Eczema and the Link with the Gut-Skin Axis
- Marcelline Goyen
- 22 hours ago
- 5 min read
Table of content
Eczema and the Gut-Skin Axis: the Role of the Microbiome, Nutrition and the Immune System
Eczema, and particularly atopic dermatitis (AD), is a chronic inflammatory skin condition characterized by redness, itching, scaling, oozing lesions, a disrupted skin barrier and an elevated skin pH. Although eczema is often regarded primarily as a skin disorder, an increasing body of scientific evidence shows that both its origin and persistence extend far beyond the skin itself. In particular, the gut-skin axis, the gut, the gut microbiome and the immune system play a crucial role.
Classical explanations for eczema
Traditionally, eczema has been explained by a combination of:
Genetic predisposition, such as mutations in the filaggrin gene, which is essential for an intact skin barrier;
Impaired skin barrier function;
Immune dysregulation, mainly Th2-driven inflammatory responses;
Environmental factors, including allergens, irritants, cosmetics, skincare products, water exposure and climate.
In constitutional (atopic) eczema, typical locations include the inner elbows and knee folds, and there is a strong association with other atopic conditions such as allergic rhinitis (hay fever), asthma and urticaria. Food allergies and intolerances (e.g. cow’s milk, egg, wheat and tomato) are also more common in this group. However, these explanations do not fully account for the complexity of eczema.
The gut–skin axis: what does science tell us?
An increasing number of studies describe the gut–skin axis, a bidirectional communication pathway between the gut, the immune system and the skin. The gut is the largest immune organ in the body: approximately 70% of the immune system resides in and around the gastrointestinal tract.
Healthy gut function depends on:
An intact mucosal layer;
A well-functioning intestinal barrier;
A diverse and stable gut microbiome;
When this balance is disrupted, systemic consequences may occur, including inflammatory skin diseases such as eczema.
Gut microbiome and eczema
Both children and adults with atopic dermatitis frequently show alterations in the gut microbiome, including:
Reduced levels of beneficial bacteria such as Bifidobacterium and Lactobacillus;
Increased presence of potentially pathogenic bacteria, fungi and parasites;
Impaired production of short-chain fatty acids (SCFAs), such as butyrate, which are essential for gut integrity and immune regulation.
These changes may result in impaired immune tolerance, increased inflammatory responses and a higher risk of allergic disease.
“Leaky gut” and systemic inflammation
A widely discussed mechanism is increased intestinal permeability, often referred to as “leaky gut”. In this situation, the tight junctions between intestinal epithelial cells are compromised, allowing bacterial fragments (e.g. lipopolysaccharides), incompletely digested food particles and toxins to enter the bloodstream. This activates the immune system and can lead to chronic low-grade systemic inflammation, which may manifest in the skin as eczema.
Several studies have reported increased markers of intestinal permeability and systemic inflammation in patients with atopic dermatitis.
Nutrition, intolerances and histamine
Nutrition plays a central role in the gut–skin axis. Food provides essential macronutrients, micronutrients and dietary fibers that are crucial for gut health, immune function and skin integrity. At the same time, diet can also introduce various “triggers” that negatively affect gut and skin health.
Food allergies and intolerances
In patients with eczema, IgE-mediated food allergies are more common, particularly to cow’s milk protein, egg, wheat/gluten and soy. In addition, non-IgE-mediated reactions (often referred to as food intolerances) may cause symptoms even when standard allergy tests are negative, for example with cow’s milk protein, casein, wheat and gluten.
Histamine-rich foods
Certain foods (e.g. strawberries, tomatoes, aged cheese and fermented products) contain high levels of histamine or stimulate histamine release. When gut function is impaired, histamine breakdown may be reduced, leading to symptoms such as headaches, fatigue, sleep disturbances, gastrointestinal complaints, anxiety or panic symptoms, and skin reactions including urticaria, itching and eczema flares.
Dietary patterns and common dietary mistakes
Many people believe they eat healthily, yet closer evaluation often reveals dietary imbalances, such as:
Eating too frequently or too infrequently
Eating too quickly and insufficient chewing
Excessive intake of refined sugars, alcohol and processed carbohydrates
High-fat diets with insufficient protein and vegetables
Excessive consumption of ultra-processed foods and snacks
Over time, these patterns may contribute to digestive complaints (bloating, gas, constipation or diarrhea), nutrient deficiencies and ultimately inflammatory skin conditions such as eczema and acne.
Infections, stress and environmental exposure
Eczema may also be triggered or exacerbated by other factors, many of which are supported by scientific evidence:
Eczema following travel, accompanied by diarrhea and altered bowel habits → possible bacterial or parasitic infection
Chronic stress, which increases intestinal permeability, alters eating behavior and negatively affects the gut microbiome; stress also directly enhances inflammatory immune responses
Disruption of the skin and gut microbiome;
New cosmetics, fragrances or scented products, which may induce contact allergy or inhalant allergy via the mucosal immune system (MIS). Examples include pollen, mold spores, parabens, cleaning agents, soaps, skincare products and formaldehyde found in paper products, new curtains or flooring
What does this mean for eczema treatment?
An integrative approach to eczema goes beyond topical treatments and symptom suppression. It also addresses underlying triggers and contributing factors, including:
Assessment of gut health and the gut microbiome;
Detection of gastrointestinal pathogens (e.g. Helicobacter pylori, bacterial overgrowth, fungi or parasites);
Identification of food allergies and intolerances;
Personalized dietary interventions and, when appropriate, guided elimination diets;
Restoration of the gut microbiome through nutrition, prebiotics and probiotics;
Stress reduction and lifestyle modification.
Meta-analyses suggest that certain probiotic strains have a modest but significant effect in atopic dermatitis, particularly in children. However, it is likely that probiotics are most effective when underlying triggers and ongoing immune activation are simultaneously addressed.
Conclusion
Eczema is not merely a skin disorder. In many individuals, it reflects a deeper imbalance in the complex interaction between the gut, immune system and skin. By addressing gut function, microbiome composition, nutrition, stress and lifestyle alongside conventional dermatological care, we gain a more comprehensive understanding of why eczema develops, persists or recurs — and open additional avenues for treatment.
You can read more about this topic in my book on the skin–gut connection, available in Dutch and now also in English and German. See LINK TO BOOKSHOP.
Marcelline Goyen, BSc Skin Therapist & Author
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