Evaluation of the urinary microbiota of women with uncomplicated stress urinary incontinence

doi:10.1016/j.ajog.2016.07.049

American Journal of Obstetrics and Gynecology

Volume 216, Issue 1, January 2017, Pages 55.e1-55.e16

https://doi.org/10.1016/j.ajog.2016.07.049 Get rights and content

Background

Female urinary microbiota are associated with urgency urinary incontinence and response to medication. The urinary microbiota of women with stress urinary incontinence has not been described.

Objective

We sought to study the cross-sectional relationships between urinary microbiota features and demographic and clinical characteristics of women undergoing stress urinary incontinence surgery.

Study Design

Preoperative urine specimens were collected from women without urinary tract infection and were available from 197 women (174 voided, 23 catheterized) enrolled in a multicenter prospective randomized trial, the Value of Urodynamic Evaluation study. Demographic and clinical variables were obtained including stress and urgency urinary incontinence symptoms, menopausal status, and hormone use. The bacterial composition of the urine was qualitatively assessed by sequencing the bacterial 16S ribosomal RNA gene. Phylogenetic relatedness and microbial alpha diversity were compared to demographics and symptoms using generalized estimating equation models.

Results

The majority of 197 urine samples (86%) had detectable bacterial DNA. Bacterial diversity was significantly associated with higher body mass index (P = .02); increased Medical, Epidemiologic, and Social Aspects of Aging urge index score (P = .04); and hormonal status (P < .001). No associations were detected with stress urinary incontinence symptoms. Increased diversity was also associated with a concomitant lower frequency of Lactobacillus in hormone-negative women.

Conclusion

Women undergoing stress urinary incontinence surgery have detectable urinary microbiota. This cross-sectional analysis revealed that increased diversity of the microbiota was associated with urgency urinary incontinence symptoms, hormonal status, and body mass index. In contrast, the female urinary microbiota were not associated with stress urinary incontinence symptoms.

Introduction

The influence of the human microbiota on health and disease is increasingly appreciated in a variety of medical fields.¹ These microbial communities are often described by their predominant organism, the diversity of organisms within the community, and the amount of those organisms.2, 3, 4

Female urinary microbiota (FUM), composed of resident bladder bacteria, were recently recognized when bacterial DNA and low levels of live bacteria were detected in catheterized urine specimens considered “sterile” by standard urine culture.5, 6, 7 Enhanced urine culture techniques have provided clear evidence that FUM microbes are alive; unlike standard urine culture protocols, these enhanced culture techniques provide the appropriate conditions for growth for a wide range of microbes.6, 8 The living microbial community within the female bladder may provide insight into a variety of common urinary disorders, including urinary incontinence and urinary tract infections (UTI). The presence and response to urgency urinary incontinence (UUI) treatment appears related to FUM diversity and/or composition in adult women with UUI.2, 9 There is also an association between the FUM and risk of UTI following urinary tract surgery¹⁰ or instrumentation.2, 5 However, there is a lack of information regarding the FUM of adult women with stress urinary incontinence (SUI). The 2 most common forms of bothersome urinary incontinence (UUI and SUI) often coexist in adult women, especially those seeking surgical treatment for SUI. Information concerning the FUM has the potential to further develop the phenotype of adult women affected by urinary incontinence, with the hope of improving the targeting of treatment to improve overall outcomes.

The National Institutes of Health sponsored a large, multicenter, clinical trial of women with uncomplicated SUI planning surgery and previously established a biorepository of urine samples collected for various scientific purposes.¹¹ In this substudy, we describe the FUM analysis using 16S ribosomal RNA (rRNA) gene sequencing to characterize the cross-sectional relationships between FUM parameters and demographic and clinical characteristics of adult women undergoing surgery for SUI.

