Microbiome in urological diseases: Axis crosstalk and bladder disorders

The gut microbiome and metabolome in children with a first febrile urinary tract infection: a pilot study

BACKGROUND

Urinary tract infection (UTI) is a common bacterial infection in the pediatric population. Febrile urinary tract infection (fUTI) can lead to severe complications such as urosepsis as well as kidney scarring, chronic kidney disease, and systemic hypertension. Recent research supports the hypothesis that dysbiosis of the microbiome may play a role in the pathogenesis and development of fUTI in infants. Our main aim was to compare the shift in gut microbiota composition between children with the first fUTI and controls.

METHODS

We conducted an observational study with 17 children with the first fUTI compared to 18 healthy controls. We performed analysis of the gastrointestinal microbiome and measurements of metabolites in stool and urine.

RESULTS

In the gut microbiome, we found significant differences with lower α-diversity the Shannon index) and significantly lower relative abundance of probiogenic bacteria (short-chain fatty acids (SCFA)) in children with the first episode of fUTI before the start of antibiotic therapy. Furthermore, our findings confirm that the length of breastfeeding has significant influence on gut microbiota composition, reducing pathogenic bacteria and enhancing beneficial taxa. Shannon diversity, duration of breastfeeding, and specific taxa, particularly Faecalibacterium and Escherichia, emerged as strong predictors linked to the development of fUTI.

CONCLUSIONS

This study demonstrates that gut microbiome changes are associated with the onset of fUTI in children. Machine learning models identified Shannon index, specific bacterial taxa, and breastfeeding as strong predictors of fUTI. The study highlighted the potential role of the gut microbiome in preventing fUTI.

Emergence of Recurrent Urinary Tract Infection: Dissecting the mechanism of Antimicrobial Resistance, Host-Pathogen Interaction, and Hormonal Imbalance

Urinary tract infection is one of the most common infections worldwide, causing numerous deaths every year. The gut-bladder axis has been recently found to be a key factor in initiating UTI pathogenesis, along with the imbalance in the gut microbiome, which is associated with advanced susceptibility to rUTI. The patients who suffer from UTIs are, more often than not, the ones who have the lowest levels of butyrate-producing gut bacteria. Antibiotics cause dysbiosis in the gut and increase the growth of uropathogenic strains. Moreover, the gut-vagina and vagina-bladder axes are involved in UTIs by transferring microbial species, modulating the immune response, and developing intracellular bacterial reservoirs in the bladder. The rising usage of antibiotics has raised antimicrobial resistance (AMR) worldwide and recently worsened the treatment of UTIs. Resistance mechanisms include enzymatic hydrolysis of antibiotics, efflux systems, biofilm formation, horizontal gene transfer, and a weakened host's immune system, allowing bacteria to escape from the treatments. Besides, in pregnant women and adolescents, the alterations in sex hormone levels increase the risk of rUTIs. Knowledge of microbiota that harbor in the gut-vagina and vagina-bladder axes might lead to the invention of nonantibiotic preventive and therapeutic techniques in the future. In conclusion, this review emphasizes the need for a study to understand the host-microbe interactions, gut health, and AMR to effectively deal with and prevent recurrent UTIs. Also, the review explores a comprehensive analysis of the epigenetic network between host UTIs and marker genes in E. coli.

Long-Term Antibiotics for Disturbed Bladder Microbiome Disorders

INTRODUCTION AND HYPOTHESIS

In recent years, there has been significant progress in understanding bladder disorders and their connection to the bladder microbiome. Emerging evidence suggests that the bladder microbiome, which is unique to each individual, plays a pivotal role in maintaining bladder health. Disruptions to the normal microbiome composition have been associated with various pathological conditions such as recurrent urinary tract infections, interstitial cystitis, and chronic recalcitrant cystitis.

METHODS

We completed a focused literature review to collect studies that evaluated the use of antibiotics for long-term treatment (more than 28 days) of infectious/inflammatory disturbed bladder microbiome DBM disorders.  RESULTS: This article reviews current literature on the composition of the bladder microbiome, describes the disorders associated with DBM, explores the utility of long-term antibiotics in managing DBM, and foresees future venues for DBM disorders research.

