Rice Lees Extract Including Molasses Improves Balance of Skin Microbiome

Abstract

The purpose of this study was to find a cosmetic ingredient that suppresses the growth of Staphylococcus aureus and promotes the growth of Staphylococcus epidermidis, and to confirm the effect of the cosmetic ingredient on human skin and the change in skin microbiome. By co- culturing S. aureus and S. epidermidis, we found Rice lees Extract including Molasses (REM) had the effect of inhibiting the growth of S. aureus. In the human in vivo study, the abundant ratio of S. aureus was significantly reduced in the REM group after 4 weeks, but not in the placebo group. Flaking degree, which was determined by using the ratio of the stratum corneum cells on the skin surface collected in tape stripping to the entire visual field, significantly increased in the REM group but did not change in the placebo group. The multilayer rate decreased in both groups, which was thought to be due to the lotion rather than REM. In a questionnaire conducted after the end of the study, 6 of 10 subjects in the REM group and 2 of 11 in the placebo group responded that their skin became smoother. REM was effective to improve skin smoothness and stratum corneum uniformity and decrease S. aureus abundance. Therefore, it can be useful for cosmetics that recover skin roughness or disorder.