Section snippets

Subject recruitment and urine collection

The Value of Urodynamic Evaluation study was an institutional review board–approved, multicenter prospective randomized trial comparing surgical outcomes using 2 strategies for presurgical testing: multichannel urodynamic testing vs standardized basic office evaluation.11, 12 Briefly, adult women were eligible if they had reported symptoms of SUI ≥3 months; a postvoid residual <150 mL; a negative urinalysis/standard urine culture; clinical assessment of urethral mobility; desire for SUI

Results

The demographic and clinical characteristics of the 197 participants we studied (Table 1) were similar to those of the overall trial population.¹¹ Most of these participants were non-Hispanic Caucasian (79%) and currently married (74%). The mean age of the subset was 51 (SD 9.7) years. Of women, 42% were premenopausal, 31% postmenopausal without current exogenous hormone use, and 18% were using exogenous hormones; the remaining 10% were unsure of their status. Consistent with the entrance

Main findings

In this study of women undergoing surgery for uncomplicated SUI, the presence of UUI symptoms appears related to increased microbial evenness, indicating that the FUM of women with UUI symptoms was less likely to be predominated by a single microbe. A similar relationship was observed between microbial evenness and both hormone status and BMI. The clinical impact of these findings is significant, given the common coexistence of UUI in women who undergo surgical SUI treatment. While considerable

Acknowledgment

We acknowledge and thank Meghan Pearce, PhD, MPH, for helping establish the DNA extraction and 16S rRNA sequencing protocol; Amy Rosenfeld, PhD, for performing the sequencing; and Eddi Lin, BS, and Qunfeng Dong, PHD, for the initial bioinformatics analysis.

References (33)

M.M. Pearce et al.
The female urinary microbiome in urgency urinary incontinence
Am J Obstet Gynecol
(2015)
C.S. Fok et al.
Day of surgery urine cultures identify urogynecologic patients at increased risk for postoperative urinary tract infection
J Urol
(2013)
C.W. Nager et al.
Design of the Value of Urodynamic Evaluation (ValUE) trial: a non-inferiority randomized trial of preoperative urodynamic investigations
Contemp Clin Trials
(2009)
L. Brubaker et al.
The new world of the urinary microbiota in women
Am J Obstet Gynecol
(2015)
L.M. Cipullo et al.
Pharmacological approach to overactive bladder and urge urinary incontinence in women: an overview
Eur J Obstet Gynecol Reprod Biol
(2014)
Y. Yu et al.
Effects of steroid hormones on morphology and vascular endothelial growth factor expression in female bladder
Urology
(2009)
S. Matsubara et al.
Estrogen levels influence beta-3-adrenoceptor-mediated relaxation of the female rat detrusor muscle
Urology
(2002)
I. Cho et al.
The human microbiome: at the interface of health and disease
Nat Rev Genet
(2012)
M.M. Pearce et al.
The female urinary microbiome: a comparison of women with and without urgency urinary incontinence
MBio
(2014)
M. Arumugam et al.
Enterotypes of the human gut microbiome
Nature
(2011)

L. Brubaker et al.

Urinary bacteria in adult women with urgency urinary incontinence

Int Urogynecol J

(2014)

E.E. Hilt et al.

Urine is not sterile: use of enhanced urine culture techniques to detect resident bacterial flora in the adult female bladder

J Clin Microbiol

(2014)

A.J. Wolfe et al.

Evidence of uncultivated bacteria in the adult female bladder

J Clin Microbiol

(2012)

T.K. Price et al.

The clinical urine culture: enhanced techniques improve detection of clinically relevant microorganisms

J Clin Microbiol

(2016)

K.J. Thomas-White et al.

Incontinence medication response relates to the female urinary microbiota

Int Urogynecol J

(2016)

C.W. Nager et al.

A randomized trial of urodynamic testing before stress-incontinence surgery

N Engl J Med

(2012)

Cited by (116)

