Seres Therapeutics, Inc., a microbiome therapeutics platform company, engages in developing bacterial consortia that are designed to functionally interact with host cells and tissues to treat disease. The company's lead product candidate is the SER-109, an oral microbiome therapeutic candidate that has completed Phase III clinical trial for the treatment of clostridium difficile infection (CDI). It is also developing SER-155, a cultivated bacteria microbiome drug, which is Phase Ib clinical trial to reduce incidences of gastrointestinal infections, bloodstream infections, and graft versus host diseases in immunocompromised patients receiving allogeneic hematopoietic stem cell transplantation and solid organ transplants. In addition, the company engages in the development of SER-287 and SER-301 that are in Phase Ib to treat ulcerative colitis; SER-401 for patients with metastatic melanoma; and SER-262 to treat Clostridioides difficile infection. It has license and collaboration agreements with Nestec Ltd. and Memorial Sloan Kettering Cancer Center. The company was formerly known as Seres Health, Inc. and changed its name to Seres Therapeutics, Inc. in May 2015. Seres Therapeutics, Inc. was incorporated in 2010 and is headquartered in Cambridge, Massachusetts.