Abstract
Soluble dietary fibers are widely used in functional foods as their adsorption of sugars and fats inhibits absorption of these substances from the gastrointestinal tract. However, they also adsorb drugs and may thus decrease the absorption volume and efficacy of pharmacological products. The present study investigated the effects of soluble dietary fiber on acetaminophen absorption. The acetaminophen absorbability of the following three types of soluble dietary fiber with different molecular weights was investigated using ultrafiltration. 1) Xanthan gum: molecular weight, 3,000,000 - 7,500,000; 2) Pectin: molecular weight, 10,000 - 400,000; and, 3) Indigestible dextrin: molecular weight, 1600. All of the soluble dietary fibers adsorbed acetaminophen in a concentration-dependent manner, and adsorption rates increased with greater fiber molecular weight. The effect of soluble dietary fiber on acetaminophen absorption from the gastrointestinal tract in rats was then investigated using portal vein catheterization. The area under the blood concentration time curve for each fiber was significantly lower than for the control group at 0.1%, 2.0% and 60.0%, respectively, for xanthan gum, pectin and indigestible dextrin; this clarified that the greater the fiber molecular weight, the greater the inhibition of low-concentration drug absorption.
