Fecal Microbiota Transplantation for the Treatment of Severe Acute Gut Graft-Versus-Host Disease

PRIMARY OBJECTIVES: I. For safety evaluation, episodes of microbial bloodstream infection attributed to fecal microbiota transplantation (FMT) within the first 7 days after start of each FMT administration. II. For tolerability evaluation, subject must ingest 50% of one dose of FMT product without grade 3 or higher adverse events (AEs) within the first 7 days post-FMT. SECONDARY OBJECTIVE: I. To collect stool, oral swabs and blood specimens for future studies to define bacterial taxa diversity, microbial translocation as well as metabolomic and proteomic changes associated with the development of graft versus host disease (GvHD). II. For clinical efficacy, \> 50% of subjects with at least 1 stage of gut GvHD improvement by 8 weeks after the first dose of FMT. OUTLINE: Patients ingest OpenBiome FMT Capsule Dose Extended (DE) orally for two consecutive days. One dose is equivalent to the ingestion of 30 capsules and thus each day the patient will ingest 15 capsules. If no response is noted after 7 days, patients may receive a second dose of FMT for an additional 2 days. Standard treatment for gut GvHD will continue during this time. After completion of study treatment, patients are followed for up to 6 months.