Gut microbiome signature of Viliuisk encephalomyelitis in Yakuts includes microbes linked to lean body mass and inflammation

Ethnometagenomics is an important tool for preserving microbial diversity of humankind and revealing potential microbial biomarkers of diseases of unknown etiology. Describing gut microbiome of indigenous human populations will help to elucidate the impact of specific dietary and environmental contexts on microbial community structure and identify risks linked to the lifestyle of such groups as well as endemic diseases. Here we performed a pilot survey of stool microbiome in Yakuts - healthy subjects (n=11) and patients with Viliuisk encephalomyelitis (n=6), a debilitating disease of neural system specific to indigenous Yakuts. The 16S rRNA sequencing showed that Yakut microbiome was quite specific in comparison with other known world populations. The patients with VE had significantly different levels of Methanobacteriaceae archaea - reported to be linked to body-mass index, metabolism and dietary habits - as well as reduced levels of commensal Clostridiales with antinflammatory activity. At the level of predicted metabolic potential, VE was associated with decreased ability to synthesize several vitamins. The identified associations suggest possible disruption of “gut-microbiome-brain” axis in Viliuisk encephalomyelitis.