News in gut-brain communication: a role of peptide YY (PYY) in human obesity and following bariatric surgery?

Recent advances in obesity research focused on neuroendocrine control of food intake, appetite and body weight balance. Gut hormones, which are sequentially released from different regions of the gut, send signals to the areas of appetite control in the central nervous system causing a release of counter-regulatory hormones also originating from the gastrointestinal system. Ghrelin, a peptide secreted from the gastric fundus is released just before meal intake and stimulates hunger and food intake. Recently, peptide YY has been suggested to counteract ghrelin by inducing satiety and reducing appetite and caloric intake. While the effects of PYY on various gastrointestinal functions are well described, its action on weight loss is less known. Controversial results on the effect of exogenous administration of PYY(3-36) opened the discussion on the respective roles of PYY and/or PYY(3-36) in body weight homeostasis in man.