Delivery of Fecal Material to Terminal Ileum Is Associated with Long-Term Success of Fecal Microbiota Transplantation.

BACKGROUND: Fecal microbiota transplantation (FMT) is a highly effective treatment for recurrent Clostridioides difficile infection (CDI). However, 10-20% of patients still fail to recover following FMT. There is a need to understand why these failures occur and if there are modifiable factors that can be addressed by clinicians performing FMT. AIMS: We sought to identify factors related to the FMT procedure itself which could impact FMT outcomes. We also aimed to identify patient demographics which might be associated with FMT outcomes and whether any factors were associated with early FMT failure compared to late CDI recurrence. METHODS: We performed a retrospective multicenter cohort analysis of FMT procedures between October 2005 and November 2020. We collected data on patient demographics, details of the FMT procedure, and procedure outcomes. Using univariate and multivariate regression, we evaluated whether these factors were associated with long-term FMT success, early FMT failure (less than 60 days following procedure), or late CDI recurrence (more than 60 days following procedure). RESULTS: Long-term success of FMT was strongly correlated with any delivery of stool to the terminal ileum (Odds Ratio [OR] 4.83, 95% confidence interval [CI] 1.359-17.167) and underlying neurologic disease (OR 8.012, 95% CI 1.041-61.684). Lower bowel prep quality was significantly associated with both early FMT failure (p = 0.034) and late CDI recurrence (p = 0.050). CONCLUSIONS: Delivery of stool to the terminal ileum is significantly associated with long-term success following FMT. This is a relatively safe practice which could easily be incorporated into the standard of care for colonoscopic FMT.