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  • Writer's pictureMarya

Sun, UV, and Your Skin Microbiome

You might have recently been hearing from every skincare guru that if you aren’t wearing sunscreen daily, then you’re not protecting your skin. What if we told you that even if you wear your SPF daily, you can still be missing an element of protection you truly need?

It sounds like the kind of declaration that could take a few moments to sink in, and yet research is beginning to expand our knowledge of what we thought we knew about sun damage and the impact that UV rays can have on not just the skin but the micro-organisms that live on it.

Sun Damage

Before diving into the research, it might be helpful to understand sun damage first. Sun damage refers to the production of free radicals from UV rays. Free radicals behave erratically and destroy anything within their path. You can think of them as little explosions going off on your skin. They primarily target protein, which are the building blocks of elastin and collagen to a point where they are beyond repair.

This impaired barrier further leads to dried and irritated skin. It can also lead to more lasting consequences such as premature and inflammatory aging. The free radicals emitted from UV rays have no mercy on the skin. They mutate cells and remove their ability to act as a protective barrier against external forces, which is the primary function of our skin.

In the absolute worst case, the mutated cells within the disturbed skin barrier can lead to skin cancer. A study has shown that individuals who demonstrate early signs of aging on their neck as a result of overexposure to the sun were four times more likely to develop skin cancer.

On a smaller scale, we can also evaluate the impact of the impaired skin barrier on the bacteria that live in the skin and how they interact with this type of damage. As potentially harmful bacteria pass through the damaged barrier of the skin, they can penetrate deeper and cause inflammation, infections, and even acne.

The Skin Microbiota

The skin microbiota is an organic ecosystem made up of trillions of good and bad bacteria that sit on the surface of your skin. It is considered to be the most resourceful part of our skin and is constantly changing. It protects the skin in numerous ways:

  1. Prevents premature aging by protecting the skin against pathogens

  2. Regulates inflammation process

  3. Hydrates the skin, preventing it from drying out

  4. Produces incredibly powerful antioxidants that can prevent the production of free radicals (Radical oxygenase of C. acnes (RoxP) and superoxide dismutases (SOD))

A recent study has shown that this main protector of the skin can be taken out in as little as 20 minutes from exposure to the sun. This leaves the skin at the mercy of harmful UV rays. In fact, it has also been found that the bacteria in the skin remains disrupted even two hours after exposure. After four hours, a small amount is recovered, but nothing like it was before.

When observing the impact of sunscreen, it did not improve the situation one bit. Exposure to the sun led to foreign microbes invading the skin and they were met with no resistance. Since the skin microbiota was not at its optimal, it was not able to produce anti-oxidants to stave off the formation of free radicals.

A Ray of Hope for your Skin

As mentioned at the beginning, it’s not all about sunscreen absorbing UV light. Sunscreen may reduce the direct damage to the skin, but it fails in protecting the skin microbiota, which is crucial to the skin’s overall health. Without a healthy skin microbiota, the skin is left vulnerable to free radicals and harmful bacteria.

There are numerous factors to take into consideration, but not all hope is lost. In fact, being aware of what happens from over-exposure to the sun can allow us to take preventative measures in a more meaningful way.

It has been found that a combination of SPF and prebiotic ingredients such as Inulin can offer the solution for heightened protection. Although prebiotic ingredients cannot shield the skin and protect its skin microbiota, they can play a crucial role in restoring it faster after exposure to the sun. This would mean that the skin remains vulnerable for less time. Incorporating it into aftercare after a long day at the beach just might be the quick and easy way to help your skin.



Skin Microbiome: refers to the collection of the genome from all the microorganisms that sit on the surface of your skin.

Skin Microbiota: an organic ecosystem made up of trillions of good and bad bacteria that sit on the surface of your skin.

Bacteria: bacteria are single-cell organisms that live everywhere on earth, including on the surface of the skin.

Prebiotic: Prebiotics act as food for the microorganisms on the skin and the rest of the body. Prebiotics help to allow good bacteria to grow and thrive.

Reference list

Burns, E.M., Ahmed, H., Isedeh, P.N., Kohli, I., Van Der Pol, W., Shaheen, A., Muzaffar, A.F., Al-Sadek, C., Foy, T.M., Abdelgawwad, M.S., Huda, S., Lim, H.W., Hamzavi, I., Bae, S., Morrow, C.D., Elmets, C.A. and Yusuf, N. (2019). Ultraviolet radiation, both UVA and UVB, influences the composition of the skin microbiome. Experimental Dermatology, 28(2), pp.136–141. doi:10.1111/exd.13854.

González, S., Aguilera, J., Berman, B., Calzavara-Pinton, P., Gilaberte, Y., Goh, C.-L., Lim, H.W., Schalka, S., Stengel, F., Wolf, P. and Xiang, F. (2022). Expert Recommendations on the Evaluation of Sunscreen Efficacy and the Beneficial Role of Non-filtering Ingredients. Frontiers in Medicine, 9. doi:10.3389/fmed.2022.790207.

Patra, V., Gallais Sérézal, I. and Wolf, P. (2020). Potential of Skin Microbiome, Pro- and/or Pre-Biotics to Affect Local Cutaneous Responses to UV Exposure. Nutrients, [online] 12(6), p.1795. doi:10.3390/nu12061795.

Wendt, J.; Schanab, O.; Binder, M.; Pehamberger, H.; Okamoto, I. Pigment. Cell Melanoma Res. 25, 234–242 (201).


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