August 13, 2025

Mary Beth Dooley
Principal Executive Officer
Synlogic, Inc.
PO Box 30
Winchester, MA 01890

       Re: Synlogic, Inc.
           Registration Statement on Form S-3
           Filed August 8, 2025
           File No. 333-289415
Dear Mary Beth Dooley:

       This is to advise you that we have not reviewed and will not review your
registration
statement.

        Please refer to Rules 460 and 461 regarding requests for acceleration.
We remind you
that the company and its management are responsible for the accuracy and
adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action
by the staff.

       Please contact Doris Stacey Gama at 202-551-3188 with any questions.



                                                           Sincerely,

                                                           Division of
Corporation Finance
                                                           Office of Life
Sciences
cc:   Nishant Dharia, Esq.