WHAT IS THE SKIN MICROBIOME?

Bacteria, fungi, viruses – trillions of microorganisms have made Earth their home even before humans existed. They adapted and evolved, but they have always been present where life exists: in the soil, in plants, on animals and on us.

In the last few decades, we have started exploring and understanding the fundamental role they play in our lives through their presence in and on our bodies: from our gut to our brain and our skin. Collectively known as the microbiome, these microbes represent around half of our body cells. 

The skin microbiome refers specifically to the multitude of microorganisms inhabiting someone’s skin. Many factors such as genetics, lifestyle, diet, personal hygiene, age, medicine (especially antibiotics) and even the people and pets a person shares their home with influence the composition of their skin microbiome. As a consequence, each person’s microbiome is unique to them, similar to the DNA.

New genome sequencing technologies have demonstrated that the skin is host to more diverse and dynamic bacterial communities than previously thought. These bacteria interact and communicate with each other and with our skin cells, and they are able to promote and inhibit the growth of good and bad bacteria, respectively. Understanding the balance of the skin microbiome, is essential to establishing the necessary harmony needed to maintain healthy skin.

WHY BACTERIA ARE
BENEFICIAL ON OUR SKIN

Contrary to common belief, not all bacteria are bad. In fact, they are key to detect and manage harmful incoming bugs on the body’s first line of defense and its largest immune organ, the skin. The bacteria on the skin warn the body of invaders and trigger a response. They also self-manage their communities, making sure that a specific type of bacteria does not become over dominant.¹ Additionally, they help the skin suppress inflammation.²
_{1 [Sanford JA, Gallo RL. Semin Immunol 2013, 25(5): 370-377] 
2 [Chau TA, McCully ML, Brintnell W, et al. Nature Medicine 2009, 15(6): 641-648 ; Lai Y, Di Nardo A, Nakatsuji T, et al. Nat Med 2009, 15(12): 1377-1382]}

The skin microbiome balance can be perturbed by internal, lifestyle and environmental factors. Hyper-cleanliness, for example, can do more damage than good particularly for children, as it blocks exposure to helpful microorganisms which contribute to the development of the immune system.¹  "The hygiene hypothesis: current perspectives and future therapies". ImmunoTargets and Therapy²:_. The more diverse the skin microbiome is, the healthier it is. When the microbiome is unbalanced, the skin is less protected and more vulnerable to external aggressors. This imbalance is associated with skin conditions such as psoriasis, atopic dermatitis and acne.³

_{1 [Stiemsma, Leah; Reynolds, Lisa; Turvey, Stuart; Finlay, Brett (2015).
2 143. doi:10.2147/ITT.S61528. ISSN 2253-1556. PMC 4918254]
3 [Skin microbiome and acne vulgaris: staphylococcus, a new actor in acne. Dreno B, Martin R, Moyal D, Henley JB, Khammari A, Seité S. Exp Dermatol. 2017 Jan 17. PMID: 28094874]}

LINK BETWEEN MICROBIOME
IMBALANCE AND SKIN CONDITIONS

Eczema

According to research, eczema is associated with a dramatic drop in bacterial diversity, with up to 30% of the ecosystem being occupied by only one bacteria: Staphylococcus aureus (Staph). This microbiome imbalance contributes to three interconnected mechanisms:

• Staph bacteria colonisation: eczema flare-ups always come back
• Skin barrier alteration: skin is very dry
• Skin inflammation: skin is itchy and there’s an urge to scratch

Acne

The microbiome of those suffering from acne presents two specific bacteria species which become too prominent – Staphylococcus sp and P.acnes.

• The bacterium P.acnes lives within the micro-hair follicule and leads to inflammation

Sensitive skin

A balanced microbiome with bacterial diversity leads to a stronger skin barrier function. When the microbiome becomes unbalanced, this can lead to sensitivity.

HOW THE SKIN
MICROBIOME IS REGULATED

There are four ways to ensure the diversity of the skin microbiome is maintained:

• Prebiotic approach: formulations for the skin which contain ingredients that stimulate the diversity of the skin’s bacteria
• Studies have shown that La Roche-Posay thermal spring water, with its unique mineral and bacterial composition, acts as a prebiotic
• Probiotic approach: introduction of very specific strains of bacteria to diversify microbiome
• Postbiotic approach: use of substances that stimulate the growth of micro-organisms, especially those with beneficial properties mimicking the natural cross-talk between bacteria in the microbiome
• A prebiotic can be combined with a postbiotic for increased efficacy as it has been demonstrated with LIPIKAR Baume AP+M, containing high concentrations of both Aqua Posae Filiformis (postbiotic) and La Roche-Posay thermal spring water (prebiotic)
• Antibiotic approach: phages or viruses that attack a single strain of bacteria

LA ROCHE-POSAY,
A PIONEER IN MICROBIOME RESEARCH

La Roche-Posay is a leader in skin microbiome research since 2011, with 19 clinical studies conducted on more than 1,200 patients and 13 articles published on this topic. As a result of this research, La Roche-Posay developed an exclusive, patented active ingredient, Aqua Posae Filiformis, which rebalances the skin microbiome, regulates inflammation and is effective on both atopic and acne prone patients.

Aqua Posae Filiformis is developed in our factory by growing the Vitreoscilla Filiformis strain in La Roche-Posay thermal spring water.

Due to its unique mineral and bacterial composition, the thermal water itself has been clinically proven to be effective on the gut and skin microbiomes.

_{From Probiotic to Prebiotic Using Thermal Spring Water, J. Zeichner MD, S.Siete PhD, 2018}