You might have noticed it yourself-how a heavy, sugary meal can lead to breakouts the next day, or how certain food allergies can trigger rashes. The connection between gut health and skin conditions is increasingly recognized, leading to a growing interest in the "gut-skin axis." This article explores the intricate relationship between your gut and your skin, how imbalances in one can affect the other, and what you can do to promote a healthy gut and radiant skin.
Understanding the Skin Microbiome
The skin is the largest organ in the human body and serves as a living barrier between our body and the environment, protecting our inner organs and tissues from pathogens, toxins, and other environmental assaults. It helps regulate body temperature and interacts with the immune system. Beyond these functions, the skin is home to a dynamic and diverse ecosystem of microbes. The human skin serves as the first line of defense against environmental factors, and the vast diversity of bacteria, fungi, and viruses that dwell within the skin’s surface are a critical part of that defense. The skin microbiome-that collective community of microorganisms within the skin’s surface-is essential for maintaining skin barrier function.
Factors like age, diet, hygiene, and clothing may impact the skin microbiome. Frequent washing with harsh soaps can disrupt the skin’s natural microbiome, stripping away beneficial oils and microbes. The skin is colonized by a diverse community of microorganisms - including bacteria, fungi and viruses - as well as mites that evolve throughout life. Most bacteria on the skin are aerobic, meaning they thrive in oxygen-rich environments-unlike the ones from gut microbiome. The distribution of these microbes varies depending on the body part (hand vs. armpit) that differs of skin type whether it’s oily, dry, or moist. As we age, the composition of the skin’s microbiota changes. During puberty, for instance, bacteria associated with oily skin increase. In adulthood, the skin’s microbial community stabilizes, even though it continues to be influenced by environmental factors.
Functions of the Skin Microbiome
The microbiome of the skin serves several key functions:
- Protection against pathogens: The healthy bacteria in your skin can help fight against harmful bacteria, germs, and pathogens, preventing potential infection. Additionally, microbes in your skin can act as a sort of warning signal to your immune system that harmful bacteria or viruses are trying to enter the body.
- Regulation of Skin pH and moisture: Good bacteria in the skin are responsible for keeping the skin acidic (low pH). By keeping the skin’s pH level low, the microbiome becomes less hospitable to harmful germs. Additionally, it’s believed that certain bacteria can help us retain moisture, keeping skin supple, smooth, and youthful looking.
- Influence on skin barrier function: The skin barrier function is vital for protecting against environmental aggressors like pollutants and allergens. A robust skin barrier helps lock in moisture while keeping out harmful substances. When in balance, the microbiome supports lipid and protein production, essential for barrier repair and maintenance.
The Gut-Skin Connection: How Your Gut Affects Your Skin
The gut and skin microbiomes communicate through the gut-skin axis, where changes in one can influence the health of the other. The skin and gut both are active, complex immunological and neuroendocrine organs that are exposed to the outside environment on a frequent basis and host a wide range of microbiomes. When the microbiome in your gut is thrown off balance, it can have real effects on your skin’s microbiome as well. This relationship is known as the gut-skin axis.
Read also: Gentle Anti-Aging Routine
The gut microbiome influences skin health by producing substances like SCFAs, which help regulate inflammation. A balanced gut is key to achieving clear, radiant skin. By nourishing your gut microbiome with probiotics, you can improve skin conditions, reduce inflammation, and enhance your complexion from the inside out. When the gut microbiome becomes unbalanced (a condition known as dysbiosis), it can lead to chronic inflammation that may manifest as skin issues such as acne, eczema, or psoriasis. Food allergies are another example of this gut-skin link-when certain foods cause an allergic reaction in the gut, the skin can break out in rashes, however the connection between the two is still unclear. Eating healthy, fiber-rich foods can help build good gut bacteria through fermentation, which in turn can boost the skin's ability to fight off bad bacteria and retain moisture.
Conversely, the skin microbiome can also influence gut health. Once the integrity of the skin is compromised, pathogens can easily breach the barrier and trigger inflammation, disrupting the delicate symbiosis and sending signals over greater distances to the gut. Severe burns can compromise the skin’s barrier, potentially leading to bacterial infections and gut dysfunction. Vitamin D, primarily synthesized in the skin through sunlight exposure, plays a key role in maintaining the gut’s barrier integrity and supporting a healthy microbiome. It also helps reduce skin inflammation.
