Effects of Beta-glucan From Barley and Oats on Glucose and Lipid Metabolism, and Satiety

The interventional study will evaluate the effects of a regularly consumption of barley and oat flakes in crude and roasted form on the glucose and lipid metabolism as well as the postprandial saturation. Moreover, the study will evaluate the effect of a regularly consumption of barley and oat flakes on the glucose and lipid metabolism over a period of three weeks.

By applying the cross-over design, all participants will run through each intervention. In total there will be four interventions: crude oat flakes, roasted oat flakes, crude barley flakes and roasted barley flakes. Each intervention period will last three weeks and will be separated by wash-out phases which also will last three weeks. The comparison will be made against white toastbread, which will be the fifth intervention. The entire duration of the study will be 27 weeks (5x 3 weeks intervention + 4x 3 weeks wash-out phases inbetween).

The participants will visit the study centrum before and after each intervention for examinations and for taking blood samples. During the examination the participants will receive a test-meal to evaluate postprandial blood glucose and insulin levels. Moreover, the kinetic of hormones that influence the satiety will be evaluated. In addition to the examination of blood samples, the microbiota of feces will be examined.

During the intervention periods the participants will receive recipes for breakfast for 21 days. In these recipes 80 gram oat or barley flakes or four slices of white toastbread will be included.

The study will provide data about the association between different processed cereals and measurable markers reflecting glucose and lipid metabolism as well as their influence on hormones of satiety and microbiota.

Inclusion criteria

• LDL-cholesterol ≥ 120 mg/dl (≥ 3 mmol/l)
• Typical western diet

Exclusion criteria

• intake of lipid-lowering medications
• gastrointestinal diseases
• diabetes mellitus type I and II
• familial hypercholesterolemia
• intake of additional dietary supplements (especially ß-glucan capsules, high-fibre compounds)
• pregnancy, lactation
• appreciable food allergies/intolerances
• patient´s request or if patient compliance with the study protocol is doubtful