Study Medication

SER-109 is an investigational medication. An investigational medicine is a product that is still being tested and has not been approved by regulatory authorities, including the Food and Drug Administration (FDA), for commercial sale. This means SER-109 can only be used in research studies. Your doctor cannot prescribe it to you.

This Ecobiotic® therapy, SER-109, is a preparation of bacterial spores highly purified from stool donations obtained from healthy, screened donors and put into capsules. These bacterial spores are inactive forms of the normal bacteria that live in a healthy intestine. SER-109 is a new investigational research medication (still in clinical trials) being studied to determine if providing normal healthy bacteria (via SER-109) to patients with recurrent Clostridium difficile infection can help replenish natural organisms in the intestines to help prevent recurrent Clostridium difficile infection.

The Food and Drug Administration (FDA) designated SER-109 as a Breakthrough Therapy in 2015, which means this research medication receives priority review from the FDA.

One (1) dose of SER-109 is given in 4 capsules on three consecutive days. Each capsule is about the size of a vitamin. These spores may help replenish natural organisms in the intestines to help prevent Clostridium difficile infections from coming back.

Can I Take Part?


  • Seres Therapeutics (Study Protocol, 20170324 Poster English20170324V1SERES-012RecruitmentBrochureEnglishCMcG, Seres 012PosterEnglish CLIENT REV & QD TRKED.DOCX)