Is There a Connection Between Leaky Gut and Atopic Dermatitis?
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
Skin barrier dysfunction and intestinal lining damage
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 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
While a significant number of people with AD have food allergies, not all food allergies are a trigger for the person’s AD. While the American Academy of Dermatology does not recommend elimination diets solely on the basis of a positive food allergy test, many patients and doctors still use elimination diets as a way to avoid food triggers.6,7
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
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 research to be done
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.
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