Urinary microbiome community types associated with urinary incontinence severity in women
2024, American Journal of Obstetrics and Gynecology
Urinary microbiome (urobiome) studies have previously reported on specific taxa and community differences in women with mixed urinary incontinence compared with controls. Therefore, a hypothesis was made that higher urinary and vaginal microbiome diversity would be associated with increased urinary incontinence severity.
This study aimed to test whether specific urinary or vaginal microbiome community types are associated with urinary incontinence severity in a population of women with mixed urinary incontinence.
This planned secondary, cross-sectional analysis evaluated associations between the urinary and vaginal microbiomes and urinary incontinence severity in a subset of Effects of Surgical Treatment Enhanced With Exercise for Mixed Urinary Incontinence trial participants with urinary incontinence. Incontinence severity was measured using bladder diaries and Urinary Distress Inventory questionnaires collected at baseline. Catheterized urine samples and vaginal swabs were concurrently collected before treatment at baseline to assess the urinary and vaginal microbiomes. Of note, 16S rRNA V4 to V6 variable regions were sequenced, characterizing bacterial taxa to the genus level using the DADA2 pipeline and SILVA database. Using Dirichlet multinomial mixtures methods, samples were clustered into community types based on core taxa. Associations between community types and severity measures (Urinary Distress Inventory total scores, Urinary Distress Inventory subscale scores, and the number of urinary incontinence episodes [total, urgency, and stress] from the bladder diary) were evaluated using linear regression models adjusted for age and body mass index. In addition, alpha diversity measures for richness (total taxa numbers) and evenness (proportional distribution of taxa abundance) were analyzed for associations with urinary incontinence episodes and community type.
Overall, 6 urinary microbiome community types were identified, characterized by varying levels of common genera (Lactobacillus, Gardnerella, Prevotella, Tepidimonas, Acidovorax, Escherichia, and others). The analysis of urinary incontinence severity in 126 participants with mixed urinary incontinence identified a Lactobacillus-dominated reference group with the highest abundance of Lactobacillus (mean relative abundance of 76%). A community characterized by fewer Lactobacilli (mean relative abundance of 19%) and greater alpha diversity was associated with higher total urinary incontinence episodes (2.67 daily leaks; 95% confidence interval, 0.76–4.59; P=.007) and urgency urinary incontinence episodes (1.75 daily leaks; 95% confidence interval, 0.24–3.27; P=.02) than the reference group. No significant association was observed between community type and stress urinary incontinence episodes or Urogenital Distress Inventory total or subscores. The composition of vaginal community types and urinary community types were similar but composed of slightly different bacterial taxa. Vaginal community types were not associated with urinary incontinence severity, as measured by bladder diary or Urogenital Distress Inventory total and subscale scores. Alpha diversity indicated that greater sample richness was associated with more incontinence episodes (observed genera P=.01) in urine. Measures of evenness (Shannon and Pielou) were not associated with incontinence severity in the urinary or vaginal microbiomes.
In the urobiome of women with mixed urinary incontinence, a community type with fewer Lactobacilli and more diverse bacteria was associated with more severe urinary incontinence episodes (total and urgency) compared with a community type with high predominance of a single genus, Lactobacillus. Whether mixed urinary incontinence severity is due to lesser predominance of Lactobacillus, greater presence of other non–Lactobacillus genera, or the complement of bacteria consisting of urobiome community types remains to be determined.
Urinary microbiota and serum metabolite analysis in patients with diabetic kidney disease
2023, Heliyon
Diabetic kidney disease (DKD) is a common and potentially fatal consequence of diabetes. Chronic renal failure or end-stage renal disease may result over time. Numerous studies have demonstrated the function of the microbiota in health and disease. The use of advanced urine culture techniques revealed the presence of resident microbiota in the urinary tract, undermining the idea of urine sterility. Studies have demonstrated that the urine microbiota is related with urological illnesses; nevertheless, the fundamental mechanisms by which the urinary microbiota influences the incidence and progression of DKD remain unclear. The purpose of this research was to describe key characteristics of the patients with DKD urinary microbiota in order to facilitate the development of diagnostic and therapeutic for DKD.
We evaluated the structure and composition of the microbiota extracted from urine samples taken from DKD patients (n = 19) and matched healthy controls (n = 15) using 16S rRNA gene sequencing. Meanwhile, serum metabolite profiles were compared using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Associations between clinical characteristics, urine microbiota, and serum metabolites were also examined. Finally, the interaction between urine microbiota and serum metabolites was clarified based on differential metabolite abundance analysis.
The findings indicated that the DKD had a distinct urinary microbiota from the healthy controls (HC). Taxonomic investigations indicated that the DKD microbiome had less alpha diversity than a control group. Proteobacteria and Acidobacteria phyla increased in the DKD, while Firmicutes and Bacteroidetes decreased significantly (P < 0.05). Acidobacteria was the most prevalent microbiota in the DKD, as determined by the Linear discriminant analysis Effect Size (LEfSe) plot. Changes in the urinary microbiota of DKD also had an effect on the makeup of metabolites. Short-chain fatty acids (SCFAs) and protein-bound uremic toxins (PBUTs) were shown to be specific. Then we discovered that arginine and proline metabolism was the primary mechanism involved in the regulation of diabetic kidney disease.
This study placed the urinary microbiota and serum metabolite of DKD patients into a functional framework and identified the most abundant microbiota in DKD (Proteobacteria and Acidobacteria). Arginine metabolites may have a major effect on DKD patients, which correlated with the progression of DKD.
Urinary microbiota and metabolic signatures associated with inorganic arsenic-induced early bladder lesions
2023, Ecotoxicology and Environmental Safety
