Effects of dietary fat and gel-forming substances on rat jejunal disaccharidase levels.

Wistar rat jejunal disaccharidases were measured after feeding low fat, low fat + 5% pectin, low fat + 0.4% galactomannan, high fat, high fat + 5% pectin and high fat + 0.4% galactomannan diets for 16 weeks. All rats fed high fat diet had significantly lower jejunal sucrase and maltase levels when compared with their respective low fat groups. Lactase was significantly lowered in the high fat pectin group compared with the low fat pectin group, but was not significantly different when comparing the high fat or high fat galactomannan with their respective low fat groups. There was no significant difference in lactase, sucrase or maltase levels between the low fat groups, or between the high fat groups. We conclude that in Wistar rats an increased dietary fat level lowers jejunal sucrase, maltase and lactase levels, while the gel-forming substances pectin and galactomannan added at the levels of 5% and 0.4%, respectively, have no effect.