The link between eczema and gut health
Research suggests that there is a link between eczema and gut health. (1) Specifically, it states that a person’s gut flora may influence the skin, in what scientists call the gut-skin axis. The gut flora, referred to as the microbiome, is the collection of bacteria, fungi, and other microorganisms that live in and on the body. While many of these organisms live in the intestines, their impact extends far beyond digestion. 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. According to a 2021 study (1), many skin disorders often occur alongside an altered gut microbiome.
The human microbiome is composed of strains of bacteria that in excess could be pathogenic, in addition to numerous health-promoting non-pathogenic microorganisms. They live side-by-side and the body strives to maintain an appropriate balance between the two. To control the resident colonizing microflora, as well as to fight pathogens, via the immune system humans have developed defence mechanisms that in most cases effectively prevent the development of invasive microbial diseases. When there is an imbalance between pathogenic and health-promoting strains in the gut or skin flora, it is known as dysbiosis.
Dysbiosis has been associated with atopic dermatitis, which is a specific type of eczema. Atopic dermatitis symptoms are associated with the immune system; when the immune system perceives a threat on the skin, it creates inflammation in response. This is what causes the itchy rash.
What causes gut and skin dysbiosis?
Dysbiosis may develop due to several factors; amongst the most common are:
- These drugs don’t differentiate between the ‘good’ and ‘bad’ species of bacteria that live in the gut. They destroy non-pathogenic species and may enable the pathogenic species to proliferate. Repeated or long-term courses have been associated with dysbiosis.
- Laxatives, metformin and proton pump inhibitors (PPIs) (2)
- Smoking and nicotine. Research states people who smoke have higher levels of the unfriendly strains of bacteria, and less of the beneficial (friendly) strains (3)
- The Western diet tends to be high in food considered to be ‘pro-inflammatory’, which may contribute to dysbiosis
- Insufficient vitamin D. Sunlight contains UVB rays that allow the skin to make this vitamin that is associated with more diversity in the microbiome
Ways to Promote Good Gut Health
A 2021 study examined the effect of different foods on the composition of the gut microbiome. (4) The authors found that a certain diet links to higher amounts of microbial species that have anti-inflammatory effects. The eating plan the researchers tested had more focus on plant-based foods and less on animal-based foods.
- Foods to eat include: fruits, vegetables, pulses, nuts and seeds, low-fat fermented dairy foods such as yoghurt, fish
- Foods to limit include: alcoholic drinks, high-sugar food and drinks, high-fat processed meat
- Beneficial bacteria supplement. A number of studies have shown Lactobacillus and Bifidobacterium can be helpful for atopic dermatitis.(1) They may also have a protective effect on the microbiome when a person has to take antibiotics, which may reduce the risk of developing dysbiosis. Some earlier studies have not demonstrated this influence on atopic dermatitis. This suggests probiotics may not be a treatment for eczema but may help promote gut health or prevent imbalances. It should be noted that probiotic (beneficial bacteria) supplements are not always suitable for everyone
Making changes that promote a healthy microbiome may help some people with their symptoms. However, more research is considered to be necessary to understand how the microbiome may be relevant to eczema treatment.
Jackie Day ND
References
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916842/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6969170/
https://www.frontiersin.org/articles/10.3389/fendo.2021.667066/full