Inorganic arsenic (iAs) contamination in drinking water is a global public health problem, and exposure to iAs is a known risk factor for bladder cancer. Perturbation of urinary microbiome and metabolome induced by iAs exposure may have a more direct effect on the development of bladder cancer. The aim of this study was to determine the impact of iAs exposure on urinary microbiome and metabolome, and to identify microbiota and metabolic signatures that are associated with iAs-induced bladder lesions. We evaluated and quantified the pathological changes of bladder, and performed 16S rDNA sequencing and mass spectrometry-based metabolomics profiling on urine samples from rats exposed to low (30 mg/L NaAsO₂) or high (100 mg/L NaAsO₂) iAs from early life (in utero and childhood) to puberty. Our results showed that iAs induced pathological bladder lesions, and more severe effects were noticed in the high-iAs group and male rats. Furthermore, six and seven featured urinary bacteria genera were identified in female and male offspring rats, respectively. Several characteristic urinary metabolites, including Menadione, Pilocarpine, N-Acetylornithine, Prostaglandin B1, Deoxyinosine, Biopterin, and 1-Methyluric acid, were identified significantly higher in the high-iAs groups. In addition, the correlation analysis demonstrated that the differential bacteria genera were highly correlated with the featured urinary metabolites. Collectively, these results suggest that exposure to iAs in early life not only causes bladder lesions, but also perturbs urinary microbiome composition and associated metabolic profiles, which shows a strong correlation. Those differential urinary genera and metabolites may contribute to bladder lesions, suggesting a potential for development of urinary biomarkers for iAs-induced bladder cancer.
Effects of aging on urinary tract epithelial homeostasis and immunity
2023, Developmental Biology
A global increase in older individuals creates an increasing demand to understand numerous healthcare challenges related to aging. This population is subject to changes in tissue physiology and the immune response network. Older individuals are particularly susceptible to infectious diseases, with one of the most common being urinary tract infections (UTIs). Postmenopausal and older women have the highest risk of recurrent UTIs (rUTIs); however, why rUTIs become more frequent after menopause and during old age is incompletely understood. This increased susceptibility and severity among older individuals may involve functional changes to the immune system with age. Aging also has substantial effects on the epithelium and the immune system that led to impaired protection against pathogens, yet heightened and prolonged inflammation. How the immune system and its responses to infection changes within the bladder mucosa during aging has largely remained poorly understood. In this review, we highlight our understanding of bladder innate and adaptive immunity and the impact of aging and hormones and hormone therapy on bladder epithelial homeostasis and immunity. In particular, we elaborate on how the cellular and molecular immune landscape within the bladder can be altered during aging as aged mice develop bladder tertiary lymphoid tissues (bTLT), which are absent in young mice leading to profound age-associated change to the immune landscape in bladders that might drive the significant increase in UTI susceptibility. Knowledge of host factors that prevent or promote infection can lead to targeted treatment and prevention regimens. This review also identifies unique host factors to consider in the older, female host for improving rUTI treatment and prevention by dissecting the age-associated alteration of the bladder mucosal immune system.
Possibilities and limitations of using low biomass samples for urologic disease and microbiome research
2022, Prostate International
With the dogma of sterile urine no longer held as truth, numerous studies have implicated distinct changes in microbial diversity and composition to diseased subgroups in both benign and malignant urological diseases, ranging from overactive bladder to bladder and prostate cancer. Further facilitated by novel and effective techniques of urine culture and sequencing, analysis of the genitourinary microbiome holds high potential to identify biomarkers for disease and prognosis. However, the low biomass of samples included in microbiome studies of the urinary tract challenge researchers to draw definitive conclusions, confounded by technical and procedural considerations that must be addressed. Lack of samples and adequate true negative controls can lead to overestimation of microbial influence with clinical relevance. As such, results from currently available studies and assessment of their limitations required a thorough understanding. The purpose of this narrative review was to summarize notable microbiome studies in the field of urology with a focus on significant findings and limitations of study design. Methodological considerations in future research are also discussed.
Recurrent urinary tract infection and estrogen shape the taxonomic ecology and function of the postmenopausal urogenital microbiome
2022, Cell Reports Medicine
Citation Excerpt :
Cluster 1 taxa included genera associated with vaginal infections, such as Bacteroides and Blautia.51 Cluster 2 exhibited the largest member set and diversity, and captured associations between urogenital microbiome genera (i.e., Peptoniphilus and Finegoldia) but whose association has not yet been reported.52,53 Cluster 2 grouped strongly around the genus Peptoniphilus.
Postmenopausal women are severely affected by recurrent urinary tract infection (rUTI). The urogenital microbiome is a key component of the urinary environment. However, changes in the urogenital microbiome underlying rUTI susceptibility are unknown. Here, we perform shotgun metagenomics and advanced culture on urine from a controlled cohort of postmenopausal women to identify urogenital microbiome compositional and function changes linked to rUTI susceptibility. We identify candidate taxonomic biomarkers of rUTI susceptibility in postmenopausal women and an enrichment of lactobacilli in postmenopausal women taking estrogen hormone therapy. We find robust correlations between Bifidobacterium and Lactobacillus and urinary estrogens in women without urinary tract infection (UTI) history. Functional analyses reveal distinct metabolic and antimicrobial resistance gene (ARG) signatures associated with rUTI. Importantly, we find that ARGs are enriched in the urogenital microbiomes of women with rUTI history independent of current UTI status. Our data suggest that rUTI and estrogen shape the urogenital microbiome in postmenopausal women.

