Skin Microbiota: Everything You Need to Know

We're going to show you the importance of keeping the skin microbiota in a good state of diversity and density to protect your health.

Written and verified by el nutricionista Saúl Sánchez.

Last update: 04 February, 2023

When we talk about microbiota, we’re often only referring to the bacteria that inhabit the interior of the digestive tract. However, there are microorganisms in many other parts of the human body, with important functions in maintaining good health. Specifically, today, we’re going to talk to you about the skin microbiota, often called skin flora, which is essential for the skin.

The set of bacteria that inhabit the intestine have been the subject of much research. Until a few years ago, experts were not aware of its existence or its importance. However, it’s now known that they can modulate health and disease states. They have even come to be categorized as an independent part of the body.

What is the skin microbiota?

With the name of skin microbiota, we’re referring to the set of microorganisms that make up the ecosystem present on the surface of the skin. On the one hand, they contribute to protecting the human body, assuming a physical and immune barrier at the same time. In fact, if there is a reduction in the diversity of these organisms, serious pathologies could develop.

It must be taken into account that the skin surface constitutes a complex ecosystem. The environment is inhospitable and the pH is acidic, so not just any living being can inhabit this place. Likewise, the humidity conditions are variable throughout the day and the seasons of the year. Despite this, there are microorganisms capable of adapting to these circumstances, achieving a state of balance that makes life possible for them.

However, it should not be thought that all the beings that make up the skin microbiota are beneficial or mutualistic. In some cases, pathogens can also proliferate, leading to different types of infections. Here, treatment will have to be proposed to restore homeostasis at a superficial level and avoid alterations that may affect the immune system.

In this sense, in recent years a series of probiotic compounds have been developed to improve skin health that have shown good results. They manage to promote the growth of beneficial bacteria, generating a better feeling of well-being and making the surface layer of the body look healthier.

Most common types of microbiota and microorganisms

There are different populations of bacteria on the surface of the skin. In the first place, we can mention the resident microbiota, made up of two types of microorganisms.

Normally these microorganisms are considered commensal and mutualistic, so they normally won’t be harmful to humans.

The transient microbiota should be highlighted. In this case, we’re talking about strains that aren’t present on the surface of the skin the whole year. They can survive a few hours or even a few days, but their renewal is practically constant. As a general rule, they aren’t pathogenic and a large number of Gram-positive bacteria can be identified in this group.

Anyway, this issue isn’t just about bacteria. There are also fungal populations on the epidermis. The recognized genera are diverse, the Candida type being the most common. In normal situations, they are not considered a risk. However, there may be ideal conditions for the populations of these living beings to grow, thus causing damage to the host.

According to research published in the journal Microorganisms, certain strains of fungi can cause infections on the surface of the skin, so it will be necessary to maintain certain hygienic measures to avoid this situation. Normally, they benefit when there are certain wounds or irregularities in the tissue, and also when the pH or humidity conditions vary.

How to keep the skin microbiota in balance?

In the same way that the intestinal microbiota must be taken care of, it will be necessary to do the same with the set of microorganisms that inhabit the skin. It’s necessary to guarantee the survival of the beneficial ones and prevent the proliferation of pathogens.

To achieve balance in terms of skin microbiota, you should promote a series of hygienic measures. Now, it isn’t advisable to go overboard in this regard either. The intensive use of soaps or bactericidal compounds could put beneficial populations of microorganisms at risk, leading to colonization by opportunists and pathogens.

You’ll also have to be careful with conditions of excessive humidity, since in this case, you can experience growth by fungi that causes damage in the medium term. For example, this class of infections are more frequent in athletes, since, due to sweating, there is an excellent breeding ground for the multiplication of certain microorganisms.

There are a series of hygienic and antiseptic methods that can be carried out to keep bacterial and fungal populations under control, avoiding their uncontrolled proliferation. This is evidenced by research published in the journal BioMed Research International .

Probiotics and prebiotics for the skin microbiota

It’s possible to include a series of probiotic and prebiotic compounds in your diet to improve the quality of the skin flora, which helps prevent pathologies and failures in your defense barriers. For example, treatment with certain strains of bacteria can be considered to control problems such as acne, according to a study published in the journal Dermatologic Therapy.

Thanks to these microorganisms, an anti-inflammatory effect could be experienced that reduces pain and swelling caused by this pathology. Even through action at the microbiota level, excess sebum production, one of the determining factors for the appearance and development of the characteristic spots would be controlled.

However, the administration of probiotics or prebiotics isn’t only carried out orally. There are several cosmetic products that include these elements, and their topical application can produce a significant benefit. The effects can even be better when combined with certain nutrients like vitamin C.

There is evidence that this vitamin is capable of increasing the endogenous synthesis of collagen, one of the most abundant proteins in the body, which is an important part of the skin. Thanks to it, wounds heal faster, and the appearance of wrinkles or skin problems is reduced.

Beauty treatments and their impact on the skin microbiota

Keep in mind that not all areas of the skin have the same characteristics. The thickness of the tissues, the production of sebum, and the humidity conditions are among the factors that can determine whether the different types of microorganisms can live there. For this reason, when applying dermatological or beauty treatments, you’ll have to be careful.

It’s important to highlight that in the most humid areas such as the armpits and the navel, there are mainly bacteria of the genera Staphylococcus and Corynebacterium . However, locations with the highest sebum production, such as the forehead, have bacteria of the ancient genus Propionibacterium. Respecting the conditions of the habitat of these microorganisms will be decisive to ensure their survival.

However, it’s true that the proliferation of certain pathogens could modify the characteristics of these skin areas, which can put the correct functioning of the immune system at risk. In this case, cosmetic products play a decisive role. As they are designed to be applied in a specific place, they’ll be able to maintain the conditions in those areas, reducing the risk of contamination by other microorganisms.

It’s necessary to ensure the diversity of the skin microbiota

In the same way that happens with the intestinal microbiota, the set of microorganisms that inhabit the surface of the skin must be diverse and dense. In this way, we can ensure that they are carrying out their functions efficiently, bringing us clear benefits. However, there are several conditions that can influence this, such as genetic load.

To achieve a balanced situation, it’s important to take care of lifestyle habits in general, including diet. Through food, the inflammatory mechanisms that take place in the body can be controlled, and that can sometimes affect the skin.

To do this, it’s worth highlighting the need to include nutrients in our diets that have been shown to help guarantee homeostasis, such as the fatty acids of the omega-3 series.

The skin microbiota, a fundamental element for skin health

The influence of bacteria and other local microorganisms on the health of the skin is decisive. We’re talking about an area totally colonized by different types of living organisms. It is necessary to guarantee diversity and minimize the presence of pathogenic populations, which will avoid health problems in the medium term.

To keep the skin looking healthy, it’s necessary to combine a series of good habits. Diet and rest are two of the most important, although hygiene and dermatological and cosmetic treatments must be guaranteed. In this way, illnesses can be avoided or they will be easier to control, as is the case with acne.