Pediatric urinary microbiome composition is associated with recurrent UTI

Recurrent urinary tract infections (UTIs) may alter the composition of the urinary microbiome (urobiome) in pediatric patients, according to recent data published in the Journal of Pediatric Urology.¹

Participants with a history of 3 or more UTIs had significantly reduced urobiome diversity compared with those with a history of only 1 UTI.

“Little is known about the urobiome in children,” explained co-author Tatyana A. Sysoeva, PhD, an associate professor of microbiology at the University of Alabama, Huntsville, in a news release on the findings.² “We only have sparse data as a field now. Our study is a pilot project aimed to characterize the urobiome of children to identify associations based on UTI history. We are showing that age, sex, and urinary tract infections affect urobiome composition. Other potential factors implicated are antibiotic use, circumcision, surgeries, and vesicouretheral reflux, but are not explored yet.”

Data from the study showed that pediatric urobiome composition varies by sex. Female participants had an insignificant increase of unique species compared with male participants, with a median of 31 species in females vs 16.5 species in males.

The urobiome of female participants also showed higher diversity per the inverse Simpson (P = .05) and Shannon indices (P = .04), but not based on the Pielou evenness index (P = .35) or the number of observed species (P = .11). Additionally, the urobiomes of female participants tended to overrepresent species from the genera Anaerococcus (P = .03), Prevotella (P = .04, and Schaalia (P = .02) compared with the urobiomes of males.

Among all patients, urobiome diversity was also shown to increase with age (rho = 0.45;P = .02). This trend was largely driven by the male participants, with samples from female participants generally unchanged by age (rho = −0.15; P = .62) and samples from male patients showing an increase in diversity as age increased (rho = 0.54; P = .07).

Additionally, findings showed that participants with a history of 3 or more UTIs had significantly reduced urobiome diversity compared with those with a history of only 1 UTI, per the Simpson (P = .03), Shannon (P = .05), and Pielou indices (P = .01). Further, the abundance of several bacteria was reduced among those with 3 or more prior UTIs compared with those who had 2 or fewer. Specifically, these were from the genera Enterococcus (decrease between 2 UTIs and 1 UTIs, P = .05), Lawsonella (decrease between 3+ UTIs vs 1 UTI, P = .05; decrease between 3+ UTIs vs 2, P = .07), and Corynebacterium (decrease between 1 UTI vs 3+, P = .05; decrease between 2 UTIs vs 3+, P = .07).

In total, the study included 54 children (31 females, 23 males) ranging from 3 months to 11 years in age (mean age, 40.7 months). Among all patients, 32% had 3 or more UTIs, 48% had 1 to 2 UTIs, and 17% never had a UTI.

Catheterized urine specimens were collected from children who had a voiding cystourethrogram conducted for a clinical indication. Overall, bacteria were detected in 61% of samples.

“We hope to learn more about the urinary tract and then be able to correlate predisposition to UTIs or other urological conditions with urobiome composition or marker microbe presence,” concluded Sysoeva in the news release.² “We will continue with pediatric and adult urobiome studies to better characterize development of the urobiome across the lifespan, to include studies of connections between recurrent UTI and urobiome, and work on characterizing those urinary microbes as well so we can understand how they function. We have a long road ahead of us.”

References

1. Kelly MS, Dahl EM, Jeries LM, et al. Characterization of pediatric urinary microbiome at species-level resolution indicates variation due to sex, age, and urologic history. J Pediatr Urol. 2024:S1477-5131(24)00280-8. doi:10.1016/j.jpurol.2024.05.016

2. One of the first of its kind, Uah study characterizes urinary microbes in children. News release. University of Alabama Huntsville. September 6, 2024. Accessed September 10, 2024. https://www.newswise.com/articles/one-of-the-first-of-its-kind-uah-study-characterizes-urinary-microbes-in-children