Skin Microbiome

Reviewed by: Iris Hansen, Aveeno Dermatology Expert

Iris has 14 years’ experience in dermatology. She has advised major organisations on dermatology best-practices and has published countless papers on skin health in prominent scientific journals.

Key takeaways:

  • Your skin microbiome is the make-up of all the good and bad bacteria that live on your skin

  • The more balanced and diverse the microbiome is, the healthier your skin

  • Factors like age, genetics and environment all affect the microorganisms that make up your skin microbiome

Your Skin Microbiome: Everything you need to know

Your skin is your body’s largest organ1, covering a surface area of between 1.5 and 2m², and plays a vital role in keeping you healthy. Your skin is important for many reasons, including keeping out dangerous organisms such as germs and protecting against the sun’s rays. It also helps to regulate your temperature and allows your body to retain its essential moisture.

As your skin is the part of your body which is most exposed to external elements, it has to deal with aggressors every day. While healthy skin is able to recover effectively from the impact of external aggressors, it never hurts to give it that little extra help to ensure your skin stays as healthy as possible.

One way your skin battles to keep itself healthy and resilient is by maintaining a healthy skin microbiome of a diverse range of microorganisms3. Your skin is home to trillions of microbes, all of which are invisible to the naked eye. Collectively, these microorganisms make up your skin microbiome4, a complex ecosystem that co-exists on the surface of your skin.

A large portion of the organisms living on your skin are microorganisms that are good for your skin and your body. It’s important that you adopt a skincare regime that seeks to find that perfect balance, nurturing a microbiome that is beneficial to your skin’s wellbeing.

In this article, you can find out more about your skin’s microbiome, the importance of diversity and how to look after your own microbiome, including:

  • What is skin microbiome?

  • How does a diverse microbiome affect my skin health?

  • What skin conditions can be caused by an unbalanced microbiome?

  • What affects skin microbiome diversity?

  • Why is a diverse microbiome important?

  • How can I improve my skin microbiome balance?

What is skin microbiome?

Microbiome is a word that has become well known in recent years, thanks to the greater understanding of the different fungi, mites and bacteria that live on and in the human body.

It was most often used to refer to the diverse bacteria maintained in the gut. Now, it’s also recognised as being present in the mouth, on the skin and in other important parts of the human body.

Your skin’s microbiome is the collective name for the ecosystem of tiny microorganisms that live on your skin. It’s made up of a diverse range of different organisms playing different roles, including:

  • Bacteria - Microorganisms that is made up of varieties which can be both harmful and beneficial to the health of your skin

  • Fungi – Microbes that can be harmful or helpful, a heavy build-up can cause fungal infections

  • Mites – Insect-like microorganisms, invisible to the human eye, that can cause irritation in large numbers5

  • Viruses – Microscopic parasites that, if allowed to multiply, can cause infection or illness on the skin6

The different microorganisms present previously led scientists to believe that they could be harmful. However, it’s now understood that maintaining the right balance can be hugely beneficial to your skin. A balanced and well-tended to skin microbiome is effectively an invisible barrier that protects your skin from disease and supports a healthy immune system7.

Previously, it was thought that the skin microbiome lived only on the skin’s surface. However, research has found that it goes much deeper – into hair follicles, sweat and sebaceous glands, having an even greater impact on the health of your skin. Studies have also found that it interacts with other microorganisms in your body8, working together to maintain a beneficial balance.

Each person’s microbiome is unique, much like a fingerprint or DNA. As such, there’s no one correct, or healthy make-up to have. It’s important to understand that the different types of microorganisms that exist on your skin are vastly different, even across other parts of your body. This means that your microbiome differs from your head, right down to your toes.

For example, several varieties of bacteria, like Corynebacterium, thrive in areas where you’re more likely to sweat, such as your forehead or under your arms. Others, such as Proteobacteria, are more suited to smoother skin, like the inside of your forearm9. Some, like Staphylococcus tend to congregate in areas of high humidity, such as the soles of your feet10.

With this in mind, it’s important to remember that an effective skincare routine will need to be varied to make sure the microbiome is well balanced across a range of different ecosystems on your skin.

Iris says: “Did you know you have more than 10 times as many microbes living on your skin than you have cells in your body?”11

How does microbiome diversity affect my skin health?

The health of your skin rests on the diversity of your microbiome12. Having the right microbes on your skin is important, but the presence of too many or too few can lead to an imbalance that negatively impacts the health of your skin.

These microbes work together to protect against harmful germs, preventing the onset of adverse skin conditions. Each individual organism also has unique strengths and weaknesses, so the broader the spectrum present, the better for your overall skin health.

A balanced community of microorganisms that are working together can keep your skin protected and healthy. A diverse microbiome also improves your skin’s appearance. A healthy complexion free of blemishes, acne and dry patches is a sign that the microbes on your skin are thriving and properly balanced13.

