Examination of the molecular phenotype and composition of endocrine cells in the gastrointestinal tract correlated to analyses of blood for hormones/analytes before and after Roux-en-Y gastric bypass surgery in morbidly obese individuals both with and without type 2 diabetes
Enteroscopy was conducted during sedation with Propofol®. The pre-surgical sampling included biopsies retrieved from the stomach and at the expected site of anastomosis. During RYGB surgery, a \~1 cm gut tissue sample was removed at the site of anastomosis. The post-surgical enteroscopy \~3 months after RYGB surgery included biopsies taken from the gastric pouch, the alimentary limb, the biliopancreatic limb and common channel. One sample from each location was immersion-fixated in formalin for subsequent histological analyses and one sample was placed in a tube with RNA-preserving media for mRNA expression analysis. Remaining samples were snap-frozen and stored at -80°C until further processing. Enteroendocrine cells were identified and isolated from biopsies obtained at several sites in the small intestine by using immunohistochemistry and laser capture technology. Isolated individual enteroendocrine cells were extensively characterised by next generation sequencing (Illumina NGS). The participants also went through four mixed meal tests with blood sampling performed: before an 8 % diet-induced weight loss was initiated and one week before/one week after/3 months after RYGB surgery. Blood was sampled at several specific time points. The plasma, serum and urine collected from study participants before and after RYGB surgery will be analysed for biomarkers/analytes and correlated with clinical data (weight, BMI, waist/hip ratio, blood pressure) and molecular phenotype found in gut samples. To study changes in gut bacteria (microbiota) composition stool samples were collected during the study and will be analysed for microbiota composition by means of bacterial DNA sequencing.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
28
Enteroscopies with biopsy retrieval and mixed meal tests with blood sampling before and after Roux-en-Y gastric bypass surgery
Altered gene expression in the endocrine secretome following Roux-en-Y gastric bypass surgery
Time frame: Each participant went through six study days (two mixed meal tests and one enteroscopy procedure before and after Roux-en-Y gastric bypass surgery, respectively)
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