Safety and efficacy of fecal microbial transplantation for the prevention and treatment of acute graft-versus-host disease: a meta-analysis

Objective In recent years, fecal microbiota transplantation (FMT) has been increasingly investigated for the prevention and treatment of acute graft-versus-host disease (aGVHD). Nevertheless, its clinical efficacy remains uncertain. Therefore, this study aims to systematically evaluate the clinical efficacy of FMT in preventing and treating aGVHD. Methods We systematically searched Cochrane Library, PubMed, Embase, and Web of Science from inception to October 2025 for studies comparing FMT with conventional regimens (corticosteroids and/or immunosuppressants) for aGVHD prevention and treatment. All statistical analyses were performed using RevMan 5.4.1 and Stata 16. Results Six studies involving 262 patients were included. Among them, 85 patients received FMT for aGVHD prevention, 65 received conventional prophylaxis, 68 received FMT for Gastrointestinal aGVHD (GI-aGVHD) treatment, and 44 received conventional treatment for GI-aGVHD. Meta-analysis showed no significant difference in the incidence of aGVHD between the FMT and conventional groups [odds ratio (OR) = 1.30, 95% confidence interval (CI) = 0.10-16.72, p = 0.84]. However, the FMT group demonstrated significantly higher 14-day and 30-day complete response (CR) rates, as well as 14-day clinical response rates, in patients with GI-aGVHD compared to the conventional group (OR = 8.54, 95% CI = 2.49–29.29, p = 0.0007; OR = 8.44, 95% CI = 2.98–23.96, p < 0.0001; OR = 4.66, 95% CI = 1.73–12.55, p = 0.002). No significant differences were observed in the incidence of bacteremia or sepsis between the two groups (OR = 0.37, 95% CI = 0.13–1.01, p = 0.05; OR = 0.38, 95% CI = 0.11–1.33, p = 0.13). Additionally, the abundances of Bacteroides and Bifidobacterium were significantly higher in the FMT group than in the conventional group [standardized mean difference (SMD) = 1.59, 95% CI = 0.15–3.03, p = 0.03; SMD = 1.01, 95% CI = 0.41–1.60, p = 0.0009]. Conclusion FMT showed favorable effects in improving clinical symptoms of GI-aGVHD and increasing the abundance of beneficial gut bacteria, and no increased risk of bloodstream infection was observed. These findings suggest that, for patients with established GI-aGVHD who may respond poorly to conventional regimens, FMT can serve as an effective adjunctive or salvage treatment. However, no significant advantage was observed for FMT in preventing aGVHD.