Based on our hypothesis that orally administered resistant starch and inulin/beta glucan will be fermented into a SCFA pattern high in acetate and that this will lead to beneficial effects on human substrate and energy metabolism, we aim to address the following primary objective:

To investigate the effects of an acute administration of inulin/beta glucan in combination with resistant starch on fecal and plasma acetate, as well as on fasting and postprandial substrate and energy metabolism in lean normoglycemic men and obese, prediabetic men.

Inclusion Criteria:

• lean (BMI ≥ 20kg/m2 and ≤ 24.9kg/m2)
• normoglycemic
• aged 30 - 65 years

OR

• overweight/obese (BMI ≥ 25kg/m2 and ≤ 34.9kg/m2)
• pre-diabetes
• aged between 30 - 65 years.

Exclusion Criteria:

• 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
• Use of antibiotics 3 months prior inclusion
• Use of probiotics or prebiotics