Patient-donor similarity and donor-derived species contribute to the outcome of faecal microbiota transplantation for ulcerative colitis

Clinical applications of faecal microbiota transplantation (FMT) for treating ulcerative colitis (UC) have shown promising results. However, whether the beneficial effects of FMT are due to the transfer and colonization of donor-derived species in patients remains unclear. Here, we investigated the factors affecting the efficacy of administration of triple antibiotics (A-FMT) and the criteria for appropriate donor and patient-donor matching. Ninety-seven patients with active UC who were enrolled between March 2014 and October 2019 underwent FMT. The clinical features were assessed based on a reduction in Lichtiger's clinical activity index 4 weeks after A-FMT, with long-term responders (LTR) defined as those with no increase or intensification within 12 months after A-FMT. Microbiome analysis was performed on 147 faecal samples (pre-A-FMT, post-A-FMT, and donor) from 49 patient-donor combinations that were assigned using the one patient-to-one donor strategy.