Although benzoyl peroxide (BPO) can improve Global Acne Grading System (GAGS) score, it can damage the epidermal barrier and reduce microbial diversity, according to findings from a study published in Dermatologic Therapy.
This study included 33 patients with acne (age 21.30±2.27 years) and 19 healthy control participants (age 24.05±2.27 years). These 2 groups did not differ significantly in terms of sex or body mass index. Topical BPO 5% gel was administered to all participants twice daily for 12 weeks, with analysis of the epidermal barrier performed at baseline and post-treatment.
During follow-up, all participants were provided with the same facial cleanser and instructed to use it exclusively. Skin microbial diversity was assessed with a high-throughput sequencing method that targeted 16S rRNA genes in the V3-V4 region. Kruskal-Wallis rank-sum tests were used to evaluate skin microbial diversity before and after treatment. The association between predominant skin microbes, microbial diversity index, and clinical data was assessed using Pearson’s correlation.
Following BPO treatment, those in the treatment group showed significant improvement in GAGS score (P <.001), red areas (P =.001), and porphyrin (P =.005), as well as increased transepidermal water loss (TEWL; 20.93±5.58 vs 17.74±6.98 g/hm≥2, respectively; P =.006), stratum corneum hydration (SCH; P =.009), and presence of sebum (P =.007). Compared with healthy control participants, microbial diversity was significantly reduced with the use of BPO (Simpson diversity index, P =.0017; Shannon diversity index, P =.0094; good coverage diversity index, P =.0017). There was an increase in Staphylococcus and a reduction in Cutibacterium after treatment, and a negative association was observed between Staphylococcus and SCH (P =.008; r=–0.286).
A limitation to the study is an inability to explain the causal relationship between Staphylococcus aureus, Cutibacterium acnes, Staphylococcus epidermidis, and the skin barrier, the researchers noted.
The study researchers concluded that “although BPO treatment for adolescents and young adults suffering from acne vulgaris may contribute to an improved GAGS score, it may lead to reduced skin microbial diversity and impaired epidermal barrier function manifested as decreased SCH and increased TEWL.” They further indicated that “the ability of BPO to treat acne vulgaris may partly depend on increasing the abundance of [S epidermis] and inhibiting the growth of C acnes.”
Zhou L, Chen L, Liu X, et al. The influence of benzoyl peroxide on skin microbiota and the epidermal barrier for acne vulgaris. Published online December 27, 2021. Dermatol Ther. doi:10.1111/dth.15288.