Characterizing the role of the urobiome in the pathogenesis of recurrent urinary tract infections (rUTIs): a systematic review.

PURPOSE: Recurrent urinary tract infections (rUTIs) are associated with substantial morbidity, repeated antibiotic exposure, and increasing antimicrobial resistance. Emerging evidence suggests that alterations in the urinary microbiome (urobiome) may contribute to rUTI pathogenesis. This systematic review evaluated the role of the urobiome in the development and recurrence of rUTIs. METHODS: This systematic review was conducted in accordance with the PRISMA 2020 guidelines. Literature searches were conducted and managed using Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia). Searches included Web of Science, MEDLINE, PubMed, and CINAHL and covered studies published from 2014 through 2026. The final search was conducted on February 1, 2026. The search incorporated terms related to 'urobiome,' 'urinary microbiome,' 'urinary tract infection,' and 'recurrent urinary tract infection.' Searches were restricted to English-language studies and human participants. After deduplication, 213 unique records underwent title and abstract screening, and 62 articles were assessed in full text. 21 studies that directly evaluated recurrent or chronic UTI populations, or reported an rUTI-specific subgroup, were included in the qualitative synthesis. Data extraction included study design, patient population characteristics, definitions of rUTI, urine collection methods, microbiome assessment methodology (including 16S rRNA sequencing and enhanced quantitative urine culture), reported microbial diversity measures, taxonomic findings, and associations between microbiome characteristics and rUTI outcomes. Given heterogeneity in study design, sequencing platforms, urine collection techniques, and definitions of rUTI across studies, a quantitative meta-analysis was not performed. Findings were synthesized descriptively, with emphasis on recurring microbial patterns, diversity measures, and clinically relevant urobiome alterations associated with recurrent infection. RESULTS: 21 studies met inclusion criteria. Recurrent urinary tract infection was associated with altered urinary microbial ecology although the direction of diversity changes varied across studies. Commonly reported differences included altered Lactobacillus abundance and enrichment of taxa, such as Gardnerella, Prevotella, and Enterobacterales. Mechanistic studies implicated intracellular bacterial persistence, biofilm formation, ecological shifts, and metabolite-microbiome interactions. Hormonal status and antibiotic exposure also influenced urobiome composition. Substantial methodological heterogeneity remained across studies. CONCLUSION: Current evidence supports a potential role for the urobiome in rUTI pathogenesis. Altered microbial diversity, loss of protective organisms, and persistent bacterial reservoirs may contribute to recurrence. Further standardized longitudinal and mechanistic studies are needed to clarify causality and guide microbiome-targeted therapeutic strategies.