Why are probiotics in skin care products? | Skin Clinica

You’ve probably heard a lot about how probiotics improve gut health, but have you noticed the rise in use of probiotics in skin care products? One leading global brand has gone so far as to stamp its product labels with the words “microbiome science”. But why are we seeing probiotics in skin care and are they just another fad?

Let’s find out.

Just as every person has a unique set of fingerprints, every person also has a unique microbiome, even twins. We get imprinted with it at the time of birth and it develops rapidly during our first three years of life.

The human microbiome comprises 10-100 trillion microbial cells. And it’s been found that we have more microbial cells than human cells! These are mainly found in the gut and on the skin, and are essential to human health, including our immune function.

More than 1000 species of bacteria have made our skin their home. They happily reside there without us even knowing it. And while we generally think of bacteria as bad, that isn’t the whole story.

Our bodies have friendly (commensal), neutral (mutualistic) and opportunistic (pathogenic) bugs, and there is a complex relationship that exists between them. The importance of the microbiome was established by the ground-breaking global Human Microbiome Project.

Maintaining the balance in favour of the friendly microorganisms is critical when it comes to preventing inflammation, infections and diseases. Unfortunately antibacterial agents, preservatives, soaps and other alkaline products are threatening this equilibrium and causing a rise in skin problems in the western world.

The microbiome of the skin

The skin microbiome is the collection of all cells, including the bacteria, fungi and viruses that are on our skin. These microorganisms keep skin healthy and prevent or treat skin conditions and disorders. They break down natural elements found on our skin to keep it clean. And they communicate with the immune system in the skin and play a role in educating it.

The microbiome on our skin protects us by maintaining an optimum pH and preventing the growth of hostile bacteria. It also boosts the skin’s immune function and increases cell metabolism. This results in balanced and healthy skin.

Microorganisms in our gut help boost our overall health and, in a similar way, those on the skin promote skin health. They help us maintain the right pH levels, keep pathogens in check and may even protect us against skin cancer.

Given the skin is teaming with a mix of friendly and unfriendly bugs, the delicate balance of our microbiome can be easily disrupted. Poor diet, stress, sun damage, pollutants and medication can affect it, as can an aggressive skin care routine or irritating products.

Skin that feels unusually dry, sensitive, red or irritated and doesn’t respond to your usual skin care may be due to a compromised microbiome. And a compromised microbiome leaves your skin more vulnerable to acne, eczema, psoriasis and rosacea.

The skin’s defence system

The microbiome forms part of the skin’s defence system.

The skin has three main lines, or layers, of defence. These three lines work together to prevent infection, keep out irritants, retain moisture and guard against damage by UV and other environmental stressors. Each plays a critical role in keeping our skin healthy.

These three lines of defence are found on and in the epidermis of the skin. They comprise: the microbiome, the acid mantle and the lipid barrier. Often these are more simply referred to this as the skin barrier.

But let’s look at these a little further to understand the individual role each plays.

1. Microbiome: The trillions of cells that live on our skin, including bacteria, viruses and fungi. It provides a physical barrier and prevents invasion by pathogens, educates our skin’s immune system and breaks down natural elements on our skin. This keeps our skin looking and feeling healthy, and prevents skin conditions.

2. Acid mantle: This sits below the microbiome. The acid mantle, as the name suggests, is a slightly acidic layer that contains sweat, sebum, water, dead skin cells, lactic acid, urocanic acid, fatty acids and pyrrolidine carboxylic acid. It inhibits the growth of unhealthy bacteria, fungi, viruses and intruders. The acid mantle has a pH of about 4.5-6.0.The acidity prevents the bad microbes from overgrowing and gaining dominance over the good microbes. The acid mantle also plays a role in helping to trap moisture and prevent it evaporating.

3. The lipid barrier: The lipid barrier is found under the acid mantle and is essentially made up of ceramides, free fatty acids and cholesterol. It sits between our skin cells, a bit like cement in a brick wall, and helps keep unwanted external substances out and moisture in. The lipids are densely packed and form a highly ordered 3-D structure.

