Deep skin dysbiosis in vitiligo patients: link with mitochondrial and immune changes

Rationale: Vitiligo is an autoimmune-disease characterized by patchy, white skin due to melanocyte loss. Commensal cutaneous or gut dysbiosis have been linked to various dermatological disorders. Here, we studied skin and gut microbiota of vitiligo patients compared to healthy controls. Methods: We recruited 20 subjects and obtained swabs and biopsies from lesional and non-lesional skin, stool and blood from each individual (total 100 samples). Results: We detected reduced richness and distribution of microbiota in stool of vitiligo subjects compared to controls (P<0.01). Skin swabs had greater alpha-diversity than skin biopsies (P<0.001), however only trends were seen between groups when examining microbiota at the skin surface. This was in contrast to sampling deeper layers of skin from the same patients which showed decreased richness and distribution of species (P<0.01) but greater phylogenetic diversity (P<0.01) in lesional compared to non-lesional sites. Biopsy microbiota from the lesional skin had distinct microbiota composition which was depleted of protective Bifidobacterium and enriched in Terenicutes, Streptococcus, Mycoplasma and mitochondrial DNA (P<0.001); the latter was linked with increased innate immunity and stress markers in the blood of the same patients (P<0.05). Conclusion: These data describe vitiligo-specific cutaneous and gut microbiota and, for the first time in humans, a link between mitochondrial alteration, innate immunity and skin microbiota.