Psoriatic lesions are characterized by higher bacterial load and imbalance between Cutibacterium and Corynebacterium.

Background: Several studies have found that the microbiota of psoriatic lesions is different from that of healthy skin.

Objective: To characterize the microbiota of lesional and unaffected skin in patients with psoriasis and controls and investigate the correlation between cutaneous microbiota and clinical features of psoriasis.

Methods: Using quantitative polymerase chain reaction and 16S rRNA sequencing, we assayed the profiles of cutaneous microbiota in controls, unaffected skin, and psoriatic lesions. We also investigated the correlation of psoriasis-associated taxa with clinical characteristics.

Results: High bacterial load was identified in the psoriatic lesions compared with unaffected skin and controls. There was an imbalance between Cutibacterium (also known as Propionibacterium) and Corynebacterium in psoriatic skin. Lesions showed a higher proportion of Corynebacterium and a lower proportion of Cutibacterium compared with unaffected skin and controls. Corynebacterium was correlated with the severity of local lesions, whereas Cutibacterium showed correlation with the abnormity of skin capacitance.

Limitations: We did not conduct a longitudinal study.

Conclusions: Psoriatic lesions are characterized by higher bacterial load and imbalance between Cutibacterium and Corynebacterium.