The Skin Microbiome, Microbial Metabolites and the Epidermal Response to Ultraviolet Radiation—Towards Next Generation Suncare

Ultraviolet radiation (UVR) presents one of the greatest challenges to human skin, with numerous studies documenting its effects on skin physiology. Recently, growing recognition of the microbiome's crucial role in skin health has led to investigations on how UVR influences skin-microbiome interactions. Research in mice suggests that the microbiome plays a key role in regulating the skin's response to UVR, impacting inflammation, immune function, and keratinocyte differentiation. These effects may be mediated by microbial metabolites (MM), yet the impact of UVR on microbial metabolism and its subsequent effects on skin health remains poorly understood. Some studies suggest that UVR exposure may modify the composition of the microbiome, which could, in turn, alter the microbial metabolome. This viewpoint reviews the current literature regarding the interplay between the skin, its microbiome, and UVR, and speculates on how UVR-induced changes to microbial composition and metabolism might affect skin health. Furthermore, future areas of research that should be considered and the potential of MM in next generation suncare, cosmetics and therapeutics will be highlighted.