October 8, 2024

Eric Shaff
Chief Executive Officer
Seres Therapeutics, Inc.
101 Cambridgepark Drive
Cambridge, MA 02140

        Re: Seres Therapeutics, Inc.
            Registration Statement on Form S-3
            Filed October 1, 2024
            File No. 333-282450
Dear Eric Shaff:

       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 Tyler Howes at 202-551-3370 with any questions.



                                                           Sincerely,

                                                           Division of
Corporation Finance
                                                           Office of Life
Sciences
cc:   Wesley C. Holmes, Esq.