Acne vulgaris (acne) is a chronic inflammatory skin disease, and the skin microbiome plays an important role in its pathogenesis and development. We aimed to investigate the characteristics of the facial skin microbiome of acne patients and microbiome differences related to different grades of acne

Acne vulgaris (acne) is a chronic inflammatory skin disease, and the skin microbiome plays an important role in its pathogenesis and development. We aimed to investigate the characteristics of the facial skin microbiome of acne patients and microbiome differences related to different grades of acne. Skin swabs from 67 patients with facial acne and 9 healthy controls were collected, and the composition and diversity of the skin microbiome were analysed using 16S rRNA (V4) gene sequencing. Significant differences in the facial skin microbiome were observed between the healthy controls and acne patients, with a differentiated beta diversity, a greater alpha diversity and increased abundances of Oscillospira, Enhydrobacter and Bacteroides in the acne patients. In addition, we found that the skin microbiome of the patients with grade 1-3 acne was similar, but patients with grade 4 acne harboured a significantly different skin microbiome compared with grade 1-3 acne, including increased alpha diversity and the proportions of Faecalibacterium, Klebsiella, Odoribacter and Bacteroides. In conclusion, the patients with acne harboured an altered skin microbiome, and more significant microbial dysbiosis was found in grade 4 acne (severe acne). Our findings may provide evidence for the pathogenic mechanisms of acne as well as microbial-based strategies to avoid and treat acne, especially grade 4 acne.