“Enzymatic landscape” of the gut microbiome

It is known that obesity is traceable to gut dysbiosis. Changes in the microbial ecosystem in the gut have major implications for the content of microbial signaling molecules in the host organism. The concentration of tryptophan (Trp) signaling molecules in the gut will have a significant impact on intestinal microbiota diversity. Using metagenomic analysis, we investigated the taxonomic representation of the intestinal microbiota in healthy individuals and obese patients, which allowed us to reconstruct its potential metabolic activity depending on the level of Trp metabolites using PICRUSt software. We found that the key microbial Trp catabolite (MICT) is indole-3-lactate. Using the data of metagenomic sequencing analysis and bioinformatic tools we have analyzed a potential metabolic activity of the microbial communities or so-called “enzymatic landscape”. We have found a twofold increase in the correlation between the content of Trp metabolites in feces and the “enzymatic landscape” of microbiome. The maximum number of statistically significant correlations between Trp metabolites and the potential metabolic activity of the microbial communities were established for indole-3-lactate. We have shown statistically significant relationships for indole-3-lactate and the abundance of genes for the metabolism of monosaccharides, nucleotides, amino acids, polyamines, and sulfosaccharides. It has been established that in obese patients there is a threefold increase in indole-3-lactate-producing microbiota. The phenotype of the microbiotic population is represented by completely different genera and species of microorganisms in obese individuals. The content of indole-3-lactate in the feces of obese patients mainly depends on the taxonomic representation of Escherichia-Shigella.