[Fecal microbiota transplantation for the treatment of intestinal disorders: An analysis of treatment of 15 000 patients].

Objective: To examine the long-term efficacy and complications of fecal microbiota transplantation (FMT) for the treatment of diseases related to intestinal dysbiosis. Methods: This was a retrospective descriptive study. Relevant data were collected from the records of 15 000 patients who had undergone FMT and been followed up for more than 3 months during the period from May 2017 to September 2024. The patient cohort comprised 3746 male and 11 254 female patients aged (45.3±12.2) years. The inclusion criterion was meeting the indications for FMT. Application of this criterion yielded 8258 patients with constipation, 684 with Clostridium difficile infection, 1730 with chronic diarrhea, 510 with inflammatory bowel disease, 432 with radiation enteritis, 1940 with irritable bowel syndrome, 365 with autism, 870 with postoperative gastrointestinal dysfunction, and 211 with neurodegenerative diseases. The three routes of delivering FMT comprised infusion of an enterobacterial solution through a nasoenteric tube into the jejunum for 6 consecutive days (upper gastrointestinal FMT group, 11 125 patients), oral intake of enterobacterial capsules for 6 consecutive days (oral capsule FMT, 3597 patients), and a single injection of a bacterial solution into the colon via colonoscopy (lower gastrointestinal FMT group, 278 patients). Other treatments were discontinued during the treatment and follow-up period and administration of other medications was not recommended unless absolutely necessary. The primary outcomes were the efficacy of FMT after 3, 12 and 36 months of treatment, and improvement in chronic constipation, C. difficile infection, chronic diarrhea, inflammatory bowel disease, radiation enteritis, irritable bowel syndrome, post-surgery gastrointestinal dysfunction, and autism. Other outcomes included the occurrence of short-term (within 2 weeks after treatment) and long-term (within 36 months after treatment) adverse reactions. Results: At 3, 12 and 36 months after treatment, the overall rates of effectiveness of treatment were 71.8% (10 763/15 000), 64.4% (7600/11 808) and 58.8% (3659/6218), respectively. Specifically, the rates of clinical improvement were 70.3% (5805/8258), 62.6% (3970/6345), and 56.5% (1894/3352), respectively, for constipation; 85.8% (587/684), 72.3% (408/564), and 67.3% (218/324), respectively, for C.difficile infection; 81.0% (1401/1730), 78.1% (1198/1534), and 72.3% (633/876), respectively, for chronic diarrhea; 64.3% (328/510), 52.3% (249/476), and 46.6 % (97/208), respectively, for inflammatory bowel disease; 77.3% (334/432), 65.4% (212/324), and 53.6% (82/153), respectively, for radiculitis; 70.6% (1370/1940), 64.5% (939/1456), and 60.4% (475/786), respectively, for irritable bowel syndrome; 75.3% (275/365), 70.0% (201/287), and 63.6% (112/176), respectively, for autism; 65.3% (568/870), 54.3% (355/654), and 46.5% (114/245), respectively, for post-surgical gastrointestinal dysfunction; and 45.0% (95/211), 40.5% (68/168), and 34.7% (34/98), respectively, for neurodegenerative diseases. At 3, 12, and 36 months post-treatment, clinical improvement rates were 77.1% (8580/11 125), 67.1% (6437/9595), and 62.1% (3196/5145), respectively, in the upper gastrointestinal route group; and 57.3% (2062/3597), 53.6% (1115/2081), and 45.0% (453/1006), respectively, in the oral capsule group; and 43.5% (121/278) , 36.4% (48/132) and 14.9% (10/67), respectively, in the lower gastrointestinal route group. No serious adverse reactions occurred during treatment or follow-up. The most common adverse reactions in the upper gastrointestinal route group, oral capsule group, and lower gastrointestinal route group were respiratory discomfort (20.4%, 2269/11 125), nausea and vomiting on swallowing the capsule (7.6%, 273/3597), and diarrhea (47.5%, 132/278), respectively; these symptoms resolved at the end of treatment. At 36 months of follow-up, 19 patients reported exacerbation of symptoms of pre-existing diseases and there had been 16 deaths that were not directly related to FMT. Additionally, no systemic diseases had developed after FMT. Conclusion: FMT for the treatment of intestinal dysfunction associated with disorders of the intestinal flora and related extraintestinal diseases is effective and not associated with serious adverse events.