Impact of allogenic Fecal Microbiota Transplantation (FMT) on lipid parameters in patients with metabolic syndrome (MetS): a meta-analysis

Background Metabolic Syndrome (MetS) has long been considered a formidable global health concern, and impaired lipid metabolism has been one of its crucial clinical manifestations. Fecal Microbiota Transplantation (FMT) has emerged as a potential therapeutic strategy for MetS, nevertheless, prior meta-analyses have not only yielded conflicting outcomes, but as well predominantly centered on glycemic parameters, leaving the potential impact of FMT on lipid metabolism remained unexplored. Purpose This meta-analysis systematically assessed the influence of allogenic FMT on lipid parameters in MetS patients, unraveling its potential as an innovative therapeutic modality for MetS. Methods A meta-analysis was performed to explore the impact of allogenic FMT on lipid parameters (low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], total cholesterol [TCHO] and triglycerides [TG]) in patients with MetS. Terms regarding FMT and metabolic syndrome were searched in PubMed/Medline, EMBASE, Web of Science, the Cochrane Library, and Scopus from the inception of the databases until 31 August 2023. Ten randomized controlled trials (RCTs) were included and mean difference (MD) of parameters were pooled using a fixed effects model. Subgroup analyses according to follow-up durations were performed, and this study was registered in PROSPERO. Results A total of 532 patients in 10 studies were included. Patients undergoing allogenic FMT manifested significantly higher HDL-c level compared with control group (receiving placebo or autologous FMT, pooled MD 0.06 [95% CI: 0.02, 0.10]), and the result remained consistent in the subgroup with 4 to 6 weeks of follow-up (MD 0.07 [95% CI: 0.02, 0.10]). Though overall pooled result did not manifest a significant LDL lowering effect (MD -0.08 [95% CI: -0.21, 0.05]), in subgroup analyses, a significantly lowered LDL level was observed at 12 weeks of follow-up (MD -0.34 [95% CI: -0.60, -0.08]). No significant difference was observed between allogenic FMT and control group concerning TCHO ant TG levels regardless of lengths of follow-up. Conclusions An overall higher level of HDL-C and lowered LDL-C at 12 weeks of follow-up was observed in MetS patients receiving allogenic FMT. The results indicated that gut microbiota from lean, healthy donors may display a beneficial effect on modulating lipid metabolism in patients with MetS. Allogenic FMT manifested promising therapeutic impact and could serve as a viable intervention for MetS patients. Future large-scale RCTs are required for further validation.