The Role of HS in the Gastrointestinal Tract and Microbiota.

The pathways and mechanisms of the production of HS in the gastrointestinal tract are briefly described, including endogenous HS produced by the organism and HS from microorganisms in the gastrointestinal tract. In addition, the physiological regulatory functions of HS on gastrointestinal motility, sensation, secretion and absorption, endocrine system, proliferation and differentiation of stem cells, and the possible mechanisms involved are introduced. In view of the complexity of biosynthesis, physiological roles, and the mechanism of HS, this chapter focuses on the interactions and dynamic balance among HS, gastrointestinal microorganisms, and the host. Finally, we focus on some clinical gastrointestinal diseases, such as inflammatory bowel disease, colorectal cancer, functional gastrointestinal disease, which might occur or develop when the above balance is broken. Pharmacological regulation of HS or the intestinal microorganisms related to HS might provide new therapeutic approaches for some gastrointestinal diseases.