Regulation of food intake by gastrointestinal hormones

Complex physiological mechanisms have evolved to control food intake in mammals, which in health ensure the relative stability of body weight in adults. Central brain centres, gut-derived peptides and adipose-derived signals result in an integrative response to defend against starvation. Enteroendocrine cells throughout the gut and pancreas secrete a number of peptides with activity on gut motility, gut secretions and appetite. Understanding the interactions between different gut peptides has produced a rewardingly active research field with many unanswered questions.

Many gut peptides are now in translational research programmes to investigate their potential in human physiology and disease. Ghrelin has been shown in short-term human studies to both increase appetite and body weight. Oxyntomodulin has been shown to reduce weight and food intake in a 4 week study in humans. Anorectic activity of peptide YY(3-36) has been confirmed in a number of animal models. Obestatin has been identified as a novel gut peptide. Increasing evidence points to the effect of gastric-bypass surgery on body weight, including alteration of gut peptide activity.

Gut peptides, or gut-peptide mimetics, show great promise for use as therapeutic agents for the treatment of obesity and cachexia.