Understanding the Gut-Skin Connection: Fixing your Gut May Fix Your Skin
The human body is home to ecosystems of bacteria, yeast, viruses and other organisms that inhabit different regions of our body. These ecosystems are often collectively called the microbiome. While specific species and strains of organisms vary based on location in the body, imbalances of organisms in any given site play a role in the health of the body as a whole. The microbiome is a key regulator for the immune system. Hence, imbalances (also called dysbiosis) of these organisms are associated with an altered immune response, promoting inflammation in potentially multiple areas of the body. (1) A dysbiosis can occur if there are too many “bad” species, not enough “good” species, or not enough diversity of species.
The skin is the largest and most external barrier of the body with the outer environment. It is richly perfused with immune cells and heavily colonized by microbial cells. These microbes help train the body’s immune cells and help determine overall well-being. The skin has a unique microbiome that is distinct from the gut microbiome, yet scientists are learning that there is a strong bidirectional relationship between the health of these two areas of the body. The relationship is often termed the “gut-skin axis.” Skin conditions including rosacea, acne, psoriasis, atopic dermatitis, skin aging and others are often associated with altered gut microbiome health.
The gut and skin connection
The intestinal tract houses a diverse collection of bacteria, fungi, and protozoa. Many of these microorganisms are essential for metabolic and immune function. An imbalance in this microbiome can result in a breakdown of gut barrier function resulting in antigenic food proteins and bacteria components entering the body’s circulation to trigger inflammation. This inflammation can affect many organs, including the skin.
Adult Acne Vulgaris
Acne is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells. Acne can be described as whiteheads, blackheads, pimples or deep cysts. Cystic acne is linked to the health of the skin’s microbiome, in particular the balance of a bacteria called Cutibacterium acnes. In a diverse, balanced skin microbiome, this bacterium is involved in maintaining a healthy complexion. However, if there is loss of the skin microbial diversity, this bacteria can also trigger cystic acne. The microbial imbalance can lead to the activation of the immune system and a chronic inflammatory condition like acne. (2) Like in the gut, the health of the skin microbiome influences the release of chemicals triggering inflammation. Optimizing both the gut microbiome and skin microbiome are important stratagies to resolve acne by controlling inflammation both at the skin level and whole body level.
Rosacea
Rosacea is a common, chronic inflammatory skin condition that causes flushing, visible blood vessels and small, pus-filled bumps on the face. The exact cause of rosacea is debated and likely related to multiple factors. Like acne, the skin microbiome and its associated inflammatory effects plays a role in rosacea's etiology. There are also numerous studies connecting rosacea to gastrointestinal disorders including celiac disease, inflammatory bowel disease, irritable bowel syndrome, Helicobacter pylori infection and small bowel bacterial overgrowth.(3) Conventional treatment of rosacea often involves managing symptoms. Identifying and addressing potential associated gut-related illnesses is an effective tool to help support rosacea management.
Eczema
Eczema, also called atopic dermatitis, is a chronic condition that makes skin red and itchy. It is common in children but can occur at any age. Atopic dermatitis tends to flare periodically and is often associated with asthma or allergies. Atopic dermatitis is the most common inflammatory skin disease affecting 7% of adults and 15% of children.(1)
Studies have shown that atopic dermatitis is associated with lower gut microbiome diversity, lower levels of beneficial species, such as Bacteroidetes, Akkermansia, and Bifidobacterium in the gut, and higher amounts of harmful bacteria species including Staphylococcus aureus on the skin.(1) The intestinal microbiome modulates the body’s immune system and inflammatory responses and thus may play a role in the development of eczema and its treatment. Targeted probiotics can play a role in prevention and treatment of this disease.(4)
Psoriasis
Psoriasis is an inflammatory, autoimmune skin disease that causes a rash with itchy, scaly patches, most commonly on the knees, elbows, trunk and scalp. The illness is associated with an intimate interplay between genetic susceptibility, lifestyle, and environment. People with psoriasis have an increased risk to develop intestinal immune disorders, such as inflammatory bowel disease like ulcerative colitis and celiac disease.(1) A growing body of evidence highlights that intestinal dysbiosis is associated with the development of psoriasis.(5) One study showed that malabsorption of nutrients in the gut was more prevalent among patients with psoriasis. Celiac disease, bacterial overgrowth, parasitic infestations and eosinophilic gastroenteritis could be possible causes of malabsorption in these patients.(6) Addressing associated gut conditions may play a role in management of symptoms.
