Abstract: 5-Hydroxytryptamine is an important neurotransmitter and gastrointestinal hormone in the body. There are two independent 5-hydroxytryptamine systems, one in the central nervous system and one in the periphery. Peripheral 5-hydroxytryptamine of serum mainly comes from gastrointestinal tract. Regulatory effect of serum 5-hydroxytryptamine on hepatic bile acids synthesis and efflux transport have been identified, and also the effect on bile acids transporters in ileum and kidney, which resulted in the bile acids alteration in enterohepatic circulation and renal excretion, indicating the important role of serum 5-hydroxytryptamine on the homeostasis of bile acids. To investigate and clarify the effect and underlying mechanism of serum 5-hydroxytryptamine on the homeostasis of bile acids will provide clues for the pathogenesis discovery of bile acids disorder-related diseases, and also provide evidences for the therapeutic strategy development.

Key words: 5-hydroxytryptamine, bile acid, synthesis enzyme, transporter, enterohepatic circulation