Dynamic changes of the skin microbiome in vitiligo patients after intervention with phototherapy and topical steroids: An observational study

Background: Vitiligo is a chronic autoimmune disease resulting in progressive skin depigmentation. Several autoimmune diseases are associated with the cutaneous dysbiosis and immune abnormalities. Although previous studies have described the cutaneous microbiome in vitiligo, dynamic changes due to treatment remain unexplored. Objectives: This study aims to assess the impact of narrowband ultraviolet B phototherapy combined with topical steroids on the microbiome of vitiligo patients. Methods: We used full-length sequencing of the 16S rRNA genes (V1-V9 regions) to analyze the skin microbiome from skin swabs. We sampled the vitiligo patients at baseline and then divided them into two groups: One receiving only topical steroids and the other receiving combined topical steroids and phototherapy over three to 6 months. Results: The study included 21 vitiligo patients: 15 received topical steroids alone, 6 were treated with combined treatment, and 6 were healthy individuals as the control group. At baseline, bacterial composition differed between vitiligo patients and healthy controls, as demonstrated by relative abundance. While alpha and beta diversity showed no significant changes posttreatment, certain bacteria, such as Porphyromonas spp., Bacteroides salyersiae, Enterobacter kobei, and Corynebacterium coylea, became more abundant in vitiligo lesions. The homolactic fermentation and glycolysis pathways were more pronounced in controls than in baseline vitiligo patients. Conclusion: Despite exhibiting clinical improvements, the large-scale composition of bacteria did not show significant changes, as both the alpha and beta diversity remained stable after treatment with combined topical steroids and phototherapy. However, some specific bacterial taxa do exhibit dynamic changes. Our study indicates further investigation is required to identify possible key bacteria in the pathogenesis of vitiligo to guide future treatment strategies.