Skin Microbiome: How to Preserve, Support, and Restore

Microbiological health has become one of the most talked-about topics today. Thanks to extensive research in this field, we now understand that none of us is ever truly alone. Billions of microorganisms live inside every human body, as well as on the surface of our skin and mucous membranes. These microbes form alliances, compete for nutrients, reproduce, and die—living rich, complex lives full of challenges and interactions. The total weight of the bacteria associated with a single person can reach up to 2 kilograms, with over 1,000 different biological species represented.

The majority of these bacteria inhabit the body's barrier zones—primarily the intestines and the skin. These are the frontiers where the internal environment interacts with the external world, making them critical in defending the body against pathogens that can cause infections.

The skin microbiome is a vast and diverse community of microorganisms, including bacteria, fungi, and protozoa (such as microscopic mites). On the face, where sebum production is high, propionibacteria are abundant. Moist areas prone to sweating attract corynebacteria and staphylococci, while drier regions of the skin host species like β-proteobacteria and flavobacteria. Saprophytic bacteria help break down secretions from the sebaceous and sweat glands, along with dead cells from the outermost layer of the epidermis. Fungi are mainly represented by yeast-like organisms from the Malassezia genus.

Here’s the most important thing to know about the skin microbiome: when the balance among these microorganisms is maintained, the skin remains healthy, and the microbes coexist harmlessly. Many are even beneficial, as they support the skin’s barrier function (these are known as commensals). However, if this balance is disrupted—for example, by environmental changes or inappropriate skincare—certain species may rapidly overgrow. This can lead to dryness, increased sensitivity, inflammation, and dermatological issues such as acne, dandruff, or candidiasis.

A few decades ago, the dominant approach in dermatology was purely hygienic: the cleaner, the better. Antibacterial soaps and alcohol-based lotions were widely recommended as part of everyday skincare. Today, experts advocate for a gentler approach—treat your microbiome with care. Avoid aggressive cleansing products, overuse of acid peels and scrubs, and protect your skin from excessive sun exposure.

What your skin microbiome loves?

Over millions of years of evolution, skin microbes have adapted to specific conditions associated with healthy skin: adequate moisture and a slightly acidic environment, typically with a pH of around 5.5. That’s why cosmetics formulated for sensitive skin often highlight a pH of 5.5 on their labels. Natural moisturizing ingredients—such as aloe vera gel, hyaluronic acid, plant-derived glycerin, and sugar beet extract—help maintain a balanced microbiome. To preserve optimal skin acidity, derivatives of citric and lactic acids are commonly used.

Unlike the gut, live bacterial cultures are not typically applied to the skin. This is because cosmetic products must meet strict microbiological safety standards. In an open jar of cream stored at room temperature, live bacteria cannot remain stable or predictable. So when products are advertised as containing "probiotics," they usually include bacterial fragments (lysates) that indirectly support local immunity.

Prebiotics in skincare, however, are a reality. These are ingredients—such as inulin or beta-glucan—that act as food for beneficial bacteria, encouraging their growth and activity.

Finally, the skin microbiome thrives when its host leads a healthy lifestyle. This includes a balanced diet low in refined sugars, adequate hydration, stress management, regular physical activity, fresh air, and quality sleep. Healthy living creates an internal environment where your microbiome can truly flourish.