837 Short Chain Fatty Acid Profiles Are Altered by Fecal Microbiota Transplantation for the Treatment of Inflammatory Bowel Disease and Recurrent Clostridioides difficile Infection

Abstract

INTRODUCTION: Recurrent C. difficile infection (rCDI) is a major challenge among patients with inflammatory bowel disease (IBD). Perturbation of microbiota-mediated metabolism of short chain fatty acids (SCFA) has been reported in IBD patients. Fecal microbiota transplantation (FMT), an established therapy for rCDI, alters gut microbiota composition, but effects on SCFA are unclear. Accordingly, this study assessed SCFA profiles in IBD patients with rCDI pre- and post-FMT. METHODS: This open-label, prospective, single-arm multi-center cohort study enrolled patients from 4 tertiary care centers. Patients with IBD and ≥2 episodes of CDI received a single colonoscopic FMT from a universal stool bank. The primary outcome was CDI recurrence up to week 8 defined as diarrhea and EIA-positive toxin testing for C. difficile. Stool for metabolomic profiling was collected pre-FMT and week 1, 8 and 12 weeks post-FMT. A targeted gas chromatography-mass spectrometry protocol was used for the identification and quantification of SCFA. SCFA concentrations were analyzed via univariate analysis, comparing groups (e.g. pre- vs post-FMT). RESULTS: 37 participants were enrolled, with mean age of 37.6 years (range 20-76) and primarily female (n = 21, 57%). 14 had Crohn’s disease (CD) (mean HBI = 6.4) and 23 had ulcerative colitis (UC) (mean Partial Mayo Score = 4.5). Mean baseline fecal calprotectin was 1804.8 +/- 2307.7 Overall, 3 participants (8%) experienced FMT failure with confirmed EIA-positive stool, and the there were no related serious adverse events. Among the nine SCFAs assessed, including two branched chain fatty acids (isovalerate and isobutyrate) most were significant altered by FMT, with rapid and sustained changes (with the exception of acetate, in which no change was appreciated) (Figure 1). Additionally, 2-hydroxybutyrate and lactate, two markers of metabolic stress, were significantly reduced after FMT. Furthermore, the baseline stool samples of those who went on to recur were compared to those who did not (Figure 2); though not significant, there was a trend towards reduced baseline levels for butyrate, propionate and caproate among those who recurred. CONCLUSION: To our knowledge, this is the largest prospective trial to assess the effect of FMT in patients with IBD-CDI. The data suggests the efficacy and safety profile is better than previous reports. SCFAs were increased significantly post-FMT, and may offer insight into mechanism of clinically efficacy seen in this study.