Abstract: Objective: To explore the improving effect of dietary fiber from Malusasiatica pomace on the defecation of mice and provide the basis for the development of dietary fibers. Methods: Kunming mice were randomly divided into 5 groups including blank control group, constipation model group and DF groups at the low, middle and high doses. The effect of dietary fiber from Malusasiatica pomace on defecation function was evaluated by ink-pushing rate in small intestine, first defecation time, first black feces time and feces weight in mice with diphenoxylate-induced constipation. Results: After mice were subjected to continuous intragastric infusion for 14 days, ink-pushing rate was increased in the small intestine of mice administered with DF at low, middle and high doses as compared to the constipation model group, which exhibited an extremely significant difference between the middle or high dose groups and the constipation model group (P ＜ 0.01); however, no significant difference was observed between the low-dose group and the constipation model group (P ＜ 0.05). The first defecation time in low and middle dose groups was shorter than that in the constipation model group (P ＜ 0.05); however, the first defecation time in high dose group revealed a significant decrease when compared with that in the constipation model group (P ＜ 0.01). Compared with the model group, the first black feces time in each DF treatment group was shortened (P ＜ 0.01). The feces weight during 12 hours in the middle dose group was higher than that of the constipation model group (P ＜ 0.05); however, the feces weight in high dose group revealed an obvious increase when compared with the constipation model group (P ＜ 0.01). Conclusion: Dietary fiber from Malusasiatica pomace plays a favorable role in improving defecation and intestinal peristalsis.

Key words: Malusasiatica, dietary fiber, constipation model, defecation function, animal experiment