Urobiome composition varies with vesicoureteral reflux grade and history of febrile urinary tract infection.

Vesicoureteral reflux (VUR) is a risk factor for urinary tract infection (UTI). However, data describing the urobiome in children with VUR are limited. Here, we characterized the urobiome in children with and without VUR to better understand its potential role in VUR pathogenesis. Catheterized urine samples were obtained from children who presented for voiding cystourethrogram (VCUG) between 12/1/2020 and 10/3/2023. Children were excluded if they had any surgical procedures of the genitourinary tract in the 30 days prior to VCUG or were on treatment antibiotics at the time of VCUG. 16S rRNA gene sequencing and taxonomical classification identified the urobiome. Statistical models using distance, abundance and distribution-based approaches were used to associate the taxonomic profiles with clinical variables. In children with VUR, there is a positive association between history of febrile UTI and increasing abundance of Anaerococcus and decreasing abundance of Streptococcus, Ezakiella, and Corynebacterium. When examined together with age, sex, antibiotic prophylaxis, and highest grade of VUR, addition of the urobiome improved prediction of history of febrile UTI. Additionally, the urobiome is responsive to VUR grade, but does not predict VUR, and beta-diversity varies with higher grade VUR.