How the Gut Microbiome Impacts the Skin
When you eat food, your bacteria, the commensal bacteria in your GI tract take that food and they break it down. They make really important metabolites, as we say on our podcast, the stuff the bugs make, right? So the stuff the bugs make can get into your systemic circulation and do some really important things or also some really bad things. So when I think about what's the most common way that our microbiome from our gut interacts with our skin, it's by way of these metabolites. And it's things like short-chain fatty acids, which I'm sure most of the audience is well aware of if they follow this particular show. So short-chain fatty acids we know are anti-inflammatory. But what you don't know is when they get into systemic circulation, they also specifically affect your skin. And so it modulates the proliferation and differentiation of your actual skin cells, the keratinocytes, and they're anti-inflammatory. You also think about other things made in the gut. Things like GABA made in the microbiome goes into systemic circulation, does a lot of great things, but as it relates to the skin, it actually can inhibit itching, which is fascinating. And I also think about things like serotonin. Most of our serotonin is made in our GI tract, and a lot of people don't actually realize that. And serotonin is important, and it's important because it regulates skin inflammation in addition to changes your mood, but in circulation, it can affect skin inflammation, skin pigmentation. We also think about things like dopamine, which is also made in your gut. When that gets into systemic circulation, it does a lot of stuff, but it also can alter hair growth, which is fascinating to think that these things that your bugs are making can alter that.
Conditions Linked to Gut-Skin Imbalance
The skin microbiome can become unbalanced, meaning there is an overgrowth of harmful bacteria, viruses, or fungi. This imbalance, called dysbiosis, has been associated with several skin conditions, including:
- Acne, which affects 85-90% of people aged 12-24, causes pimples, blackheads, and occasionally painful cysts. Acne is caused by clogged pores and the presence of the bacteria named Cutibacterium acnes.
- Eczema (atopic dermatitis) leads to itchy, inflamed patches of skin and can be triggered by food or environmental allergens.
- Psoriasis is a chronic autoimmune disease where the immune system attacks healthy skin cells, causing red, scaly patches. Psoriasis is a stubborn skin condition linked to the body’s immune system.
- Rosacea: Gut dysbiosis has been linked to rosacea through increased intestinal permeability and inflammatory cascades.
- Lupus, a systemic autoimmune disease, affects the skin, causing rashes and inflammation.
- Vitiligo is an autoimmune disease characterized by patches of white skin due to the loss of melanocytes, the cells responsible for producing melanin (skin pigment). People with vitiligo exhibit distinct gut and skin microbiomes.
- Wounds that will not heal.
Research has found that people with acne seem to have higher levels of pathogenic gut bacteria such as E coli and Salmonella and lower levels of the beneficial Lactobacillus and Bifidobacteria strains so maintaining good gut flora should be high up on the list of the ‘clear skin’ protocol.
Read also: Reducing Sagging Skin
The Impact of Diet on the Gut-Skin Axis
Food is one of the major modifiable factors regulating the gut microbiota, the community of microorganisms living in the intestines. Diet and probiotics have an enormous impact on the composition and metabolic activities of gut microbiome, which subsequently impacts the skin.
Eating a Western diet can cause rapid change to the gut’s microbial community and its functions. “Earlier studies have shown that Western diet, characterized by its high sugar and fat content, can lead to significant skin inflammation and psoriasis flares,” said Sam T. Hwang, professor and chair of dermatology at UC Davis and senior author on the study. The researchers wanted to test if switching to a balanced diet can restore the gut microbiota, despite the presence of IL-23 inflammatory proteins. They fed mice a Western diet for six weeks before giving them an IL-23-inducing agent to trigger psoriasis and psoriatic arthritis features. Their study showed that eating a diet high in sugar and fat for 10 weeks predisposed mice to skin and joint inflammation. Mice that were switched to a balanced diet had less scaling of the skin and reduced ear thickness than mice on a Western diet.
A diet high in sugar, refined carbs, and processed foods can fuel inflammation and feed acne-causing bacteria. A 2022 review in the Journal of Investigative Dermatology found that dietary fiber intake influences the gut microbiome and in turn, regulates skin inflammation through short-chain fatty acids (SCFAs).
Maintaining a Healthy Gut and Skin Microbiome
So, what are the keys to microbiome and skin care?
Diet and Nutrition
- Probiotic-rich foods: Include probiotic rich foods such as kombucha, kimchi, sauerkraut, fermented tofu and kefir to support the skin’s (and the gut’s!) microbiome. Probiotic-rich foods like yogurt, sauerkraut, miso, and kimchi support beneficial gut flora.
- Prebiotic-rich foods: Prebiotics are a type of fiber that feed your friendly gut bacteria and can be found in foods like oats, onion, garlic, bananas, apples, and legumes. Prebiotics-found in garlic, onions, bananas, and asparagus-act as fuel for those good bacteria.
- Fiber: Including adequate amount soluble and insoluble fibre from a variety of plant-source will improve the microbial diversity of our gut. Think about eating for a rainbow!
- Identify trigger foods: It is important to identify trigger foods and intolerances. Eliminating dairy may be a good idea as it seems to aggravate acne and eczema.