CONCLUSION

This review has demonstrated encouraging outcomes regarding the use of long-term antibiotics in managing infectious disorders of DBM, such as recurrent urinary tract infections and chronic recalcitrant cystitis, while no benefit was seen in interstitial cystitis patients. The studies showed that long-term cephalexin, fluoroquinolones, and fosfomycin are well-tolerated and effective options, with cephalexin being favored given its low side-effect profile.

Neural crosstalk and symptom overlap: The correlation between urinary and intestinal symptoms in patients undergoing colonoscopy

PURPOSE

Neural crosstalk in the pelvis involves intrinsic communication networks among pelvic structures that direct afferent inputs to converge on neurons, leading to viscerovisceral and somatovisceral reflexes. We aimed to explore the overlap between intestinal and urinary symptoms and their correlations in patients undergoing colonoscopy.

MATERIALS AND METHODS

Cross-sectional study with 167 participants who underwent colonoscopy and were assessed using three self-administered questionnaires: the International Prostate Symptom Score (IPSS) for lower urinary tract symptoms, the International Consultation on Incontinence Questionnaire Overactive Bladder (ICIQ-OAB) for overactive bladder symptoms, and the Gastrointestinal Symptom Rating Scale (GSRS) for gastrointestinal (GI) symptoms.

RESULTS

Among the participants, 55.1% were male, and the median age was 57 years. Most colonoscopies (80.8%) were performed for screening, and the most common finding was diverticular disease (DD) (35.9%). The IPSS and ICIQ-OAB were strongly correlated (rho=0.544, p<0.001), while the IPSS and GSRS scores showed a moderate correlation (rho=0.304, p<0.001). In the DD subgroup, both ICIQ-OAB and IPSS (rho=0.568, p<0.001), and IPSS and GSRS (rho=0.493, p<0.001) showed strong correlations. In contrast, the subgroup without DD showed a strong correlation between the ICIQ-OAB and IPSS (rho=0.510, p<0.001), but only a weak correlation between the IPSS and GSRS (rho=0.188, p=0.057), suggesting that the urinary-GI connection is influenced by the presence of DD.

CONCLUSIONS

The findings revealed intrinsic relationships between urinary and GI symptoms, with DD as a significant factor influencing these relationships, suggesting that a more integrated approach to evaluate and manage these patients can potentially improve diagnostic accuracy and treatment outcomes.

Unveiling the microbial orchestra: exploring the role of microbiota in cancer development and treatment

The human microbiota comprises a diverse microbial ecosystem that significantly impacts health and disease. Among its components, the gut microbiota plays a crucial role in regulating metabolic, immunologic, and inflammatory responses. Dysbiosis, an imbalance in microbial composition, has been linked to carcinogenesis through mechanisms such as chronic inflammation, metabolic disturbances, epigenetic modifications, and immune system dysregulation. Additionally, dysbiosis influences the efficacy and toxicity of cancer therapies. Given these associations, there is growing interest in leveraging the microbiota as a biomarker for cancer detection and outcome prediction. Notably, distinct microbial signatures have been identified across various cancer types, suggesting their potential as diagnostic markers. Furthermore, modulation of the microbiota presents a promising avenue for improving cancer treatment outcomes through strategies such as antibiotics, prebiotics, probiotics, fecal microbiota transplantation, dietary interventions, small-molecule inhibitors, and phage therapy. To explore these relationships, we conducted a comprehensive literature review using Web of Science, Scopus, PubMed, MEDLINE, Embase, and Google Scholar as our primary online databases, focusing on indexed peer-reviewed articles up to the present year. This review aims to elucidate the role of dysbiosis in cancer development, examine the molecular mechanisms involved, and assess the impact of microbiota on cancer therapies. Additionally, we highlight microbiota-based therapeutic strategies and discuss their potential applications in cancer management. A deeper understanding of the intricate interplay between the microbiota and cancer may pave the way for novel approaches to cancer prevention, early detection, and treatment optimization.

