This study aimed to clarify the influence of dietary habits and the daily intake of fermented milk product containing Bifidobacterium breve strain Yakult, 1．0 × 1010 cfu/100 mL/day on bowel habits in healthy young Japanese women. To clarify the interaction of a fermented milk product containing Bifidobacterium breve strain Yakult, 1．0 × 1010 cfu/100 mL/day, and food intake on bowel habits in healthy young Japanese women. A total of 150 female university students participated in this study. They recorded the amount of food intake using a food-frequency questionnaire （FFQ） during the pre-experiment period and bowel habits in a diary during the study. After the exclusion of 30 subjects who defecated every day, 120 subjects were randomly divided two groups.Pre experiment they recorded the amount of food intake using food-frequency questionnaire （FFQ） and bowel habits. After excluded 30 subjects who defecated every day, we divided two groups. We conducted an open cross-over ,study, which was composed of a non-intake period （4 weeks）, a washout period （2 weeks）, and an intake period （4 weeks）. Sixty-two subjects, who completed the study and fully recorded in a diary, were included in the analysis. We conducted an open cross-over study. The study period was 10 weeks including a non-intake period, washout period, and an intake period. During the intake period the defecation frequency was increased from 72．2 ± 18．6 to 77．7 ± 18．8％ （p ＜ 0．01）. The Bristol Stool Scale was increased from 3．2 ± 0．8 to 3．4 ± 0．9（p ＜ 0．01）. As assessed by a 5-point Likert scale, the average scores of straining and feeling of incomplete evacuation was decreased from 2．0 ± 0．8 to 1．7 ± 0．7 （p ＜ 0．01）. As assessed by a visual analog 10-point scale, the average scores of constipation awareness was decreased from 4．1 ± 2．0 to 3．3 ± 1．9 （p ＜ 0．01）. In contrast, tThe amount of calorie intake was remarkably smaller than that in recommended value （1532 ± 314 v.s.1950 kcal）. Especially the consumption of potato, beans, vegetable, and fruits were smaller than recommended value. The defecation frequency during the intake period was positively correlated with each amount of calorie intake and carbohydrate intake（each p ＜ 0．05）but not with the amount of dietary fiber intake. These findings suggest that a daily intake of fermented milk containing Bifidobacterium and an adequate food intake might provide benefits improving the bowel habit in healthy young Japanese women.
