Skin Microbiome: Why Is It So Important?
The skin microbiome is a concept that is being studied more and more among dermatologists, and also among immunologists. We should not confuse the microbiome with the intestinal microbiota, which, being similar, is not the same.
When we refer to a microbiota, we are talking about microorganisms that live in another larger organism. We have as an example the group of microbes that inhabit the human intestine. But another concept is the microbiome, which includes microorganisms plus their genetic information.
Thus, the skin microbiome is the set of microorganisms and their genetic material, which is usually found in our skin tissue. Because, although we do 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, weighing – if we could weigh it – up to half of our body mass – including the skin itself. This volume works as a defensive barrier against the outside.
What is the skin like?
For many, the microbiome is part of the definition of skin. It is assumed that we cannot exist without having these microorganisms living there and that, therefore, the concept of skin includes them.
The skin is part of a system called the integumentary. Here we include the skin, the appendages, 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 reality, it is the first physical and immunological barrier available to the body to stop the advance of infections and harmful external agents.
As a physical barrier, it intervenes with the outside, and as an immunological barrier we count multiple defense cells that are distributed throughout the skin tissue.
The regulation of homeostasis also finds a necessary and vital organ in the skin. To maintain body temperature, for example, we require the skin to perform the necessary heat and cold exchanges. At the same time, substances and hormones must pass through the skin to become active, such as vitamin D.
The functions of the skin microbiome
At the beginning of the article we anticipated that the skin microbiome is part of the immune system. The set of microorganisms that inhabit the skin contributes to its barrier functions.
In the same way, this habitat created by common bacteria and fungi repels other harmful external agents that would like to settle there. If a pathogenic bacterium wants to invade the skin, it first has to establish a competition with the bacteria that are there previously.
The microbiome of the skin has its own pH, that is, it works at a certain acidity that determines skin acidity. This pH value is also immune, and serves to create environments inhospitable to certain microbes.
Another function is healing and repairing. When skin lesions appear, healing will depend in part on the health of the microbiome, which will help the scar process to take place in the best possible way. The inflammation will happen controlled if the cutaneous microorganisms are in harmony.
Every part of the skin has its own microbiome
Some scientific studies around the world have sought to catalog the skin’s microbiome to find out, with some accuracy, which microorganisms inhabit each region of the body. The findings suggest that c ada skin region has its own microbiome.
Despite the differences between them, the regions are quite stable over time. This means that the bacteria on the face, for example, tend to be the same over the years, even if we face different conditions.
The areas that most maintain their populations are the fatty regions of the skin. A very stable place in the bacterial population is the external auditory canal, which also has fungi as its habitual inhabitants.
On the contrary, humid regions are more unstable. In the feet there are changes in the microbiome that are not registered 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.
The skin microbiome is key
We all have a skin microbiome. It is not bad, but quite the opposite: necessary. Thanks to these microscopic organisms we avoid diseases that could complicate our existence. We must understand that skin care will affect the care of this habitat and, by extension, will improve our defenses.
