Our microbiota: A tenant in the skin's defense.

By Sarah-Eve Papineau, Chemist at Corpa Flora specialized in cosmeceuticals

It's sometimes hard to believe that we have billions of bacteria on our skin and even harder to know that they are continually protecting us. This happy mix of bacteria, yeast and molds, commonly known as the microbiota, has been studied extensively in the gut, but the skin also hides some secrets.

Who are these occupants, what do they eat and why are they safe?

First of all, although there are about four hundred different families of bacteria, we can recognize the good bacteria from the bad:

Good :

Staphylococcus epidermidis

Bifidobacterium (group)

Bad :

Propionibacterium acnes

Streptococcus pyogenes

Staphylococcus Aureus

Malassezia furfur

Distinguishing between "good" and "bad" bacteria is important to understand how our skin works so we can tailor our skincare routine to benefit the right group.

[Image Malassezia furfur SEM lores] ID#: 213 Description: Scanning Electron Micrograph of Malassezia furfur. Content Providers(s): Robert Simmons/Janice Carr Photo Credit: CDC/Janice Carr

Some of our habits are harmful to the health of our microbiota. For example, when we use a foaming cleanser that contains abrasive emulsifiers, it removes all the oil from the skin and damages the hydrolipidic film. Since the hydrolipidic film is the home of beneficial bacteria, they are left without shelter and food.

Sometimes the pH of the cleanser affects the pH of the skin, making the environment uncomfortable for the good bacteria. They leave the skin, leaving an unoccupied space. Bad bacteria quickly colonize this space. This is when the problems start: inflammation, acne, dehydrated skin and so on.

In some cases, bacteria can produce bacteriocins, a chemical compound to control unwanted ones. To win the game, they must be in the majority.

💡 Bacteriocins are actually studied in science since they have natural antibiotic properties. We often try to copy them, as it was the case of penicillin which is made by molds.

A question of pH

Over and above the fine meals they can find, good bacteria are especially concerned about the pH, the degree of acidity or basicity of the skin. In fact, this is the first factor that disturbs them and makes them run away.

The normal pH of a skin is about 5, but it can vary according to the type of skin since sebum is basic. Thus, a dry skin has a pH that tends towards 4 and an oily skin is more in the 6.

At Corpa Flora you will find in the ingredient list (INCI) of our hyaluronic acid serums, the Antidotes HB5, H+ and H3, preservatives in the form of ferments: LACTOBACILLUS FERMENT and LEUCONOSTOC / RADISH ROOT FERMENT FILTRATE.

These two preservatives also act as moisturizing agents. The "Leuconostoc/Radish Root Ferment Filtrate" for example, produces an antimicrobial peptide caused by its defense mechanism that allows the formula to remain effective. This particular system dispenses the use of some of the more conventional preservatives that can disrupt the microbiome and cause sensitivity. In this way, not only do these preservatives help preserve bacterial biodiversity, but they help strengthen the epidermal barrier.

Which skin care product is recommended to respect our useful bacteria?

If pH is so important for the health of our microbiota, then choosing the right beauty routine is essential.

The most common mistake is during the cleansing stage where the pH and foaming agents unbalance the skin's bacterial flora. This decisive moment can be the source of many skin problems.

Using a cleanser that respects the microbiota is the first step to more beautiful skin, like Beauté Divine cleansing oil.

First, massage this oil onto dry skin with dry hands. Add warm water and the oil will emulsify into a milky solution. This feature removes excess oil to leave skin nourished and moisturized.

In conclusion, although the skin holds great secrets, the health of the microbiota is obvious to maintain optimal natural defenses and thus have a radiant skin.

Source : Journal of cosmetic science, Nov-Dec 2012, Physiological effect of a probiotic on skin