Topical Application of Bifidobacterium-Fermented Soy Milk Extract Containing Genistein and Daidzein Improves Rheological and Physiological Properties of Skin

The study investigated the effects of Bifidobacterium-fermented soy milk extract (BE) containing genistein and daidzein on the skin properties of hairless mice and humans. Over six weeks, topical application of BE significantly improved the elasticity, viscoelasticity, hydration, and thickness of mouse skin by increasing hyaluronic acid (HA) content. In humans, applying a gel with 10% BE to the forearm for three months significantly reduced the decline in skin elasticity. The findings suggested that BE could be a promising cosmetic ingredient for preventing skin elasticity loss by enhancing HA production.