A guide to the skin microbiome: How can it impact skin health?

Maintaining a healthy body is no small feat. Luckily, you have a few trillion friends helping you out.

We’re talking about your body’s microbiome: the community of microorganisms, including bacteria, fungi, mites, and viruses, that reside in your body. Microorganisms outnumber human cells in your body 10 to one, and they perform all sorts of essential functions that help keep you healthy.¹ When developing a skincare routine, it’s critical to work with your skin microbiome to foster a healthy ecosystem of beneficial organisms.

A balanced and healthy skin microbiome (aka skin flora) may assist your body in performing vital functions, including protecting it from the invasion of more harmful organisms.² We’ll look at the impact your microbial diversity can have on your skin health and explain why it’s important to keep it balanced.

What is the skin microbiome?

As the body’s largest organ, the skin serves as a physical barrier that protects the body from foreign organisms and toxic substances. Inside everyone’s skin lives a microbial community with a unique makeup of fungal, viral, and bacterial species. Scientifically speaking, the skin is an ecosystem of living biological and physical components, and there’s a delicate balance between you and your skin’s microorganisms.

When the ecology of your skin microbiome is disrupted, you may experience skin diseases or infections, such as atopic dermatitis (the most common form of eczema), acne vulgaris, and psoriasis. Many factors contribute to this ecosystem's health, including your environment, immune system, lifestyle, and underlying medical conditions.³

What does the skin microbiome do?

Healthy skin flora acts like a bouncer for your body—it won’t let in anyone who isn’t on the list. Beneficial microorganisms can help form a barrier between your skin and unhealthy pathogens.⁴

In other words, the skin microbiome is part of the body’s first line of defense. In addition to being a physical barrier, your skin is an immunological barrier. Its immune response controls the microbiota that lives on your skin, playing a vital role in how your body responds to wounds and infections. Although researchers are still exploring exactly how the skin microbiome works, studies show that friendly bacteria may help diminish the growth of their potentially harmful counterparts.⁵

How does the skin microbiome affect your health?

Believe it or not, an estimated 1 million bacteria inhabit each square centimeter of your skin!⁶ Here are a few ways your skin microbiome may impact your health: 

• Protect against infection: Alongside your gut microbiome, your skin flora is an essential defender against infection. Current research suggests that the skin plays a critical role in assisting the immune system, which can distinguish between beneficial and harmful microbes.⁷ 

• Boost immunity: A healthy skin microbiome produces antimicrobial peptides (AMPs) that contribute to your body’s immune response.

• Reduce inflammation: Some skin bacteria in a healthy microbiome may help reduce inflammation.⁸

The importance of a balanced skin microbiome

Much like our planet, the human body benefits from a diverse array of stable ecosystems. As mentioned above, maintaining a balanced skin microbiome is important because it may help maintain skin barrier function, protecting the body from unwanted irritants and pathogens. Imbalances in the skin microbiome may contribute to various skin conditions, including the following: 

Psoriasis 

Psoriasis is a chronic inflammatory cutaneous condition that affects 2–3% of the population. It’s characterized by raised, scaly, red patches of skin that often appear on the extensor surfaces of joints, such as the elbows and knees. It can cause intense itching. Psoriasis may be triggered by genetics, environmental factors, or immune system disruptions. People with psoriasis often have an unbalanced skin microbiome with reduced bacterial diversity.⁹

Acne  

The role of bacteria in acne vulgaris has been studied for decades, and the relationship between acne and bacteria is complex, to say the least. The cause of acne lesions may be related to antimicrobial interactions rather than the presence of one particular microbe.¹⁰ Still, studies show populations of Propionibacterium acnes (the bacteria that causes acne, aka C. acnes) in the skin are associated with acne.¹¹ Humans produce more triglyceride-containing sebum (skin oil) than other mammals, and this increased oil secretion can lead to a greater abundance of P. acnes (aka C. acnes).¹²

Targeting the skin’s microbiome is a promising avenue for developing acne treatments,¹³ and some studies have attempted to create an acne therapy by decreasing C. acnes colonization.¹⁴

