How Does Gut Health Impact Eczema? And More on the 'Gut-Skin' Axis

What is the gut-skin axis?

The “gut-skin axis” refers to all the connections between our skin and digestive system.

Much of this communication is done through our body’s microbiome. The bacteria, fungi, and other living things live mainly in our gut and on our skin.

These microbes play an important role in our health. An imbalance in either the skin or gut microbes often affects the other. Alterations in the microbiome are seen in a variety of health conditions. These include mental health conditions, irritable bowel syndrome (IBS), diabetes, and skin conditions.

Microbiome through the life cycle

The makeup of the microbiome starts from birth. There are a number of factors that influence the colonies that set up residence in your gut and on your skin.

These include:

• birth method (vaginal or cesarean birth)
• how you were fed as an infant (breastmilk or formula)
• your age
• stress
• your genetic makeup
• where you live in the world
• use of certain medications, including antibiotics

There’s no one single healthy microbiome. One healthy person will not have the same microbiome as another healthy person.

Research has noted distinct differences in the microbiome of people with certain diseases. It’s unclear what happens first.

In babies and children, eczema can be an early sign of allergy risk. Eczema and allergies are both triggered by an abnormal immune response.

The immune system usually only responds to a true threat, such as a virus or harmful bacteria. It will send out an army of inflammatory proteins to fight off an invader. With allergies or eczema, the immune system gets triggered by something that shouldn’t trigger it.

Babies with eczema are more likely to develop food allergies or asthma. Allergy testing is often recommended for babies and children with eczema. Removing any allergens from the diet will often improve the skin.

Children with eczema have different skin bacteria compared with children without eczema.

Studies of the gut microbiome support the idea that skin and gut health are connected. Children without eczema have more gut microbiome diversity compared with those with eczema. Greater diversity in the gut microbiome is often a sign of better health.

Sometimes, children grow out of eczema. In adults, especially older adults, several changes naturally occur in the skin. This alters the skin’s microbiome to favor more beneficial bacteria. This crowds out many of the inflammatory bacteria associated with eczema. This may explain why some cases of eczema improve with age.

Eczema treatment and the microbiome

There are theories that changing the gut microbiome could improve eczema. Everyone’s microbiome is slightly different. It’s impossible to know what the “perfect” microbiome would look like to prevent or manage eczema.

There is also the ongoing question of what comes first. Does something cause a shift in the microbiome, leading to disease? Or does the disease cause a change in the microbiome?

Common treatments for eczema include topical creams or narrow band ultraviolet treatment, called phototherapy. These are found to change the skin’s microbiome. They promote healthy bacteria and reduce inflammatory bacteria on the skin. This relieves eczema symptoms.

Probiotic and prebiotic treatment for eczema

You may have heard about fecal transplants. This is when gut bacteria from a healthy donor are delivered into the gut of someone else. It’s been done to restore healthy gut bacteria in people with inflammatory bowel disease (IBD) or Clostridium difficile (C. diff) infection.

Skin microbiome transplants may be the next step. Research is exploring whether it may help to treat eczema. In theory, healthy donor skin bacteria could restore balance to the skin microbiome. There is still more work to do before this becomes a routine practice.

Probiotic supplements can be helpful for people with digestive symptoms. With skin and gut microbes so connected, could oral probiotics also support skin health? There are theories that changing gut bacteria with probiotics may improve skin, too. So far, there are no results to support this idea.

A 2018 review of 39 randomized controlled trials on this topic looked at whether oral probiotics would improve eczema. There were no trials that showed significant improvement in eczema with probiotic supplements.

In 2024, an over-the-counter probiotic with the bacteria Roseomonas mucosa became available for the treatment of eczema. The bacteria was determined to be effective in treating the symptoms of eczema in both adults and children.

There may be some promise with synbiotics. Synbiotic supplements include both probiotics and prebiotics. Probiotics are the healthy bacteria and prebiotics are food to nourish the probiotics. This combination may increase the odds of certain bacteria thriving in the gut.

A 2021 study found that daily use of synbiotics noticed a decrease in the severity of their symptoms and a better quality of life.

An older 2016 meta-analysis looked at whether synbiotics could be helpful for those with eczema. It showed that specific synbiotics could help treat dermatitis in children aged 1 year and older.

More research is needed to learn whether synbiotics may play a role in eczema prevention.

Staphylococcus aureus and eczema severity

People with eczema have more Staphylococcus aureus (S. aureus) bacteria on their skin. This bacteria is associated with greater inflammation. The more severe the eczema, the greater amount of S. aureus bacteria are present.

There are several species of helpful bacteria that live on the skin. Many act as barriers to prevent harmful invaders from entering the body. Some bacteria actually have antimicrobial properties to block pathogens. The population of S. aureus makes it harder for beneficial bacteria to live on affected areas of the skin.

Recommendations for a healthy gut

There are things that you can do to support gut health. At this point, it’s not known exactly what the “best” gut microbiome is for eczema. People with eczema and other inflammatory conditions tend to have less diverse microbiomes.

Certain lifestyle choices can support greater diversity within your microbiome:

• Eating a high-fiber diet: A high-fiber diet is associated with greater diversity in your gut microbiome. Fiber sources feed healthy bacteria in your gut. You can get fiber in your diet from whole grains, nuts, seeds, beans, vegetables, and fruits.
• Incorporating fermented foods: Fermented foods are created using microbes. They are great sources of probiotics and can improve your gut health. Fermented foods include yogurt, kefir, tempeh, kimchi, and sauerkraut.
• Limiting alcohol intake: Alcohol intake is shown to change the gut microbiome. This can lead to gut dysbiosis. It’s best to reduce alcohol intake if you can.
• Managing stress: If you often feel stressed, you know that stress can really affect how you feel. Research suggests it may also change our microbiome. It’s not realistic to completely get rid of your stress, but finding ways to manage stress may help.

Takeaway

We have trillions of bacteria, fungi, and other living things that live in and on our body. This makes up our microbiome. Most of these microorganisms live on our skin and in our gut. These microorganisms are in constant communication. This is known as the gut-skin axis.

Everyone’s microbiome is a little different and there isn’t one perfect microbiome. There are distinct changes seen with certain conditions. People with eczema have different bacteria colonies compared to people without eczema.

There is belief that changing these colonies may play a part in treating eczema. Many current treatments reduce inflammatory bacteria and support the growth of helpful bacteria. There are things you can do to support a healthy and diverse gut microbiome. This may improve skin health, too.