Efficacy and safety of single fecal microbiota transplantation for Japanese patients with mild to moderately active ulcerative colitis

Background The clinical utility of fecal microbiota transplantation (FMT) in patients with ulcerative colitis (UC) is still controversial. We investigated the efficacy and safety of single FMT for patients with mild to moderately active UC in a Japanese population. Methods Fifty-seven patients were evaluated for eligibility, and 16 patients were excluded. Forty-one patients with UC refractory to standard medical therapy were treated with single FMT by colonoscopic administration. Changes in the fecal microbiota were assessed by 16S ribosomal DNA based terminal restriction fragment length polymorphism analysis. Results At 8 weeks after FMT, no patient achieved clinical remission, and 11 of 41 patients (26.8 %) showed clinical response. The full Mayo score and the Mayo clinical score significantly decreased at week 8 [full Mayo score 5.5 +/- 2.4 (mean +/- standard deviation) at initiation and 4.6 +/- 2.2 at week 8, P < 0.004; Mayo clinical score 4.0 +/- 2.0 at initiation and 3.0 +/- 1.9 at week 8, P < 0.001], but there were no statistically significant effects on the Mayo endoscopic score. No adverse events occurred after FMT or during the follow-up period of 8 weeks. The proportion of Bifidobacterium was significantly higher in the donor feces used for responders than in the donor feces used for nonresponders. The proportion of Lactobacillales and Clostridium cluster IV were significantly higher in the donor feces used for nonresponders. Conclusion Single FMT by colonoscopy was performed safely in all patients, but sufficient clinical efficacy and microbial restoration were not confirmed in patients with mild to moderately active UC.