Skin
GABRIELLA NAGY
3 MIN READ

How Your Skin Microbiome Could Be Nature’s Sunscreen

How Your Skin Microbiome Could Be Nature’s Sunscreen

As we step into the height of summer and spend more time outdoors, our skin is naturally exposed to increased levels of sun and heat. While we often reach for SPF to protect against UV damage, exciting new research suggests our skin may already have an inbuilt line of defence - its own microbiome. Scientists are now uncovering how the bacteria living on our skin play a surprising role in shielding us from the sun’s harmful effects, opening the door to a more holistic approach to sun protection.

A groundbreaking study published in the Journal of Investigative Dermatology reveals a remarkable discovery: certain skin bacteria can metabolise compounds that help our skin better survive UV exposure.1

What The Study Found

Researchers uncovered that specific skin microbes possess an enzyme called urocanase, which converts cis-Urocanic acid - a byproduct of UV exposure - into safer metabolites. This biochemical process helps fine-tune the skin’s immune response to sunlight, suggesting your microbiome actively supports skin health, not just passive protection.1

Why This Matters

  • Natural UV Defence: Until now, sunscreens have been our frontline defence. This study introduces the concept that our skin microbiome itself contributes to photoprotection.
  • Immune Modulation: This interplay highlights how microbes shape inflammatory responses and support the skin’s integrity against environmental insults.1,2

The Broader Scientific Narrative

UV radiation consistently alters the skin microbiome’s composition, diminishing protective species (like Lactobacillaceae) and promoting UV-resilient ones (like Cyanobacteria).3 Another study identified that Sphingomonas - a bacteria enriched by sun exposure - can neutralise harmful reactive oxygen species, reducing oxidative damage to skin cells.4

Carving A New Path In Skincare And Sun Care

Researchers argue that truly effective sunscreens should protect both skin cells and the skin microbiome. Products that preserve microbial diversity could offer dual protection: shielding against UV and maintaining microbiome balance, unlocking healthier, more resilient skin.5

Why The Skin Microbiome Matters

  • Skin’s microbial ecosystem: Hosting around one million bacteria per cm², the skin microbiome is a complex barrier that influences immunity, inflammation, collagen maintenance, and even wound healing.
  • Guard against UV damage: Bacterial enzymes can help repair and modulate UV-related oxidative stress and DNA damage - adding another layer to our natural defence.6

What This Means For You

  1. Think microbiome-friendly sunscreen - Look for formulas designed to preserve microbial diversity, like those incorporating gentle UV filters shown to protect beneficial bacteria.7
  2. Support your skin from the inside out - A diet rich in antioxidants and probiotics (e.g. fermented foods) can support beneficial microbes on both skin and gut.
  3. Avoid over-cleansing - Excessive washing disrupts microbial balance. Instead, use mild, pH-balanced products to maintain your skin's natural ecosystem.8

The Bigger Picture

With this new discovery, we’re entering an era of microbiome-aware sun protection. We can still rely on SPF, shade, and clothing, but this research encourages a holistic approach, viewing skin and its microbial residents as a united defence system.

Your skin’s microbes aren’t just bystanders; they’re active players in protection against sun damage. It's time for future skincare to value both microbial health and sun protection, promising better long-term outcomes for skin wellness.

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References

  1. VijayKumar et al. Urocanase-Positive Skin-Resident Bacteria Metabolize cis-Urocanic Acid and in Turn Reduce the Immunosuppressive Properties of UVR. Journal of Investigative Dermatology. Available at: https://www.jidonline.org/article/S0022-202X(25)00405-1/fulltext
  2. Byrd et al. 2018. The human skin microbiome*. Nat Rev Microbiol* 16, 143–155.
  3. Burns et al. Ultraviolet radiation, both UVA and UVB, influences the composition of the skin microbiome. Exp Dermatol. 28(2):136-141.
  4. Harel et al. 2023. Skin microbiome bacteria enriched following long sun exposure can reduce oxidative damage. Res Microbiol. 174(8):104138.
  5. Grant et al. 2024. A narrative review of the impact of ultraviolet radiation and sunscreen on the skin microbiome. Photodermatol Photoimmunol Photomed. 40(1):e12943.
  6. Lee, H.J., Kim, M. 2022. Skin Barrier Function and the Microbiome. Int J Mol Sci. 23(21):13071.
  7. Schuetz et al. Sunscreens can preserve human skin microbiome upon erythemal UV exposure. Intern. Journal of Cosm. Science. Available at: https://onlinelibrary.wiley.com/doi/10.1111/ics.12910?utm_source=chatgpt.com
  8. Mahmud et al. Impact of gut microbiome on skin health: gut-skin axis observed through the lenses of therapeutics and skin diseases. Gut Microbes. 14(1):2096995.