Microbiome skincare is not something that involves simply including a single probiotic-based ingredient in a product. Caring for the microbiome is an entire philosophy in product design that needs to permeate into every element of the way a product is created.
We call these Biotech ingredients – they’re Prebiotics, Postbiotics, and Probiotics.
True probiotics are living microorganisms that, when administered in adequate amounts, provide a health benefit to the host (that’s you). So, by definition, they’re good for you. They’re also alive. It’s a challenge to include live microbes in a skincare product and there are very few brands that have successfully achieved this. Living probiotics offer benefits that other microbe-based ingredients don’t. They produce lactic acid to maintain skin’s pH and hyaluronic acid to improve hydration. They produce substances that fend off harmful microbes, and they calm skin’s immune system to control inflammation while improving barrier function, which leads to more resilient skin.
It’s common for a brand to state that they use probiotic ingredients, while not including living microbes in their products. In most cases, the ingredients they refer to are actually postbiotics – they’re non-living preparations of beneficial microbes.
Postbiotic ingredients include lysates (microbial cells are broken open to release cell contents) and tyndallised microbes (heat-killed probiotic microbes). These are not living microbes, but they can still provide benefits for skin and its microbiome. These benefits include calming the immune system, defending from pathogens, and improving barrier function.
Postbiotic ingredients are easier to include in products than live probiotics and therefore most microbiome skincare products would opt to include one of these types.
Prebiotics are substances that promote the growth of beneficial microbes. So, they don’t contain microbes or any parts thereof, but they support a healthy microbiome by increasing populations of good microbes.
Preservatives exist in a product to stop the product from spoiling – that is, to stop microbes from growing in it. So, preservatives kill microbes or inhibit their growth. That’s what they’re meant to do in a product, so it isn’t a problem when the product is on a shelf. However, that product must then be applied onto skin. This is where the problem begins. If the product contains harsh preservatives like parabens or phenoxyethanol, they will continue to inhibit and kill microbes after application, which may damage the skin microbiome – the last thing we want is to kill the microbes that are helping us. For this reason, a product that truly cares for the skin microbiome uses as mild a preservative system as possible. Synthetic preservatives also have other potential problems, such as links to allergies and hormone disruption.
The modern skincare industry has a problematic relationship with skin’s natural oils. There is a tendency to remove them with harsh cleansers, as if they are somehow the enemy. It’s common to use harsh surfactants like Sodium Laureth Sulfate, Sodium Lauryl Sulfate, and other sulphated surfactants in cleansers. These foaming agents are known irritants and they damage the skin barrier. They also strip the natural oil (sebum) off skin, which isn’t a good thing, as sebum is important for barrier function and a balanced skin microbiome. The average person has become accustomed to foamy cleansers, often assuming that they are necessary to achieve clean skin. This isn’t the case. It’s possible to make cleansers containing mild (or no) surfactants, which aren’t as foamy and don’t strip sebum as aggressively. Sebum is an important nutrient source for microbes, so a good microbiome skincare product won’t strip it with very foamy products.
The microbes in a healthy skin microbiome rely on sebum. This complex oil mixture acts as the perfect nutrient source, feeding beneficial microbes while killing harmful ones. Mineral oils, petrochemicals, and other occlusive oils form a layer on the skin’s surface, which signal the presence of oil here, so skin reduces sebum production. These occlusive oils are not a useful nutrient source for beneficial microbes, and they produce other nasty side effects. This is an undesirable outcome for the microbiome because the production of their valuable nutrient source is threatened. It’s also an undesirable outcome for the healthy function of your skin because sebum is a key part of the barrier, being necessary for retaining moisture.
Skin is a very selective environment. It’s a microbial ecosystem, but it doesn’t want just any microbes to grow there. It only supports the growth of a very specific group of microbes – the ones that evolved with our skin. The “familiar friends” that help skin work better. One way that skin keeps the right kind of microbes is by producing acids. Keeping the skin environment acidic makes life difficult for the wrong types of microbes, but those familiar friends can handle it – they’ve been dealing with the acidic environment for a long time. If a product supports a healthy microbiome, it should support the healthy pH of skin – somewhere between 4.5-5.5.
A good microbiome skincare product can achieve all these using natural and organic ingredients while being effective.