Table 1.

Gut microbiota functions

Bacterial phylum	Key representatives	Functions
Firmicutes	Members of the genera Enterococcus, Ruminococcus, Clostridium, Lactobacillus, Faecalibacterium, Roseburia, and Eubacterium	Metabolism of amino acids[23,24], carbohydrates[25], bile acids, and their salts[22]. Lipid metabolism and cholesterol synthesis[25]. Synthesis of vitamins К2, B1, B2, B6, B7, B9, and B12[26]. Maintenance of a proper immune response[28,29] and intestinal epithelial barrier integrity[31,32]. Protection against enteric pathogens[33]
Bacteroidetes	Members of the genera Bacteroides and Prevotella	Metabolism of amino acids[24], carbohydrates[25,141], bile acids, and their salts[22,142]. Synthesis of vitamin К2[27]. Regulation of appetite[143]. Maintenance of a proper immune response[28-29] and intestinal epithelial barrier integrity[31]. Protection against enteric pathogens[33]
Actinobacteria	Members of the genera Bifidobacterium and Corynebacterium	Metabolism of bile acids and their salts[22]. Synthesis of vitamins К2, B1, B2, B6, B7, B9, and B12[26]. Protection against enteric pathogens[33]
Proteobacteria	Members of the genera Desulfovibrio, Escherichia, and Shigella	Metabolism of amino acids[144]