The Importance Of The Skin Microbiome

Thanks to these microscopic organisms, we avoid diseases that can complicate our existence. Proper skin care will thus improve our defenses.

The importance of the skin microbiome is something we should all be aware of. It is a concept that dermatologists and immunologists study more every day (however, we should not confuse microbiome with intestinal microbiota, which is not the same, although it has some similarities).

When we talk about a microbiota, we are talking about microorganisms that live in another larger organism. We have as an example the group of microbes that live in the human gut. Another concept, however, is the microbiome, which includes microorganisms plus their genetic information.

Thus, the skin microbiome is the set of microorganisms and their genetic material that is normally found in our skin tissues. Although we may not suspect it, bacteria and fungi live on the skin all the time without causing disease.

It is said that the microbiome of the skin is very large and weighs – if we could weigh it – up to half of our body mass (including the skin itself). This amount acts as a defensive barrier against the outside world. Therefore, the importance of the skin microbiome is very obvious!

What is in our skin?

For many, the microbiome is part of the definition of skin. Specialists believe that we cannot exist without having these microorganisms living there, and that the term “skin” therefore includes them.

The skin is part of a system called the integumentary system. Here we include the skin, the glands and part of the mucous membranes that extend from the skin into the cavities.

A key function of the skin is protection. In fact, it is the first physical and immunological barrier available to the body to stop the development of infections and harmful external agents.

As a physical barrier, it settles between the body and the external environment, and as an immunological barrier, we count several defense cells that are distributed in the skin tissue.

The regulation of homeostasis also makes the skin a necessary and vital organ. To maintain e.g. body temperature, we require the skin to perform the necessary heat and cold exchange. At the same time, substances and hormones, such as vitamin D, must pass through the skin to become active.

Functions of the skin microbiome

At the beginning of the article, we mentioned that the microbiome of the skin is part of the immune system. The set of microorganisms that inhabit the skin contributes to the skin’s barrier functions.

Similarly, this habitat, created by common bacteria and fungi, rejects other harmful external agents that would like to settle there. If a pathogenic bacterium wants to invade the skin, it must first establish competition with the bacteria that are already there.

The skin’s microbiome has its own pH, which means that it acts at a certain acidity that determines the acidity of the skin. This pH is also immunological and serves to create environments that are inhospitable to certain microbes.

Another function is healing and repair. When skin lesions occur, healing will depend in part on the health of the microbiome, which will help the scar formation process to go as smoothly as possible. Inflammation will be controlled if the microorganisms of the skin are in harmony.

Each part of the skin has its own microbiome

Some scientific studies around the world tried to catalog the microbiome of the skin in order to know with some accuracy which microorganisms inhabit each region of the body. The results suggest that each region of the skin has its own microbiome.

Despite the differences between them, the regions are fairly stable over time. This means that the bacteria in the face, for example, tend to remain the same over the years, even when faced with different circumstances.

The areas that maintain their microbiome the most are the oily areas of the skin. One place with a very stable bacterial population is the outer ear canal, where fungi also commonly live.

In contrast, humid areas are more unstable. In the feet, there are changes in the microbiome that are not detected in other similar parts, such as the hands. The explanation lies in the accumulation of moisture, which is a fundamental factor in the growth and development of microbes.