Tryptophan metabolism: a critical bridge linking gut microbiota to depression
Depression is a major global public health challenge with limitations in current therapies. Emerging evidence highlights that gut microbiota (GM) critically regulates the gut-brain axis via tryptophan (Trp) metabolism. Trp is metabolized through host-directed serotonin (5-HT) and kynurenine (KYN) pathways, as well as m...