The role of gut endocrine cells in control of metabolism and appetite

•What is the topic of this review? Gut hormones, especially glucagon-like peptide-1 (GLP-1), have beneficial effects in diabetes and obesity. Recent research addresses the underlying mechanisms of the secretion and action of GLP-1. •What advances does it highlight? The development of transgenic reporter mice with fluorescently tagged GLP-1-secreting cells has helped to characterize the molecular mechanisms underlying hormone secretion and has challenged the traditional classification of enteroendocrine cells by hormone expression alone. Recent adoption of this strategy to label GLP-1-receptor-positive cells has highlighted that peripheral and centrally released GLP-1 acts on a number of different targets, including a variety of neurons. Evidence for their role in glucose homeostasis and appetite control is discussed. After food is ingested, nutrients pass through the gastrointestinal tract, stimulating the release of a range of peptide hormones. Among their many local, central and peripheral actions, these hormones act to mediate glucose metabolism and satiety. Indeed, it is the modification of gut hormone secretion that is considered partly responsible for the normalization of glycaemic control and the reduction in appetite seen in many patients after certain forms of bariatric surgery. This review describes recent developments in our understanding of the secretion and action of anorexigenic gut hormones, primarily concentrating on glucagon-like peptide-1 (GLP-1).