Adsorption of bile salts from aqueous solution by plant fibre and cholestyramine

1. Adsorption of bile salts by dietary fibre is believed to promote their excretion and hence to reduce the serum cholesterol level in man and experimental animals. 2. We have tested a number of plant fibre fractions and other related materials for their ability to adsorb bile salts from aqueous solution. The "insoluble" plant fractions were from "dry grain" (a residue from brewing), apple, wheat bran, lucerne (Medicago sativa), soya beans, mung beans (Phaseolus mungo), chick peas (Cicer arietinum), rolled oats, spinach (Spinacia oleracea), sunflower seeds, sawdust and sheep faeces. The other materials were cholestyramine, pectin and lignins prepared from wheat bran and from sawdust. 3. Only cholestyramine and the fibre from lucerne, soya beans, mung beans, chick peas, spinach, and sunflower seeds adsorbed enough of either sodium cholate or sodium deoxycholate for adsorption to be detectable. 4. This result conflicts with a report that the lignin component of dietary fibre is responsible for adsorption of bile salts. 5. Adsorption of bile salts, when it occurs, may depend on the presence of saponins bound to the fibre.