BackgroundSkin aging is one of the most abundant aging‐related disorders that can be accelerated by excessive exposure to ultraviolet irradiation. Topically applied fermented skincare ingredients have gained mounting attentions due to their high concentration of various skin nourishing nutrients and bioactive components and low skin irritation potency.AimsIn the present study, we aim to fully demonstrate the skin‐related benefits of a novel extract of Thermus thermophilus and Bacillus subtilis mixed‐culture ferment (TBFE).MethodsTBFE was prepared through an innovative mixed‐culture fermentation process. The contents of nutrients and bioactive ingredients were quantified by different methods accordingly. Both in vitro tests and randomized controlled human trial were utilized to further demonstrate multifaceted beneficial effects on human skin, as well as the potential mechanisms.ResultsOur results showed that TBFE upregulated the expression of type IV collagen, elastin, aquaporin‐3, and dermal‐epidermal junction markers, while inhibited production of melanin, in different skin cell models. Moreover, TBFE inhibited the generation of reactive oxygen species and pro‐inflammatory mediators induced by ultraviolet irradiation in normal human keratinocytes, while stimulated autophagy in senescent keratinocytes. Results from clinical studies confirmed those in vitro findings, demonstrating that TBFE at 5% and 20% concentration provides anti‐aging properties in subjects with sensitive skin, in terms of improving wrinkles, moisturization, and skin lightening.ConclusionsIn summary, we demonstrate that a novel mixed‐culture ferment extract has promising anti‐aging effects, which may be attributed to anti‐oxidation, anti‐inflammation, and promotion of autophagy in skin cells.
