Potential Associations Between Alterations in Gut Microbiome and Obesity-related Traits After the Bariatric Surgery

This study aimed to examine the effects of obesity and bariatric surgery on gut microbiota in a Turkish population, and to contribute to the literature by bringing multi-dimensional parameters including dietary intake, metabolic and inflammatory markers. This case-control study was conducted between June 2015 and August 2019. All participants were followed during the six-month period. Face-to-face interviews and physical examinations were held, and blood and fecal samples were collected at the baseline (M0) and at the end of 3 (M3) and 6 months (M6). Dietary intakes of subjects were assessed using 24-h dietary recall method in each interview and a detailed quantitative food frequency questionnaire that involved 85 food items. Subjects were recruited to the study as three groups: 15 patients who had bariatric surgery as study group, 8 morbidly obese participants who did not have bariatric surgery as control group-1 and 11 participants who were non-obese (lean (n=5) and pre-obese (n=6)) as control group-2. All subjects in the study group had sleeve gastrectomy. Subjects in control groups were selected as age and gender matched with the participants in the study group. Individuals were excluded if (a) they were under 19 or above 65 years old, (b) they had an acute or chronic inflammatory disease, (c) they were diagnosed with infectious diseases, cancer or alcohol addiction, (d) they used antibiotics in last 3 months before the screening.

Study Overview

• Status: Completed
• Conditions: Obesity; Bariatric Surgery
• Intervention / Treatment: Procedure: Bariatric surgery

• Study Type: Observational
• Enrollment (Actual): 34

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 22 years to 56 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Subjects were recruited to the study as three groups: 15 patients who had bariatric surgery as study group, 8 morbidly obese participants who did not have bariatric surgery as control group-1 and 11 participants who were non-obese (lean (n=5) and pre-obese (n=6)) as control group-2.

Description

Inclusion Criteria:

• morbidly obese participants for study and control group-1
• non-obese participants for control group-2

Exclusion Criteria:

• they were under 19 or above 65 years old,
• they had an acute or chronic inflammatory disease,
• they were diagnosed with infectious diseases, cancer or alcohol addiction,
• they used antibiotics in last 3 months before the screening.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Study group; 15 patients who had bariatric surgery	Procedure: Bariatric surgery; A procedure for morbidly obese patients whose body mass index (BMI) is higher than 40 kg/m2 or 35 kg/m2 and having comorbidities of obesity.
Control group-1; 8 morbidly obese participants who did not have bariatric surgery
Control group-2; 11 participants who were non-obese

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in gut microbial profiles of participants	Changes in bacterial phyla and sub-phylum levels	6 months
Changes in gut bacterial biodiversity of participants	Changes in gut bacterial alpha and beta biodiversity of participants	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in dietary energy and nutrient intakes	Changes in dietary energy in calories, macro-, micronutrient intakes in grams	6 months
Changes in food intakes	Changes in certain food groups in grams	6 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in body weight	Changes in body weight in kilograms	6 months
Changes in body mass index	Changes in body mass index in kg/m^2	6 months
Changes in body fat and fat free mass	Changes in fat mass and fat free mass in kilograms	6 months
Changes in waist circumferences	Changes in waist circumferences in centimeters	6 months
Changes in serum glucose levels	Changes in serum glucose in mg/dL	6 months
Changes in lipid related biochemical parameters	Changes in triglyceride, total cholesterol, LDL cholesterol, HDL cholesterol levels in mg/dL	6 months
Changes in liver function tests	Changes in ALT and AST levels in U/L	6 months
Changes in serum IL-6 and TNF-alpha levels	Changes in serum IL-6 and TNF-alpha levels in ng/mL	6 months
Changes in serum hs-CRP levels	Changes in serum hs-CRP in mg/L	6 months

Collaborators and Investigators

• Sponsor: Hacettepe University

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2015
• Primary Completion (Actual): September 1, 2018
• Study Completion (Actual): August 1, 2019

Study Registration Dates

• First Submitted: September 7, 2021
• First Submitted That Met QC Criteria: October 19, 2021
• First Posted (Actual): October 20, 2021

Study Record Updates

• Last Update Posted (Actual): October 20, 2021
• Last Update Submitted That Met QC Criteria: October 19, 2021
• Last Verified: October 1, 2021

More Information

Terms related to this study

• Keywords: obesity; bariatric surgery; gut microbiome; diet
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity
• Other Study ID Numbers: GO14/533

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No