Modulation of immunity by tryptophan microbial metabolites

Tryptophan (Trp) is an essential amino acid that can be metabolized via endogenous and exogenous pathways, including the Kynurenine Pathway, 5-Hydroxyindole Pathway (also Serotonin pathway), Microbial pathway. Of these, Trp metabolic pathways in gut have recently been extensively studied for their production of bioactive molecules. The microbiota plays important role host metabolism immunity, microbial metabolites influence development progression various diseases, inflammatory, cardiovascular neurological cancer, by mediating body’s immunity. This review briefly outlines crosstalk between microorganisms body, starting from three Trp. mechanisms which act on organism immunity are summarized, potential implications disease prevention treatment highlighted.