Bowel movement improvement by Mulukhiyah (Corchorus olitorius)-containing food (AOTSUBU (R)) consumption: A randomized, double-blind, placebo-controlled, parallel- group comparison trial

Background: Mulukhiya (Corchorus olitorius) richly contains dietary fiber and is suggested to improve bowel movement. Objective: This study aimed to investigate the effects of mulukhiya-derived dietary fiber (MDF) on the intestinal environment in healthy Japanese adult subjects. Methods: This randomized, double-blinded, placebo-controlled study enrolled 22 healthy Japanese adult subjects who typically defecate three to five times per week and do not consume enough dietary fiber. All subjects were randomly allocated into the MDF group (4 men and 7 women; 45.1 +/- 11.4 years) or the placebo group (3 men and 8 women; 41.6 +/- 9.5 years) by using a computerized random number generator. Each subject was administered with assigned 30 tablets (active [77-mg dietary fiber] or placebo) daily for two weeks. We asked the subjects to record their defecation condition in a bowel movement diary from 1 week before the start of test food consumption to the day before two weeks after the start of the test-food consumption (three weeks in total). Then, we evaluated the items in the bowel movement diary such as the occupancy rate of enteric, organic acids in feces, and subjective symptoms related to constipation. Results: At one and two weeks after the start of the test-food consumption, the MDF group exhibited a significant increase in stool days, stool frequency, and stool volume compared with the placebo group (P <0.05). Regarding the occupancy rate of enteric bacteria, Prevotella (P = 0.025) and Clostridium cluster IV (P = 0.045) were significantly increased in the MDF group compared with those in the placebo group at 2 weeks after the start of the test-food consumption. As for organic acids in feces, n-butyric acid was significantly higher in the MDF group than in the placebo group at 2 weeks after the start of the test-food consumption (P = 0.037). Furthermore, no safety concerns were noted. Conclusions: The consumption of MDF-containing food for 2 weeks resulted in the increase of stool frequency, stool volume, useful enteric bacteria, and organic acids in feces in healthy Japanese adult subjects.