    
Auditor Name KPMG LLP    
Auditor Location Boston, Massachusetts, U.S.    
Auditor Opinion

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of Synlogic, Inc. and subsidiaries (the Company) as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss, stockholders’ equity, and cash flows for the years then ended and the related notes (collectively, the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for the years then ended, in conformity with U.S. generally accepted accounting principles.

   
Documents Incorporated by Reference

DOCUMENTS INCORPORATED BY REFERENCE

The following documents (or parts thereof) are incorporated by reference into the following parts of this Form 10-K: Certain information required in Part III of this Annual Report on Form 10-K is incorporated from the registrant’s definitive proxy statement for the 2026 annual meeting of stockholders to be filed pursuant to Regulation 14A with the U.S. Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2025.

   
Common Stock [Member]      
Document Information [Line Items]      
Title of 12(g) Security Common Stock, par value $0.001 per share