The influence of guar gum on intestinal cholesterol transport in the rat | British Journal of Nutrition | Cambridge Core (original) (raw)

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. Everted sacs of rat proximal small intestine were used to determine the effect of guar gum (5 g/l) on the uptake of cholesterol (0·1 mM) from a solution of micelles.

2. The uptake of cholesterol was found to be linear both in the presence and absence of guar gum. When guar was present throughout the whole of the incubation medium, the uptake of cholesterol was reduced to approximately 40% of control values. Sacs which had been pre-incubated in guar gum before exposure to cholesterol in a guar-free medium also showed a reduction in cholesterol uptake but this was less pronounced.

3. A two-stage perfusion technique, previously described (Blackburn & Johnson, 1981), was used to determine the effect of a guar layer adsorbed to the mucosal surface on cholesterol absorption in vivo. Such a layer leads to a reduction of approximately 36%: itwas concluded that guar slows the absorption of cholesterol from micelles by a mechanism, or mechanisms, involving an increased resistance to diffusion in the aqueous medium.

4. Groups of rats were meal-fed for at least 30 d on semi-synthetic diets with or without the inclusion of guar gum (20 g/kg). Rates of intestinal absorption of cholesterol, glucose and fluid were then determined by the perfusion technique in vivo. There was no reduction in absorption in the test animals compared with the controls.

5. It is proposed that guar gum is able to slow the intestinal transport of cholesterol from a suspension of pre-formed micelles, but only when both are present in the lumen together. No evidence was obtained to suggest that the consumption by rats of a diet containing guar gum, at a level similar to that used in human studies, leads to any adaptive reduction in their rates of cholesterol or glucose absorption.

Type

Papers of direct relevance to Clinical and Human Nutrition

Copyright

Copyright © The Nutrition Society 1983

References

Jenkins, D. J. A., Reynolds, D., Slavin, B., Leeds, A. R., Jenkins, A. L. & Jepson, E. M. (1980). American Journal of Clinical Nutrition 33, 575–581.CrossRefGoogle Scholar

Khan, A. R., Ghazala, Y. K., Mitchel, A. & Qadeer, M. A. (1981). American Journal of Clinical Nutrition 34, 2446–2449.CrossRefGoogle Scholar

Miyamoto, Y., Hanano, M., Iga, T. & Ishikawa, M. (1982). Journal of Pharmacobio-Dynamics 5, 445–447.CrossRefGoogle Scholar

National Research Council (1972). Nutrient Requirements of Laboratory Animals, 2nd ed. p. 64. Washington DC: National Academy of Sciences.Google Scholar

Vahouny, G. V., Roy, T., Gallo, L. L., Story, J. A., Kritchevsky, D. & Cassidy, M. (1980 a). American Journal of Clinical Nutrition 33, 2182–2191.CrossRefGoogle Scholar

Vahouny, G. V., Roy, T., Gallo, L. L., Story, J. A., Kritchevsky, D., Cassidy, M., Grund, B. M. & Treadwell, C. R. (1978). American Journal of Clinical Nutrition 31, S208–S212.CrossRefGoogle Scholar

Vahouny, G. V., Tombes, R., Cassidy, M. M., Kritchevsky, D. & Gallo, L. L. (1980 b). Lipids 15, 1012–1018.CrossRefGoogle Scholar

Wilson, J. D., Lindsey, C. A. & Dietschy, J. M. (1968). Annals of the New York Academy of Sciences 149, 808–821.CrossRefGoogle Scholar