Leaky gut may be a key contributor to many conditions, including irritable bowel syndrome (IBS), celiac disease, and food intolerances.1 But how is leaky gut related to atopic dermatitis (AD)? Researchers have been uncovering clues between the two conditions.
What is leaky gut?
Leaky gut is a condition in which the intestinal lining is compromised. The intestinal lining is made up of layers. When a person has leaky gut, the normal covering in the intestines has cracks. While normally only the smallest particles of food and nutrients are absorbed through the intestinal wall, in a person with leaky gut, larger food particles or toxins can make their way into the bloodstream. The body’s immune system attacks these particles as foreign invaders, and this immune response can lead to inflammation and food intolerances or allergies.2,3
Research from several studies indicates that there may be a higher incidence of leaky gut in people with AD, even as young as infancy.2
One of the features of AD is a dysfunction in the skin barrier, and when the skin barrier is compromised, many irritating substances can enter the skin, including irritants, bacteria, viruses, or allergens. 4 Similarly, when the intestinal lining is damaged in someone with leaky gut, particles of food that have not been fully digested get absorbed into the blood stream, along with toxins, bacteria, or other pathogens. These particles are recognized by the body as foreign, and the immune system launches a response, which may result in the development of food allergies or chronic inflammation.1,3
The damage in the barrier of the two surfaces (intestines and skin) may also be a connection between these two conditions. Both the outer layer of the skin and the outer layer of the intestines are composed of epithelial cells. And while the surfaces may seem unrelated, some researchers believe it’s not unreasonable to consider if you follow the path from the lips through the mouth and down through the digestive system.2
The importance of the microbiome
The intestines, or gut, is more than just a tube for absorbing nutrients from food. Scientists have established that the lining of the intestines hosts a variety of beneficial bacteria called the microbiome or gut microbiota, and this microbiome is critical for proper digestion, a healthy immune system, metabolism, and our mental health.2,5 An imbalance in the types of bacteria in the intestines can cause a number of issues, including leading to leaky gut.1,3
In AD, there is also an imbalance in the microbiome found on the skin. People with AD have higher levels of bacteria on their skin, particularly Staphylococcus aureus, known as “staph.” Over 90% of AD skin lesions are found to have staph, compared to 5% on the skin of healthy people.6
Leaky gut may explain some of the food allergies seen in people with AD, as the disruption in the intestinal wall allows larger food particles through to the bloodstream. The immune system produces elevated levels of immunoglobulin E (IgE) when exposed to an environmental allergen. Immunoglobulin is a type of protein that is part of the immune system and that acts as an antibody to attach and destroy foreign substances. There are five different types of immunoglobulin, and the IgE protein is found in increased levels in people with allergy. IgE causes the body to release histamine when it comes into contact with an allergen.2,8
Implications for treatment
Diet continues to be an area of interest for researchers, as many people with AD report that eliminating certain foods reduces their skin disease. Known food allergies can also cause inflammation in the gut, leading to or exacerbating leaky gut. However, more research is needed to understand which types of dietary modifications help individual patients.2
Probiotics are another area of interest. A healthy microbiome contains a variety of good bacteria, and probiotics have been promoted as a way to boost the good bacteria in the body. Unfortunately, the research data on probiotics and AD hasn’t been definitive. Some studies have shown that probiotics may be helpful in preventing AD, but they are not effective for treatment of established disease. Still, probiotics are another area to watch, as there are many different strains, different formulations, and doses of probiotics. Additional research will need to be completed to fully understand the role probiotics can play in AD.2,9
More to come
While the mounting evidence is compelling, there are still many questions left to be answered on how leaky gut and AD are connected, as well as how treating leaky gut may impact a person’s skin disease.
Lopetuso LR, Scaldaferri F, Bruno G, Petito V, Franceschi F, Gasbarrini A. The therapeutic management of gut barrier leaking: the emerging role for mucosal barrier protectors. Eur Rev Med Pharmacol Sci. 2015;19(6):1068-76.
Leaky gut and atopic dermatitis. National Eczema Association. Available at https://nationaleczema.org/leaky-gut/. Accessed 12/5/17.
Leaky gut: what it is and how to heal it. US News & World Report. Available at https://health.usnews.com/health-news/blogs/eat-run/2014/03/06/leaky-gut-what-it-is-and-how-to-heal-it. Accessed 12/5/17.
Tollefson MM, Bruckner AL. Atopic dermatitis: skin-directed management. Am Acad Pediatrics. 2014 Dec;134(6):e1735-1744. doi: 10.1542/peds.2014-2812.
Jandhyala SM, Talukdar R, Subramanyam C, Vuyyuru H, Sasikala M, Reddy DN. Role of the normal gut microbiota. World Journal of Gastroenterology: WJG. 2015;21(29):8787-8803. doi:10.3748/wjg.v21.i29.8787.
Peterson JD, Chan LS. A comprehensive management guide for atopic dermatitis. Dermatology Nursing. 2006;18(6):531-542. Available at http://www.medscape.com/viewarticle/551352_5. Accessed 12/6/17.
Sidbury R, et al. Guidelines of care for the management of atopic dermatitis. J Am Acad Dermatol. 2014;71(6):1218-1233.
Immunoglobulin, Medical dictionary. Available at http://medical-dictionary.thefreedictionary.com/immunoglobulin. Accessed 12/6/17.
Rosenfeldt V, Benfeldt E, Valerius NH, Paerregaard A, Michaelsen KF. Effect of probiotics on gastrointestinal symptoms and small intestinal permeability in children with atopic dermatitis. J Pediatr. 2004 Nov;145(5):612-6./li>