News flash: we’re not alone. No, really: we have trillions of microorganisms living in and on our bodies. So many, in fact, that scientists estimate that only one to ten percent of the DNA we carry around is actually human.

Though the vast majority of this microbiome resides within our gut, many of these tiny organisms inhabit the miniscule nooks and crannies of our skin. An increasing body of research is shedding light on just how much of an impact these tiny microbes have on our skin health. Here’s everything you need to know about your skin microbiome.

What exactly is the microbiome?

Much like your fingerprint, your microbiome is unique to you. Initially, the microorganisms living in and on your body are passed on from your mother, while the remainder are picked up from whatever in the world you encounter: your food, your phone, your bathwater — even your family, friends and pets.

If you’ve already got a case of the ew’s, consider this: though some of these critters can be harmful, we can’t live without our microbiome. Scientists classify these organisms into three categories:

• Commensalistic: microbes that benefit from humans but don’t affect us
• Mutualistic: organisms that help us, and vice versa
• Pathogenic: microbes that can cause disease

We now know that having a balanced microbiome — that is, keeping each species at optimal levels — is essential for human health.

What makes up our microbiome?

Without getting too technical, there are a handful of different types of organisms that comprise the microbiome, including bacteria, viruses, and fungi — oh my.
The exact makeup of each person’s microbiome is dependent on factors like:

• Age
• Nutrition
• Lifestyle
• Hormones
• Inherited genes
• Overall health
• Environment

How does the microbiome affect skin health?

Most of the microorganisms living on our skin are bacteria, with a smattering of fungi and viruses. Scientists estimate that there are somewhere around 1,000 different species of bacteria living on our skin. On a microscopic level, our largest organ is a bit like a desert: dry (and acidic) — but dotted with oases (aka your oil-plentiful hair follicles) that are teeming with non-human life. Microorganisms that live in certain areas of your body — like your face, feet, or underarms — are adapted to variations in things like sweat, water, and oil levels.

In recent years, researchers have discovered a complex relationship between bacteria, skin cells, and our immune system. It’s now clear that our skin microbiome plays a key role in many skin functions, including:

• Training our immune system
• Reinforcing and repairing the skin barrier
• Boosting protection from infection
• Regulating inflammation

Does the microbiome affect skin conditions?

This is an emerging field of science, but many new studies suggest that the microbiome falling out of balance — a condition known as dysbiosis — may contribute to a variety of skin concerns. It’s not clear at this time whether dysbiosis is the cause or the result, but researchers are looking into links between the microbiome and all of these common conditions:

• Acne
• Keratosis pilaris
• Rosacea
• Eczema
• Psoriasis

Evidence of a connection between the gut microbiome and the skin microbiome — known as the gut-skin axis — has been trending lately. Scientists are also investigating whether other organs, like the brain, may also have a microbiome — and how these organisms may all interconnect.

How to keep your skin microbiome healthy

According to SLMD Skincare founder Sandra Lee, MD (aka Dr. Pimple Popper), keeping skin healthy and balanced isn’t complicated. Here are her top tips:

• Cleanse twice a day. Washing your face with a gentle exfoliating cleanser that’s formulated for your face will help remove excess oil and dead skin, without stripping natural moisture. Try: SLMD Salicylic Acid Cleanser
• Moisturize. Even oily and acne-prone skin needs moisturizer to prevent transepidermal water loss (TEWL) that can weaken the skin barrier. Try: SLMD Facial Moisturizer
• Use treatments wisely. Targeted solutions are great, but don’t overdo it. Too much exfoliating, masking, or mixing of active ingredients can do more harm than good. Try: SLMD Retinol Resurfacing Serum, AHA/BHA Swipes
• Wear sunscreen. UV rays cause DNA damage and inflammation, which can leave skin susceptible. Use a broad-spectrum sunscreen daily. Try: SLMD Dual Defender
• Make healthy choices. Eating a balanced diet, exercising, managing stress, and getting a good night’s sleep all help keep your microbiome happy.