Gut reactions and gut instincts: regulation of intestinal homeostasis by receptor guanylyl cyclase C (GC-C).

The important role that the gut plays in directing and modulating the well-being of the entire organism cannot be underestimated. We are beginning to dissect molecular players that are intrinsic to the functioning of the epithelial cells of the gut, which, in turn, control the responses of various tissues. In this review, we provide an overview of the role of a receptor guanylyl cyclase in regulating fluid-ion homeostasis, cell proliferation and the microbiome in the gut. Further elucidation of molecular details, aided by the development of novel mouse models and organoid cultures, should increase our understanding of the role of this receptor and cyclic guanosine 3',5'-monophosphate in congenital secretory diarrhoea and inflammatory bowel disease.