Dextrose Prolotherapy's Impact on the Urinary Microbiome in Interstitial Cystitis/Bladder Pain Syndrome

Background: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating chronic condition affecting millions globally. Dextrose prolotherapy, a minimally invasive and safe treatment, has emerged as a potential way to promote tissue healing in these patients. This study investigates how dextrose prolotherapy impacts the urinary microbiome, aiming to uncover the underlying mechanisms involved in its effectiveness. Methods: Midstream urine samples from healthy controls and IC/BPS patients were collected before and after administering intravesical 10% dextrose injections. Microbiome profiling was conducted using 16S rRNA gene sequencing to analyze bacterial composition. Results: Significant differences in urinary microbiome diversity were observed between healthy controls and IC/BPS patients. Proteobacteria, Firmicutes, and Bacteroidota were more abundant in IC/BPS patients. Importantly, dextrose prolotherapy led to a decrease in harmful bacteria (Subgroup_22, Chryseolinea, and Ureaplasma) while enriching beneficial species such as Luteolibacter, Lactococcus, and L. lactis, correlating with improved clinical symptoms. Conclusions: Dextrose prolotherapy (DP) not only reduces the presence of harmful bacteria but also fosters the growth of beneficial microbes in IC/BPS patients. These findings suggest that the modulation of the urinary microbiome may be a key factor in its therapeutic success.

Novel technologies for the diagnosis of urinary tract infections

Urinary tract infections (UTIs) impose a substantial burden on patient quality of life and urine testing accounts for the majority of workload in many clinical microbiology laboratories. Traditional UTI diagnosis relies on symptoms, urinalysis, and culture which are interpreted based on historical guidelines. This approach, while foundational, presents limitations, particularly in complex cases. Low-level bacteriuria and the presence of fastidious organisms are often overlooked or entirely missed in standard urine culture, stressing the need for novel diagnostic methods and technologies. This mini-review summarizes the existing state of UTI diagnostics in 2024 and covers current and upcoming technologies including rapid molecular-based pathogen identification, next-generation sequencing, and advanced antimicrobial susceptibility testing. However, these methods represent unique challenges, and as they are implemented, they will require the field to adapt to new concepts to avoid misdiagnosis and overtreatment.

Microbiome and bladder cancer: the role of probiotics in treatment

Bladder cancer (BCa) remains a significant global health challenge, with increasing interest in the role of the bladder microbiome in its pathogenesis, progression and treatment outcomes. The complex relationship between bladder cancer and the microbiome, as well as the potential impact of probiotics on treatment effectiveness, is currently under investigation. Research suggests that the microbiota may influence BCa recurrence prevention and enhance the efficacy of the Bacillus Calmette-Guérin (BCG) vaccine. Recent studies reveal differences in the bladder microbiome between individuals without bladder cancer and those with the disease. In the healthy bladder, Streptococcus and Lactobacillus are consistently identified as the most prevalent genera. However, in men, the predominant bacterial genera are Staphylococcus, Corynebacterium and Streptococcus, while in women with bladder cancer, Gardnerella and Lactobacillus are dominant. Probiotics, particularly Lactobacillus spp., can exhibit anti-tumor properties by competing with pathogenic strains involved in carcinogenesis or by producing regulatory substances. They regulate cancer signaling, induce apoptosis, inhibit mutagenic activity, downregulate oncogene expression, induce autophagy, inhibit kinases, reactivate tumor suppressors and prevent metastasis. These mechanisms have shown promising results in both preclinical and some clinical studies.

Associations of overactive bladder (OAB) with suicidal ideation incidence and all-cause mortality among the U.S. population

BACKGROUND

Few studies have explored the correlation between overactive bladder (OAB) and suicidal ideation. This study aims to investigate the association between OAB and suicidal ideation, as well as the relationship between OAB and all-cause mortality among individuals with suicidal ideation.

METHODS

Data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) were analyzed using cross-sectional and cohort study designs. Weighted multivariable logistic regression models were used to examine the association between OAB and suicidal ideation. Kaplan-Meier curves and weighted multivariable Cox proportional hazards models assessed the relationship between OAB and all-cause mortality among those with suicidal ideation. Interaction analyses on subgroups were conducted to validate the findings. Mediation analysis was performed to examine the effect of depression on the relationship between OAB and suicidal ideation.

RESULTS

Among 33,426 participants aged ≥ 20 years, 1,290 (3.8%) reported suicidal ideation. After adjusting for potential confounders, participants with OAB were 2.57 times more likely to have suicidal ideation (P < 0.001). Over an average follow-up of 87 months, 197 participants with suicidal ideation died. The Cox model revealed that participants with OAB had a 3.08 times higher risk of death (P = 0.006). Kaplan-Meier curves indicated higher survival rates for non-OAB participants. Mediation analysis indicates that depression significantly mediates the relationship between OAB and suicidal ideation, with a mediation proportion of 75.25% (P < 0.001).

