The Microbiology of Bariatric Surgery

NCT03181347 | Completed

• 1 other identifier: Pro00071705
• Study Type: interventional
• Target: 74
• Locations: 1 country
• Sites: 1

Brief Summary

Obesity and its associated diseases are increasing worldwide. However, the mechanisms behind the development of obesity is not fully understood. There is evidence that intestinal bacteria may play a role in the development and perpetuation of obesity through regulation of energy and fat storage. Bariatric surgery is currently the most effective modality for treating severe obesity with evidence to support long-term sustained weight loss and improvement in obesity-related comorbidities. The two most commonly performed bariatric surgical procedures are the Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). RYGB leads to greater weight loss than SG and improved diabetes control in patients following surgery. Despite the success of RYGB and SG in inducing weight loss and improving comorbidities, the underlying mechanisms leading to clinical improvement following these operations is not completely understood. Multiple factors are thought to play a role including reduced caloric intake, decreased nutrient absorption, increased satiety, release of hormones and shifts in bile acid metabolism. Recent evidence has suggested that the gut bacteria mediates a number of the beneficial effects of bariatric surgery. Small studies have demonstrated changes in the composition and diversity of the gut microbiota after RYGB and SG in humans. One study also confirmed long-term microbial changes for RYGB. However, comparative trials have been small (less than 15 participants per treatment group) and important differences between specific bacterial populations have not been well elucidated. Furthermore, no human study has examined the differences in bacterial composition following RYGB and SG in relation to their metabolic consequences. The aim of this study is to investigate and compare the metabolic and microbial changes that occur with RYGB, SG, and dietary controls. Specifically, the investigators aim to use a systems biology approach utilizing powerful analytic techniques including metagenomics, metabolomics, and multiplex immune profiling to define the combined microbial, metabolic and immunologic changes that occur after bariatric surgery.

Conditions

Morbid Obesity

Keywords

Bariatrics; Microbiology

Outcome Measures

Primary Outcomes (3)

• Fecal microbial analysis

  The microbial community composition of fecal samples will be assessed using 16S rRNA gene analyses

  2 to 6 weeks prior to intervention

• Fecal microbial analysis

  The microbial community composition of fecal samples will be assessed using 16S rRNA gene analyses

  3 month post intervention

• Fecal microbial analysis

  The microbial community composition of fecal samples will be assessed using 16S rRNA gene analyses

  9 month post intervention

Secondary Outcomes (10)

• Urine metabolomics

  2 to 6 weeks prior to intervention

• Serum metabolomics

  2 to 6 weeks prior to intervention

• Urine metabolomics

  3 month post intervention

• Serum metabolomics

  3 month post intervention

• Urine metabolomics

  9 month post intervention

Study Arms (3)

Roux-en-Y Gastric Bypass (RYGB)

EXPERIMENTAL

Severely obese patients scheduled for Roux-en-Y Gastric Bypass surgery

Procedure: RYGB

Sleeve Gastrectomy (SG)

EXPERIMENTAL

Severely obese patients scheduled for Sleeve Gastrectomy surgery

Procedure: SG

Non-surgical

ACTIVE COMPARATOR

Severely obese controls with dietary and activity modifications and excludes meal replacement or pharmacologic interventions

Behavioral: Dietary and behavioral

Interventions

RYGB PROCEDURE

Roux-en-Y Gastric Bypass

Roux-en-Y Gastric Bypass (RYGB)

SG PROCEDURE

Sleeve Gastrectomy

Sleeve Gastrectomy (SG)

Dietary and behavioral BEHAVIORAL

Dietary and activity modifications and excludes meal replacement or pharmacologic interventions

Non-surgical

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• severely obese controls: BMI \> 35 kg/m2
• severely obese patients scheduled for sleeve gastrectomy
• severely obese patients scheduled for Roux-en-Y gastric bypass
• Cohorts will be BMI matched

You may not qualify if:

• Antibiotic, liraglutide, or methotrexate usage within two months preceding enrollment
• Meal replacement use within one month
• Previous bowel resection
• Inflammatory bowel disease
• Previous bariatric surgery

Sponsors & Collaborators

• University of Alberta: lead
• Society of American Gastrointestinal and Endoscopic Surgeons: collaborator
• Alberta Health services: collaborator

Study Sites (1)

CAMIS, Royal Alexandra Hospital

Edmonton, Alberta, T5H 3V9, Canada

Location

MeSH Terms

Conditions

Obesity, Morbid

Interventions

Diet

Condition Hierarchy (Ancestors)

Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Daniel W Birch, MD MSc

  University of Alberta

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MSc, MD, FRCSC, FACS, CAMIS Medical Director, Professor of Surgery

Study Record Dates

• First Submitted: June 2, 2017
• First Posted: June 8, 2017
• Study Start: September 3, 2017
• Primary Completion: February 3, 2020
• Study Completion: February 3, 2020
• Last Updated: November 18, 2020

Record last verified: 2020-11

Locations

CA (1)