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The Skin Microbiome: A Brief Introduction

The “Micro” What?

We all have that friend who, seemingly every month, announces their new miracle diet. They use language like: “this new [insert trendy diet here] has absolutely changed my life in only 4 days!” 

This friend is constantly sharing (unsolicited) advice about the perfect diet for your body type that is guaranteed to help you lose those last 5lbs you never remember saying you wanted to lose, but OK.

This friend has also probably thrown the word “microbiome” around in casual conversation, to which you scoffed and chalked it up to yet another fad diet term… 

You may be utterly shocked to hear that your “fad friend” is onto something big! The microbiome has been a massive question mark in the scientific community for years. Only in the past decade have researchers acquired the technology necessary to study the function and interconnectivity of the microbiome and how it impacts our health. In brief, the “microbiome” is a big deal, especially the skin microbiome as it pertains to skincare and skin health restoration.

What is a “Microbiome”?

Remember learning about ecosystems in environmental science class? Yeah, us either. Let’s refresh our memories. 

An ecosystem is the symbiosis of living and nonliving things in a specific geographical location. Biotic factors are the “living things” in an ecosystem, which include plants, animals, and organisms. Abiotic factors are the nonliving factors in an ecosystem, which include things like soil, temperature, humidity, and more. 

Why this walk down memory lane? 

Well, your microbiome is the ecosystem of your body. Your microbiome comprises the microorganisms that cohabitate on and in your body, living either in harmony or discord with your individual biology. 

Yes, you read that correctly. At any given moment, with a high tech microscope you could observe microorganisms living on and in your body. A little freaky, but let’s go with it for the sake of science, OK? 

Every single individual living on planet Earth has a unique microbiota composition, just as we each have a unique genetic code. These microbiota include bacteria, fungi, viruses, archaea (single cell organisms), and they thrive in various locations throughout your body. 

Gut, oral, and vaginal microbiota have had more attention over the years, but recent discoveries in the microbiology field have brought the skin microbiome into the spotlight.

What is the Skin Microbiome?

The skin microbiome is the skin’s ecosystem. In just 1 square centimeter of your skin, there are an estimated 1 billion bacteria that live on the epidermis and deep into the dermal layer alongside the sebaceous glands. 

The lifecycle of a skin cell lasts approximately 28 days (this cycle varies depending on age and other factors). New skin cells are developed in the basal layer of skin, rising up through the dermis and epidermis as they mature and eventually die. The outermost layer of your skin is technically a thick layer of dead skin cells, which is sloughed off through natural or physical processes (think, exfoliators or retinol). 

This lifecycle of a skin cell is important to note because the skin’s microbiome is composed of two different types of microbiota: resident microbes and transient microbes. Resident microbes are the microorganisms that routinely live in the layers of skin and renew themselves throughout the desquamation process (the shedding of dead skin cells). Transient microbes, on the other hand, are “temporary” microorganisms that arrive on the skin as a result of environmental factors and remain on the skin for a short period of time. 

Current research has identified approximately 1,000 species of bacteria living on the skin. The species of bacteria vary based on location (the back, the groin, the legs, etc.), the internal health of the individual, and an array of environmental factors (skincare routine, pollution levels, various fabrics, etc.). While bacteria often carries a negative connotation, you may be surprised to hear that not all bacteria is bad, in fact, some bacteria actually helps to keep your body functioning at optimum levels. 

What Does the Skin Microbiome Do?

A balanced skin microbiome ensures healthy skin function including sufficient hydration, exfoliation, and protection against environmental assaults. A healthy microbiome can also improve the appearance of the skin by reducing acne breakouts and various forms of inflammation. 

But, that’s not all! The skin microbiome has also been found to communicate with immune cells, which expands the impact of this ecosystem to many other key bodily functions including: preventing infection, controlling inflammation, and countless “housekeeping” tasks like wound healing and reducing exposure to allergens.

Prevents Harmful Infection

When the skin microbiome is in perfect accord, good bacteria can effectively ward off pathogenic organisms that cause infection. 

Since the skin is your largest organ, there is a lot of opportunity for pathogenic organisms to infiltrate the skin barrier and weasel their way into your vital organs. Protecting the skin microbiome is crucial to ensure your body’s first line of defense is in tip-top shape for the ultimate protection. 

Controls Unnecessary Inflammation

An out of balance skin microbiome sends SOS signals to your body’s immune cells. As a result, your immune system releases antimicrobial peptides (AMP’s), which help to smooth things over. 

Sometimes a microbiome imbalance has due cause and inflammation is necessary to protect the body from harmful pathogens; other times, a microbiome imbalance results from mild alterations to the diversity of microbiota including over sanitizing, shifts in diet, harsh skincare ingredients, and more.  

A healthy and balanced skin microbiome ensures unnecessary inflammation, triggering your body’s inflammatory response only if absolutely necessary to properly heal the body.

Various “Housekeeping” Tasks

The skin microbiome also has a variety of maintenance functions including: 

  • Healing minor wounds and abrasions
  • Reducing the body’s exposure to common allergens
  • Decreasing the chances of oxidative stress

While these “housekeeping” tasks seem minor in comparison to larger functions like controlling inflammation and preventing infection, they are crucial to maintaining biological harmony.

How Does Skin Microbiome Research Impact Esthetics?

Microbiologists and dermatologists are buzzing with excitement at the latest developments regarding the skin microbiome.

Researchers found massive alterations in the skin microbiome, particularly during flare ups, indicating a dysbiosis in the skin’s microbiome. In addition, recent studies found that children who hand wash dishes had greater microbial diversity than children who use a dishwasher. The result of healthy microbial diversity from hand washing dishes resulted in a reduction of allergic disease development compared to children who used a dishwasher in their household. Crazy! 

This is only the beginning

Skin microbiome research is truly in its infancy. We are living in an exciting time where trailblazing research is radically changing the fields of microbiology and dermatology daily. As a result, we are witnessing changes to how we perceive skin health and how we treat skin conditions.

NOW is the time to pursue your passion for skincare and esthetics. 

At Avenue Five Institute, we offer a hybrid esthetics program with online learning and hands-on experience from licensed esthetics instructors. Whether you desire to work in a spa, at a dermatologist’s office, or at a laser clinic, you can become a professional esthetician in as little as 6 months. 

As a part of our curriculum, you will dive into topics including: skin analysis, general anatomy, physiology, chemistry of the skin, ingredient analysis, and more. Visit our esthetics program page to learn more about our program offerings and upcoming program start dates. 


May your skin microbiome forever be healthy, balanced, and full of lots of good bacteria!