Normal and abnormal intestinal absorption by humans

Environmental Health Perspectives
W D Heizer

Abstract

Adults eating a Western diet digest and absorb ingested food containing approximately 100 g fat, 350 g carbohydrate, and 75 g protein daily. Normal fat absorption requires adequate gastric, pancreatic, liver-biliary, mucosal, and lymphatic function. Carbohydrate and protein absorption is much less dependent on liver-biliary and lymphatic function. The intestine has a large reserve capacity for digestion and absorption of nutrients which is due to both excess function and to adaptive changes which increase function in one segment of the digestive-absorptive system when it is decreased or lost in another segment. The large reserve capacity explains why most of the prevalent intestinal diseases seldom cause clinically detectable changes in absorption. However, there are more than 30 less-common human diseases which cause malabsorption of one or more nutrients. Those that cause the malabsorption syndrome, i.e., steatorrhea and weight loss, can be conveniently categorized according to the major deficiency leading to the absorptive defect as follows: insufficient pancreatic enzyme activity, insufficient bile acid, disease of the small intestinal wall, multiple defects, mechanism unknown, and drug-induced malabsorption. A few diseases...Continue Reading

References

Feb 1, 1975·American Journal of Clinical Pathology·E L Krawitt, W L Beeken
Jun 22, 1978·The New England Journal of Medicine·R C Williamson
Jun 1, 1978·Australian Veterinary Journal·G M Robins
Sep 1, 1976·Disease-a-month : DM·E P DiMagno, V L Go
Oct 1, 1975·Physiological Reviews·D M Matthews
Dec 11, 1975·The New England Journal of Medicine·A D NewcomerA F Hofmann
Oct 25, 1972·Biochimica Et Biophysica Acta·H Nakayama, E Weser
Mar 1, 1973·The American Journal of Clinical Nutrition·I T Beck
Apr 19, 1973·The New England Journal of Medicine·E P DiMagnoW H Summerskill
Feb 1, 1971·The American Journal of Digestive Diseases·J G MooreR W Clark
Dec 14, 1968·Nature·J Russell, J M Osborn
Feb 21, 1957·The New England Journal of Medicine·J A BENSONE BOUGAS
Jan 12, 1961·The New England Journal of Medicine·G D DRUMMEYC M JONES
Sep 1, 1964·Annals of Internal Medicine·J M FINLAYK J WIGHTMAN

Related Concepts

Bile Salts
Dietary Carbohydrates
Ghee
Dietary Proteins
Pharmaceutical Preparations
Intestinal Absorption
Malabsorption Syndrome

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