The exact mechanism by which FMT is effective is presently unknown. A recent study of 14 patients with recurrent CDI treated with FMT35 showed decreased diversity pre-FMT with gut microbiota becoming more diverse and similar to donors post-FMT. This group showed significant changes in 3 taxonomic orders but no single organism or species was universally associated with success. Weingarden et al. showed that FMT restored normal bile acid composition in patients with recurrent CDI36, suggesting that correction of bile acid metabolism is likely a major mechanism by which FMT results in a cure and prevents recurrence of CDI. Understanding mechanisms of FMT more completely may enable development of synthetic microbiota-based therapeutics which would be a safe and effective alternative to traditional FMT. We hypothesize that early changes in distal gut microbiota post-FMT may help identify key species associated with efficacy. Furthermore, we believe there are measurable metabolic and immunologic effects which may also be beneficial after FMT. This study aims to document early changes in the distal gut microbiota (both fecal and mucosa-associated) post FMT. Furthermore, whole blood and urine samples will facilitate collaborative immunologic and metabolomic analyses.~This will be an open label clinical trial of FMT to prevent further recurrence in patients who have suffered at least a third episode of Clostridium difficile infection (CDI) and who have previously been treated with oral vancomycin. Subjects will consist of 6 adult outpatients referred after 3 (or more) episodes of CDI. Subjects, who will have been treated with at least a 10 day course of anti-CDI therapy (metronidazole, vancomycin or fidaxomicin) for the most recent acute infection, will then receive FMT with donor stool administered at the time of sigmoidoscopy. After the procedure, subjects will be followed for 8 weeks for C. difficile recurrence. Subjects who relapse during that period will be offered a repeat FMT using donor stool. We plan to collect baseline and post-FMT stool samples for microbiome analyses as well samples of urine and blood for metabolomic and immunologic studies. Subjects will be contacted at 24 weeks to assess long term safety outcomes
This study aims to document early changes in the distal gut microbiota (both fecal and mucosa-associated) post FMT. Furthermore, whole blood and urine samples will facilitate collaborative immunologic and metabolomic analyses.~This will be an open label clinical trial of FMT to prevent further recurrence in patients who have suffered at least a third episode of Clostridium difficile infection (CDI) and who have previously been treated with oral vancomycin.