Dietary Fiber and Diabetes

Abstract

Diabetes is a long-term metabolic disorder that is characterized by high blood glucose, insulin resistance, and relative lack of insulin. The inclusion of dietary fiber helps controls glucose and insulin levels and favorably influences plasma lipid levels in patients with type 2 diabetes. Soluble fiber is characterized by its ability to dissolve in water and form viscous gels, which allows the intestinal transit time to decrease and delay absorption and complete digestion of nutrients, related to the decrease of postprandial glucose peaks, reduction of insulin and serum lipid levels. Some of the main types of soluble fiber are: β-glucans, inulin, fructoligosaccharides, arabinoxylans and pectins. The consumption of insoluble fiber can act as a physical barrier so it could reduce the speed of digestive products through the brush border of the enterocyte. One of the mechanisms of action for dietary fiber and prebiotics is fermentation in the colon and changes in the intestinal microbiota. Prebiotics are non-digestible food ingredients that selectively stimulate the growth and/or activity of a limited number of colonic bacteria and, subsequently, improve the health of the host. The general recommendation of fiber intake in patients with type 2 diabetes is 20–35 g/day.