The effects of galactooligosaccharide (GOS) on peripheral insulin sensitivity and body weight control in obese adults with impaired glucose homeostasis

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 46

Inclusion Criteria

Overweight/obese (BMI * 28 kg/m2 < 40 kg/m2) insulin impaired men and post-menopausal women with impaired glucose tolerance (IGT: 2h plasma glucose during 75g OGTT 7.8-11.1 mmol/l) and/or impaired fasting glucose (plasma glucose * 5.6 mmol/l) aged 45-70 years will be included in the study.
In addition, subjects have to be weight-stable for at least 3 months prior to participation (no change in bodyweight, i.e. < 3kg).

Exclusion Criteria

Subjects will be excluded from participation when one or more of the following aspects are present:
- diabetes mellitus
- gastroenterological diseases or major abdominal surgery (allowed i.e.: appendectomy, cholecystectomy)
- lactose intolerance and other digestive disorders
- cardiovascular disease, cancer, liver or kidney malfunction (determined based on ALAT and creatinine levels, respectively)
- disease with a life expectancy shorter than 5 years
- abuse of products (alcohol consumption > 15 units/week, or any drugs)
- excessive nicotine use defined as >20 cigarettes per day
- plans to lose weight or follow a hypocaloric diet
- regular supplement of pre- or probiotic products
- intensive exercise more than three hours a week
- - use of any medication that influences glucose or fat metabolism and inflammation, like i.e. *-blockers, lipid lowering-drugs (e.g. PPAR * or PPAR* (fibrates) agonists), glucose-lowering agents (including all sulfonylureas, biguanides, *-glucosidase inhibitors, thiazolidinediones, repaglinide, nateglinide and insulin), anti-oxidants or chronic corticosteroids treatment.
- use of laxation products in the last three months or during the study period;- use of antibiotics in the last three months or during the study period.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Primary endpoint: whole-body insulin sensitivity as assessed by a one-step<br /><br>hyperinsulinemic euglycemic clamp </p><br>

Secondary Outcome Measures

Name	Time	Method
<p>- energy expenditure and substrate oxidation (indirect calorimetry)<br /><br>- adipose tissue and skeletal muscle gene/protein expression<br /><br>- faecal and circulating SCFA<br /><br>- faecal microbiota composition<br /><br>- circulating incretins, metabolites and inflammatory parameters<br /><br>- body weight, BMI and body composition (DEXA scan)<br /><br>- volatile organic compounds (VOCs) in exhaled air</p><br>