The Urethral Microbiota: A Missing Link in the Female Urinary Microbiota

Area of Science:

• Microbiology
• Urology
• Gynecology

Background:

• The lower urinary tract microbiome is increasingly recognized for its role in urogenital health.
• Understanding the distinct microbial niches within the female urinary tract is crucial for identifying health and disease associations.

Purpose of the Study:

• To compare the urethral microbiota with the bladder urinary microbiota.
• To assess if urethral microbiota composition differs based on patient demographics and lower urinary tract symptoms.

Main Methods:

• Analysis of urine and swab samples from 49 women using Expanded Quantitative Urine Culture and MALDI-TOF mass spectrometry.
• Comparison of microbial diversity between sample types (bladder, urethra, periurethral, voided urine) using Bray-Curtis dissimilarity.
• Statistical analysis including Kruskal-Wallis, chi-square, and Fisher's exact tests to determine significance.

Main Results:

• Bladder microbiota were significantly different from urethral, periurethral, and voided urine microbiota (p <0.0001).
• Urethral and periurethral microbiota were similar, but urethral microbiota differed from voided urine microbiota (p=0.001).
• Younger women (<55 years) showed higher frequencies of *Lactobacillus* and *Gardnerella* in urethral samples compared to older women, correlating with premenopausal status and sexual activity.

Conclusions:

• Microbial niches in the female lower urinary tract are influenced by age, menopausal status, and sexual activity.
• No significant association was found between lower urinary tract symptoms and urethral bacterial composition.
• Further research is necessary to elucidate the functional and clinical significance of the urethral microbiome.