Bariatric surgery effects in obesity: correlation between gut microbiota changes and metabolic parameters

• Grant number: 10/18691-1
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2012
• End date: May 31, 2015
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Mario Jose Abdalla Saad
• Grantee: Mario Jose Abdalla Saad
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated researchers: Bruno Geloneze Neto ; Claudio Saddy Rodrigues Coy ; José Carlos Pareja ; Sabrina Nagassaki

Abstract

Metabolic Syndrome is associated to insulin resistance related to type 2 diabetes, obesity and inflamation (with increases in proinflamatory citocines expression). Gut microbiota shown be different between lean and obese subjects and moreover, gut microbiota composition could play a role in pathophysiology of type 2 diabetes. GLP-1, the major gut hormone, is released immediately after food ingestion, proportional to calories ingestion. This hormone is reduced in obese subjects and in insulin resistance. Both bariatric surgery and gut microbiota is associated with impaired GLP-1 release. Moreover, gut microbiota has been related to low grades of chronic inflammation due to diet-induced metabolic disorders, leading to increases of plasma LPS (abundant in gut flora). Increases of plasma LPS was related with obesity, diabetes and hepatic steatosis both in human and animals. In this present study, 10 subjects (10 eutrophic, 10 obeses and 20 obeses with impaired glucose tolerance subjects) will be studied. Obeses with insulin resistance will be studied prospectively to bariatric surgery. Differences in gut microbiota among these groups will be analysed as well as differences in gut microbiota associated to surgery (biliopancreatic diversion procedure, or Scopinaro surgery and roux-en-y gastric bypass). These alterations will be analysed regarding to their link with metabolic disorders. Small intestine fragments (duodeno, proximal jejuno and ileo) will be colleted by enteroscopy to study of enterocytes: morphology, FOXA1/2, GLP-1, GLP-2 and PYY expression (imunohistochemistry), neoglicogenesis protein activity (immunoblotting) and gut microbiota study. Genetic characterization of microbiota will be made by 16S rRNA Sequencing and hydrogen breath test will be used to investigate small intestine bacterial growth. Measurements of LPS, TNF- ±, IL-6 e Adiponectin will be realized to investigate possible alterations of inflammatory parameters due to microbiota composition related to differences in physiologic characteristics and to bariatric surgery. It is hypothesed that there are differences among groups regarding to gut microbiota and to metabolic parameters. Moreover, it is expected that biliopancreatic diversion procedure might modulate these parameters, by gut intestinal diversity. (AU)