Oats is a cereal rich in betaglucans, antioxidants, vegetable sterols, proteins, unsaturated fatty acids and fibre. It is the only cereal not connected with genetical modification up to now. Oats reduces cholesterol, controls glucose and insulin response, the body weight, improves gastro-intestinal system activity. Also is rich in vitamins and minerals, above all vitamin B and magnesium, calcium. Betaglucan contained in oats is a non-starch polysaccharid, which thickens a gut content, that is decomposed by enzymes harder what causes a digestion slow-down and consequently increases satiety. It helps to promote the immune system. Foods we consume are usually rich in sugars which are digestible very quickly and absorbed from the intestine to the bloodstream, what causes the high Glycemic index. Foods with low GI are recommended also in preventing cardiovascular diseases, diabetes and obesity. The oat fiber fulfills these. The oat bran fiber is an extra source of soluble and insoluble fiber, which is well known for its prebiotic characteristics. The both types helps to improve health digestion.