Effects of dietary fiber on prostanoid concentrations in cecal mucosa of rats.

Changes were investigated in prostanoid contents in cecal mucosa of rats fed with guar gum, a fiber diet. The rats were divided into 3 groups, the control group fed non-fiber diet and 2 groups fed respectively diets containing 7.5% and 15% of guar gum. Twelve rats in each group were sacrificed 10, 20, and 30 days respectively after initiation of diets, and length and weight of cecum and prostanoid contents in cecal mucosa were determined. The length and weight of cecum increased significantly 10 days after commencement of the fiber diets, and more remarkable changes were observed in the 15% fiber diet group. The ratio of prostaglandin (PG) E2 to PGD2 (PGE2/PGD2) was also increased by the content of guar gum dependently. These results suggest that alteration in prostanoid profiles is implicated in the fiber diet-induced enlargement of large bowels.