Binding of bile salts to fibre-enriched wheat bran

A new commercial product of fibre-enriched wheat bran was tested for its binding of bile salts in vitro. The wheat bran preparation was standardized and through enzymatic digestion of protein and starch contained 78 per cent fibre (w/w). Fibre-enriched wheat bran bound with high capacity both conjugated and unconjugated bile salts. Binding was saturable, reversible and showed no specificity towards tauro- or glycine-conjugated bile salts. Binding was rapid, dependent on pH, was enhanced by the presence of high salt concentrations and partially inhibited by 6 M urea. This indicated that binding was a combination of hydrophobic and hydrophilic interactions.