Incretins. Role in central regulation of metabolism

The central nervous system (CNS) and the gastrointestinal tract can communicate in mutual interaction via neuronal, endocrine and immunological information channels. In this system glucagon-like peptide-1 (GLP-1) plays an important role because it is synthesized as a peptide hormone in the gastrointestinal tract and as a neurotransmitter in the brain. Peripheral GLP-1 modulates glucose metabolism as a so-called incretin by enhancing insulin secretion and inhibiting glucagon release. Furthermore, glucose metabolism and food intake are regulated through activation of central GLP-1 receptors (GLP-1R). Glucagon-like peptide-1 receptor agonists are already used for the treatment of patients with type 2 diabetes and can cause clinically relevant weight loss. In addition, the intestinal microbiota may modulate GLP-1 secretion and thereby contribute to the regulation of body weight and appetite.