How are the gut microbiome and eczema connected?

Is eczema linked to gut health?

Although research is ongoing, a 2024 review suggests a link between eczema and gut health.

The body contains many species of microorganisms, including bacteria, fungi, and viruses. These organisms have different effects on human health.

Most of these microbes live inside the gut, particularly the large intestine. However, some also live on the skin. Scientists have discovered that the gut microbiome and skin microbiome influence each other.

An imbalance in gut or skin flora is known as dysbiosis. This can happen if there:

• are too many “bad” species
• are not enough “good” species
• is not enough variety of species

In people with atopic dermatitis (AD), a type of eczema, dysbiosis may contribute to disease development.

How gut health influences eczema

Here is what researchers know so far about the connection.

Dysbiosis

Studies have shown that, in people with AD, there is often a compromise to the health of their gut microbiome.

The 2021 review notes that AD is associated with lower bacterial variety and lower levels of beneficial species, such as Bacteroidetes, Akkermansia, and Bifidobacterium.

People with AD may also have higher levels of bacteria that can contribute to inflammation, such as Clostridium and Escherichia.

A 2024 review suggests no difference in the overall variety of gut bacteria between people with and without AD. However, some bacteria, including Bacteroidales, Enterobacteriaceae, and Clostridium perfringens, were more common in people with AD.

More research is still necessary to understand the link between eczema and dysbiosis.

Immune response

The immune system plays a role in AD symptoms. When the immune system perceives a threat on the skin, it creates inflammation, causing the itchy rash.

Scientists believe dysbiosis in the gut and on the skin may cause this. The immune system may be detecting harmful levels of “bad” microbes on the skin and reacting to them.

Dysbiosis and eczema may then create a cycle of inflammation that perpetuates symptoms.

According to the 2021 review, changes in the microbiome may also alter the immune response, leading to dysregulation.

Intestinal permeability

A 2024 review suggests some researchers believe there is an association between AD and intestinal barrier dysfunction.

Some beneficial bacteria species produce byproducts that help the intestinal barrier work more effectively. These include some species that people with AD may have less of, such as Bifidobacteria.

However, more research is necessary to fully understand the connection.

What causes gut and skin dysbiosis?

Many aspects of daily life influence the microbiome. Dysbiosis may develop due to:

• Oral antibiotics: Oral antibiotics do not discriminate between “good” and “bad” species in the gut. Early life, repeated, or long-term courses of antibiotics are associated with dysbiosis.
• Other medications: A 2020 study evaluated the effect of different medications on the microbiome. Those with the strongest link to dysbiosis, aside from antibiotics, included laxatives, metformin, and proton pump inhibitors (PPIs).
• Smoking and nicotine: A 2021 review states that in previous research, people who smoked tobacco had higher amounts of harmful bacterial strains and lower amounts of beneficial strains. Quitting smoking led to an increased variety of bacteria.
• Lack of human contact during and after birth: Vaginal birth, skin-to-skin contact, and nursing provide newborns with early exposure to another human’s microbiome, helping them begin developing their own. Babies who arrive via C-section, have little contact with others, or who only receive formula, may miss out on this. This disproportionately affects people from low-income backgrounds.

Other potential causes

Many other factors also impact the microbiome, though less research connects them directly to dysbiosis. They include:

• Diet: The Western diet tends to be high in inflammatory foods, such as saturated fat, which may contribute to dysbiosis.
• Lack of vitamin D: Sunlight contains UVB rays, which allow the skin to produce vitamin D. Vitamin D is associated with greater microbiome diversity, so a lack of this nutrient may inhibit this.
• Stress: According to a 2023 review, there is a well-established link between chronic stress and changes in the gut microbiome in humans.

Diagnosing eczema and gut dysbiosis

There is currently no way to prove if a person’s eczema is gut-related. Tests to measure the gut microbiome are available, but they are imperfect tools.

Microbiome tests cannot measure every species, as there are so many in the microbiome. Additionally, they capture only a snapshot of a person’s gut microbiota at a given point in time.

Despite this, a doctor may still suggest one if there is a strong suspicion of dysbiosis. They may also use the following tests to assess overall gut health in someone with eczema:

• a fecal Calprotectin test, which measures gut inflammation
• gut permeability tests
• tests for celiac disease, which can occur alongside AD

Will diet affect eczema?

Research into the link between the gut microbiome and eczema is ongoing. More research is necessary to understand whether changes in diet will affect this relationship.

A 2021 study examined the effect of different foods on the composition of the gut microbiome. The authors associated a specific diet with higher levels of microbial species with anti-inflammatory effects.

Foods to eat included:

• fruits
• vegetables
• beans and peas
• nuts
• low fat fermented dairy foods, such as yogurt
• fish

Foods to avoid included:

• alcohol
• sodas
• high fat processed meats

However, it is important to note that this is not a cure for eczema. Instead, dietary changes may support overall health. This can have a knock-on effect on the skin and reduce symptoms for some people.

Will probiotics help with eczema?  

Probiotics are microorganisms that may have therapeutic benefits for some people. They are available in fermented foods or supplements.

The research so far on whether probiotics help with eczema is mixed. The 2021 review notes that several studies have shown that Lactobacillus and Bifidobacterium are helpful for atopic dermatitis.

They may also have a protective effect on the microbiome when a person takes antibiotics, thereby reducing the risk of dysbiosis.

A 2025 meta-analysis suggests that probiotics are a promising alternative therapy for children with AD, but the results note that they may only be effective for people with moderate to severe symptoms, not mild symptoms.

Probiotics may not be suitable for everyone, and they can have side effects and risks. Speak with a doctor before trying any new supplement or major dietary change.

Questions to ask a doctor

If someone suspects that their eczema may be related to dysbiosis, they can speak with a doctor to learn more about the available options.

A person may want to ask the following:

• Could I have dysbiosis?
• Is there a way to test for it?
• What could have caused it?
• Could my medication be damaging the microbiome? If so, what other options are there?
• What can I do to help my skin and gut microbiome?
• Can I try an anti-inflammatory diet? If so, how should I start?
• Can I try a probiotic supplement? Do you have recommendations?

If there is a potential gut-skin link, working with a gastroenterologist, a dermatologist, or both may be beneficial.

Summary

The link between eczema and gut health lies in the gut-skin axis, which refers to how intestinal flora influences the skin microbiome. An imbalanced microbiome may play a role in the inflammation and immune response that causes eczema.

Microbiome imbalance, or dysbiosis, is when someone has too many “bad” species of microbe, not enough “good” species, or a general lack of variety.

More research is necessary to understand how the microbiome may be relevant to eczema treatment. People can speak with their doctor for more information if they believe their gut is influencing their eczema symptoms.