Even though our skin is cleverly arranged and has these three lines of defence, our protection can break down. This can be due to poor diet, stress. sun damage or incorrect skin care, such as excessive exfoliation, use of irritating ingredients or overuse of actives. Sometimes even alkaline products, such as soap, can compromise the skin. When the skin becomes stressed and its equilibrium is affected, it becomes more vulnerable to pathogenic microbes. It’s important that we create the right environment for the good microorganisms to flourish and crowd out those opportunistic ones that are always looking to take control.

What are probiotics?

If you’ve taken probiotics to improve gut health, then you already know about the role they play. These probiotics are live bacteria and yeasts, and they help keep us healthy. Not only are probiotics available as supplements, they also can be found in some foods and drinks.

Probiotics naturally occur in fermented products such as kefir, kimchi, sauerkraut, tempeh and yoghurt. Fermented foods are created through the growth and metabolic activity of live microbial cultures.

There are seven strains we know most about and are more commonly found in probiotic products: Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Escherichia and Bacillus. Probiotics are generally beneficial to gut health and immune function, however different strains confer different specific benefits.

How do probiotics help?

Probiotics have come into their own over the past decade or so as new research has uncovered their benefits. They’re now part of mainstream medical science, whereas once they were considered a fringe interest.

Probiotics are important for digestive health, immune function and the production of serotonin, a chemical in the body that functions as a mood stabiliser. For optimum health, we need to ensure our intestinal tract is populated with the right type and adequate diversity of friendly microbes to keep the bad guys under control. An imbalance can lead to health issues such as digestive problems, IBS, leaky gut, nutritional deficiencies and even inflammatory skin conditions.

Why are probiotics in skin care?

But do probiotics applied to the skin work in the same way as those you ingest?

Not quite. There is promising emerging research on the use of probiotics in skin care, but there are still many limitations and challenges. In the future, there may be extraordinary things we can do with probiotics, such as excrete sun protection. For now, though, we don’t have evidence that they actually repopulate the skin’s microbiota, but they still offer important benefits.

Many skin care companies and brands have jumped on the probiotic bandwagon and now there’s a plethora of products claiming to contain probiotics. Problem is, almost all of them don’t contain probiotics! Even brands such as Algenist and Paula’s Choice refer to probiotics when they don’t contain live bacteria or yeasts.

Generally speaking, it isn’t desirable to have live probiotics in a skin care product. Regulations in most countries require skin care products to use preservatives to prevent the growth of microbes. So most skin care brands claiming to contain probiotics actually uses prebiotics or post-bionics (deactivated probiotic fragments). And that’s an important distinction.

I say ‘generally’ as there are some smaller brands using live probiotics. Some of these don’t use preservatives and have a very short shelf-life. Remember that the role of preservatives is to prevent microbes from growing and preservatives can’t distinguish between those that are friendly and unfriendly. Be warned, however, the safety and stability of these non-preserved products may not be assured. I also found a brand that keeps the probiotics separate from the carrier until the customer is ready to apply them. And I came across another that uses ammonia-oxidising bacteria found in rich soil. The brand claims that ammonia-oxidising bacteria converts the urea and ammonia found in sweat and on the skin into nitrite and nitric oxide, which are said to have certain anti-inflammatory and antimicrobial effects.

Before buying into the probiotic story, look a little more closely into the product and what probiotic ingredients, if any, it actually contains.

Don’t be deflated if you can’t find any probiotics. Prebiotics and post-biotics are still good for the skin and can help to support the skin’s microbiome. They enable your skin to boost its defences and spend more of its energy on regenerating, rather than fighting inflammation.

Types of probiotics in skin care

Prebiotics

Malassezia spp, Cutibacterium acnes and Staphylococcus aureus are examples of pathogenic microbes that cause skin diseases. But, as already mentioned, there are other natural microorganisms present in our skin that can improve or even treat it.

