The Female Microbiome in Patients Undergoing Bladder Instillation Therapy

The underlying pathophysiology for BPS/IC is currently an active area of research. There is speculation that there may be alteration in the bladder and vaginal microbiome that contributes to the symptomatology of BPS/IC, however existing literature is limited and contradictory. Nickel et al (2015) studied the bladder microbiota in women with IC/BPS during a flare versus nonflare. The study collected initial stream and midstream urine specimens and detected overall, there was no significant differences in the species composition. However, a greater prevalence of fungi (Candida and Saccharomyces) was seen in the flare group (15.7%) versus the non-flare group (3.9%) midstream urine specimens. Pearce et al (2015) sought to characterize the urinary microbiome via catheterized specimens from women with urgency urinary incontinence, a condition that can present similarly as IC/BPS. The study found that more than half of the patients were sequence positive, most commonly for Lactobacillus (45%) or Gardnerella (17%), with 25% made up of various other bacteria. In contrast, Abernethy et al (2017) showed via catheterized urine specimens from patients with IC/BPS that the urinary microbiome is less diverse and less likely to contain Lactobacillus species. There have been two recent studies investigating the female urinary microbiome in patients with IC/BPS. Nickel et al (2019) found no differences in species composition between urine from patients with IC/BPS versus controls. Meriwether et al (2019) reported similar findings, and additionally found no differences when comparing the vaginal bacterial microbiome in patients with IC/BPS versus controls. However, in evaluating the bladder microbiome, both studies utilized uncatheterized urine specimens. Wolfe et al (2012) showed microbiome differences between clean-catch and catheterized urine specimens, therefore vaginal contamination in both studies cannot be ruled out.

This study uses samples collected under an interventional study and consented for use in future research - this study is use of those samples under the future research provision, and this study was deemed to meet exempt category 4.