The skin microbiome is an extremely complex ecosystem of micro-organisms that inhabit the surface and deeper layers of the human epidermis. It consists mainly of bacteria, fungi, viruses and mites that function in close symbiosis with the skin cells. Their presence is not only natural, but also essential for the maintenance of skin homeostasis, the proper functioning of the protective barrier, and local immunity.

In recent years, with the development of research into the human microbiota, the skin microbiome has received significant attention from scientists, dermatologists and cosmetologists.

The role of the microbiome in skin function.

1. immunological protection

Skin microorganisms compete with pathogens for space and nutrients, which prevents the colonisation of the skin by pathogenic microorganisms. In addition, some commensal bacteria, such as the Staphylococcus epidermidis, exhibit antimicrobial properties against pathogens, including. Staphylococcus aureus.

2. regulation of pH and skin barrier integrity

The microbiome helps to maintain the skin's slightly acidic pH (approximately 4.5-5.5), which is crucial for the integrity of the epidermal barrier. Bacteria also produce metabolites such as lactic acid, propionic acid and lipids that support the function of the intercellular cement.

3 Influence on inflammatory processes

The composition of the microbiome influences the activation of Toll-like receptors (TLRs), which play a role in the immune response. A balanced microbiome modulates the inflammatory response of the skin and protects against over-reactivity.

Consequences of disorders of the skin microbiome (dysbiosis).

1. inflammatory skin diseases

Microbial imbalance can lead to the development of dermatoses such as:

• acne vulgaris (excess Cutibacterium acnes in a pathogenic form),
  
• atopic dermatitis (predominance of Staphylococcus aureus),
  
• seborrhoeic dermatitis (Malassezia spp.),
  
• psoriasis and eczema.
  
  

2. increased skin permeability

Dysbiosis weakens the protective barrier, increasing transepidermal water loss (TEWL) and susceptibility to external factors - allergens, pollutants, UV radiation.

3. premature ageing of the skin

A disturbed microbiome can exacerbate oxidative stress and chronic microinflammation (known as inflammaging), which contributes to loss of elasticity, wrinkles and hyperpigmentation.

Care to support the skin microbiome.

1. Gentle cleansing

Choosing the right cleaning products is crucial. Recommended products are:

• with a physiological pH (approx. 5.5),
  
• without strong detergents (e.g. SLS, SLES),
  
• containing soothing substances (e.g. allantoin, panthenol, bisabolol).
  
  

Excessive skin washing, especially with hot water, and the use of antibacterial products without medical indications should be avoided.

2. use of pre-, pro- and postbiotics

Prebiotics

These are nutrients that support the growth of beneficial micro-organisms, e.g. inulin, α-glucan oligosaccharide, chicory root extracts.

Probiotics

These are live bacterial cultures (e.g. Lactobacillus, Bifidobacterium), used in cosmetics in the form of cell lysates. They strengthen the protective barrier and modulate the microbiome.

Postbiotics

Products of bacterial metabolism, e.g. lactic acid, peptides, short-chain fatty acids - show anti-inflammatory and regenerative effects.

3. protection from environmental factors

UV radiation, smog and heavy metals disrupt the composition of the microbiome. Daily use of sunscreens (SPF 30 or more) and antioxidant cosmetics (vitamin C, E, coenzyme Q10, niacinamide) can prevent negative effects.

4. avoiding excessive disinfection and antibiotic therapy

Antibacterial preparations, especially alcohol-based, and topical antibiotics destroy not only pathogens, but also beneficial bacteria. Their use should be limited to medically justified cases.

A holistic approach to skin care.

Diet and supplementation
Healthy skin starts from within. During autumn and winter, it is worth ensuring an adequate supply:
● Omega-3 fatty acids - present in flaxseed oil and fish, among others, improve skin hydration and elasticity.
● Vitamin D - its deficiency in winter can reduce immunity and accelerate skin inflammation.
● Antioxidants (e.g. selenium, zinc, coenzyme Q10) - promote protection against oxidative stress.

Hydration
Despite the cold weather, the body continues to lose water. It is worth remembering to drink water regularly and to reach for herbal teas (e.g. nettle, chamomile) to support detoxification.

Care rituals
● Gentle cleansing - avoid aggressive detergents. Milks, creamy foams or cleansing oils are ideal.
● Layer care - using moisturising toners, antioxidant serums and emollient creams to finish.
● Nourishing masks - 1-2 times a week it is worth using regenerating masks based on algae, hyaluronic acid or honey.

Summary.

The skin microbiome is an indispensable part of its normal functioning, playing a key role in immune protection, maintenance of epidermal barrier integrity and prevention of inflammation. Its imbalance leads to numerous dermatological problems and even accelerated skin ageing.

From the cosmetologist's point of view, the priority should be care that supports the natural microbiome through the use of gentle formulations, appropriate active ingredients and the avoidance of destructive actions to the skin. Educating patients and clients about the importance of the microbiome is an essential part of a holistic approach to skincare in the 21st century.