Key role of the gut-microbiota-brain axis via the subdiaphragmatic vagus nerve in demyelination of the cuprizone-treated mouse brain

Multiple sclerosis (MS) is the most common demyelinating disease that attacks the central nervous system. Di-etary intake of cuprizone (CPZ) produces demyelination resembling that of patients with MS. Given the role of the vagus nerve in gut-microbiota-brain axis in development of MS, we performed this study to investigate whether subdiaphragmatic vagotomy (SDV) affects demyelination in CPZ-treated mice. SDV significantly ameliorated demyelination and microglial activation in the brain compared with sham-operated CPZ-treated mice. Furthermore, 16S ribosomal RNA analysis revealed that SDV significantly improved the abnormal gut microbiota composition of CPZ-treated mice. An untargeted metabolomic analysis demonstrated that SDV significantly improved abnormal blood levels of metabolites in CPZ-treated mice compared with sham-operated CPZ-treated mice. Notably, there were correlations between demyelination or microglial activation in the brain and the relative abundance of several microbiome populations, suggesting a link between gut microbiota and the brain. There were also correlations between demyelination or microglial activation in the brain and blood levels of metabolites. Together, these data suggest that CPZ produces demyelination in the brain through the gut-microbiota-brain axis via the subdiaphragmatic vagus nerve.

Automated summary

Multiple sclerosis (MS) is a common demyelinating disease that affects the central nervous system. This study investigated the effects of subdiaphragmatic vagotomy (SDV) on demyelination in cuprizone (CPZ)-treated mice and found that SDV significantly improved demyelination and microglial activation in the brain. Analysis of gut microbiota composition and blood metabolites revealed that SDV also improved the abnormal levels in CPZ-treated mice. These findings suggest a link between the gut microbiota-brain axis and demyelination in the brain.