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The gut gets the majority of the attention when we talk about the microbiome (even though your mouth has a vast microbiome as well!). The digestive system is home to trillions of organisms that can affect the body, but it is definitely not the only place these bacteria exist.
What Is a Microbiome?
Microbiome has become a household word! It refers to the mix of bacteria, yeasts, and parasites that live on your skin, in your nose and trachea, and in your gut from your mouth to your anus. The mix of those bacteria, yeasts, and parasites is closely linked to weight, mental health, autoimmune health, blood pressure, diabetes, heart disease, and even cancer.
Our bodies are ecosystems that harbor a microbial universe. Each of us has approximately 10 trillion human cells, 100 trillion bacteria, yeasts, and single cell protozoa (representing thousands of different species), and 1,000 trillion viruses in and on our bodies.
Scientists now consider the microbiome an important organ that helps us maintain the necessary metabolism to keep the chemistry of life running as effectively as possible. If properly tended, our microbiome can keep us lean, joyful, and pain free. But when our metabolism malfunctions, too many free radicals are made, inflammation increases, and our chemistry falters, leading to ill health.
Recent research shows that we may have an equally diverse and important microbiome in other parts of the body such as in the mouth and on the skin.
What Is the Skin Microbiome?
A microbiome is simply the collection of microorganisms in a particular place. The gut microbiome is the entire collection of microorganisms in the gut, and similarly, the skin micrombiome is simply all of the organisms present on the skin.
The term “microbiota” is also used to describe these organisms and specifically means: “the ecological community of commensal, symbiotic and pathogenic microorganisms that literally share our body space.”
Because research is proving the importance of the gut microbiome, many of us now understand how important it is to consume probiotic rich foods, and why overuse of antibacterial soaps is a bad idea for gut health. It turns out that these same factors also affect the microbiota on our skin and protecting it may be just as important!
In fact, most skin problems (from acne to eczema) likely affect the skin microbiome and may be a result of changes to this ecosystem due to modern lifestyle.
The Assault on Skin Microbiota
Our modern lifestyle assaults our gut microbiome through antibiotic overuse, consumption of foods that disrupt gut flora, and overuse of antibacterial products. These same factors can alter the bacterial balance on the skin and may be even more damaging!
The skin is under constant assault from environmental agents, harsh cleansers and soaps, deodorants, and even medications and cosmetics. Our obsession with cleanliness may be doing more harm than good for microbiota balance on the skin.
Like the gut, the skin is home to over a trillion organisms at any given time, including thousands of species of bacteria as well as viruses and fungi. (source) These all serve a purpose and are important for proper balance. Like the gut, when the balance is altered, it can create problems.
SALT: Skin Associated Lymphoid Tissue
Skin was once thought to be just a physical barrier from the outside world, though the existence of skin-associated lymphoid tissue shows that it is much, much more. I find these lymphocytes absolutely fascinating. Here’s why:
Researchers estimate that these lymphocytes exist on the skin in a 1:1 ratio with bacteria. The theory is that these immune cells are capable of sensing and dealing with a great deal of bacteria on their own. They also communicate with lymph nodes within the body. These lymph nodes carry immune signals to the rest of the immune system and help determine the body’s appropriate response. (source)
In short: your skin contains trillions of lymphocytes that are like soldiers protecting your body’s perimeter and radioing in information about approaching attacks to the main base (your immune system).
The Skin Microbiome Starts Before and During Birth!
A healthy skin microbiome appears to begin during and shortly after birth with a flurry of immune activity. Unfortunately, many of the modern practices surrounding birth may have a dramatic and unfortunate impact on gut bacteria.
Researchers at the University of California San Fransisco found that an important part of the skin microbiome is established within days of birth. Mainly, that within days of birth, there is a large amount of T-cell activity that creates tolerance in the immune system to the bacteria on the skin. This is a critical factor in the immune system knowing not to attack the normal and healthy bacteria on the skin.
Unfortunately, the wide use of antibiotics for mom during labor (and for mom and baby after birth) may have some big unintended consequences.
“One major clinical implication of this study is giving antibiotics to a child in early neonatal life is likely a disservice because this will limit the amount and type of bacteria that is seen by the adaptive immune system and this could be linked to the development of autoimmune, inflammatory skin diseases later in life,” said Rosenblum.
Logically, this could be part of the reason we are seeing a rise in skin related disorders and why the research in the movie Microbirth is even more critical! The research indicates that if this window is missed, it is difficult or impossible to recreate as an adult. (This is also a good reason to hold off on a first bath for the first few days of a baby’s life!)
Here’s the full text of the study if you want to read it.
Gut and Skin Microbiome Interaction
No part of the body’s microbiome exists in a vacuum, which is why it is important to continue to understand the different parts of the biome and how they interact. As the study above indicated, the skin is home to trillions on lymphocytes that interact with the rest of the immune system via lymph nodes. Just like the bacterial organisms in the gut, they comprise a valuable part of the immune system.
This also gives reason to rethink the overuse of antibacterial and antimicrobial soaps on the skin.
Are We Too Clean?
I’ve posted before about the importance of “good clean dirt” and how most of us aren’t getting enough of it. This new evidence suggests that our obsession with being “clean” may come at a big price for our microbiome.
