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

It was most often used to refer to the diverse network of microorganisms that maintained a healthy balance 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 and beneath the surface of your skin. It’s made up of a diverse range of different organisms playing different roles, including:

• Bacteria – A variety of microscopic organisms which can be both potentially 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 numbers
• Viruses – Microscopic molecules that, if allowed to multiply, can cause infection or illness on the skin

The different organisms present previously led scientists to believe that they could be potentially 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 system.

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 sweat and hair glands, having an even greater impact on the health of your skin. Studies have also found that it interacts with other (immune) cells in your body, working together to maintain a beneficial balance.

Each person’s microbiome is unique, much like their fingerprints or DNA. As such, there’s no one correct, or healthy make-up to have. It’s important to understand that the different mixes of organisms 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 microbe, 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, drier skin, like the inside of your forearm. Some, like Staphylococcus, tend to congregate in areas of higher humidity and pH, such as the elbow and knee crease and the soles of your feet.

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.

The health of your skin is linked to the diversity of your microbiome. Having the right microbes on and beneath the surface of 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 that you may encounter in the environment – by producing compounds to help fight off the harmful germs and by alerting your skin’s immune system to defend the skin to prevent skin issues and infections. Each individual organism also has unique strengths and weaknesses, so the broader the spectrum present, the better for your overall health.

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

External factors such as environment (climate, pollution) and lifestyle (occupation, hygiene) can influence/have an impact on your microbiome’s natural balance. This can weaken the skin barrier, making your skin feel dry, sensitive and itchy.

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 and dryness and has been associated with the development of skin conditions.

This is partly because your skin acts as a natural barrier between your body and the external environment. It helps prevent ingress 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 barrier is compromised, so less effective at fending off harmful bacteria.

An unhealthy and imbalanced microbiome has been linked 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 oil. Usually common on naturally oily areas like your face, upper back, shoulders and chest. An excess of microorganisms like Propionibacterium and Malassezia is a contributing factor in acne
• Atopic dermatitis – A form of eczema, symptoms can include red, itchy and flaky skin. This can occur anywhere on the body and can flare-up at any time of the year. However, eczema is most common on parts of the body such as the elbow and knee creases where Staphylococcus aureus is primarily found. Levels of the bacteria has been shown to be higher when the disease flares
• Dandruff – A skin condition that inflames the affected area, usually the scalp. Skin can become irritated and flaky, with a red appearance. Dandruff or seborrhoeic dermatitis is associated with a proliferation of the fungus Malassezia, an organism commonly found on the scalp

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. Men generally sweat more than women, for example
• Genetics – Your DNA contributes to the health of your skin. For example, certain people are naturally more susceptible to skin disorders, such as eczema, than others

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 organisms found on and beneath the surface of your skin
• Workplace – Different organisms 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 weather
• Diet – The foods you eat can alter your microbiome, with effects lasting for years, or possibly even a lifetime
• 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 routines.

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.