The effect of dietary fiber on pancreatic amylase activity in vitro.

In vitro the influence of wheat bran, guar gum, psyllium and lignin (2.5-50 g/l) on porcine pancreatic amylase (5-10 U/ml) was investigated. Enzyme activity was decreased in the presence of these substances with the exception of lignin. The reduction depended upon fiber concentration. In bran (50 g/l) it was 92 +/- 1%, in guar gum (25 g/l) 46.3 +/- 0.6%, and in psyllium (50 g/l) 41 +/- 1.4%. The effect was partly reversible if urea (1M) was added. Variations in pH (5.8-7.8) had no influence. Glucose formation from starch catalyzed by amylase was inhibited in the presence of bran, guar gum and psyllium, suggesting that the observed effect was also of functional significance.