Metagenomic analysis of taxonomic and functional changes in gut microbiota of patients with the alcohol dependence syndrome

The first metagenomic study of gut microbiota in patients with the alcohol dependence syndrome (ADS) has been performed in the whole-genome sequencing (“shotgun”) format. Taxonomic analysis revealed changes in the relative abundance of the predominant bacteria associated with inflammatioln (including increased levels of Ruminococcus gnavus and R. torques, and decreased levels of Faecalibacterium and Akkermansia genera). The microbiota of ADS patients was characterized by the presence of opportunistic pathogens rarely detected in metagenomes of healthy individuals from different countries. Comparative analysis of total metabolic potential revealed increased relative abundance of KEGG pathways associated with the response to oxidative stress. ADS patients also had increased levels of two specific groups of genes encoding enzymes involved in the metabolism of alcohol, as well as virulence factors. It is possible that gut microbiota of ADS patients demonstrating changes in both taxonomic and functional composition plays a role in modulating the effects of alcohol on the host body