We’ve looked at the microbiome in eczema and now focus has turned to the microbiome in acne.
[Dréno B, Dagnelie MA, Khammari A et al. The Skin Microbiome : A New Actor in Inflammatory Acne. Am J Clin Dermatol 2020;21(Suppl 1):S18-S24.]
We know that the organism Cutibacterium acnes (formerly known as Proprionibacterium acnes) is resident in acne skin and contributes to the formation of acne. There have been studies which show that there is a loss of microbial diversity in acne skin and also there is a loss of balance between the different phylotypes or subtypes of C. acnes in acne, with phylotype 1A1 being the prominent phylotype.
What does phylotype 1A1 do?
Phylotype 1A1 is associated with an increase in innate immune cytokines which promote inflammation. We also know that if we increase the diversity of the types of C. acnes on the skin, this can reduce inflammation.
[Dagnelie MA, Corvec S, Saint-Jean M et al. Cutibacterium acnes phylotypes diversity loss: a trigger for skin inflammatory process. J Eur Acad Dermatol Venereol. 2019;33(12):2340-8.]
What about the gut microbiome?
Yes, the gut microbiome has been found to be different in acne patients compared to healthy controls.
There is decreased diversity of organisms which is thought to be due to the Western diet with its high consumption of refined carbohydrates, chocolate and saturated fats. Also a high ratio of omega-6 to omega-3 fatty acids, typically found in Western diets might also contribute.
[Deng Y, Wang H, Zhou J et al. Patients with acne vulgaris have a distinct gut microbiota in comparison with healthy controls. Acta Derm Venereol. 2018;98(8):783-90.]
So what is the solution?
So a possible aim would be to not to kill the organism C. acnes but to prevent or treat the microbial dysbiosis.
How do we do that?
Topical probiotics have been shown to directly alter the skin microbiome and subsequent immune response.
Oral probiotics can also alter the intestinal microflora and indirectly influence the skin.
[Yu Y, Dunaway S, Champer J et al. Changing our microbiome: probiotics in dermatology. Br J Dermatol 2020:182(1):38-46.]
The authors suggest that antimicrobial peptides (AMPs), which have been shown to play a role in other skin diseases such as psoriasis, atopic dermatitis and rosacea, may also play a role in the treatment of acne. They could be a novel topical antibiotic modulator of the microbiome on the skin.
They also suggest bacteriophages of naturally occurring C. acnes could be used to encourage repartitioning of the different phylotypes of C. acnes.
Lastly, they discuss acne immunotherapy by targeting virulence factors secreted by C. acnes. One such target is (wait for it!) Christie-Atkins-Munch-Peterson (CAMP) factor 2 which is secreted by C. acnes and triggers inflammatory responses. A study targeting CAMP factor 2 has shown that they can inhibit the pathogenicity of C. acnes.
[Wang Y, Hata TR, Tong YL et al. The anti-inflammatory activities of Proprionibacterium acnes CAMP factor-targeted acne vaccines. J Invest Dermatol. 2018:138(11):2355-64.]
So there is more work to be done and there are exciting times ahead in this field of acne but we may all soon be feeding our teenagers Korean kimchi to get their acne better!
Dr Sandy Flann, Consultant Dermatologist.