Pilot Study: Next-generation Sequencing of the Semen Microbiome in Vasectomized Versus Nonvasectomized Men

Semen microbiota are dramatically altered in men with abnormal sperm parameters

There has recently been an explosion of studies implicating the human microbiome in playing a critical role in many disease and wellness states. The etiology of abnormal semen analysis (SA) parameters is not identified in 30% of cases; investigations involving the semen microbiome may bridge this gap. Here, we explore the relationship between the semen microbiome and alterations of sperm parameters. We recruited men presenting for fertility evaluation or vasectomy consultation with proven biological paternity. SA and next generation sequencing was performed. Differential abundance testing using Analysis of composition of Microbiota with Bias Correction (ANCOM-BC) was performed along with canonical correlational analysis for microbial community profiling. Men with abnormal (N = 27) sperm motility showed a higher abundance of Lactobacillus iners compared to those with normal (N = 46) sperm motility (mean proportion 9.4% versus 2.6%, p = 0.046). This relationship persisted on canonical correlational analysis (r = 0.392, p = 0.011). Men with abnormal sperm concentration (N = 20) showed a higher abundance of Pseudomonas stutzeri (2.1% versus 1.0%, p = 0.024) and Pseudomonas fluorescens (0.9% versus 0.7%, p = 0.010), but a lower abundance of Pseudomonas putida (0.5% versus 0.8%, p = 0.020), compared to those with normal sperm concentration (N = 53). Major limitations are related to study design (cross-sectional, observational). Our results suggest that a small group of microorganisms may play a critical role in observed perturbations of SA parameters. Some of these microbes, most notably Lactobacillus iners, have been described extensively within other, fertility-related, contexts, whereas for others, this is the first report where they have potentially been implicated. Advances in our understanding of the semen microbiome may contribute to potentially new therapeutic avenues for correcting impairments in sperm parameters and improving male fertility.

Comparative Effectiveness Randomized Clinical Trial Using Next-generation Microbial Sequencing to Direct Prophylactic Antibiotic Choice Before Urologic Stone Lithotripsy Using an Interprofessional Model

Background

Next-generation sequencing (NGS) methods for microbial profiling have increased sensitivity to detect urinary pathogens.

Objective

To determine whether NGS microbial profiling can be used to guide antibiotic prophylaxis and reduce infection compared with the standard of care.

Design setting and participants

A prospective randomized controlled clinical trial of patients undergoing urologic stone interventions at an academic health center from December 2019 to January 2022 was conducted. Urine was collected at the preoperative visit for standard culture and intervention NGS diagnostics. Evaluable patients were culture negative, met 2-wk follow-up, and did not cancel surgery. Of 240 individuals (control = 121, intervention = 119), 83 control and 74 intervention patients were evaluable.

Intervention

Microbial findings (paired quantitative polymerase chain reaction and NGS) were sent to an infectious disease pharmacist to recommend prophylactic antimicrobial regimen.

Outcome measurements and statistical analysis

The primary outcome was postoperative urinary infection within the follow-up period (Fisher's exact test). The primary outcome was analyzed by modified intent-to-treat (mITT) and per-protocol analyses. Secondary endpoints considered included positive culture concordance, antibiotic use, and adverse events. Additional post hoc analyses investigated factors contributing to infection (univariate logistic regression).

Results and limitations

The intervention significantly reduced postsurgical urinary infection risk by 7.1% (-0.73%, 15%) compared with the standard of care in the mITT analysis (1.4% vs 8.4%, p = 0.045) or by 8.5% (0.88%, 16%) compared with the per-protocol analysis (0% vs 8.5%, p = 0.032). NGS-guided treatment altered the distribution of antibiotics used (p = 0.025), and antibiotics poorly matched with NGS findings were associated with increased infection odds (odds ratio [OR] = 5.9, p = 0.046). Women were at greater odds to develop infection (OR = 10, p = 0.03) and possessed differentiated microbial profiles (p < 0.001).

Conclusions

Urinary microbial NGS-guided antibiotic prophylaxis before endoscopic urologic stone lithotripsy improves antibiotic selection to reduce healthcare-associated urinary infections; however, treatment efficacy may be limited by the ability to adhere to the recommended protocol.

Patient summary

We investigated whether microbial DNA sequencing could improve the selection of antibiotics before kidney stone surgery in patients not known to have any bacteria in the urine on standard culture. We found that using microbe DNA to guide antibiotic choices decreased postoperative infection rate and may encourage individualized use of available antibiotics.

Vasectomy has No Impact on Future Lower Urinary Tract Symptoms Diagnoses: A Retrospective Cohort Claims Database Analysis

Purpose

The aim of this study was to assess whether there is an association between vasectomy and benign prostatic hyperplasia with associated lower urinary tract symptoms (BPH/LUTS) due to inflammatory etiology.

Materials and Methods

We assessed the incidence of BPH/LUTS in men who had undergone vasectomy in a matched cohort analysis using the TriNetX Research Network. We identified men aged 30 to 60 years who underwent vasectomy and had a follow-up visit within 6 months to 5 years after vasectomy from January 2010 through December 2022 and compared them with matched controls. Outcomes recorded include diagnoses of BPH (N40, N40.1), BPH-related medication prescriptions, and BPH-related procedures. We accounted for confounding variables through propensity score-matching for age; race; and history of comorbid medical conditions: hyperlipidemia (International Classification of Disease-10: E78), metabolic syndrome (E88.81), overweight or obesity (E66), testicular hypofunction (E29.1), hypertension (I10-I16), nicotine dependence (F17), and obstructive sleep apnea (G47.33).

Results

There was no significant difference in BPH diagnosis between postvasectomy men vs controls (0.84% vs 0.80%, RR: 0.95, 95% CI 0.86-1.05) or BPH/LUTS diagnosis (0.48% vs 0.44%, RR: 0.92, 95% CI 0.81-1.05) within 6 months to 5 years after vasectomy, respectively. No differences in BPH medication prescription (0.94% vs 0.84%) or rate of BPH procedures (0.022% vs 0.017%) were detected between the 2 groups.

Conclusions

This study suggests that vasectomy does not increase the risk of BPH development and/or LUTS worsening compared with the general population, providing assurance to both patients and health care providers who may consider vasectomy as a safe family planning option.