Probiotics are live bacteria and yeasts and, when applied to the skin, may promote a healthy microbiome by conferring a number of key benefits:

Protecting: maintaining an optimal pH, reducing oxidation, keeping unfriendly bacteria under control and preventing skin conditions through antimicrobial action
Soothing: reducing sensitivity to external irritants and aggressors
Repairing: stimulating hyaluronic acid and collagen production
Moisturising: increasing skin hydration and improving elasticity

Probiotics produce acidic compounds that reduce the pH of the skin, creating an environment that inhibits the pathogenic microbes. They strengthen the skin barrier against environmental threats and reduce factors that cause breakouts, irritation, redness and sensitivity. They also help the skin retain moisture, which diminishes signs of skin ageing.

While there is research looking at the different strains of probiotics and how they can benefit us when taken orally, investigation of their use topically is limited. The more commonly used ones in skin care are Bifidobacterium, Lactobacillus, Nitrosomonas and Vitroscilla.

Here are some strains that have been studied for their topical use:

Enterococcus fecalus, in one study where it was applied to the face for eight weeks, it reduced acne inflammation by 50% compared to a placebo.

Lactobacillus paracasei also decreased inflammation in the skin and thereby improved the appearance of acne lesions. This bacteria is commonly found in the gut and is in fermented dairy products.

Lactobacillus planetarium, at 5%, was found to decrease acne marks and redness on the face, but showed no benefit at 1%.

Streptococcus thermophiles increased the production of ceramides in the skin. Ceramides form an essential part of the skin barrier and help protect against infection, moisture loss and premature ageing, as well as improving acne.

Streptococcus salivarius improved the skin’s immune function. It was found to decrease inflammation in the skin by acting as an immune modulator.

Probiotics may be helpful for those with a compromised skin barrier and certain skin conditions. But a word of warning first for those who are immunocompromised: Do not use skin care products with live probiotics without consulting a medical professional first.

Prebiotics

Prebiotics provide nourishment to stimulate the growth or metabolic activity of friendly bacteria and help it thrive. This may regulate the microbiome and help it maintain a healthy balance.

Botanically based sugars and oils provide the skin with useful prebiotics. The most commonly used prebiotics are glucans, glucomannan, inulin, pectin, oligosaccharides, polysaccharides, rhamnose and xylitol.

It’s important to understand that good bacteria do not kill bad bacteria; rather they prevent them from growing by eating the available food. The prebiotics serve to selectively stimulate the growth and metabolic activity of the friendly ones. This mechanism is known as competitive inhibition. So think of those prebiotics as providing a tasty banquet for the good bacteria to feast on.

Post-biotics

Post-biotics have a symbiotic relationship with prebiotics and probiotics. Post-biotics are beneficial by-products that are created by the breakdown of the cell walls, metabolites and peptides of probiotics. These are created by our own skin when the bacteria that lives on it dies off. These naturally occurring post-biotics contain a myriad of active molecules, including amino acids, enzymes, isoflavones, flavonoids, peptides, peptidoglycans, polysaccharides, phospholipids, proteins, vitamins, minerals, organic acids, teichoic acids. Of particular interest are antimicrobial peptides (AMPs), which are effective against gram-negative and gram-positive bacteria, viruses and fungi, and may even alter cancer cells.

Ferments, filtrates and lysates are a mainstay of Japanese and Korean skin care and are often used for their post-biotic benefits. These are actually post-biotic derivatives rather than true post-biotics and you’ll see them listed on ingredient labels as Lactobacillus Ferment, Fermented Yeast Extract, Radish Root Ferment, Galactomyces Ferment Filtrate (Pitera), Saccharomyces Ferment Filtrate (Kombucha), Bifida Ferment Lysate, Lactococcus Ferment Lysate or Alteromonas Ferment Extract. They don’t contain live bacteria, but they appear to have similar effects on the skin. Post-biotics are key to the success of the SK-II brand and the Advanced Night Repair serum by Estee Lauder.