Rosacea 

Rosacea is a chronic inflammatory skin condition that’s more common in individuals over age 30 with fair skin. Symptoms can include recurrent episodes of facial flushing, redness, pustules, and widened blood vessels (telangiectasia). A recent study showed that imbalances in the skin microbiome may play an important role in developing rosacea. Treatments that help balance the skin microbiome have been shown to improve symptoms.¹⁵

Seborrheic dermatitis 

Seborrheic dermatitis is characterized by red, flaky, inflamed skin that can feel itchy. It typically affects the scalp, and fungus plays a role in its development. Symptom improvement is associated with a reduction of Malassezia fungi on the scalp, but this doesn’t occur when the scalp is treated with antibiotic agents. It is possible that fluctuations in the skin microbiome may be a possible trigger for this skin condition.¹⁶

Probiotics and prebiotics

Various skin disorders may be influenced by an imbalance in your skin’s microbiome, so consider taking supplements that boost good bacteria in your body. Preliminary microbiology studies show that some strains of probiotics and prebiotics may help improve the symptoms of dermatological diseases, which may include atopic dermatitis, acne, and psoriasis.¹⁷

If you think your skin flora could use a realignment and would like to explore how to restore your skin microbiome, please consult your primary care provider before you start a new supplement. If you’re considering changing your skincare routine, speak with your dermatology provider, as they may be able to offer additional guidance!

Curology cares for your skin

Microbiome skincare is worth investigating, but our experts believe there’s no substitute for well-researched ingredients when combating acne, rosacea, and the signs of aging. Active ingredients, such as tretinoin, clindamycin, azelaic acid, and more, have clinically proven topical benefits for treating whiteheads, blackheads, fine lines, wrinkles, and redness. That’s why they’re found in our personalized skincare treatments.

Founded in 2014 and supported by board-certified dermatologists, Curology is a full-service skincare company offering affordable products customized to your skin's needs. Sign up for a consultation with one of our in-house, licensed dermatology providers, and they’ll provide expert guidance throughout your skincare journey.* Getting started is easy: Just take a quick quiz and snap a few selfies for our experts to review. 

Curology can take the guesswork out of your skincare routine and help you meet your skincare goals. Your personalized treatment comes with any of our recommended skincare products, such as our cleanser, moisturizer, or sunscreen. 

P.S. We did the homework so you don’t have to:

1. NIH Human Microbiome Project defines normal bacterial makeup of the body. National Institutes of Health. (2012).

2. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. (2011)

3. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. (2011)

4. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. (2011)

5. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. (2011)

6. Chen, Y., Tsao, H. The skin microbiome: Current perspectives and future challenges. Journal of the American Academy of Dermatology. (2013).

7. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. Ibid.

8. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. Ibid.

9. Ellis, S.R., et al. The Skin and Gut Microbiome and Its Role in Common Dermatologic Conditions. Microorganisms. (2019).

10. Ellis, S.R., et al. The Skin and Gut Microbiome and Its Role in Common Dermatologic Conditions. Microorganisms. Ibid.

11. Fitz-Gibbon, S., et al. Propionibacterium acnes strain populations in the human skin microbiome associated with acne. J Invest Dermatol. (2013).

12. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. Ibid.

13. Woo, T., Sibley, C. The emerging utility of the cutaneous microbiome in the treatment of acne and atopic dermatitis. Journal of the American Academy of Dermatology. (2020).

14. Ellis, S.R., et al. The Skin and Gut Microbiome and Its Role in Common Dermatologic Conditions. Microorganisms. Ibid.

15. Daou, H., et al. Rosacea and the Microbiome: A Systematic Review. Dermatol Ther (Heidelb). (2021).

16. Grice, E.A., Segre, J.A. The skin microbiome. Nat Rev Microbiol. Ibid.

17. Notay, M., et al. Probiotics, Prebiotics, and Synbiotics for the Treatment and Prevention of Adult Dermatological Diseases. Am J Clin Dermatol. (2017).

Laura Phelan is a board-certified Family Nurse Practitioner at Curology. She earned her Masters of Science in Nursing at Benedictine University and went on to get her post-master’s certificate as a Family Nurse Practitioner at the University of Cincinnati.

* Subject to consultation. Subscription is required. Results may vary. 

Written by

Curology Team

Medically reviewed by

Laura Phelan, NP-C