Effects of Very Low-calorie Diet Versus Bariatric Surgery on Body Composition and Gut Microbiota Pattern

July 3, 2023 updated by: Chanawit Saiyalam, Mahidol University

Effects of Very Low-calorie Diet Versus Bariatric Surgery on Body Composition and Gut Microbiota Pattern in Obese Patients

Obesity is a chronic disease characterized by the excessive accumulation of fat in body and it continues to be a major public health problem worldwide. Treatment options for obesity include lifestyle modification, pharmacotherapy and bariatric surgery. Bariatric surgery is a highly effective treatment for obesity and results in rapid and sustained weight loss. Also, it significantly alters gut microbiota composition and function. A very low-calorie diet (VLCD) is a rapid weight loss program which calorie intake is severely restricted (< 800 kcal/day). It has been shown to be very effective to induce rapid weight loss and result in comorbidities resolution similar to bariatric surgery. Therefore, this study was aimed to study the effects of 12-week VLCD compare to bariatric surgery (Laparoscopic Roux-en-Y gastric bypass (LRYGB) or Laparoscopic Sleeve Gastrectomy (LSG)) on weight loss, body composition, gut microbiota pattern and other metabolic parameters.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The study will include obese patients (body mass index; BMI ≥ 37.5 kg/m2 or BMI ≥ 32.5 kg/m2 with comorbidities), aged 15-65 years at Ramathibodi Hospital, Thailand. The VLCD group will received total diet replacement for 12 weeks and the bariatric surgery group will undergo LRYGB or LSG. Study participants in both groups will be matched according to their age, sex, body mass index (BMI) and diabetic status. Body weight reduction and body composition, gut microbiota pattern, liver stiffness and steatosis, glycemic and other metabolic parameters (glucose, insulin, c-peptide, lipid profile, liver function test, kidney function test, complete blood count, electrolyte blood test, thyroid function tests, serum ketone and adiponectin), health-related quality of life, depression score and twenty-four-hour diet recall and physical activity will be assessed at baseline and at month 1, 3, 6, 9 and 12.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
54

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Thailand
      • Bangkok, Thailand, 10400
        • Faculty of Medicine Ramathibodi Hospital Mahidol University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

15 years to 65 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Aged 15-65 years
  • Male or female
  • Body mass index ≥ 32.5 kg/m2 with obesity related co-morbidity
  • Body mass index ≥ 37.5 kg/m2 with or without an obesity related co-morbidity

Exclusion Criteria:

  • End stage disease such as cancer, cirrhosis Child-Pugh C, critical/acute illness
  • Type 1 diabetes mellitus
  • Recent eGFR < 30 ml/min/1.73 m2
  • Weight loss ≥ 5% in the previous 3 months
  • Use of antibiotics in the previous 1 month
  • Use of probiotic or prebiotic supplement in form of tablet or sachet in the previous 14 days
  • Current treatment with anti-obesity drugs
  • Pregnancy or breast feeding
  • Substance abuse
  • Uncontrolled psychiatric disorder and eating order
  • History of allergy to any components in meal replacement product or whey protein product
  • Unable to give informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Very low-calorie diet
Patients in the very low-calorie diet group will be prescribed a very low-calorie diet (meal replacement) for 12 weeks, then the patients will be monitored up to 1 year
Other: Very low-calorie diet
Meal replacement (800 kcal/day, protein 90 g/day)
Experimental: Bariatric surgery
Patients in the bariatric surgery group will be undergone bariatric surgery LRYGB and will be follow-up according the current guideline
Procedure: Bariatric surgery
Bariatric surgery will be performed by single surgeon at Ramathibodi Hospital Mahidol University, Thailand. Postoperative diet progression according to the current guideline will be prescribed from early post-op period to 1 year after surgery

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Changes in body weight
Time Frame: From baseline to 12 weeks
Weight in kg
From baseline to 12 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Body Composition
Time Frame: From baseline to 12 weeks
The percentage of body fat and skeleton muscle mass
From baseline to 12 weeks
Gut microbiota pattern
Time Frame: From baseline to 12 weeks
Measured by 16S ribosomal RNA (rRNA) gene sequencing on the fecal samples
From baseline to 12 weeks
Liver stiffness
Time Frame: From baseline to 12 weeks
Measured by FibroScan® instrument
From baseline to 12 weeks
Liver steatosis
Time Frame: From baseline to 12 weeks
Measured by FibroScan® instrument
From baseline to 12 weeks
Blood pressure
Time Frame: From baseline to 12 weeks
Systolic and diastolic blood pressure
From baseline to 12 weeks
Fasting plasma glucose
Time Frame: From baseline to 12 weeks
Measured in mg/dl
From baseline to 12 weeks
Hemoglobin A1c
Time Frame: From baseline to 12 weeks
Measured in %
From baseline to 12 weeks
Fasting insulin
Time Frame: From baseline to 12 weeks
Measured in μIU/l
From baseline to 12 weeks
Insulin resistance
Time Frame: From baseline to 12 weeks
Measured by the homeostatic model of insulin resistance (HOMA-IR)
From baseline to 12 weeks
Triglyceride
Time Frame: From baseline to 12 weeks
Measured in mg/dl
From baseline to 12 weeks
Total cholesterol
Time Frame: From baseline to 12 weeks
Measured in mg/dl
From baseline to 12 weeks
LDL-cholesterol
Time Frame: From baseline to 12 weeks
Measured in mg/dl
From baseline to 12 weeks
HDL-cholesterol
Time Frame: From baseline to 12 weeks
Measured in mg/dl
From baseline to 12 weeks
Health-related quality of life
Time Frame: From baseline to 12 weeks
Measured by the EQ-5D-5L questionnaire
From baseline to 12 weeks
Depression
Time Frame: From baseline to 12 weeks
Measured by the PHQ-9 questionnaire
From baseline to 12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Mahidol University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 20, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 20, 2022

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 20, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 2, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 14, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 15, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 5, 2023

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 3, 2023

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • MURA2016/647

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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