Abstract
Objective: The present study aimed to examine the effects of fermented milk containing Bifidobacterium breve strain Yakult, Streptococcus thermophilus, Lactococcus lactis, galactooligosaccharide, and polydextrose on the defecation ability of young Japanese women classified according to the stress level.
Study design: A randomized double-blind placebo-controlled parallel-group study.
Subjects: Ninety-two female university students with stool frequency ≤5 times per week.
Methods: The total intervention period was 8 weeks including a non-intake period and an intake period. The subjects maintained a diary in which they daily recorded on defecation, skipping of meals, frequency of staple food intake, wake-up/bedtime, and special circumstances that may have influenced defecation. The food frequency questionnaire and Cornell Medical Index-health questionnaire (classification of stress level) were administered once a month during this study.
Results: The defecation frequency of the test group following the intake period was significantly increased as compared with that within the observation period; however, this difference was not observed for the placebo group. The test group with a low stress level experienced a significant increase in defecation frequency and a significant reduction of urinary phenol as compared with the placebo group. However, a group with a stress level higher than domain 1 showed no increase in the defecation frequency by the test drink or reduction of urinary phenol.
Conclusions: The results of this study indicate that stress confers a negative influence on the effects of fermented milk for constipation.
