Effect of dietary fiber on pancreatic lipase activity in vitro

Lipase activity was measured in buffer solutions and in human duodenal juice after incubation with wheat bran, psyllium, pectin, lignin, guar gum, and cellulose. In the presence of wheat bran and pectin, activity of both enzymes was inhibited, whereas psyllium reduced only lipase activity in duodenal juice. The influence was relatively small, it measured between 12.0 and 34.8% if 12.5 g/L of dietary fiber were tested. Maximal effect required about 60 min of incubation. Inhibitory activity was destroyed after 30-min treatment with hydrochloric acid (pH 1.5) or cooking (95 degrees C). Inhibitors in pectin were more heat-resistant. It is concluded that dietary fibers exert inhibitory actions on pancreatic lipase; in man unfavorable effects could occur in exocrine pancreatic insufficiency.