Effect of Arabinoxylan and Rye Kernels on Second Meal Responses

Effect of Arabinoxylan and Rye Kernels on Second Meal Responses in Subjects With the Metabolic Syndrome

Sedentary lifestyles and increasing obesity are main causes of the global increase in the prevalence of the metabolic syndrome (Mets) and type 2 diabetic (T2DM). Diet quality, particularly composition of carbohydrate play also a significant role. Barley, oat and rye may in addition to reducing the acute post prandial glucose response also reduce glucose response at a subsequent meal. Purified dietary fibre has been shown to reduce GI and affect levels of satiety hormones. In contrast, our knowledge of the physiological effect of arabinoxylan, which constitute a substantial part of dietary fibre in cereal products, is limited in relation to second meal effects. The investigators also lack knowledge of the second meal effect of arabinoxyan in combination with rye kernels.

Hypothesis: Porridge rich in arabinoxylan and/or whole rye kernels can increase the formation of short chain fatty acids and improve the glycemic response.

The aim of the present study is to compare the effect of porridge test meals based on purified arabinoxylan, rye kernels, a combination of arabinoxylan and rye kernels, and semolina porridge as control on acute postprandial response as well as response at a subsequent standardized meal. The study will be conducted in subjects with the metabolic syndrome. The primary endpoint is glucose response. Secondary endpoints are the following items: insulin, incretins, inflammatory markers, ghrelin, free fatty acids, metabolomics, breath hydrogen and subjective satiety feeling.

This project will improve opportunities for identifying and designing foods with low GI that is particularly suited to people who are at high risk of developing T2DM. The investigators also expect to gain a greater understanding of the metabolic fingerprint, as seen after ingestion of low-GI foods and thereby gain a molecular understanding of how low-GI foods affect health by altering metabolic processes. This will give us a deeper insight into the metabolic processes that are necessary for maintaining normal glucose homeostasis

Using a cross-over design, 15 subjects with Mets will consume test meals containing four different porridges in randomized order. Blood samples will be collected over 2 hours after ingestion of test meals and 2 hours after ingestion of a standard second lunch meal served 4 hours after the test meals. The amount of porridge and the standard lunch are equivalent to 50 g available carbohydrate. Visual Analog Scale (VAS) will be used for determination of subjective satiety feeling and measurements of breath hydrogen will be used as a marker for colon fermentation.

Inclusion Criteria:

Central obesity (Female > 94 cm; Male > 80 cm) with two of the following:

1. fasting triglyceride (> 1,7 mmol/L),
2. HDL-cholesterol: (Female:< 1,03 mmol/L; Male:< 1,29 mmol/L),
3. blood pressure (≥ 130/85 mmHg) and
4. fasting plasma glucose (≥ 5,6 mmol/L)). Subjects who are in medical treatment with lipid and blood pressure-lowering drugs can continue with their habitual treatment provided that the treatment is stable throughout the trial.

Exclusion Criteria:

• fasting plasma glucose > 7,0 mmol/l,
• fasting plasma triglyceride > 5,0 mmol/l,
• blood pressure > 160/100 mmHg ,
• legal incapacity , endocrine, cardiovascular or kidney disease,
• BMI > 38kg/m2,
• corticosteroid treatment,
• alcohol or drug addiction and
• pregnancy or lactation.