The effects of guar gum or wheat bran on the disappearance of 14C-labeled starch from the rat gastrointestinal tract.
An animal model was used to test the hypothesis that guar gum, a source of soluble fiber, will slow the disappearance of starch from the gastrointestinal tract. Male Wistar rats were adapted for 1 wk to a purified diet and then divided into three groups and given 30 min to consume a test meal. The test meal contained 5% fiber derived from guar gum (GG) or wheat bran (WB) or was fiber-free (FF), and each contained 2.5 microCi 14C-labeled starch. At 1, 2.5, or 5 h postprandial, a group from each dietary treatment was killed, and stomach, small and large intestine and cecum were removed to determine the distribution of radioactivity. The isotope emptied from the stomach at a similar rate for all three groups. The percent ingested dose in the small intestine (SI) was highest in the upper half at 1 h and highest in the lower half at 2.5 h for all groups. The percent ingested dose of 14C-starch was significantly higher from upper SI segments in the GG group than from those in the FF group at 2.5 and 5 h, whereas percent ingested dose did not differ in the upper SI segments in the WB group compared to the FF group at 1, 2.5 and 5 h. These data indicate that a viscous polysaccharide (GG) can delay the disappearance of starch from the SI whereas a source of insoluble fiber (WB) did not slow starch disappearance.
Tinker
L F
LF
Department of Nutrition, University of California, Davis 95616.
Schneeman
B O
BO
D000818:Animals; D001835:Body Weight; D004043:Dietary Fiber / Q000494:pharmacology*; D004064:Digestive System / Q000187:drug effects / Q000378:metabolism*; D004435:Eating; D005685:Galactans / Q000494:pharmacology*; D007408:Intestinal Absorption / Q000187:drug effects*; D007420:Intestine, Large / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism; D008297:Male; D008351:Mannans / Q000494:pharmacology*; D053149:Plant Gums; D051381:Rats; D011919:Rats, Inbred Strains; D012995:Solubility; D013213:Starch / Q000378:metabolism / Q000493:pharmacokinetics*
D004043:Dietary Fiber; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D013213:Starch; C007894:guar gum