The effect of dietary fibre on D-xylose absorption.

Healthy probands ingested 25 g D-xylose dissolved in water or mixed with a test meal, with or without a supplement of guar or wheat bran. Viscosity increased to a maximum of 22,167mPa.s. Five or 10 g guar delayed xylose excretion only when administered in aqueous solution. When mixed with a test meal, guar accelerated xylose excretion. Bran had no effect on xylose excretion, independent of the manner of administration. Our results show that under these experimental conditions, the effect of guar on absorption is not dependent on the degree of viscosity.