Dr. Kara Fitzgerald explains:
A robust skin microbiome protects against infection or dysbiosis in much the same way a good gut microbiome does, by colonization resistance (i.e. crowding out overgrowth of pathogenic organisms) and by maintaining relatively acidic environment (pH is around 5.0), which inhibits growth of pathogens. Staphylococcus epidermidis, a major commensal bacterium, produces phenol-soluble modulins that inhibit pathogens such as S. aureus and Group A Streptococcus. Commensals can also inhibit inflammation through cross-talk via Toll-like receptors 2 and 3, and stimulate production of antimicrobial peptides such as cathelicidin, which can kill bacteria, fungi and viruses.
The microbiome aids in wound healing, limits exposure to allergens and UV radiation, minimizes oxidative damage and helps to keep the skin barrier intact and well-hydrated.
Rather than thinking of the skin as a complex microbiome to be nurtured and protected, we often think of it as a static surface that needs to be clean. Over the long term, this may have a negative effect on skin health and even the immune system!
How to Nurture Your Skin Biome for Healthy Skin
While the bad news is that we don’t seem to have a good way to encourage proper immune system and skin bacteria interaction after the important newborn window, there are some things we can do to encourage a healthy skin biome in older children and adults.
Don’t Be Afraid to Get Dirty
It may sound crazy, but in today’s world, we just don’t get enough dirt… or soil based organisms to be precise.
Think about this… for most of human history, we worked outside or interacted with the outdoor world in some way each day. Food came from the ground and while it may have been rinsed, it wasn’t “washed” and it certainly wasn’t irradiated like many foods are today. Through these interactions with the soil, we came in contact with soil based organisms (SBOs) that are natural strains of probiotics found in the gut and on the skin.
Now, we are deficient in dirt and don’t come in contact with these beneficial organisms enough. Heck, we don’t come in contact with anything dirty regularly.
Sure, we could take a probiotic supplement, but most of them don’t have the same strains of bacteria. Unless they are SBOs (also known as spore-forming bacteria) they may not survive the harsh environment in the stomach and upper digestive system to get to the small intestine.
What I do: I make sure to spend time outdoors doing activities like gardening and camping to get natural exposure to a variety of soil based organisms. I also take a probiotic with a wide variety of soil based organisms.
Use a Skin Probiotic
Many of us take probiotics but few of us have ever thought of using a skin probiotic. I’ve experimented with this before by using a probiotic face mask made from yogurt, and noticed good results on my skin. Lately, I’ve also been experimenting with a probiotic skin line that has made my skin softer and not as oily.
Mother Dirt has a line of soaps, shampoo, and a body mist that are designed to not interfere with the body’s natural biome and to help restore the natural microbiome. So far, I’ve found them to work very well.
Avoid Antibacterial Soaps & Choose Biome Friendly Soap
Avoiding antibacterial soaps is as important as using products that support the skin’s natural microbiome. Triclosan, one of the most-used antibacterial ingredients in soaps, was recently banned, but others are still used.
At our house, we avoid antibacterial soaps and make or use natural soaps instead. I always keep natural liquid castile soap on hand since it is very versatile and works for over a dozen household uses.
There are also soaps and shampoos (like these) that are designed to not interfere with the skin biome. The Mother Dirt product contains ammonia-oxidizing bacteria (AOB) that research suggest may help restore healthy skin bacteria. (Cool fact- the majority of people who used these products found they could use fewer skin products and many stopped needing deodorant at all!)
I’ve written about the benefits of homemade soap on several occasions, and have even created several of my own recipes. You read more about those here.
Think About The Laundry
You may not be able to get pregnant by doing laundry together (as the old joke suggests) but it seems you can certainly exchange some microbiota that way. It’s crazy to think about, but you may share some of the skin bacteria with those in your household through the laundering process:
The laundering process caused a microbial exchange of influent water bacteria, skin-, and clothes-related bacteria and biofilm-related bacteria in the WM. A variety of biofilm-producing bacteria were enriched in the e?uent after laundering, although their presence in the cotton sample was low. Nearly all bacterial genera detected on the initial cotton sample were still present in the washed cotton samples. A selection for typical skin- and clothes-related microbial species occurred in the cotton samples after laundering. (source)
In other words- laundering clothes may make them smell better, but it won’t kill the bacteria they contain. The study also found that natural fiber like cotton, linen and hemp seemed to hold a more natural balance of bacteria while synthetic fibers harbored bacteria that were out of balance with the normal skin ecosystem.
TIP: If anyone in your family struggles from skin issues, it may be worth addressing the bacteria found in washing machines and clothes. Drying clothes in the sun, even just a few times, may reduce or balance the bacteria naturally.
There is also evidence that sweat may contribute to healthy skin bacteria by serving as a prebiotic. Considering the other benefits of sweating (through exercise or sauna use), this one is an easy thing to add with a lot of other benefits as well.
Our skin microbiome would love it if we could ditch the harsh synthetic and antibacterial skin products and stick to ones that naturally protect and replenish the skin’s natural bacterial balance.
This article was medically reviewed by Madiha Saeed, MD, a board certified family physician. As always, this is not personal medical advice and we recommend that you talk with your doctor.
Did you know all this fascinating info about the skin microbiome?