With October being National Eczema Awareness Month, there is robust research about the power of the microbiome and eczema.
The power of the microbiome is on everyone’s mind. Research is growing on how the human microbiome works with exogenous exposures and the body to create a homogenous environment promoting ultimate health. An imbalance of the microbiome or "dysbiosis" can significantly impact the immune system, which can lead to the severity of inflammatory skin diseases such as atopic dermatitis, psoriasis, seborrheic dermatitis, hidradenitis suppurativa, acne vulgaris, and skin cancer. With October being National Eczema Awareness Month, there is robust research about the power of the microbiome and the disease, and sharing this information is vital as it is a component that could significantly influence the treatment of over 30 million people in the United States who suffer from it.
The fact that a healthy microbiome landscape is postulated to develop in the womb is critical regarding the possibility of preventing or decreasing inflammatory skin disease severity, such as atopic dermatitis. In early development, the microbiota protects the immune system from allergic over-sensitization, contrary to poor development or dysbiosis, which affects the cutaneous immune response, predisposing a child to atopic dermatitis or other immune conditions.1 A study published in the Journal of the American Society of Microbiology has "revealed important associations between the gut microbiome and eczema in infancy and has established the basis for the potential prevention and treatment of eczema via modulation of the gut microbiota."2 Although atopic dermatitis runs in families, it is impossible to explain its increased prevalence with genetics alone. The skin and gut microbiota can be continually affected by factors predisposing to AD, such as the Western diet and urban settings.1
One can think of the individual skin microbiome makeup as a "fingerprint" defining one's overall health. It is an essential part of our immune system and can protect us from harmful microbial species. Synergistically, a solid barrier and microbial balance with diverse species are vital to healthy skin, especially atopic dermatitis. However, it does not stop there, as the gut shares similar features with both highly innervated and vascularized surfaces covered with epithelial cells in direct communication with the exogenous environment. With the gut-skin axis, "the immune system is continuously primed to distinguish between harmful and beneficial compounds."3
We know the skin is acidic, with a pH ranging from 5.4 to 5.9, and it makes the environment uninhabitable to bacterial growth from the potential pathogens that can wreak havoc on the skin, cause exacerbations of eczema, and lead to infections. "Sebum produced by the sebaceous glands acts as a seal for hair follicles and contains several antimicrobial molecules and specific nutritional lipids for beneficial microorganisms."3 S.Aureus strives in less acidic environments, especially with the stratum corneum being less acidic.3 A higher percentage of S.Aureus is found in normal and affected skin in people with atopic dermatitis. Still, the increased number has not been shown to correlate with disease severity. However, other Staphylococcus species are found to be increased on the involved skin. Generally, a low diversity of microbiota is found in all ages with atopic dermatitis compared to people without the disease."In particular, inflamed AD skin is associated with a decrease in the genera Cutibacterium, Streptococcus, Acinetobacter, Corynebacterium, and Prevotella, and an increase of Staphylococcus, especially S. aureus.4
Genetics is the most substantial contributor to atopic dermatitis. However, looking at other contributing factors that can affect the severity is essential. The dermatology practitioner must take extra steps in counseling about the importance of the skin barrier, environmental exposures, and the powerful impact the microbiome can have on disease severity. Prebiotics and probiotics are showing some promise in restoring the gut microbiota balance that can ultimately slow down or stop the inflammatory cascade leading to skin diseases. And finally, diet can play a significant role in preventing dysbiosis and inflammation.
In the end, an increase in microbial diversity drives healthy skin, and more research is finding that this can stem from the gut overall. "There is a growing body of research on oral probiotics, prebiotics, and dietary modifications that may help improve symptoms for a variety of dermatologic conditions."5 Having a commensal bacterial landscape along with maintaining right from the beginning of one's life can have a tremendous impact. Educating our patients on the multifactorial approach to managing these inflammatory skin diseases, such as atopic dermatitis, is of the utmost importance for the best management approach.
1. Kim JE, Kim HS. Microbiome of the skin and gut in atopic dermatitis (AD): understanding the pathophysiology and finding novel management strategies. J Clin Med. 2019 Apr 2;8(4):444. doi: 10.3390/jcm8040 44.
2. Cheung MK, Leung TF, Tam WH, et al. Development of the early-life gut microbiome and associations with eczema in a prospective Chinese cohort. mSystems. 2023;e0052123. doi:10.1128/msystems.00521-23
3. De Pessemier B, Grine L, Debaere M, Maes A, Paetzold B, Callewaert C. Gut skin axis: current knowledge of the interrelationship between microbial dysbiosis and skin conditions. Microorganisms. 2021 Feb 11;9(2):353. doi: 10.3390/microorganisms9020353.
4. Hrestak D, Matijašić M, Čipčić Paljetak H, Ledić Drvar D, Ljubojvić Hadžavdić S, Perić M. Skin microbiota in atopic dermatitis. Int J Mol Sci. 2022 Mar 23;23(7):3503. doi: 10.3390/ijms23073503
5. Sinha S, Lin G, Ferenczi K. The skin microbiome and the gut-skin axis. Clin Dermatol. 2021 Sep-Oct;39(5):829-839. doi: 10.1016/j.clindermatol.2021.08.021.