title: Gut-brain communication: how does it stand after bariatric surgery?
abstract: OBJECTIVE
  This article aims to critically review the literature, describing the possible implications of different bariatric surgery techniques in gastrointestinal peptides and their relation with the neural paths involved in the central regulation of appetite and satiety: the gut-brain axis.
  
  
  RESULTS
  Bariatric surgery operations change orexigenic and anorexigenic gastrointestinal peptide levels. Forty-one studies were analyzed in order to understand the effects of different operations on the behavior of gut peptides (ghrelin, cholecystokinin, peptide YY, glucagon-like peptide-1, gastric inhibitory polypeptide, pancreatic polypeptide). The authors have tried to correlate these findings with weight loss/maintenance via different surgical techniques.
  
  
  CONCLUSIONS
  The present line of research is recent and there is a lack of comparability between studies. There are different design approaches and study protocols, different laboratorial exams. Prospective long-term studies with larger samples are needed to clarify the effects of bariatric operations on the gut-brain axis.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Federal University of Minas Gerais, Brazil. mfhsdiniz@ufmg.br
authors.forename: Maria
authors.initials: M
authors.lastname: de Fátima Haueisen Sander Diniz
authors.forename: Valéria Maria
authors.initials: VM
authors.lastname: de Azeredo Passos
authors.forename: Marco Túlio Costa
authors.initials: MT
authors.lastname: Diniz
mesh_terms: D001069:Appetite Regulation / Q000502:physiology*; D050110:Bariatric Surgery; D005768:Gastrointestinal Hormones / Q000378:metabolism*; D054439:Ghrelin; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism; D006801:Humans; D009767:Obesity, Morbid / Q000378:metabolism / Q000601:surgery*; D010191:Pancreatic Polypeptide / Q000378:metabolism; D036361:Peptide Hormones / Q000378:metabolism; D019894:Peptide YY / Q000378:metabolism; D012528:Satiety Response / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D005768:Gastrointestinal Hormones; D054439:Ghrelin; D036361:Peptide Hormones; D019894:Peptide YY; D010191:Pancreatic Polypeptide; D052216:Glucagon-Like Peptide 1