But sometimes, factors like climate, UV rays and pollution can have an impact on your microbiome’s natural balance. This can weaken the skin barrier, making your skin feel dry, sensitive and itchy.

Iris says: “Your skin microbiome has a more diverse range of bacteria and other microbes than those found in your gut – making it just as important to care for”14.

What skin conditions can be caused by an unbalanced microbiome?

While a strong balance in your skin’s microbiome can be beneficial to the health and the appearance of your skin, imbalances can result in irritation, dryness and the development of skin conditions15.

This is partly because your skin acts as a natural barrier between your body and the external environment. It helps prevent the invasion ofingress of any harmful microbes that can cause infection and illness. Whenever this balance is off, you’re at increased risk of developing a skin condition as your skin is now compromised and less effective at fending off harmful bacteria.

An unhealthy and imbalanced microbiome can lead to a wide range of related skin conditions, including:

  • Acne – A skin disorder that develops when follicles on your skin become clogged with natural skin oils that promotes the growth of microorganisms like Propionibacterium acnes and Malassezia in the skin microbiome16. Usually common on naturally oily areas like your face, upper back, shoulders and chest17

  • Atopic dermatitis – A form of eczema, symptoms can include red, itchy, flaky and peeling skin, which is associated with increased Staphylococcus aureus18. This can occur anywhere on the body and can flare up at any time of the year20

  • Dandruff – A skin condition that inflames the affected area, usually the scalp. Skin can become irritated and flaky, with a red appearance21

Iris says: “Certain harmful microbes that are found on your skin can contribute to skin disorders, such as acne, atopic dermatitis and psoriasis22

What affects your skin microbiome diversity?

To effectively nurture diversity and bring about a beneficial balance in your skin’s natural ecosystem, it’s important to know what can affect the microbiome. Here are just a few of the factors that can come into play:

  • Age – Your skin microbiome is constantly changing and evolving from the minute you’re born, through puberty, right through to adulthood and old age – altering alongside your body’s growth

  • Gender – Hormonal differences between men and women can produce different microbiomes. For example, men generally sweat more than women.

  • Genetics – Your DNA contributes to the health of your skin. For example, certain people are naturally more susceptible to skin disorders than other23

On top of this, there are also several external factors to be aware of, including:

  • Environment – The air quality and your surroundings vary greatly between rural and urban locations, affecting the microorganisms found on and beneath the surface of your skin24

  • Workplace – Different microorganisms thrive indoors and outside, affecting various places of work, from offices to industrial surroundings

  • Climate – If you live in a warmer climate, your skin microbiome will generally be different to those who live in areas with colder weather25

  • Diet – The foods you eat can alter your microbiome, with effects lasting for years, or possibly even a lifetime26

  • Hygiene – How often you wash and which products you use, have an impact on the amount and type of microbes that live on your skin

While you can’t affect many of these directly, developing a strong and effective skincare routine means being aware of what is having an impact and taking those factors into account when choosing products or routines27.

How can I improve my skin microbiome balance?28

Improving and maintaining the balance of your skin’s microbiome is vital to ensuring your skin is healthy. Nurturing your skin is key to this and there are several simple ways to do this and ensure you keep your skin looking its radiant best. Here are just a few top tips:

1. Keep hydrated

Drinking plenty of water helps keep your skin healthy. Healthy skin is hydrated, so dehydration can negatively affect your microbiome balance29. Try to drink the recommended eight glasses of water every day to replenish your cells and rehydrate yourself.

2. Don’t over-cleanse

Over-cleansing your skin can be just as bad as not cleaning it enough. Using hand-sanitisers, shower gels and soaps that contain harsh ingredients too frequently can deplete and damage your skin microbiome, as it washes away natural oils and beneficial bacteria on your skin30. Be smart by allowing natural oils to build up and use moisturizing washes with natural ingredients in the morning and at night.

3. Get out and exercise

Your skin microbiome is affected by your environment and your interactions with nature, as well as how much you exercise32. Take more walks in the countryside, hit the gym or join a class to nurture a healthy microbiome. Working up a sweat can contribute to the overall diversity of your skin microbiome and to positive overall health and wellbeing33.

4. Moisturise your skin daily

Keeping your skin hydrated with moisturizing lotions/creams made of natural ingredients is the key to a healthy microbiome. Look for products formulated with pre-biotic ingredients such as colloidal oatmeal. Prebiotic oats not only keeps dry and sensitive skin moist and smooth, but feeds your skin’s natural bacteria, keeping it in perfect balance. Add it to your morning routine or apply any time when your skin feels dry.

Achieving a healthy skin microbiome is important for healthy skin. Look after the trillions of microorganisms present on your body to help your skin look after you.