Loss of microbial diversity and body site heterogeneity in individuals with Hidradenitis Suppurativa

Hidradenitis Suppurativa (HS) is a chronic, scarring, inflammatory skin disease affecting hair follicles in axillae, inguinal, and anogenital regions. Dysbiosis in HS patients compared to healthy subjects is documented. However, whether dysbiosis is specific to particular body sites or skin niches is unknown. We investigated the follicular and skin surface microbiome of the axilla and groin of HS patients (n=11) and healthy individuals (n=10) using 16S rRNA gene sequencing (V3-V4). We sampled non-lesional (HSN) and lesional skin (HSL) of HS patients. β-diversity was significantly decreased (p<0.05) in HSN and HSL skin compared to normal skin with loss of body site and skin niche heterogeneity in HS samples. The relative bacterial abundance of specific microbes was also significantly different between normal and HSN (15 genera) or HSL (21 genera) skin. Smoking and alcohol use influenced the β-diversity (p<0.08) in HS skin. We investigated metabolic profiles of bacterial communities in HS and normal skin using a computational approach. Metabolism, Genetic Information Processing , and Environmental Information Processing were significantly different between normal and HS samples. Altered metabolic pathways associated with dysbiosis of HS skin suggest mechanisms underlying the disease pathology and information about treatment with drugs targeting those pathways. * FWER : family-wise error rate HS : Hidradenitis Suppurativa HSN : HS non-lesional HSL : HS lesional KEGG : Kyoto Encyclopedia of Genes and Genomes MCC : mock-community control MiRKAT : Microbiome Regression Kernel Association Test OTUs : operational taxonomic units PICRUSt : Phylogenetic Investigation of Communities by Reconstruction of Unobserved States PSU : pilosebaceous unit STAMP : Statistical Analysis of Metagenomic Profile