In Vitro Study of Possible Role of Dietary Fiber in Lowering Postprandial Serum Glucose

Abstract

There have been many reports concerning the role of dietary fiber in lowering postprandial serum glucose, and the main mechanism was regarded as the viscosity of different dietary fibers in hampering diffusion of glucose and postponing absorption and digestion of carbohydrates. In this paper, two kinds of water-insoluble dietary fibers, water-insoluble dietary fiber of wheat bran and enzyme-resistant starch of maize amylose, and four kinds of water-soluble dietary fibers, water-soluble dietary fiber of wheat bran, carboxymethyl cellulose, guar gum, and xanthan gum, were used to investigate their postprandial serum glucose lowering mechanism in vitro. The results showed that these dietary fibers lowered postprandial serum glucose levels at least by three mechanisms. First, dietary fibers increase the viscosity of small intestine juice and hinder diffusion of glucose; second, they bind glucose and decrease the concentration of available glucose in the small intestine; and, third, they retard alpha-amylase action through capsuling starch and the enzyme and might directly inhibit the enzyme. All of these decreased the absorption rate of glucose and the concentration of postprandial serum glucose.

Determination of in vitro antidiabetic effects of Zingiber officinale Roscoe

“…The results suggested that the part of the antihyperglycemic actions of ginger may be by decreasing glucose absorption in vivo. The main mechanism concerning the role of dietary fiber in lowering postprandial serum glucose is the viscosity of different dietary fibers in hampering diffusion of glucose and postponing absorption and digestion of carbohydrates as these bind glucose and resultantly decrease the concentration of available glucose in the small intestine (Ou et al, 2001). Gallagher et al (2003) studied the ability of different plants to inhibit glucose diffusion.…”

In vitro physicochemical, phytochemical and functional properties of fiber rich fractions derived from by-products of six fruits

“…Glucose adsorption capacity and amylase activity inhibition rate Glucose adsorption capacity and amylase activity inhibition rate were determined by the methods given by Ou et al (2001). The glucose content of the supernatant was determined using glucose assay kit (Coral, Tulip group, India).…”

“…Glucose diffusion and GDRI were determined according to the method of Ou et al (2001) with slight modifications. The fiber sample weighing 0.5 g was mixed with 25 mL of 50 mmol/L glucose solution.…”

Fenugreek: Potential Applications as a Functional Food and Nutraceutical

“…Trapping the glucose inside the gel may leach out slowly and prevent the sudden rise of the bloodglucose level. The viscous and gel-forming properties of soluble dietary fiber prevent macronutrient absorption, reduce postprandial glucose response and beneficially affect certain blood lipids (39). It is claimed that oral glucose tolerance in normal, type 1 or type 2 diabetic rats could be remarkably improved by administration of soluble dietary fiber (SDF) fraction.…”