Metabolomics and metagenomics in mice reveal the role of the gut microbiota in tryptophan metabolism

Tryptophan metabolism plays a key role in host-microbiota interactions, producing a wide array of bioactive metabolites. However, our understanding of the interactions between tryptophan metabolites and the gut microbiota is still limited. Using targeted quantitative metabolomics and metagenomics in mice across various compartments, we showed that the cecal microbiota massively impacts tryptophan metabolism both in the gut and systemically. Grouping bacterial taxa in co-abundance guilds better reflected the links between gut microbes and tryptophan metabolites than single taxa taken individually and suggested the involvement of complex microbial interactions in tryptophan metabolism regulation. Finally, analyzing functional data, we shed light on the potential links between tryptophan metabolism and bacterial enzymes or metabolic pathways.