Longitudinal Phenotyping of Bariatric Surgery Patients

October 15, 2020 updated by: Imperial College London

Recent studies have shown that bacteria within the gut play an important role in diabetes improvement after bariatric (weight-loss) surgery. Bariatric surgery fundamentally changes the environment within the gut, which results in changes to the makeup of the trillions of bacteria living within it. These changes in the gut bacteria can affect the body in a number of complex ways, which we are only just beginning to understand. For example, gut bacteria breakdown food we are unable to absorb ourselves, leading to altered sugar levels and can release molecules that act to reduce appetite.

In this study we aim to find out how bariatric surgery changes the gut bacteria and how this leads to weight loss and improvement of diabetes. With this understanding we hope to discover potential targets for future treatments, such as identifying beneficial bacteria that could be supplemented with probiotics in patients.

Additionally, although highly successful, up to 30% of obese patients do not undergo improvement of their diabetes after bariatric surgery. We aim to identify molecules within the patient's blood or urine that are able to predict the likely chance a patient will undergo improvement in their diabetes after bariatric surgery to help clinicians select patients most likely to benefit.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

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

This study aims to assess how the gut microbiome affects the host phenotype following bariatric surgery through altered gut microbiome-host co-metabolism. The secondary objective is to identify novel biomarkers for the preoperative prognostication of T2DM remission following bariatric surgery.

The study will longitudinally phenotype obese diabetics and non-diabetics undergoing Roux-en-Y Gastric Bypass or Sleeve Gastrectomy surgery. Patients will be assessed preoperatively and at 3 months and 1 year postoperatively. Clinical measures recorded will include; 1) anthropometric & physiological measurements, 2) demographic details, 3) biochemical parameters including HbA1c, 4) anti-hyperglycaemic and other medication use, 5) co-morbidity status and 6) dietary choices through 24hr dietary recall questionnaires.

Blood, urine and stool samples will be collected at the above time points. Changes to the microbiome will be assessed using metagenomic sequencing. Global metabonomic profiles of serum, urine and faecal water will be generated using 1H-NMR. Further targeted analyses of bile acid and short-chain fatty acid profiles will be performed using LC-MS / GC-MS.

The study will utilise multivariate statistical analysis techniques to identify metabolic pathways altered following intervention, and novel host-microbiome co-metabolism pathways that impact upon phenotype. A supervised multivariate analysis, mapping T2DM outcomes to metagenomic and metabonomic data will be performed with the aim of identifying novel preoperative biomarkers that are able to prognosticate T2DM resolution following bariatric surgery.

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.
Observational

Enrollment (Actual)

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.
158

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

  • United Kingdom
      • London, United Kingdom, W2 1NY
        • Imperial Weight Centre

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Participants with obesity undergoing bariatric surgery

Description

Inclusion Criteria:

  • Obese (BMI>30kg/m2)
  • Type 2 Diabetes Mellitus and non-diabetic
  • Failure of efforts at lifestyle modification and dieting
  • Fitness for anaesthesia and procedure
  • Willingness to comply with the trial protocol

Exclusion Criteria:

  • Previous bariatric surgery
  • Pregnancy or intention to become pregnant during trial period
  • Lack of capacity to consent
  • Previous major abdominal surgery (Small or large bowel resection, stomach, liver, pancreatic or splenic surgery. Does not include patients who have previously had an appendicectomy, cholecystectomy or hernia repair).

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
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.
Group 1
Roux-en-Y Gastric Bypass
Procedure: Laparoscopic Roux-en-Y Gastric Bypass
Group 2
Sleeve Gastrectomy
Procedure: Laparoscopic Sleeve Gastrectomy

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
Number of Participants With Complete Diabetes Remission at 3 Months
Time Frame: 3 months
Participants with HbA1c <6% (42mmol/mol), off anti-diabetic medication, at 3 months
3 months

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
Partial Diabetes Remission
Time Frame: 3 months
HbA1c <6.5% (48mmol/mol), off anti-diabetic medication, at 3 months. (Includes participants with complete remission).
3 months
HbA1c Improvement
Time Frame: 3 months
Reduction in HbA1c at 3 months
3 months
Weight Loss
Time Frame: 3 months
Weight loss at 3 months
3 months
BMI Reduction
Time Frame: 3 months
BMI reduction at 3 months
3 months
Complete Diabetes Remission
Time Frame: 1 year
HbA1c <6% (42mmol/mol), off anti-diabetic medication, at 1 year
1 year
Partial Diabetes Remission
Time Frame: 1 year
HbA1c <6.5% (48mmol/mol), off anti-diabetic medication, at 1 year. (Includes participants with complete diabetes remission).
1 year
HbA1c Improvement
Time Frame: 1 year
Reduction in HbA1c at 1 year
1 year
Weight Loss
Time Frame: 1 year
Weight loss at 1 year
1 year
BMI Reduction
Time Frame: 1 year
BMI reduction at 1 year
1 year

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.
Imperial College London

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ara Darzi, MB, BCh, MD, Imperial College London

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.
June 1, 2015

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.
February 1, 2019

Study Completion (Actual)

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.
February 1, 2019

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).
April 15, 2015

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.
April 15, 2015

First Posted (Estimate)

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.
April 20, 2015

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.
November 6, 2020

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.
October 15, 2020

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.
October 1, 2020

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • 15SM2479

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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