CONCLUSIONS

OAB is positively associated with the incidence of suicidal ideation and all-cause mortality among participants with suicidal ideation. Additionally, the association between OAB and suicidal ideation is mediated by depression.

Unraveling the association of bacteria and urinary stones in patients with urolithiasis: an update review article

Urinary stone disease (USD) is a prevalent urological condition, ranking as one of the most common urinary tract disorders globally. Various risk factors influence the formation of kidney stones, and recent research indicates a rising prevalence of urolithiasis worldwide, particularly in developing countries. While the morbidity associated with urinary stones has decreased in recent years, long-term complications such as stone recurrence, kidney failure, and uremia continue to burden patients. Understanding the etiologies of urolithiasis, including the role of bacteria, is crucial as they can contribute to stone recurrence. The incidence of urinary tract infection (UTI) stones can be attributed to specific infectious risk factors, socio-demographic factors, and comorbid metabolic disorders. This review article explores the emerging evidence suggesting the involvement of bacteria in USD. It discusses the potential role of microorganisms in non-infection stones and highlights the association between UTIs and urolithiasis. Furthermore, it surveys the relationship between kidney stones and recurrent UTIs and the formation of bacterial biofilms in UTIs. Considering various risk factors, including biochemical stone analysis and the presence of bacteria, is essential for treating patients with infectious stones optimally. This review aims to provide an updated understanding of the association between bacteria and urinary stones in patients with urolithiasis, shedding light on the pathophysiology of urinary stone formation, urinary stone characteristics, and the urinary microbiome in urinary stones.

Lactobacillus-Polydopamine System for Targeted Drug Delivery in Overactive Bladder: Evidence from Bladder Cell Spheroids, Rat Models, and Urinary Microbiome Profiling

INTRODUCTION

Overactive bladder (OAB) is a highly prevalent condition with limited treatment options due to poor efficacy, side effects, and patient compliance. Novel drug delivery systems that can target the bladder wall may improve OAB therapy.

METHODS

We explored a polydopamine (PDA)-coated lactobacillus platform as a potential carrier for localized OAB treatment. Urinary microbiome profiling was performed to identify the presence of lactobacillus in healthy and OAB groups. Lactobacillus-PDA nanoparticles were synthesized and characterized by electron microscopy and spectrophotometry. A rat bladder perfusion model and human bladder smooth muscle cell spheroids were used to assess the distribution and penetration of the nanoparticles. The efficacy of the Lactobacillus-PDA system (LPS) for delivering the antimuscarinic drug solifenacin was evaluated in an OAB rat model.

RESULTS

Urinary microbiome profiling revealed lactobacillus as a dominant genus in both healthy and OAB groups. The synthesized Lactobacillus-PDA nanoparticles exhibited uniform size and optical properties. In the rat bladder perfusion model, the nanoparticles distributed throughout the bladder wall and smooth muscle without toxicity. The nanoparticles also penetrated human bladder smooth muscle cell spheroids. In the OAB rat model, LPS facilitated the delivery of solifenacin and improved treatment efficacy.

DISCUSSION

The results highlight LPS as a promising drug carrier for targeted OAB therapy via penetration into bladder tissues. This bacteriotherapy approach may overcome limitations of current systemic OAB medications. Lactobacillus, a probiotic bacterium present in the urinary tract microbiome, was hypothesized to adhere to and penetrate the bladder wall when coated with PDA nanoparticles, making it a suitable candidate for localized drug delivery.

Korean urobiome platform (KUROM) study for acute uncomplicated sporadic versus recurrent cystitis in women: Clinical significance

PURPOSE

To investigate urine microbiome differences among healthy women, women with recurrent uncomplicated cystitis (rUC), and those with sporadic/single uncomplicated cystitis (sUC) to challenge traditional beliefs about origins of these infections.

MATERIALS AND METHODS

Patients who underwent both conventional urine culture and next-generation sequencing (NGS) of urine were retrospectively reviewed. Symptom-free women with normal urinalysis results as a control group were also studied. Samples were collected via transurethral catheterization.

