Plain English Summary
Background and study aims
Obesity represents a global epidemic, and increases the risk of developing Type 2 Diabetes Mellitus (T2DM), hence the introduction of the term “diabesity”. The most effective and long-lasting solution for severe obesity is bariatric surgery. Two widely used types of bariatric surgery are gastric bypass and gastric sleeve. Gastric bypass involves re-routing the digestive system past most of the stomach, so less food is digested and it takes much less to feel full. Gastric sleeve involves removing some of the stomach to reduce the amount of food that's required to feel full. Obesity causes changes in the bacteria that live in the gut (microbiota). After bariatric surgery there are changes in the gut microbiota and in intestinal hormones (e.g. GLP-1) that control satiety (fullness) and food intake. Although gut microbiota changes have been suggested to alter levels of GLP-1, the mechanism and its importance in bariatric surgery remain to be determined. The aim of this study is to investigate the changes in the gut microbiota after two different types of bariatric surgery, as well as the relationship with blood levels of GLP-1.
Who can participate?
Women aged 18-65 who are severely obese and not diabetic
What does the study involve?
Participants are randomly allocated into two groups to undergo either gastric bypass or gastric sleeve surgery. Participants are followed for 6 months after surgery, and fecal and blood samples are collected before surgery as well as 3 and 6 months after surgery. Meal-stimulated blood GLP-1 levels are measured before and 3 and 6 months after surgery.
What are the possible benefits and risks of participating?
This study may increase knowledge of the mechanisms controlling obesity and help develop better and less invasive treatments, as well as providing more information regarding the participant’s own outcome of surgery and a more extensive follow-up after surgery. The risks of participating can be considered low as participation only involves repeated blood sampling.
Where is the study run from?
Södertälje Sjukhus AB (Sweden)
When is the study starting and how long is it expected to run for?
February 2017 to September 2020
Who is funding the study?
1. Mats Kleberg Foundation (Sweden)
2. Fredrik och Ingrid Thurings Stiftelse (Sweden)
3. Tore Nilsons Stiftelse för Medicinsk Forskning (Sweden)
Who is the main contact?
Dr Camilla Krizhanovskii
Trial website
Contact information
Type
Scientific
Primary contact
Dr Camilla Krizhanovskii
ORCID ID
http://orcid.org/0000-0003-2195-165X
Contact details
Lagmansvägen 15
Södertälje
15286
Sweden
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
nr1
Study information
Scientific title
Characterization of the incretin response and microbiota in women before an after bariatric surgery, aiming to determine how the microbiota regulates metabolism, and its role for weight loss: a randomized controlled trial
Acronym
Study hypothesis
Alteration of gut microbiota following bariatric surgery contributes to its efficacy as a weight loss treatment through modulation of the secretion of the anorectic hormone GLP-1.
Ethics approval
Regionala etikprövningsnämnden i Stockholm (regional ethics board in Stockholm), 26/08/2015, ref: 2015/795-31/2
Study design
Randomized controlled trial
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Hospitals
Trial type
Treatment
Patient information sheet
No participant information sheet available
Condition
Obesity
Intervention
Non-diabetic patients with severe obesity (that is, BMI >40 kg/m. or BMI >35 kg/m. with comorbidities) will be randomized into two groups receiving either gastric bypass (RYGB) or gastric sleeve. Patients will be followed for 6 months post-surgery, and fecal and blood samples will be collected before surgery, as well as 3 and 6 months after surgery. Meal stimulated GLP-1 plasma levels will be determined prior to and 3 and 6 months after surgery. The primary endpoint is the proportion of subjects achieving a 15% relative change in meal stimulated GLP-1 plasma levels following gastric bypass surgery (RYGB)/gastric sleeve compared to pre-surgical meal stimulated GLP-1 release, as assessed by GLP-1 specific ELISA of serum samples. Secondary endpoints are whether a 15% weight reduction of presurgical body weight is observed following gastric bypass surgery (RYGB)/sleeve.
Intervention type
Procedure/Surgery
Phase
Drug names
Primary outcome measure
1. Plasma GLP-1, measured using the meal tolerance test and GLP-1 specific ELISA of serum samples
2. Gut microbiota composition, analyzed from fecal samples
Timepoints: before 10-day diet, after 10-day diet/before surgery, 3 months after surgery, 6 months after surgery
Secondary outcome measures
1. Plasma inflammatory markers, analyzed by specific ELISAs
2. Lipid profile, determined by commercially available HDL and LDL/VLDL Cholesterol Assay Kits, Free Fatty Acid Quantification Kit, as well as Triglyceride Quantification Kit
Timepoints: before 10-day diet, after 10-day diet/before surgery, 3 months after surgery, 6 months after surgery
Overall trial start date
01/10/2016
Overall trial end date
01/09/2020
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Obese non-diabetic females
2. 18-65 years of age
3. Signed informed consent form
Participant type
Patient
Age group
Adult
Gender
Female
Target number of participants
30 subjects (15 in each group)
Participant exclusion criteria
1. Type 2 diabetes
2. Any history of receiving GLP-1 analogues or DPP-4 inhibitors
3. Previous treatment with insulin (any regimen) within 3 months
4. Current or history of drug and alcohol abuse
Recruitment start date
27/02/2017
Recruitment end date
30/03/2020
Locations
Countries of recruitment
Sweden
Trial participating centre
Södertälje Sjukhus AB
15286
Sweden
Funders
Funder type
Charity
Funder name
Mats Kleberg Foundation
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Funder name
Fredrik och Ingrid Thurings Stiftelse
Alternative name(s)
Fredrik and Ingrid Thurings Foundation
Funding Body Type
private sector organisation
Funding Body Subtype
foundation
Location
Sweden
Funder name
Tore Nilsons Stiftelse för Medicinsk Forskning
Alternative name(s)
Tore Nilsson Foundation, Tore Nilsson Fond
Funding Body Type
private sector organisation
Funding Body Subtype
foundation
Location
Sweden
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journal
IPD sharing plan
The datasets generated during and/or analysed during the current study are/will be available upon request from Camilla Krizhanovskii
Intention to publish date
30/11/2020
Participant level data
Available on request
Basic results (scientific)
Publication list