2016 年 35 巻 3 号 p. 105-112
Although persistent constipation is considered to be associated with skin problems, the supporting evidence is limited. Hence, this study investigated the effects of probiotic and prebiotic fermented milk on skin and intestinal conditions in an open-label trial. Among the 101 Japanese healthy young female students that participated, the 81 subjects in the intake group consumed a bottle of probiotic and prebiotic fermented milk containing Bifidobacterium breve strain Yakult and galactooligosaccharides daily for 4 weeks after a pre-intake period of 4 weeks, while the 20 subjects in the non-intake group did not consume the test beverage. Defecation patterns, skin conditions including hydration levels in the stratum corneum, and urinary phenol and p-cresol levels were evaluated before (baseline) and after intake. All subjects completed the study. No differences in dietary intake and body mass index were observed between both groups during the trial. In the intake group, hydration levels of the stratum corneum, defecation frequency, and feces quantity significantly increased, and urinary phenol and p-cresol levels significantly decreased after intake compared with the corresponding baseline values. However, they did not significantly change in the non-intake group. A significant difference was observed between the intake group and non-intake group in regard to clearness of the skin as assessed by visual analogue scale. Therefore, consecutive intake of probiotic and prebiotic fermented milk might have beneficial effects on the skin that prevent dryness and beneficial effects on the intestinal conditions that stimulate defecation and decrease phenol production by gut bacteria in healthy young women.