My sensitive skin diary

Microbiome: The living shield that helps keep your skin happy

The term “barrier function” is often used in dermatology articles, but what exactly does it mean? Traditionally, doctors have used this term to refer to the layer of dead cells at the skin’s surface, plus the waterproof oily layer on top of them. Together, they stop external aggressors (allergens, irritants, pollution…) from being able to penetrate through and reach the deeper skin layers.

Barrier dysfunction: When skin’s defenses start to crumble

Sensitive, reactive and all-round grouchy skin often exhibits barrier dysfunction. In other words, skin is not properly protected against the world around it. And that means skin can’t fulfil its role as our first line of defense against the outside world. The more “annoyed” skin becomes, the drier and more exposed it gets. Skin enters a vicious cycle of sensitivity and irritation.

Could bacteria break the vicious cycle of sensitivity?

In the wake of the latest research into the microbiome - the sum total of the organisms living on your skin - the whole concept of the barrier function has had to be revised. Why?

  • When there is barrier dysfunction, the biodiversity at skin’s surface is depleted.
  • When skin’s bacterial diversity is restored, skin is once again soothed.

Traditional “plain” moisturizers are pretty retro nowadays. To lastingly relieve symptoms of sensitivity and restore skin’s comfort, a modern-day moisturizer needs to work on both skin’s constituent barriers – its precious lipids and its fragile microbiome.

Skin and bacteria: A match made in heaven

Skin exists in symbiosis (in other words, a win-win situation) with its resident microbial populations.

  • Our beneficial bacteria help keep out the ones that cause infections.
  • There is constant “dialog” between bacteria and skin to keep it calm and soothed.
In other words, skin’s friendly bacteria help it perform its famous “barrier function” and defuse the vicious cycle of dry, “annoyed” skin.

So, which bacteria are friends, and which are frenemies?

When it comes to cultivating a healthy microbiome, your buzzword is diversity. Every single cm2 of skin is home to no fewer than a billion microbes. And the more diverse your bacteria, the healthier it is for your skin. [We suggest the following example from Fun Facts could be “floating” nearby: 1,000,000,000,000 – one thousand billion – is the number of micro-organisms living on a human’s skin… that’s ten times the number of stars in the Milky Way!] Nonetheless, certain bacteria aren’t exactly “friendly.” Some actually break down skin’s surface lipids, as well as causing grumbling inflammation. Luckily we have our microbiome to stop the baddies from colonizing our skin!

Could prebiotics be the future of skincare?

Healthy skin is the perfect “culture medium” for friendly bacteria. It is warm, moist and nutrient-rich. But sometimes it needs a helping hand to become the most hospitable environment possible for your microbiome…

Your top 3 “good” bacteria boosters

Every day, skin is hounded by environmental aggressors that can alter the balance of its microbiome. Result? Drier, more irritable, more reactive skin… But advanced research into the microbiome has opened the doors to a brand new era of prebiotic skincare. By driving biodiversity on skin, these microbe-boosting innovations might just be the breakthrough your skin has been waiting for.
All of the scientific information referenced in this article is based on the article "The Role of Cutaneous Microbiota Harmony in Maintaining a Functional Skin Barrier" by H. Baldwin et al, published in the Journal of Drugs in Dermatology in 2017.

1 Willis CM, Shaw S, de La Charrière O, et al Sensitive skin: an epidemiological study Br J Dermatol 2001;145:258-63.