The most noticeable signs of aging that we can see with our own eyes happen on our skin. As we get older, the structure and function of our skin begin to change, and this can come from “intrinsic” and “extrinsic” factors.
Intrinsic factors that cause aging come from things like hormonal, metabolic, or immune system changes. Extrinsic factors like regular exposure to sunlight, smoking, and certain temperatures can trigger immune processes that impact the skin’s structure and rejuvenation.
But that’s not all. As the body’s largest organ, the skin provides protection from the outside environment. And even though you can’t see them, bacteria, fungi, and viruses all make their home on the skin.
All of these different factors contribute to skin changes–like more wrinkles, decreased elasticity, impaired barrier function, and bruising more easily–as we age. But according to one new study, how your skin ages actually comes down to just one surprising thing.
The Skin Microbiome
As Medical News Today explains, commensal microbial communities on the skin are known as the skin microbiome. They don’t cause disease, though. They can actually benefit the body. While some of these communities can be fixed, others exist on the skin temporarily.
There’s an intrinsic connection between the skin microbiome and your immune system, as well as your gut. Your skin microbiome interacts with your immune system and can impact its function. At the same time, your immune system regulates the makeup of your skin microbiome.
Your skin microbiome is linked to gut health through the “Gut-Skin Axis,” which gut health expert Carla Oates says is “super important” for people to understand.
“The gut and skin enjoy a constant dialogue via what has become known as the gut-skin axis. While it might not sound very glamorous, the gut is where 70 percent of our immune system lies,” Oates told Byrdie.
“It’s where we make nutrients, metabolize hormones and detoxifying enzymes, neutralize pathogens and make neurotransmitters—so it’s super important to get your digestive health in check in order to feel well and of course, experience clear, glowing skin.”
The Skin Microbiome And Aging
Aging can cause the skin microbiome to change, which was already known in the medical community. But, everyone’s skin ages differently, and the details as to why are unknown.
A team from NIZO Food Research in the Netherlands set out to determine if there is a connection between skin aging and the body’s cellular processes (co-metabolism), genes, or bacterial functionalities.
That study, which was recently published in the journal PLOS One, determined that how your skin ages could come down to one surprising factor–bacteria.
“[The study] went one step beyond what we already knew,” explained Dr. Dina F. Bierman, a board-certified dermatologist at Providence Saint John’s Health Center, told MedicalNewsToday. “They separated the population based [on] how their skin had aged. […] Making that distinction is very important, in terms of understanding how the bacteria and their presence are influencing the skin and the metabolic processes that influence aging.”
What Affects The Composition Of The Skin Microbiome?
Previous studies have indicated the skin microbiomes of all humans do generally have one thing in common–they contain certain species of Staphylococcus, Cutibacterium, Corynebacterium, and Acinetobacter bacteria.
However, many things affect the composition of an individual’s skin microbiome. Most notably, age, body area, gender, and geographic location. Researchers have known for a while that there is a relation between the makeup of the skin and aging. But, until this latest study, they hadn’t been able to understand the mechanisms behind those changes.
The study, which was partially funded by Estée Lauder, began with researchers combing through existing scientific literature. The goal was to try to “identify common biologic pathways between humans and skin microbes linked to intrinsic skin aging.”
Next, they tested cheek samples from 25 female participants in two age groups—one aged 20-28, the other aged 59-68—who had experienced various age-related skin changes. They used these samples to confirm the changes in participants’ skin microbiome composition that researchers saw in previous studies.
The study excluded participants who suffered from skin conditions like acne, eczema, and psoriasis. They also excluded anyone who used skin medications within one month of the study, those with a history of smoking, those who drank more than three servings of alcohol per day, and those who regularly tan or sunbathe.
More Research Is Needed
The study concluded that bacterial pathways linked to skin aging were related to ceramide production. Ceramides are lipids that compose the natural skin barrier, fatty acids, and pigmentation.
Researchers also determined that an accumulation of glycation of collagen and elastin end products can cause skin elasticity and sagging.
However, the study was very small and lacked diversity, which could have affected the findings. Dr. Bierman told MedicalNewsToday that ultimately, more research is needed.
“A lot of research [is needed] before we can actually, for sure, say what the different bacteria are doing and how they interact with each [other], too, and might influence how our skin ages,” she said.