The Impact of Solar Radiation on the Skin Microbiome: Study

A May 2024 article from Photochemistry and Biology, the journal of the American Society for Photobiology, delves into existing knowledge on solar radiation’s impact on the skin microbiome.

The authors of “Exploring the impact of solar radiation on skin microbiome to develop improved photoprotection strategies,” note that solar radiation exposure can alter microbiome composition, potentially leading to dysbiosis, compromised skin barrier function and immune system activation.

Key Findings

The key findings from the study include:

• The incorporation of topical sunscreens with film-forming properties not only offers effective sun protection but also enhances the skin barrier, potentially aiding in the preservation of a healthy microbiome by reducing the penetration of harmful UV radiation and environmental stressors.

• Novel sun-protecting products containing pre and probiotics and other beneficial ingredients may potentially help to protect the skin microbiota from SR damages and help to limit the exposome-induced immunosuppression of the host.

• There is evidence that UVR destroys substances such as porphyrins which are absorbed in the long UVA range and especially in the visible range and which are produced by several microorganisms including the skin commensal Cutibacterium acnes and Pseudomona aeruginosa. Thus, UVR may impact the skin microbiome composition leading to dysbiosis and an altered skin barrier.

In the study, researchers compared two groups of healthy volunteers exposed to solar radiation (SR). One group was exposed to the sun in the summer. That group was compared with a group wearing clothes throughout the year including the summer period. The study compared the seasonal effects on the skin microbiome before and after summer. Three skin sites were sampled (the inner forearm, dorsal forearm and cheek). According to the publication’s authors, to significant differences in the diversity of the microbiome were observed and no significant seasonal differences in high-abundance species at any of the sampling sites were observed, in any group. Authors note that these findings suggest a certain stability of the skin microbiome, even after several months of exposure to SR. However, significant differences were observed in low-abundance species in the unprotected areas of the inner and outer arms in the group exposed to SR during the summer months. These changes in low-abundance species are of interest requiring further research, the authors noted.

Authors content tailored sun protection products that prioritize both skin and microbiome health may offer enhanced defense against solar radiation-induced skin conditions.