A metagenomics study of the elbow of psoriasis subjects and their healthy relatives

Abstract

Introduction: Psoriasis is a multifaceted immune-mediated skin disease and has been associated with other comorbidities. Previous studies in psoriasis reported the abundance of microbial taxa above the species rank (family Firmicutes and genus Staphylococcus), or the combined abundance of multiple taxa (Corynebacterium, Propionibacterium, Staphylococcus, and Streptococcus) were associated with psoriasis [1–3]. Characterizing the skin microbiome of psoriasis subjects and family controls can further our understanding of microbiota’s role in this disease. Objectives: This study aims to reveal the difference of skin microbiome between skin lesion area and normal area of the elbow as well as family controls. Methods: DNA samples was extracted from 21 elbow-skin. 14 of 21 were from 7 psoriasis subjects’ lesion side and normal side. The rest were from a healthy family member whom the subject lives with. Shotgun metagenomic sequencing was adapted to resolute the skin microbiota. Partially overlapping t-test was used to investigate differentially abundant taxa. PERMANOVA was used to test the difference of microbial community composition influenced by psoriasis and sampling families. Results: Bacteria phyla Proteobacteria, Actinobacteria, and Bacteroidetes were three most abundant microbial taxa in both lesion and normal skin. Bacteria phyla Cyanobacteria and Candidatus Parcubacteria, family Hymenobacteraceae were less abundant on lesion skin than normal skin (p<0.05). Sampling families had significantly different elbow-skin microbial composition for bacterial genus level profile (p=0.001). Conclusions: Several bacterial taxa different from those previously discovered are more abundant on normal skin than lesion skin in the elbow. References: [1] Unexplored diversity and strain-level structure of the skin microbiome associated with psoriasis. NPJ Biofilms Microbiomes. 3,14 (2017). [2] Statnikov, A. et al. Microbiomic signatures of psoriasis: feasibility and methodology comparison. Sci. Rep. 3, 2620 (2013). [3] Alekseyenko, A. V. et al. Community differentiation of the cutaneous microbiota in psoriasis. Microbiome. 1, 31 (2013).