Altered Skin and Gut Microbiome in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by the formation of nodules, abscesses, and fistula at intertriginous sites. The skin-gut axis is an area of emerging research in inflammatory skin disease and is a potential contributory factor to the pathogenesis of HS. 59 patients with HS provided fecal samples, nasal and skin swabs of affected sites for analysis. 30 healthy controls provided fecal samples and 20 healthy controls provided nasal and skin swabs. We performed bacterial 16S rRNA gene amplicon sequencing on total DNA derived from the samples. Microbiome alpha diversity was significantly lower in the fecal, skin and nasal samples of individuals with HS which may be secondary to disease biology or related to antibiotic usage. Ruminococcus gnavuswas more abundant in the fecal microbiome of individuals with HS, which is also reported in Crohn’s disease (CD), suggesting comorbidity due to shared gut microbiota alterations. Finegoldia magnawas over-abundant in HS skin samples relative to healthy controls. It is possible local inflammation is driven by F. magnathrough promoting the formation of neutrophil extracellular traps (NET).These alterations in both the gut and skin microbiome in HS warrant further exploration, and therapeutic strategies including fecal microbiota transplant (FMT) or bacteriotherapy could be of benefit.