Anna M. Tingler, Charulekha Packirisamy, Alyssa Gutierrez, Adelaide E. Horvath, Makenna Grozis, Sigmund J. Haidacher, Kathleen M. Hoch, Anthony M. Haag, Numan Oezguen, Kristen A. Engevik, Amy C. Engevik, Thomas D. Horvath, Melinda A. Engevik
produced L-DOPA. Interestingly, none produced serotonin or its intermediates despite consuming tryptophan. Multiple species also generated short-chain fatty acids (SCFAs). These findings demonstrate that commensal microbes contribute to host neurochemistry by producing diverse neuroactive metabolites and SCFAs, highlighting the therapeutic potential of modulating the gut microbiota to influence human health.