Skin: Your Outside is Showing Your Inside

Evidence shows a shared connection between our gut microbiome and skin contributing to three common skin disorders: acne, atopic dermatitis, and psoriasis. The gut microbiome includes five types of microorganisms that usually live in harmony, though when they get impaired through consumption of a typical western diet (especially lack of fiber), overuse of antibiotics, and other lifestyle habits common to Americans, the effects can show up on the outside and be displayed by our skin.

It may seem strange to think the gut and our skin could be linked, but consider that both are neuroendocrine and immune organs that serve as a home for a large community of microbes. Since the gut provides a semipermeable barrier to prevent pathogenic material from entering the body, it can cause inflammation if a food or lifestyle choice irritates the gut lining. This then causes a stress response to be triggered to fight the irritation, which can cause intestinal permeability (“leaky gut”) and ultimately allows the tight barrier of the gut to loosen, which gives unwanted bacteria the opportunity to escape. When this happens, there is significantly more inflammation around the gut, which also travels to our skin. 

The skin performs various functions, including protection, water retention, and temperature regulation when in a state of equilibrium. However, when our gut barriers become irritated, intestinal bacteria (and their metabolites) gain access to our bloodstream, accumulate in the skin, and disrupt this homeostasis. To fight this, we can eat a high fiber diet which will result in short chain fatty acids (SCFAs) and increase the growth of healthy bacteria species Lactobacilli, Bifidobacteria, and Prevotella.

Acne

Approximately 85% of children and young adults between the ages of 12 to 25 are affected by acne, and it represents the 8th most common medical disorder worldwide. Acne used to be a thing of just teenage years, though recently adults, and women especially, are continuing to have acne into their thirties and sometimes beyond. In fact, 40% of women between 25 and 40 years old still have some type of acne. 

Acne is most common in western countries, which may be a result of consumption of highly refined carbohydrates (high fructose corn syrup, white bread, baked goods, etc) that create a high glycemic load. Eating in this way contributes to an insulin growth factor (IGF-1) which ultimately triggers the development of acne. Further, acne is also associated with an overgrowth of Propionibacterium acnes and low levels of stomach acid, which cause dysbiosis, or imbalance of the gut, and can lead to small intestinal bacterial overgrowth, otherwise known as SIBO. 

To combat this, you can consider incorporating more fiber into your diet. Amongst its many benefits, one of the most important things that our microbiome does with fiber is create short chain fatty acids (SCFAs).  As its name implies, SCFAs make the colon more acidic, preventing the growth of inflammatory and pathogenic bacteria. It can also fix leaky gut over time through a type of SCFA called butyrate which repairs leaky gut by increasing the expression of tight junction proteins where we need them in order for the gut-blood barrier to stay strong. Additional types of fiber fermentation by our microbes, such as propionate and acetate, are believed to play a key role in determining immune defense mechanisms and ultimately the appearance of our skin. 

Lastly, topical and oral antibiotics may be included in conventional acne treatment regimens. The concern with using antibiotics for acne is that they do not only affect the bacteria living on the skin, but also affect the bacteria living in the gut microbiome. Retinoids, antibiotics, oral contraceptives, and steroid injections, as well as the chemical peels and other types of therapies that are often marketed as wellness initiatives, can cause long term damage to the microbiome and result in a reduction of bacterial diversity. An unconventional method to treat acne instead is through the use of probiotics, such as Align, or through consuming probiotic rich food and drinks, like kombucha, additive-free yogurt, kimchi, kefir, and sauerkraut. 

Atopic Dermatitis (Eczema) 

Atopic dermatitis (AD), a form of eczema, affects 2-10% of adults, and as much as 15-30% of children! Skin barrier dysfunction and altered immune responses are primary causes of AD. Like with acne, the gut microbiome’s ability to maintain immune homeostasis is disrupted under our western diet. The general low fiber intake of the general population combined with high fat intake results in a deficient production of immunomodulatory metabolites, such as SCFAs. 

Rather than immediately grabbing for an antihistamine or corticosteroid, both of which have substantial side effects, relief can also come from changes to the diet. Foods high in omega-3 fatty acids such as eggs, flaxseeds,  hemp seeds, soaked chia seeds, walnuts, salmon, herring, and sardines can regulate inflammation and leaky gut. Also, foods that contain quercetin, particularly citrus fruits, apples, cherries, and spinach, can reduce histamine levels.

Psoriasis

Between 7-11% of individuals with inflammatory bowel disease (IBD) are diagnosed with psoriasis, indicating a association between gastrointestinal inflammation and this inflammatory dermatosis. Metabolites produced by the microbiome can have immune-modifying effects which can alter the balance between either immune tolerance or inflammation. In these individuals, studies suggest a lack of certain types of beneficial bacteria, like Bifidobacteria, Lactobacilli, and Faecalibacterium prausnitzii as well as colonization with certain pathogenic types of bacteria like such as Salmonella and Escherichia coli.

Like the other skin conditions mentioned above, the use of a probiotic, consumption of omega-3 fatty acids, and also consumption of Vitamin E through sources like sunflower seeds, avocado, cod, and almonds can help to keep the skin healthy. Further, the consumption of zinc (think: pumpkin seeds, chickpeas, cashews) can help regulate inflammation. 

In Conclusion… 

Keeping a healthy microbiome allows your skin to look clearer and healthier. A high fiber diet, probiotics, omega-3, quercetin, vitamin E, and zinc can help. 

*While problems of antibiotic resistance and damage to the microbiome are serious, antibiotics have saved countless lives and it is the writer's hope to only reduce the reader’s use of unnecessary antibiotics.

Heal Your Gut, Heal Your Life!

With Love,
Katherine

Is your gut causing you issues? Do you need help losing weight, or maintaining weight loss? Book an appointment with me to see if the Ahimsa Signature Plan can help you, or check out one of our food plans.

Works Cited

Bulsiewicz, Will. Fiber Fueled. Avery, 2020.

Salem, Iman, et al. “The Gut Microbiome as a Major Regulator of the Gut-Skin Axis.” Frontiers in Microbiology, Center for Medical Mycology, Department of Dermatology, Case Western Reserve University, 10 July 2018, https://www.frontiersin.org/articles/10.3389/fmicb.2018.01459/full.

Lee, Young Bok, et al. “Potential Role of the Microbiome in Acne: A Comprehensive Review.” Journal of Clinical Medicine, MDPI, 7 July 2019, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6678709/.