Physiology of gut hormones: An overview

Purpose of review: Thus far more than 30 peptides have been identified as being expressed within the digestive tract, making the gut the largest endocrine organ in the body. Understanding of the physiology of many of these peptides has progressed rapidly. This paper provides an overview of advances in our understanding of the physiology of ghrelin, motilin, cholecystokinin, glucagon-like peptide-1 and oxyntomodulin, glucose-dependent insulinotropic peptide, gastrin-releasing peptide, enterostatin, galanin, and gut leptin. Recent findings: The review highlights how, in anticipation of and in response to food intake of a particular amount and composition, changes in gastrointestinal hormone synthesis and release occur in order to regulate and coordinate gastrointestinal function, appetite control, and intermediary metabolism. Abnormalities of gut hormones in disorders such as diabetes mellitus, disorders of body weight, and eating disorders are highlighted. The paucity of data relating to the human physiology of enterostatin, galanin, and gut leptin stands in contrast to the other hormones discussed and highlights areas for further investigation. Summary: An increase in the understanding of the physiology of gut hormones and their role in integrating food intake and intermediary metabolism have led to novel therapies for the management of diabetes mellitus and also has the potential for new approaches for the management of disorders of food intake and body weight.