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.

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.

One size does not fit all: variations by ethnicity in demographic characteristics of men seeking fertility treatment across North America.

OBJECTIVE: To compare racial differences in male fertility history and treatment. DESIGN: Retrospective review of prospectively collected data. SETTING: North American reproductive urology centers. PATIENT(S): Males undergoing urologist fertility evaluation. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Demographic and reproductive Andrology Research Consortium data. RESULT(S): The racial breakdown of 6,462 men was: 51% White, 20% Asian/Indo-Canadian/Indo-American, 6% Black, 1% Indian/Native, <1% Native Hawaiian/Other Pacific Islander, and 21% "Other". White males sought evaluation sooner (3.5 ± 4.7 vs. 3.8 ± 4.2 years), had older partners (33.3 ± 4.9 vs. 32.9 ± 5.2 years), and more had undergone vasectomy (8.4% vs. 2.9%) vs. all other races. Black males were older (38.0 ± 8.1 vs. 36.5 ± 7.4 years), sought fertility evaluation later (4.8 ± 5.1 vs. 3.6 ± 4.4 years), fewer had undergone vasectomy (3.3% vs. 5.9%), and fewer had partners who underwent intrauterine insemination (8.2% vs. 12.6%) compared with all other races. Asian/Indo-Canadian/Indo-American patients were younger (36.1 ± 7.2 vs. 36.7 ± 7.6 years), fewer had undergone vasectomy (1.2% vs. 6.9%), and more had partners who underwent intrauterine insemination (14.2% vs. 11.9%). Indian/Native males sought evaluation later (5.1 ± 6.8 vs. 3.6 ± 4.4 years) and more had undergone vasectomy (13.4% vs. 5.7%). CONCLUSION(S): Racial differences exist for males undergoing fertility evaluation by a reproductive urologist. Better understanding of these differences in history in conjunction with societal and biologic factors can guide personalized care, as well as help to better understand and address disparities in access to fertility evaluation and treatment.

Reproductive endocrinologists are the gatekeepers for male infertility care in North America: results of a North American survey on the referral patterns and characteristics of men presenting to male infertility specialists for infertility investigations.

OBJECTIVE: To characterize the referral patterns and characteristics of men presenting for infertility evaluation using data obtained from the Andrology Research Consortium. DESIGN: Standardized male infertility questionnaire. SETTING: Male infertility centers. PATIENT(S): Men presenting for fertility evaluation. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Demographic, infertility history, and referral data. RESULT(S): The questionnaires were completed by 4,287 men, with a mean male age of 40 years ± 7.4 years and female partners age of 37 years ± 4.9 years. Most were Caucasian (54%) with other races being less commonly represented (Asian 18.6%, and African American 5.5%). The majority (59.7%) were referred by a reproductive gynecologist, 19.4% were referred by their primary care physician, 4.2% were self-referred, and 621 (14.5%) were referred by "other." Before the male infertility investigation, 12.1% of couples had undergone intrauterine insemination, and 4.9% of couples had undergone in vitro fertilization (up to six cycles). Among the male participants, 0.9% reported using finasteride (5α-reductase inhibitor) at a dose used for androgenic alopecia, and 1.6% reported exogenous testosterone use. CONCLUSION(S): This broad North American patient survey shows that reproductive gynecologists are the de facto gateway for most male infertility referrals, with most men being assessed in the male infertility service being referred by reproductive endocrinologists. Some of the couples with apparent male factor infertility are treated with assisted reproductive technologies before a male factor investigation. The survey also identified potentially reversible causes for the male infertility including lifestyle factors such as testosterone and 5α-reductase inhibitor use.