Skincare Routine
- Gentle cleansers: Gentle cleansers remove dirt and impurities without stripping away essential moisture. Instead of harsh soaps that could wash away healthy bacteria, opt for body washes formulated with gentle ingredients like Prebiotic Oat. Body products formulated for sensitive skin will keep your skin healthy-looking and soft.
- Moisturize: After washing, keep your skin barrier well-hydrated by using a moisturizer. Daily use of moisturizing body products can reduce dryness and the likelihood of irritation.
- Avoid over-exfoliating: "Keep your skin hydrated, but don’t overdo it, as clogging the pores can be counterproductive,” advises the expert. “The skin self-regulates naturally, and using too many products can disrupt its natural balance.”
- Consider prebiotics, probiotics, and postbiotics in skincare: Some skincare products now include prebiotics, probiotics, and postbiotics to help balance the skin’s natural microbiome. While these products show promise, this area of research is still in its early stages, and more studies are needed to understand how they truly impact skin health.
Lifestyle Factors
- Manage stress: Lack of sleep and stress may increase inflammation and enhance chronic skin condition progression, such as acne. Regular sleeping patterns and reduction of blue light before bed are hugely important.
- Protect from UV damage: Using sunscreen is essential to protect your skin from UV damage. Some studies in mice and human suggest that certain probiotics might even help protect skin cells from UV damage by improving hydration and boosting antioxidant activity.
- Stay hydrated: Ensuring that you drink plenty of water and include all the essential electrolytes for proper hydration is crucial for skin hydration and barrier function. Several studies have found that upping your intake of water may help keep your skin soft and smooth.
Quick Tips for Clear Skin
Collagen
For a quick and effective result, collagen is a good place to start both externally and internally. Supporting collagen formation through nutrition could slow down this process and may provide you with a glowing, luminescent, clear skin just that little bit longer.
Read also: Weight Loss & Excess Skin: Surgery Costs
- Sunshine: While moderate sun exposure is encouraged to allow your skin to synthesise Vitamin D, excessive ultraviolet (UV) radiation has been shown to reduce collagen production in the skin (1).
- Vitamin C: It’s found in many foods such as citrus fruits, green leafy vegetables, strawberries, red peppers, apples, kiwi fruits and broccoli just to mention a few.
- Beta carotene can increase the skin’s defence against UV radiation and helps to maintain skin health and appearance (3). Good food sources include carrots, pumpkin, sweet potatoes, orange peppers, broccoli, paprika and chilies.
- Bioflavonoids, particularly, rutin and hesperidin may be beneficial for collagen production. Apples, buckwheat, most citrus, figs, and both black and green tea are all good sources.
Detox
Investigating liver, kidney, and gut function is important when addressing skin issues to ensure these processes are functioning properly.
- Rebounding on a trampoline for drainage of the lymphatic system is a fun yet effective exercise to get those lymph nodes stimulated. Rebounding seems to increase pathways of removing waste products from the cells and from the body.
- Ionic foot bath is a safe, gentle and non-invasive detoxifying modality.
- Emotional detox: Let go of limiting thoughts, identify and release outdated emotions to relieve excess stress. Try journaling, using deep breathing to encourage the release of toxic thoughts and emotions and begin replacing old thoughts with new, expansive, positive, and empowering affirmations (7).
- Eat plants containing polyphenolic compounds (raspberry, blueberry, strawberry, grape, etc.) for their ability to protect genetic material from ionizing radiation (8).
- Add powdered mustard seeds to cooked broccoli to increase formation of one of the major detox compounds from cruciferous vegetables, sulforaphane (9).
- Greens contain chlorophyll which has the ability to bind to toxins (10).
- Use spices, especially turmeric and rosemary, when cooking to offset the formation of unhealthy compounds (e.g. heterocyclic amines) that form with heat (11).
- Choose organic honey as it has been shown to help reduce DNA damage from pesticides (12).
- Increase your fibre intake to support your gut microbiome and the final phase of detox, the elimination.
- Liver health can be supported by consuming high-quality hypoallergenic proteins, green tea, and cruciferous vegetables.
- Increasing your mineral (calcium, zinc, iron, selenium) stores is crucial to reduce heavy metal absorption.
Hydration
- Upping your water intake can be a healthy and easy way to improve skin hydration.
- Include Omega 3 rich foods as they improve skin hydration and help reduce inflammation (29). Mackerel, sardines, anchovies are good sources but always make sure they are from sustainable and traceable sources. Flax, chia, seaweed, spirulina and some nuts and seeds are good veggie alternatives.
- Add water-rich foods such as watermelon, strawberries, and cucumber. These can help give your skin and body the hydration it needs to look and feel its best.