RESULTS

In the control group, urine microbiome was detected on NGS in 83.3%, with Lactobacillus and Prevotella being the most abundant genera. The sensitivity of urine NGS was significantly higher than that of conventional urine culture in both the sUC group (91.2% vs. 32.4%) and the rUC group (82.4% vs. 16.4%). In urine NGS results, Enterobacterales, Prevotella, and Escherichia/Shigella were additionally found in the sUC group, while the recurrent urinary tract infection (rUTI)/rUC group exhibited the presence of Lactobacillus, Prevotella, Enterobacterales, Escherichia/Shigella, and Propionibacterium. Moreover, distinct patterns of urine NGS were observed based on menopausal status and ingestion of antibiotics or probiotics prior to NGS test sampling.

CONCLUSIONS

Urine microbiomes in control, sUC, and rUTI/rUC groups exhibited distinct characteristics. Notably, sUC and rUC might represent entirely separate pathological processes, given their distinct urine microbiomes. Consequently, the use of urine NGS might be essential to enhancing sensitivity compared to conventional urine culture in both sUC and rUTI/rUC groups.

Urine microbes and predictive metagenomic profiles associate with abnormalities in sperm parameters: implications for male subfertility

OBJECTIVE

To explore the taxonomic and predicted functional relationship between the urine microbiome and alterations of semen analysis (SA) parameters.

DESIGN

Cross-sectional study.

SETTING

Academic medical center.

PATIENT(S)

Men presenting for fertility evaluation or men presenting for vasectomy consultation with proven biological paternity were recruited and stratified on the basis of alterations, or lack thereof, in SA parameters.

MAIN OUTCOME MEASURE

Changes in the functional and taxonomic urine microbiome profiles of participants with or without alterations in SA parameters.

RESULTS

Seventy-three participants were included in our study. Men with abnormal sperm motility (N = 27) showed a nearly 50-fold higher abundance of Dialister micraerophilus compared with those with normal sperm motility (N = 46). This relationship persisted on canonical correlational analysis (r = 0.439). Men with abnormal sperm concentration (N = 20) showed a lower abundance of Enterococcus faecalis and Staphylococcus aureus, compared with those with normal sperm concentration (N = 53). The urine of participants with impaired sperm motility demonstrated dramatic differences in predictive functional profiles in pathways involved in oxidation-reduction balance and cell longevity.

CONCLUSIONS

Our findings underscore differences in the urinary microbiome and abnormalities in semen parameters, especially sperm motility. By incorporating predictive functional profiling, we also highlight possible mechanisms that may drive the observed differences in sperm parameters.

Bacterial lipopolysaccharide related genes signature as potential biomarker for prognosis and immune treatment in gastric cancer

The composition of microbial microenvironment is an important factor affecting the development of tumor diseases. However, due to the limitations of current technological levels, we are still unable to fully study and elucidate the depth and breadth of the impact of microorganisms on tumors, especially whether microorganisms have an impact on cancer. Therefore, the purpose of this study is to conduct in-depth research on the role and mechanism of prostate microbiome in gastric cancer (GC) based on the related genes of bacterial lipopolysaccharide (LPS) by using bioinformatics methods. Through comparison in the Toxin Genomics Database (CTD), we can find and screen out the bacterial LPS related genes. In the study, Venn plots and lasso analysis were used to obtain differentially expressed LPS related hub genes (LRHG). Afterwards, in order to establish a prognostic risk score model and column chart in LRHG features, we used univariate and multivariate Cox regression analysis for modeling and composition. In addition, we also conducted in-depth research on the clinical role of immunotherapy with TMB, MSI, KRAS mutants, and TIDE scores. We screened 9 LRHGs in the database. We constructed a prognostic risk score and column chart based on LRHG, indicating that low risk scores have a protective effect on patients. We particularly found that low risk scores are beneficial for immunotherapy through TIDE score evaluation. Based on LPS related hub genes, we established a LRHG signature, which can help predict immunotherapy and prognosis for GC patients. Bacterial lipopolysaccharide related genes can also be biomarkers to predict progression free survival in GC patients.

Urinary microbiota and metabolic signatures associated with inorganic arsenic-induced early bladder lesions

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.