More and more hygiene products claim to be “microbiome friendly,” but how essential is our skin microbiome, and can an unbalanced bacterial community lead to skin disorders like eczema and dryness?
Each of us is seeded with trillions of bacteria cells that live and grow on our skin from the moment we are born. Our skin microbiome is made up of these cells. Each person’s microbiome has a unique makeup, and as we travel through life meeting new people, engaging with different settings, adopting different lifestyles, and changing with age, so does the diversity and health of our microbiome.
Our skin microbiota can adjust to something as easy as leaving the house. Living with someone can do the same thing, to the point that two people’s microbiomes become so entwined that computers can correctly identify cohabiting couples only by looking at their microbiomes.
Dr Martin Kinsella, a cosmetic doctor and skin specialist, states, “The skin microbiome is a natural ecology of bacteria that dwell on the skin.” “It works to protect the skin from hazardous pathogens to the point where a healthy immune system is built on the foundation of a well-functioning skin microbiome.”
The microbiota thrives on the salt, water, and oil (sebum) that we produce naturally when they colonize our skin. This helps to maintain the delicate balance of our ecology. When a virus comes into contact with a healthy microbiome, it gets crowded out and is unable to colonise the skin. Antimicrobial substances and nutrients are produced by our microbiome as a sort of defence.
If our skin is our first line of defence against viruses and harm, our microbiome is the armour that protects us.
Studies have identified associations between babies born through caesarean section, which means they don’t come into contact with vaginal microorganisms during birth, and increased cases of allergies and asthma later in life, indicating this protective nature. Skin-to-skin contact has been named a fundamental component of Unicef’s birthing criteria, citing the practice’s ability to “allow colonisation of the baby’s skin with the mother’s friendly bacteria, therefore offering protection against infection.”
The delicate balance of the microbiome can be thrown off-kilter when this protection is impaired by damage or the presence of dangerous microorganisms. Dry skin, eczema, acne, and psoriasis have all been linked to a microbiome imbalance, and the Skin Microbiome in Healthy Ageing (SMiHA) network estimates that half of the UK population suffers from a microbiome-related skin complaint each year.
“The chemicals in skin care products can upset the delicate balance of oil and bacteria in the skin’s natural microbiome,” Kinsella explains. “Antibacterial agents, as well as other cosmetics containing harsh chemicals that disrupt the skin’s natural pH balance, play a key role in this.”
This was demonstrated at COVID-19, where researchers discovered that “changes in microbial flora” produced by higher sanitiser use were connected to an increase in skin damage. Antibiotics and medications have been demonstrated to kill healthy microorganisms on the skin, making it more susceptible to infection. Acne and dandruff are two examples of skin conditions that can indicate an unbalanced microbiota.
When the microbiome is out of balance, it can’t properly protect against new harmful bacteria, creating a vicious cycle. Nasty bacteria causes eczema, which causes the skin to become inflamed. Patients scratch their skin, further injuring it and allowing more bad bacteria to enter.
“More severe eczema and dry skin have been related to an abundance of a bacteria called as Staphylococcus aureus,” says Kate Porter, founder of skincare brand Harbour. There’s some evidence that lowering S. aureus and restoring a more diversified microbiome population can help with eczema symptoms. However, it’s a case of chicken and egg. Is it the imbalanced microbiota that causes these problems, or is it the other way around?”
As we become older, our microbiome changes even more. This shift is linked to both external and internal changes, such as wrinkles, dark patches, and dry skin. According to one school of thinking, our skin’s ability to shield us from UV radiation decreases as our microbiome changes with age. As a result, we are more susceptible to skin cancer.
Recent research has found that the skin microbiome is a better predictor of chronological age than the gut microbiome. According to this notion, a person’s microbiome might be utilised to predict life expectancy, at least in theory. The SMiHA team notes, “Aging has a tremendous influence on the skin microflora in terms of both species and numbers.” “As a result, human skin is a good system for determining how microbiome changes influence biological age.”
That isn’t to argue that disruption to our skin’s ecology is the only cause of such disorders and diseases — genetics and lifestyle play important roles, too – but it is a contributing element. Modern hygienic practices, such as daily showers, are thought to play a part. The use of harsh skin care products is frequently implicated. Researchers from Finland discovered a link between the rise in allergies and atopic diseases and the loss of biodiversity in metropolitan areas.
However, because common items have been linked to disturbing the microbiome, a growing number of firms are developing products infused with prebiotics, probiotics, and postbiotics to counteract this disruption.
While probiotics are ‘friendly’ bacteria, and prebiotics are the foods that feed them, postbiotics are the byproducts of the process. The benefits of topical probiotic and prebiotic skincare are still up in the air, owing to the early stages of research and the fact that using live bacteria in cosmetics is a regulatory stumbling block, while postbiotics in skin products are already prevalent.
Lactic acid, for example, is a by-product of the fermentation of a probiotic called Lactobacillus, which is found in over-the-counter cosmetics. It has been proved to moisturise, decrease the effects of ageing, and calm redness when used topically.
Microbiota transplants may also be a solution to skin disorders, according to researchers. An excess of S. aureus in the microbiomes of persons with atopic dermatitis was replaced with a bacteria known as Roseomonas mucosa in one study published in the journal JCI Insight in 2018, “with significant improvements in indices of disease severity, and topical steroid use.”
The problem with almost all of these studies, however, is that the skin microbiome’s underlying mechanisms are largely unknown, and its significance is debatable. For every study that finds a link between C-section deliveries and reduced immunity, there is research that either fails to discover the same correlations or finds statistically irrelevant associations.
“We believe the skin microbiota is healthy when the skin is healthy, but we don’t know for sure,” the SMiHA team explains. “We still have a lot of learning to do when it comes to manipulating the skin microbiota with common items.”
“As consumers, we like to be able to link a specific component in our skincare to a specific result,” Porter continues, “yet our microbiota is influenced by a variety of things.” “Because the microbiome varies so much between people, it’s difficult to change it for the better with just one thing.” There isn’t a single optimal way to change things.”
Initiatives like the Skin Trust Club have recently begun collecting samples from the general population in order to learn more about our skin’s health and inner workings. Researchers are also looking at the impact of antibiotics on the skin microbiota in order to see if we can reduce antimicrobial resistance.
However, it is considerably easier said than done.
The SMiHA team concludes, “There is a big commercial drive to research how to improve skin using a microbiome-targeted strategy.” “However, distinguishing the impacts of topical products on the microbial population and skin cells – in a way that allows us to unequivocally claim that microbial targeting leads to healthier skin – is a difficult task for the scientific community.”