# Distinct microbiome profiles on vaginally inserted polypropylene midurethral mesh slings compared to vaginal, urinary, and skin microbiomes

## TL;DR

This study shows that polypropylene mesh slings used to treat urinary incontinence in women have unique microbial communities that may contribute to complications like chronic pain and mesh exposure.

## Contribution

The study identifies distinct microbiome profiles on midurethral mesh slings and links microbial differences to mesh-related complications.

## Key findings

- Mesh microbiomes were dominated by Firmicutes, Proteobacteria, and Actinobacteria, with high Enterococcus abundance.
- Microbial diversity was higher on mesh compared to vaginal and skin samples, but not urine.
- Differences in mesh microbiomes were associated with clinical complications like chronic pain.

## Abstract

Midurethral slings are widely used in the treatment of stress urinary incontinence in women. However, little is known about the microbiomes that develop on these implants, their relationship to the urinary and vaginal microbiomes, or their potential role in mesh-related complications. In this study, we characterized the microbiomes of explanted midurethral slings and examined associations with clinical complications. Seventy-four women provided a total of 397 samples, including explanted mesh, urine, and swabs from the vagina and groin or suprapubic skin. Participants were categorized into clinical groups: chronic pain, vaginal mesh exposure, lower urinary tract perforation, or recurrent incontinence (control group). Samples underwent 16S rRNA gene sequencing. The mesh microbiome was dominated by Firmicutes, Proteobacteria, and Actinobacteria, with Enterococcus particularly abundant. Microbial diversity was significantly higher in mesh samples compared to vaginal and skin swabs, but not urine. The mesh microbiome was compositionally distinct from the urinary, vaginal, and skin microbiomes, potentially reflecting vaginal microbiome alterations due to urinary incontinence at the time of implantation. Differences in microbial diversity in mesh and skin samples among women with pain suggest a possible microbial contribution to mesh complications. These findings demonstrate the presence of distinct, site-specific microbial communities on explanted midurethral slings, with potential implications for understanding mesh-related complications.

Stress urinary incontinence commonly affects women, and effective treatment is essential. Midurethral mesh slings have provided effective relief; however, long-term complications such as chronic pain, vaginal mesh exposure, and lower urinary tract perforation have emerged. The pathophysiology of these complications is not well understood but is thought to involve a heightened inflammatory response to mesh implants. The local microbiome may contribute to this inflammation. We have shown that the mesh samples harbored a distinct microbiome and that differences in microbial composition may be associated with mesh complications. Understanding the role of specific bacteria in modulating host responses may offer new insights into the pathogenesis of mesh complications and inform future clinical approaches.