X0206 3 2022-02-07 1 0001609809 Seres Therapeutics, Inc. MCRB 0001744682 Cloghessy Paula C/O SERES THERAPEUTICS, INC. - 4TH FLOOR 200 SIDNEY STREET CAMBRIDGE 02139 0 1 0 0 See Remarks Executive Vice President, Chief People Officer Exhibit List: Exhibit 24 - Power of Attorney /s/ Thomas J. DesRosier, Attorney-in-fact for Paula Cloghessy 2022-02-08