Microbiome Dynamics in Male Infertility

The human male reproductive tract hosts a complex microbiota whose composition and functional dynamics have been increasingly implicated in sperm quality and fertility outcomes. Seminal fluid, once regarded as sterile, is now known to harbour bacterial communities that interact with host cells through metabolic, immunological and inflammatory pathways. Dysbiosis of this microbiota—characterised by shifts in the relative abundance of key genera such as Lactobacillus, Prevotella, Pseudomonas and Streptococcus—has been associated with reduced sperm motility, concentration and altered morphology. Metabolite profiling has uncovered bioactive compounds, for example hexadecanamide, that modulate sperm function. Evidence also suggests cross-talk between gut, urinary and genital microbial communities, indicating a systemic axis influencing reproductive health. Challenges in sampling low-biomass environments and standardising sequencing methods have so far limited large-scale longitudinal studies, yet emerging multi-omics approaches are beginning to resolve causative links. Understanding these interactions offers the prospect of novel diagnostics, probiotic interventions and targeted therapies to restore microbial homeostasis and improve fertility outcomes on a global scale.

Research from Nature Portfolio

Studies in animal models have revealed that genetic factors shape the seminal fluid microbiome. Work using knockout mice lacking oestrogen receptor-α demonstrated that alteration of host genetics leads to shifts in microbial inhabitants and correlates with prostatic disease risk, highlighting propagative effects on offspring health. In parallel, clinical investigations have profiled the seminal microbiota of men with different types of dysspermatism, identifying distinct bacterial biomarkers—including Ureaplasma, Bacteroides and Anaerococcus—in asthenospermic and oligoasthenospermic patients. Functional inference from these data points to pathogenic pathways and potential targets for microbial modulation, underlining a precision-medicine approach to male infertility management.

Microbiome Dynamics in Male Infertility publication trend

The graph below shows the total number of articles in microbiome dynamics in male infertility across all publications each year (not limited to Nature Index journals).

Technical terms

Dysbiosis: Perturbation of the normal microbial community balance that can impair host health.

16S rRNA sequencing: Molecular technique to profile bacterial communities based on ribosomal RNA gene fragments.

Multi-omics analysis: Integrated study of multiple molecular data types (metabolites, transcripts, proteins) to reveal complex biological interactions.

Bacteriospermia: Presence of bacteria in semen, often associated with altered sperm quality.

Metabolite: Small molecule produced or modified by microbial or host metabolic processes, affecting cell function.

References

1. Changes in seminal plasma microecological dynamics and the mechanistic impact of core metabolite hexadecanamide in asthenozoospermia patients. iMeta (2024).
2. Male Tract Microbiota and Male Infertility. Cells (2024).
3. Human Male Genital Tract Microbiota. International Journal of Molecular Sciences (2023).
4. Effect of environmental factors on seminal microbiome and impact on sperm quality. Frontiers in Endocrinology (2024).
5. Characterization of the semen, gut, and urine microbiota in patients with different semen abnormalities. Frontiers in Microbiology (2023).
6. Discovery of a Novel Seminal Fluid Microbiome and Influence of Estrogen Receptor Alpha Genetic Status. Scientific Reports (2016).
7. Potential Pathogenic Bacteria in Seminal Microbiota of Patients with Different Types of Dysspermatism. Scientific Reports (2020).