Efficacy and safety of fecal microbiota transplantation in reducing recurrence of colorectal adenomas after endoscopic resection: study protocol for a multicenter, open-label, randomized, no-treatment-controlled trial.

[BACKGROUND] Endoscopic resection is the standard treatment for colorectal adenoma (CRA), a key precursor to colorectal cancer (CRC). However, a high rate of recurrence post-procedure poses a significant challenge for long-term CRC prevention. Growing evidence suggests gut microbial dysbiosis contributes to adenoma development and recurrence. This trial will test the hypothesis that restoring a healthy gut microbiome with fecal microbiota transplantation (FMT) can reduce the recurrence of CRA after endoscopic resection.

[METHODS] This protocol describes a multicenter, open-label, randomized, no-treatment-controlled trial that will enroll 466 participants with CRA following endoscopic resection. Participants will be randomly assigned in a 1:1 ratio to receive either FMT or no treatment (control). The FMT intervention consists of an initial colonoscopic infusion and oral capsules, followed by oral maintenance capsules at months 3, 6, and 9. The primary outcome is the rate of CRA recurrence at the 12-month follow-up colonoscopy. Key secondary outcomes include the incidence of all polypoid lesions, changes in the gut and mucosal microbiota composition, the incidence of CRC, and a comprehensive assessment of adverse events to evaluate safety.

[DISCUSSION] This trial is designed to provide high-quality evidence on the efficacy and safety of FMT for preventing CRA recurrence. The findings may support a novel, microbiome-based strategy for the secondary prevention of CRC and provide mechanistic insights into the role of the gut microbiota in colorectal carcinogenesis.

[TRIAL REGISTRATION] ClinicalTrials.gov NCT06205862. Registered on 16 January, 2024. https://clinicaltrials.gov/study/NCT06205862.