Adsorption of bile salts by soya-bean flour, wheat bran, lucerne (Medicago sativa), sawdust and lignin; the effect of saponins and other plant constituents.

1. The adsorption of bile salts from aqueous solution on the soya-bean flour, wheat bran, fine dry sawdust and lucerne (Medicago sativa) was measured. Adsorption on to the residuum after the first three of these substances had been extracted with organic solvents, pronase or solvents, pronase and acid (to produce lignin) was also measured. 2. The removal of saponins from soya-bean flour did not affect bile salt adsorption, and bile salts were adsorbed on to lignin and on to wheat bran (deficient in saponins). Although our methods differed from Oakenfull & Fenwick (1978) we were unable to substantiate their conclusions that saponins are responsible for most bile salt binding to fibrous substances in vitro.