Exploring the neuromodulatory potential of a wide arsenal of fermented foods.

The gut microbiome is increasingly implicated in the development and progression of various neurological disorders, via the modulation of the microbiota-gut-brain axis (MGBA). The intestinal milieu is modulated by various dietary interventions, one such involves the use of fermented foods (FFs). FFs house beneficial microbes and metabolites and can therefore be used to positively impact the gut-brain axis. We screened >250 diverse FFs, collected from across the globe and mined the food microbiome for their ability to influence gut and brain health, using a range of computational and laboratory-based pipelines. We found that most of the FFs encapsulated microorganisms which contain genes involved in the production of metabolites that are associated with MGBA communication. Fermented sugar demonstrated most of the genes relating to tryptophan metabolism, and this was supported by the incorporation of an additional 300 sugar-based FFs in this study. Downstream metabolites of tryptophan metabolism are implicated in the maintenance of cognitive function and overall gut health. Computational analysis allowed us to narrow our search to 10 FFs. These foods were then subjected to metabolomics analysis, to determine the abundance and diversity of neuromodulatory metabolites. Fermented dairy products demonstrated a distinct metabolomic profile compared to other FF categories. Fermented foods also revealed a distinct neuromodulatory metabolite panel compared to unfermented controls, indicating the fermentation process might influence presence of these metabolites. This data, coupled with bioinformatics screening of the FF microbiome, aided in the identification of key substrate categories that can be harvested for further preclinical and clinical investigation.