View all citing articles on Scopus

: Supported by National Institutes of Health (NIH) grants U01 DK58229 and R21 DK097435 (to A.J.W. and L.B.). Loyola University Chicago Stritch School of Medicine’s research computing facility was developed through grant funds awarded by the Department of Health and Human Services as award number 1G20RR030939-01. Our funding sources had no role in design and conduct of the study; collection, management, analysis, and interpretation of the data; or preparation, review, and approval of the manuscript. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Urinary Incontinence Treatment Network and investigators were supported by cooperative agreements from the NIDDK, U01 DK58225, U01 DK58229, U01 DK58231, U01 DK58234, U01 DK60379, U01 DK60380, U01 DK60393, U01 DK60395, U01 DK60397, and U01 DK60401. Support was also provided by the Office of Research in Women's Health, NIH. Registered at www.clinicaltrials.gov as NCT00803959.

: Disclosure: Dr Rickey has been a paid consultant for Analytica and Health Monitor Network. Dr Lukacz received a grant from Uroplasty and research support from Pfizer. Dr Richter has been a paid consultant for Kimberly Clark. Dr Wolfe received research support from Astellas Scientific and Medical Affairs. Drs Lukacz, Rickey, Richter, and Brubaker received editorial royalties from Up to Date.

: Cite this article as: Thomas-White KJ, Kliethermes S, Rickey L, et al. Evaluation of the urinary microbiota of women with uncomplicated stress urinary incontinence. Am J Obstet Gynecol 2017;216:55.e1-16.

¹: These authors contributed equally to this article.

View full text

Published by Elsevier Inc.

Original ResearchGynecologyEvaluation of the urinary microbiota of women with uncomplicated stress urinary incontinence

Background

Objective

Study Design

Results

Conclusion

Introduction

Section snippets

Subject recruitment and urine collection

Results

Main findings

Acknowledgment

Am J Obstet Gynecol

J Urol

Contemp Clin Trials

Am J Obstet Gynecol

Eur J Obstet Gynecol Reprod Biol

Urology

Urology

The human microbiome: at the interface of health and disease

Nat Rev Genet

The female urinary microbiome: a comparison of women with and without urgency urinary incontinence

MBio

Enterotypes of the human gut microbiome

Nature

Urinary bacteria in adult women with urgency urinary incontinence

Int Urogynecol J

Urine is not sterile: use of enhanced urine culture techniques to detect resident bacterial flora in the adult female bladder

J Clin Microbiol

Evidence of uncultivated bacteria in the adult female bladder

J Clin Microbiol

The clinical urine culture: enhanced techniques improve detection of clinically relevant microorganisms

J Clin Microbiol

Incontinence medication response relates to the female urinary microbiota

Int Urogynecol J

A randomized trial of urodynamic testing before stress-incontinence surgery

N Engl J Med

Original Research
Gynecology
Evaluation of the urinary microbiota of women with uncomplicated stress urinary incontinence