Urinary microbiome differences between lichen sclerosus induced and non-lichen sclerosus induced urethral stricture disease

Objective To describe differences in the urinary microbiome of patients with pathologically confirmed lichen sclerosus (LS) urethral stricture disease (USD) vs non-lichen sclerosus (non-LS) USD pre- and post-operatively. Methods Patients were pre-operatively identified and prospectively followed, all underwent surgical repair and had tissue samples obtained to make a pathological diagnosis of LS. Pre- and post-operative urine samples were collected. Bacterial genomic DNA was extracted. Alpha and beta diversity measurements were calculated and compared. A zero-inflated negative binomial model was utilized to compare taxa abundances between disease status and surgery status. Results Urine samples were obtained from both cohorts, 69 samples in total: 36 samples were obtained pre-operatively and 33 samples were obtained post-operatively. Ten patients provided both a pre-operative and post-operative urine sample. Twenty-six patients had pathological evidence of LS and 33 patients did not. There was a statistically significant difference in alpha diversity between the pre-operative urine samples of patients with non-LS USD and LS USD, (p = 0.01). There was no significant difference in alpha diversity within post-operative urine samples between patients with non-LS USD and LS USD, (p = 0.1). A significant difference was observed in Weighed UniFrac distances with respect to disease and operative status, (p = 0.001 and 0.002). Conclusions LS USD have significant alterations in diversity and differential abundance of urine microbiota compared to non-LS USD controls. These findings could be used to guide further investigations into the role of the urinary microbiome in LS USD pathogenesis, severity of presentation, and stricture recurrence.