The Safety of Fecal Microbiota Transplantation for Crohn’s Disease: Findings from A Long-Term Study

Introduction Fecal microbiota transplantation (FMT) has been used as a potential treatment option for Crohn’s disease (CD). However, there is still lack of safety and efficacy evidence based on large samples of CD undergoing FMT. This study aimed to evaluate the risk factors of adverse event (AE) in the long term and the efficacy of FMT in the short term for patients with CD. Methods FMT via mid-gut for mild to severe CD in a single center trial (NCT01793831) was performed from October 2012 to December 2016. The possible factors with AE and efficacy after FMT were prospectively recorded. Results A total of 184 frequencies of FMT were performed for 139 patients who received FMT. During 1 month after FMT, 13.6% of mild AEs occurred, including increased frequency of defecation, fever, abdominal pain, flatulence, hematochezia, vomiturition, bloating and herpes zoster. No AE beyond 1 month was observed. Therefore, a 1 month cut-off could be suggested to define short-term and long-term AEs of FMT. Among the possible risk factors, only fecal microbiota purification methods were closely associated with the occurrence of AEs. The rate of AEs in patients undergoing manual methods for the preparation of fecal microbiota was 21.7%, which was significantly higher than the 8.7% in those experiencing an automatic method. The manual or automatic purification of fecal microbiota had no correlation with the efficacy of FMT. Conclusion This cohort study based on the largest size of cases demonstrated that improved fecal microbiota preparation reduced the rates of AEs, but did not affect the clinical efficacy in patients with CD.