How Stable Is Your Skin Biome?
By Brian Stanton
Change isn’t easy. Starting a new career, a new relationship, even a new skincare routine: all these things take effort.
Why do we so often resist this effort? Because we are, as they say: creatures of habit.
We are not, however, the only creatures of habit around town. Colonizing our skin, invisible to the naked eye, are trillions of microorganisms known as the skin biome. And like us, these skin-dwelling critters tend towards stability.
At least, in certain conditions they do. Sometimes, for one reason or another, the composition of the skin biome changes — and these changes may affect your skin health. For better or worse.
Let’s plant a flag there for later. But first, let’s review a 2016 study called “Temporal Stability of the Human Skin Microbiome” published by Julia Oh and her colleagues in the journal Cell. Skin microorganisms, according to this research, may be more stable residents than you think.
Stable Skin Biomes
Here’s the study design. The researchers sampled skin from 12 healthy people across 17 skin sites, then measured shifts in skin microbes over short (1-2 months) and long (1-2 years) time intervals. The punchline? Skin biomes, despite exposure to numerous environmental factors, remained relatively stable over time.
Let’s go a little deeper. In a prior study, researchers identified humans solely by the genetic signature of their skin microbes. This study took things a step further, suggesting that, like a fingerprint: the skin biome of a healthy person remains part of their identity over time.
Is microbial stability the rule? Even at skin sites like the palm? I mean, think about your palm. It’s constantly in action making contact with myriad things — soap, dirt, food, saliva, and whatever else you happen to touch throughout the day. Because of this, you’d expect palm microbes to change drastically over time.
Yet surprisingly enough, palm microbes did not change drastically in the 12 individuals studied. Instead the colonies maintained their basic genetic fingerprint.
By now you’re probably wondering what kind of microbes we’re talking about — so let’s cover that now.
Common Skin Dwellers: P. Acnes and S. Epidermidis
If you sampled your skin, two of the most common bacteria you’d find are Propionibacterium acnes (P. acnes) and Staphylococcus epidermidis (S. epidermidis). These bacteria can either be commensal or pathogenic — good or bad — for your skin. It depends on the strain.
For instance, many strains of P. acnes cause acne. Obviously that falls into the “bad” category. Yet good or bad, skin colonies of both bacteria, Julia Oh and colleagues showed, stayed fairly stable over time.
But just because 12 people had stable skin biomes, it doesn’t mean your skin biome can’t, under any circumstance, change.
What Shifts the Skin Biome?
The skin biome, it’s true, can shift. Large bacterial shifts, in fact, have been linked to skin disorders like atopic dermatitis. This is, however, a chicken and egg situation- hard to say if the shift causes the disorder or the disorder causes the shift.
Environment matters too. In one study, researchers followed seven families over six weeks, measuring the interaction between their skin biomes and home environments. They found, as expected, that people receive and share microbes from these indoor settings. Translation: where you live affects your skin bacteria.
So does nutrition. Remember P. acnes? Well, it turns out that B12 supplementation can promote the growth of this acne-causing bacterium. But only in a subset of individuals.
Finally, antibiotics can affect the skin biome. Antibiotics are often used to treat acne, but these drugs are becoming less effective by the day. Plus most antibiotics don’t differentiate between good and bad bacteria.
There is, however, promising research on a topical probiotic — a lotion containing the lactic-acid producing bacteria, E. faecalis — for reducing acne lesions. Researchers believe that good bacteria from the lotion may “crowd out” bad bacteria like P. acnes, and may be a safer acne treatment option than antibiotics.
Bottom line? Even though the skin biome tends towards stability, many things — skin disorders, environment, diet, and drugs — can provoke shifts in these resident bacteria.
Change Can Be Good
Change isn’t easy for you, me, or skin bacteria. We’re creatures of habit — and, like us, the skin biome often stays stable across time and environment.
But your skin biome isn’t set in stone. Changing your diet, environment, or skincare regimen can change these microbes. And these changes likely influence your skin health.
This is such an exciting area of research. Keep checking back — right here — for the latest.
Brian Stanton is a professional health and science writer. His job, in other words, is to translate complex science into simple English.
Related reading: How Differences In Skin Bacteria May Affect Skin Health
Related reading: The Future is Here: The Rise of the Microbiome