Effect of the Roux-en-Y gastric bypass on the gut microbiota of obese women with type 2 diabetes: association with metabolic parameters

• Grant number: 12/23935-2
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2013
• End date: January 31, 2014
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Mario Jose Abdalla Saad
• Grantee: Ana Carolina Junqueira Vasques
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The presence of insulin resistance (IR) in obesity and T2DM is associated with subclinical inflammation, which may have different mechanisms of generation and maintenance. Scientific evidence indicates that gut flora may participate in the pathophysiology of inflammation and IR in obesity. The gastric bypass Roux-en-Y (RYGB) provides significant improvement in inflammatory and metabolic profiling, and lead to anatomical and functional changes that may affect the gut microbiota. Thirty women will be studied and divided into 3 groups: 10 lean, 10 obese, both with normal glucose tolerance, and 10 obese with T2DM, which will be submitted to RYGB and will also be studied post surgery. The differences between the gut microbiota before and after surgery will be analyzed, relating to possible changes in metabolic parameters. The meal tolerance test will be applied to assess IR, ²-cell function and incretin secretion. Fragments of the small gut will be collected by enteroscopy for the study of enterocytes (morphology, expression of fox1/2, GLP-1, GLP-2, PYY and by immunohistochemistry and activity of proteins from gluconeogenesis - by immunoblotting), and the material of these gut areas will be collected to study the gut microbiota. Genetic characterization of gut microbiota will be performed by sequencing, and the overgrowth of the bacteria will be analysed by exhaled air. Measurements of lipopolysaccharides, TNF-a, IL-6 and adiponectin will determine possible changes of inflammatory parameters for the diversity of the gut microbiota after RYGB. It is expected that there are differences between the study groups regarding the gut microbiota and metabolic parameters, and that RYGB may modulate these parameters by the diversity of the gut microbiota.