Skin Aging
Skin aging is associated with multiple degenerative processes including oxidation and inflammation. Multiple factors including diet, UV exposure, and environment play a role in the regulation of the aging process. New research shows that healthier diets are linked to fewer signs of skin aging.(7) Additionally, oral probiotics may play a role in regulating skin aging through influences on the gut-skin axis. In a study published in 2015, the oral probiotic Lactobacillus plantarum HY7714 was shown to improve skin hydration, skin elasticity and UV related skin changes.(8)
Skin Care may need to Start with Gut Care
Optimizing the gut microbiome has a role in addressing skin disorders. The following strategies can improve the microbiome:
Eat better. The microbiome is influence by the food we eat. Beneficial bacteria thrive on fiber that comes from eating a variety of vegetables regularly. The growth of unfavorable bacteria is influenced by sugar, saturated fats and a lack of fiber/vegetables in the diet. To optimize your microbiome, avoid refined sugar and saturated fats like those found in sodas, breakfast cereals, candies, cakes, red meat (limit to 1 or 2 servings a week to prevent overconsumption) and what is commonly referred to as “junk food”.
Use antibiotics wisely. Antibiotic treatment is necessary from time to time. However antibiotics can significantly lower microbiome diversity and the quantity of beneficial bacteria.(9) When prescribed an antibiotic, ask your health care provider if it is truly necessary. Speak with your provider about using prebiotics and probiotics to support the microbiome after the antibiotic use.
Repair the gut flora. In addition to a fiber-rich diet, probiotics may play a role in optimizing gut function. Probiotic science is in its infancy, but there is research suggesting that certain strains may benefit certain medical conditions. Speak with your health care provider for probiotic recommendations that may best suit your medical needs.
Identify other ways to care for your digestive system, such as repairing the wall of the small intestine which may have been irritated by a poor diet, poor digestion, medications or stress. Identifying food sensitivities, restoring nutritional deficiencies and eating adequate nutrients to support healing are important.
Many of the interventions above can be easily implemented without need for laboratory tests. There are no specific gastrointestinal lab markers that are known to directly cause skin issues. However, assessments of the GI system may reveal abnormalities indirectly impacting skin health. Relish Health relies on multiple tools such as stool microbiome testing, breath tests and food sensitivity tests to understand the health of the gut-skin axis and develop targeted interventions to address gut and skin conditions.
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References:
De Pessemier B, Grine L, Debaere M, Maes A, Paetzold B, Callewaert C. Gut–Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions Microorganisms. 2021 Feb; 9(2): 353. doi: 10.3390/microorganisms9020353
Dréno B,. Pécastaings S, Corvec S, Veraldi S, Khammari S, Roques C. Cutibacterium acnes (Propionibacterium acnes) and acne vulgaris: a brief look at the latest updates. J Eur Acad Dermatol Venereol 2018 Jun;32 Suppl 2:5-14. doi: 10.1111/jdv.15043.
Daou H, Paradiso M, Hennessy K, Seminario-Vidal L. Rosacea and the Microbiome: A Systematic Review. Dermatol Ther. 2021 Feb;11(1):1-12. doi: 10.1007/s13555-020-00460-1.Epub 2020 Nov 10.
Fiocchi A, Pawankar R, Cuello-Garcia C, et. al. World Allergy Organization-McMaster University Guidelines for Allergic Disease Prevention (GLAD-P): Probiotics World Allergy Organ J. 2015; 8(1): 4. Published online 2015 Jan 27. doi: 10.1186/s40413-015-0055-2
Sikora M, Stec A, Chrabaszcz M, Knot A, Waskiel-Burnat A, Rakowska A, Olszewską M, Rudnicka L. Gut Microbiome in Psoriasis: An Updated Review. Pathogens. 2020 Jun; 9(6): 463. Published online 2020 Jun 12. doi: 10.3390/pathogens9060463
Ojetti V, De Simone C, Sanchez J, Capizzi R, Migneco A, Guerriero C, Cazzato A, Gasbarrini G, Pierluigi A, Gasbarrini A. Malabsorption in psoriatic patients: cause or consequence? Scand J Gastroenterol. 2006 Nov;41(11):1267-71.
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Katta R, Sanchez A, Tantry E. An Anti-Wrinkle Diet: Nutritional Strategies to Combat Oxidation, Inflammation and Glycation. Skin Therapy Lett. 2020 Mar;25(2):3-7.
Lee, D. E. et al. (2015) “Clinical Evidence of Effects of Lactobacillus plantarum HY7714 on Skin Aging: A Randomized, Double Blind, Placebo-Controlled Study,” Journal of Microbiology and Biotechnology. Journal of Microbiology and Biotechnology. https://doi.org/10.4014/jmb.1509.09021
Ramirez J. Guarner F, Fernandez, L, Maruy A, Sdepanian V, Cohen H. Antibiotics as Major Disruptors of Gut Microbiota. Front. Cell. Infect. Microbiol., 24 November 2020 | https://doi.org/10.3389/fcimb.2020.572912
Stubbe C. The Gut Microbiome in Dermatology. Anti-aging Medical News. Spring 2022. p76-80.