Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-205253) of Seres Therapeutics, Inc. of our report dated March 14, 2016 relating to the financial statements, which appears in this Form 10-K.   

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

March 14, 2016