Oral

Introduction:
The efficacy of fecal microbiota transplantation (FMT) in ulcerative colitis (UC) is inconsistent because of lack of prognostic factors on outcomes.

Objectives:
We aimed to investigate potential prognostic markers for post-FMT outcomes.

Methods:
A prospective study was conducted with 10 active patients with UC who completed two FMTs with a 1-month interval. Intestinal and systemic markers were analyzed for prognostic factors across clinical outcomes and temporal sequences for 6 months after FMT. Gut microbes and their genes were analyzed with shotgun metagenomic sequencing, followed by a decision tree classifier.

Results and Conclusion:
Based on partial Mayo score at 1 month after the second FMT (T60), patients were regrouped into remission (R) and non-remission group (NR) and traced back to the pre-FMT timepoint (T0) to determine prognostic factors. The remission rate was 40%, and C-reactive protein (CRP) level significantly decreased from T0 to T60. Compared with the CRP level, intestinal factors were more disceible, characterized by lower abundance of Bacteroidetes (R vs. NR at T0, p<0.001; T0 vs. T60 in R, p<0.05; abundance threshold, 17.8%) and higher glycerol dehydrogenase (R vs. NR at T0, p<0.01; T0 vs. T60 in R, p<0.05; gene number threshold, 280.88) and mannosylglycerate hydrolase genes (R vs. NR at T0, p<0.05; T0 vs. T60 in R, p<0.05; gene number threshold, 17.62) at T0. 

Gut microbes and their genes are potential prognostic markers for FMT outcome assessment. Bacterial phylum and intestinal inflammation should be evaluated before FMT to select the right patients and achieve better efficiency.