Eczema and the Skin Microbiome
Wednesday 24th February 2021
Humans have over 1000 species of bacteria naturally living on the skin. The species vary on different areas of the body.
Most of these bacteria are commensals (non-harmful to us) and contribute to maintaining good health of the skin. They do this by taking up space, preventing pathogenic (disease causing) bacteria from taking up residence.
In addition, the commensal bacteria can actively protect the skin by secreting antimicrobial substances. Commensals also communicate with the skin immune system, directing it to attack disease-causing microbes or telling it to tolerate certain organisms or substances.
Eczema is a chronic inflammatory skin disease affecting up to 20% of the global population. The causes are multifactorial, and treatments are aimed mainly at reducing inflammation and improving the quality of the skin barrier.
In eczema sufferers a combination of skin barrier impairment and dysregulated immune response favours pathogenic bacterial growth - particularly of the species Staphylococcus aureus (S. aureus). S. aureus produces toxins which lead to eczema flares and infections, as the immune system reacts to these.
Eczema sufferers often have increased numbers of S. aureus and a less diverse population of bacteria on the skin. This is seen on the affected areas of skin as well as the non-affected areas, so there is a body-wide affected microbiome. Microbiome diversity is important as lower diversity is related to more severe eczema. More S. aureus are present during eczema flares and reduce in number when eczema has improved.
It seems that the gut microbiota diversity may have an impact on the early development of eczema. For example, infants with atopic eczema have less Bifidobacterial spp and low diversity of microbes early in life. So looking to the gut, and balancing the gut bacteria may be one therapeutic strategy.
The use of probiotic supplements for the treatment of eczema has been explored in several research studies. Overall results are promising, although mixed. The effect may depend on the species and strain of bacteria in the probiotic, so it is advisable to consult a health practitioner with probiotic knowledge if you are thinking of using probiotics to help your eczema.
Topical probiotics (directly on the skin) have been trialled in research, although there are only a few studies. Early results show that topicals can protect against the pathogenic bacteria and again this seems to be species specific. Clearly, the microbiome plays an important role in eczema and may be a target as a therapeutic approach.
However, it should be noted that eczema is a multi-factorial condition, and therefore a multi-pronged attack is often needed to get eczema flares under control and reduce their frequency. Each person's root causes of their eczema will be a different combination of factors which is why a holistic, Functional Medicine approach is the best approach for those seeking to tackle this distressing and debilitating chronic condition.
If you would like to find out more about how I can help you to seek out the root causes of your skin condition, please get in touch.