Dietary fiber viscosity

Several physicochemical properties of dietary fiber contribute to its physiological role. Water-holding capacity, ion-exchange capacity, solution viscosity, density, and molecular kiteractions are characteristics determined by the chemical stmcture of the component polysaccharides, thek crystallinity, and surface area. 

Various mechanisms have been proposed to explain the hypocholesterolemic effect of GA (Annison et al., 1995 Tiss et al., 2001). Some studies have suggested that the viscosity of fermentable dietary fiber contributes substantially to the reduction of lipids in animals and humans (Gallaher et al., 1993 Moundras et al., 1994). However, other studies suggested that this property is not related to plasma lipids (Evans et al., 1992). The mechanism involved is clearly linked to increased bile acid excretion and fecal neutral sterol or a modification of digestion and absorption of lipids (Moundras et al., 1994). 

JENKINS D A (1978) Dietary fibers and fiber analogues and glucose tolerance importance of viscosity. Merf/, 1 1392-4. 

Guar gum is a low-viscosity water-soluble dietary fiber that has been used to treat diabetes because it slows the absorption of glucose from the gut. However, adverse effects such as regurgitation, obstipation, abdominal... 

Guar gum is a low-viscosity water-soluble dietary fiber that has been used to treat diabetes because it slows the absorption of glucose from the gut. However, adverse effects such as regurgitation, obstipation, abdominal cramps, diarrhea, and itching are common (1). Partially hydrolysed guar gum has been added to enteral formulas and food products as a source of dietary fiber it can reduce laxative use, diarrhea in septic patients receiving total enteral nutrition, and symptoms of irritable bowel sjmdrome (2). 

It is often difficult to manage hyperlipidemia in FHC with standard dietary management. Specific fibers in appropriate amounts exert a pronounced hypolipidemic effect in man and animals. Pectin and Guar have been especially effective in lowering cholesterol in normal and hyperlipidemic patients.10-H However, not all fibers are effective in iowering lipids. No two sources of dietary fiber have the same effect on lipid metabolism. 2 Some dietary fibers, although effective as hypolipidemic agents, are not palatable or are difficult to incorporate into food because of increased viscosity or other chemical or taste properties. 

Dikeman, C. L. Fahey, G. G. (2006). Viscosity as related to dietary fiber a review. Critical reviews in food science and nutrition, 46, 649-663. 

Despite the fact that a plethora of dietary factors could, and will, affect the absorption characteristics of phytochemicals, this area has not been systematically explored. One reason might be the complexity of dietary factors and their interactions that could affect absorption. A nonexhaustive list would include the volume and composition of the food consumed, pH, caloric density, viscosity, nutrients (carbohydrates, protein, fat, fibers), alcohol, caffeine, and the presence of other phytochemicals. Such dietary factors affect the functional status, motility, and acidity of the gastrointestinal tract in a complex manner and modify the physicochemical properties, formulation, and dissolution characteristics of the compound of interest. Calcium in dairy products, for example, has the potential to chelate tetracyclines and fluoroquinolones and, thereby, reduce their bioavailability and biological activity [31]. 

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