Fecal Microbiota Transplantation for Ulcerative Colitis: The Optimum Timing and Gut Microbiota as Predictors for Long-Term Clinical Outcomes.

Introduction: The previous researches aimed to evaluate the efficacy and safety of fecal microbiota transplantation (FMT) for ulcerative colitis (UC) in a short-term observation. The present study aimed to explore the optimum timing of FMT for maintaining the long-term clinical benefits and to target the gut microbiota that may help to predict the long-term success or failure of FMT in UC.

Methods: Two hundred two patients with UC were recruited from November 2012 to September 2018. The primary endpoint of this study was the maintaining time of the first and second courses of FMT. Relapse was defined as partial Mayo score ≥2 after achieving clinical remission and an increase of partial Mayo score ≥1 after achieving clinical response. The stool samples were analyzed by 16S rRNA gene sequencing.

Results: The median maintaining time of the efficacy was 120 days (IQR, 45-180) and 182.5 days (IQR, 105-311.25) from the first course and second course of FMT, respectively. No FMT-related serious adverse events were observed. The differences of the relative abundance in Eggerthella, Lactobacillus, and Ruminococcus between pre-FMT and 5 days post-FMT were remarkably correlated with the long-term clinical remission (P < 0.05).

Discussion: This study demonstrated that patients with UC should undergo the second course of FMT within 4 months after the first course of FMT for maintaining the long-term clinical benefits. The short-term alterations of microbiota after FMT may be conducive to predicting the long-term efficacy of FMT in UC (see Visual Abstract, Supplementary Digital Content, http://links.lww.com/CTG/A363).