Clinical response and changes in the fecal microbiota and metabolite levels after fecal microbiota transplantation in patients with inflammatory bowel disease and recurrent Clostridioides difficile infection

Objectives: We determined the efficacy of fecal microbiota transplantation (FMT) and subsequent changes in fecal microbiota and short-chain fatty acid (SCFA) levels in patients with ulcerative colitis (UC), Crohn’s disease (CD), and recurrent Clostridioides difficile infection (rCDI). Methods: A filtered solution of Japanese donor feces was endoscopically administered. The efficacy of FMT was evaluated after 8 weeks using the Mayo score, Crohn’s Disease Activity Index (CDAI), and the absence of diarrhea with stool toxin negativity in patients with active UC, CD, and rCDI, respectively. For fecal microbiota analysis, the 16S ribosomal RNA gene was sequenced, and fecal SCFA levels were measured. Results: Clinical response was achieved in 5/20 (25%), 3/4 (75%), and 4/4 (100%) patients with UC, CD, and rCDI, respectively. Clinical remission was achieved in 4/20 (20%) and 1/4 (25%) patients with UC and CD, respectively. Linear discriminant analysis illustrated that UC responders had lower counts of Clostridium cluster XIVa before FMT and higher counts after FMT. Higher Fusicatenibacter saccharivorans counts in donors were significantly correlated with 8-week clinical remission. Patients with CD exhibited lower Blautia, Dorea, and Eubacterium counts before FMT and higher Collinsella, Dorea, and Eubacterium counts after FMT, accompanied by functional profiles predictive of SCFA fermentation and elevated fecal butyrate concentrations. Patients with rCDI displayed significantly lower abundances of Clostridium clusters IV and XIVa before FMT and higher abundances after FMT accompanied by elevated fecal propionate concentrations. Conclusions: FMT exhibited various efficacy against UC, CD, and rCDI by altering the gut microbiota and SCFA production