Fecal microbiota transplantation in treating methylmercury-poisoned rats: Reconstruction of gut microbiome and modulation of gut-brain axis related metabolites

Abstract

Background Methylmercury (MeHg) can bring devastating neurotoxicity to animals and human beings. Gut microbiota has been found to demethylate MeHg while MeHg exposure was found to destroy the diversity and abundance of gut microbiota. Besides, some neurotransmitters such as GABA, glutamate and other metabolites were altered due to MeHg exposure. Fecal microbiota transplantation (FMT) has been successfully applied to treat a series of diseases like Tourette syndrome, irritable bowel syndrome, necrotizing enterocolitis and to treat ulcerative coliti. The objective of this study was to investigate the effects of FMT in treating MeHg-poisoned rats. Results: It was found that FMT for 14 days promoted body weight gain, enhanced demethylation of MeHg and increased fecal excretion of Hg in MeHg-poisoned rats. Furthermore, the gut microbial bacteria associated with demethylation, such as sulfate-reducing bacteria were restored and some metabolites related to neuroactivity through gut-brain axis were increased after FMT, there is also repair of brain derived neurotrophic factor(BDNF)-related factor levels in the intestine, brain and serum. Conclusions: In all, it was showed that FMT can be a effective way in treating MeHg-poisoned rats through the reconstruction of gut microbiota, especially the bacteria that are associated with the demethylation of MeHg. Furthermore, the modulation of metabolites that are related to gut-brain axis after FMT also contributed to the treating of MeHg-poisoning. This study provides a novel way to treat MeHg-poisoning, which may contribute to the health promotion of mercury exposed population and shed lights on the treatment of other neurological diseases like Parkinson’s disease.