IDDF2024-ABS-0248 Gut microbiome from patients are associated with fecal microbiota transplantation related adverse events

<h3>Background</h3> Fecal microbiota transplantation (FMT) for inflammatory bowel disease (IBD) is an effective means of treatment; adverse events (AE) may influence the use of FMT and make patients worry about its safety. At present, there are still few studies on the safety of FMT in the world. Most of the previous studies on the safety of FMT focus on the donors but ignore the patients. This study is the first to analyze the risk factors of the occurrence and clinical efficacy of FMT-related AE from the perspective of patients. <h3>Methods</h3> 102 IBD patients who had received FMT were included in the study. Clinical efficacy was followed up for 3 months, and AE that occurred during the course of the disease was recorded. Fecal samples were collected before treatment for 16sDNA sequencing. <h3>Results</h3> IBD patients were divided into AE group (N=34) and non-AE group (N=68) according to the occurrence of AE. By sequencing the fecal microbiota of patients, it was found that enterococcus and bifidobacterium were the dominant bacteria genus in the AE group, which was higher than that in the non-AE group. Bifidobacterium and enterococcus are independent risk factors for the occurrence of FMT-related AE using univariate and multivariate logistic regression analysis. AE group is divided into the fever subgroup and gastrointestinal complications (GC) subgroup; LEfSe analysis showed a high abundance of enterococcus in the fever group and a high abundance of bifidobacterium in the GC group. Moreover, the abundance of bifidobacterium in the diarrhea subgroup in the GC group was again higher than that in the non-AE group. AE group was divided into subgroups according to clinical efficacy. The abundance of enterococcus in the non-response group was higher than that in the other groups. (IDDF2024-ABS-0248 Figure 1) <h3>Conclusions</h3> Enterococcus and bifidobacterium may be risk factors for FMT-related AE, and the increase of enterococcus in patients may affect the efficacy of FMT.