I'm glad to see more studies on this, as it's long been misunderstood how strong of a connection there is between the gut microbiome and mental health. Some go as far to referring to the gut as our second-brain, due to its critical role.

Serotonin (the moood-regulating neurotransmitter), for instance, is produced _primarily_ in the gut (up to 95% of it). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469458/#:~:tex....