Post-biotic derivatives help balance pH, soothe irritation and sensitivity, refine skin texture and stimulate cell renewal.

These ingredients are created by fermenting with bacteria or yeasts, but these live agents are then deactivated. Fermentation creates a brew that contains amino acids, antioxidants, organic acids, vitamins, minerals and other compounds, while also breaking down molecules into smaller sizes, and this may allow them to absorb more deeply into the epidermis.

Post-biotic derivatives are helpful but probably work best when combined with post-biotics naturally found in the skin, such as ceramides, hyaluronic acid and peptides.

Put simply in summary:

prebiotics provide the fuel that helps probiotics grow
probiotics are live bacteria and yeasts with direct skin benefits
post-biotics help maintain a healthy skin environment and barrier

Which biotics are best?

It’s difficult to say whether prebiotics, probiotics or post-biotics are best for the skin. They all work together to help strengthen the skin’s defences, maintain hydration, diminish signs of skin ageing and maintain a healthy tone. The sum is greater than the parts.

Keep in mind that biotics need to be carefully formulated. They’re delicate creatures that can easily deteriorate due to the presence of other incompatible ingredients or exposure to light and air. Store them correctly in a cool, dark place and ensure you use them within the time period specified.

Don’t expect probiotics in skin care to do all the heavy lifting. They may be helpful for people experiencing skin issues, however you shouldn’t start applying them to an unknown skin condition without having it checked first by a medical professional. They also may be helpful for those who want to keep their skin healthy and resilient.

Tips for a healthy microbiome

Here are some tips to help protect your skin microbiome and keep it functioning at its best.

Don’t over-cleanse or use drying cleansers, especially those that are alkaline, such as soap-based cleansers. High-alkaline products increase the skin’s permeability, making it more vulnerable to irritants and microorganisms.
Avoid harsh scrubs and loofahs as these can damage the skin and make it vulnerable to the opportunistic microbes on the skin. Aggressive exfoliation removes or damages your skin’s first line of defence, the microbiome.
Don’t overuse skin acids or other actives. Acids alter the skin’s pH and overdoing it as can make the skin inhospitable to some good microbes.
Protect your skin from the damaging effects of the sun by using sunscreen daily.
Cleanse gently and moisturise daily, even if your skin is oily. A cleanser removes makeup, sunscreen and pollutants, helping to keep our skin clear. A moisturiser adds hydration, replenishes what’s lost from the skin and has a soothing effect. Hydration is important to all skin types as it’s needed for repair and renewal, allowing younger skin cells to replace older ones.
Incorporate ceramides, hyaluronic acid and peptides into your skin care routine. Replenish your skin with plant oils, especially if you have dry or sensitive skin. Choose those that have the right fatty acid composition for your skin.
Add in some biotic-specific products or look for those that include them. There are many skin care products that include prebiotics or post-biotics but they’re not always overtly labelled as such. Check out the ingredients list; you may be surprised.
Keep your gut healthy. Eat fibre-rich plant foods for their prebiotics and fermented foods for their probiotics. This will improve your immune function boost the good bacteria in your gut and deliver overall health benefits, as well as skin benefits.
Limit the use of antibiotics to only when strictly required as these indiscriminately wipe out good and bad bacteria alike.

Putting it all together

Most ‘probiotics’ in skin care don’t contain live bacteria or yeasts and therefore aren’t actually probiotic. It is exceptionally difficult to formulate with probiotics and so these products are not easily available. Most brands use prebiotics or post-biotics, but label their products probiotic. This is confusing and misleading for consumers.

The use of biotics may be helpful for those who need to recover a compromised skin a barrier, are struggling with skin issues or just want to maintain a healthy microbiome function. A balanced microbiome is essential to the skin’s defences and reduces susceptibility to irritation, skin conditions and premature ageing. Biotics can be incorporated into a skin care routine easily and help you achieve skin that looks clear, radiant and youthful.