The skin is a complex organ. Its function is determined by a symbiotic relationship between the tissue and numerous microorganisms such as bacteria, fungi and viruses living within it. This community of microorganisms is made up of two groups: resident microorganisms, which are usually harmless and provide some benefit to the host, and transient microorganisms, which come from the environment, and last for a matter of hours or days. In normal conditions, neither group is pathogenic. Microorganisms and their genetic material as a whole, known as the “microbiome”, contributes to genetic diversity, modulates specific diseases, affects epidermal metabolic processes and is essential for immunity.

French bacteriologist Louis Pasteur was the first scientist to claim that microorganisms and human beings form a large metabolic unit, recognising that the bacteria living within the body are, in actual fact, protecting it. There are estimated to be over 10,000 different microbial species living in the body.

Microbiome variability

Microbiome variability among individuals is high, since this is constantly exposed to various endogenous factors (from the host) and exogenous factors (from the environment).

Age also has a role to play in this. During childhood, flora diversity is limited, while in adulthood, this increases and is relatively more stable. Dominant strains are usually common, and those responsible for variability are the less abundant ones.

Staphylococcus, Propionibacterium and Corynebacterium are known to be the dominant skin bacteria and their percentages differ according to the location (hair follicles, eccrine and apocrine glands, and sebaceous glands).

These findings raise the question of when and how a microorganism becomes a skin pathogen. A recent study showed that, while the abundance of microorganisms does not differ, some strains have unique genetic elements which are not present in the strains associated with individuals with health skin, which could contribute to virulence and pathogenicity.

There are many examples which demonstrate this theory:

  • Acnes, the microorganism related to acne, is part of the microbiota even in those who do not have acne.
  • The increased colonisation of Demodex skin mites in individuals with rosacea.
  • Lack of immunological tolerance to the microbiota can result in psoriasis.

The importance of having a balanced microbiome

In the case of healthy skin, the microbiome is stable and properly functioning. This balance is known as eubiosis. However, the microbiome can become unstable. This loss of balance is known as dysbiosis, and can be caused by a specific pathology, or by external agents such as contamination, heat shock, eating habits and stress. It can also be conditioned by the individual’s genetics.

If this ecosystem is unable to restore balance after an illness, the epidermis can undergo problems such as atopic dermatitis, psoriasis, rosacea, wounds which do not heal normally and other skin diseases or ailments.

Microbiota and ageing

The role of the microbiota in skin ageing, such as wrinkles and sagging, remains unclear and is an area in which microbiota-based skin treatments could be promising. For example, it is expected that certain metabolites produced by the skin microbiota can provide benefits by modulating the pro- and anti-inflammatory skin responses. This process acts in a similar way to what has been demonstrated in the gastrointestinal tract.

Can the skin’s microbiota be actively cared for?

Microbiota variations can be found in different areas of the skin, and in each of these areas there can be an infinite number of different bacterial phyla. This is why it is important to respect the specific characteristics of each of these ecological niches as far as possible.

Respecting the skin’s pH by avoiding aggressive products is, a priori, a good option for maintaining the skin balance of each individual.

The microbiota is by no means immobile and stationary, but rather a dynamic parameter which can be influenced, partly, by each individual’s lifestyle. It would be logical to assume that it is important to be as respectful as possible with the ecological niches of the microorganisms of each area of the skin.

The benefits of probiotics and prebiotics

From the cosmetic point of view, the influence on the skin’s microbiota lies in providing probiotics and prebiotics. Probiotics are live microorganisms with known health benefits which allow to stimulate cell immunity and restore flora balance. An example of this would be Lactobacillus intake. Prebiotics are substrates (usually polysaccharides) which provide nourishment and promote the growth of good bacteria. More research is needed to identify the probiotic strains and prebiotic substrates which could benefit the skin’s microbial communities and, as a result, the overall health of the skin.

How Neftis Laboratorios is helping

Here at Neftis Laboratorios, we are proactive and always aim to anticipate future skincare needs. To this end, we have developed a serum rich in prebiotics, which contribute to maintaining and/or restoring microbiota balance. This serum restores the skin’s pH balance and educates and increases the skin’s defence capacity. We believe that this could be an alternative to antibiotics, with such treatments being called into question over developing resistance with prolonged use and which exert non-selective pressures on the microorganisms. The aim of this is to achieve a more even and healthy complexion.