Overview

In this project the investigators will test if it is possible to measure changes in intestinal gas production after supplementation of a complex fiber mixture over a 36 hour period in both lean normoglycemic individuals and individuals with insulin resistance and/or prediabetes with overweight when compared with a placebo

Changes in intestinal gas production will also be related to energy expenditure, substrate metabolism, microbial composition and related metabolites in feces, blood and urine.

Eligibility

Inclusion Criteria:

• Lean normoglycemic individuals:
• Lean (BMI ≥ 18.5 kg/m2 and ≤ 24.9 kg/m2 );
• Normal fasting glucose (plasma glucose < 5.6 mmol/L) and a HOMA-IR< 2.2

Individuals with overweight/obesity and prediabetes/insulin resistance:

• Overweight/obesity (BMI ≥ 28 kg/m2 and ≤ 40 kg/m2 );
• insulin resistance (HOMA-IR>2.2) and/or impaired fasting glucose (IFG: plasma glucose ≥ 5.6 mmol/l)

For both subject groups:

• Aged 30 - 75 years;
• Normal blood pressure (systolic blood pressure 100-150mmHg, diastolic blood pressure 60-100 mmHg);
• Weight stable for at least 3 months (± 2 kg)

Exclusion Criteria:

• T2DM (defined as fasting plasma glucose ≥ 7.0 mmol/L)
• Gastroenterological diseases
• Abdominal surgery affecting the GI tract;
• Cardiovascular diseases, cancer, liver or kidney malfunction, disease with a life expectancy shorter than five years;
• Abuse of products;
  • Alcohol (> 15 standard units per week)
  • Drugs
  • Excessive nicotine use defined as >20 cigarettes per day;
• Plans to lose weight or following of a hypocaloric diet
• Regular supplementation of pre- or probiotic products, use of pre- or probiotics three months prior to the start of the study;
• Intensive exercise training more than three hours a week;
• Use of most medications that influence glucose or fat metabolism, like some lipid lowering-drugs (e.g., PPAR γ or PPARα (fibrates) agonists), glucose-lowering agents (including all sulfonylureas, biguanides, α-glucosidase inhibitors, thiazolidinediones, repaglinide, nateglinide and insulin), inflammation (e.g., anti-inflammatory* or immunosuppressive drugs) and anti-oxidants;
• Regular use of laxatives;
• Use of antibiotics in the last three months (antibiotics use can alter substantially the gut microbiota composition).
• Veganism
• Lactose intolerance
• For women: pregnancy or lactation