News | Male Reproductive Tract Microbiome: Hidden Effects on Health and Disease
Microbiome research has expanded rapidly in recent years. The human microbiota is closely linked to health and affects disease development and immune balance. However, compared with research on the gut, oral cavity, and female reproductive system, the male reproductive tract microbiome has received limited attention. A systematic review published in Microorganisms summarized the microbial composition of the male genital mucosa, including the foreskin, glans, and coronal sulcus, and examined its potential effects on reproductive health.
Background: Why Is the Male Reproductive Tract Microbiome Important?
The microbiota plays an essential role in maintaining health, regulating the immune system, and influencing disease development. The male reproductive tract microbiome may affect fertility and susceptibility to sexually transmitted infections. Some microorganisms may increase the risk of HIV infection, while others may influence genital tract inflammation or infertility.
This study combined available data on the male reproductive tract microbiome and focused on differences between healthy men and men with reproductive tract disorders.
Methods: A systematic review of microbial diversity
The team searched Google Scholar, Scopus, Web of Science, and PubMed for all relevant studies published through August 2022. Ten eligible studies were included. All used 16S rRNA gene amplicon sequencing, although the amplified regions differed.
The review examined microbiome changes at different male genital sites, including the foreskin, glans, and coronal sulcus, and assessed how age, sexual behavior, and circumcision affected microbial composition.
Key Findings: Complex Diversity in the Male Reproductive Tract Microbiome
1. Microbial communities differ significantly by site
Foreskin: The main genera included Winkia, Mobiluncus, Peptoniphilus, Corynebacterium, Staphylococcus, and Prevotella.
Coronal sulcus: The microbiome was strongly influenced by circumcision and included Porphyromonas, Finegoldia, Prevotella, Peptoniphilus, Anaerococcus, Staphylococcus, and Corynebacterium. Urine samples were dominated by Veillonella, Gardnerella, Lactobacillus, and Streptococcus.
Urethra: The urethral microbiome differed substantially from that of the coronal sulcus, and some bacteria, such as Lactobacillus, were more common in the urethra.
2. Effects of circumcision on microbial composition
Before surgery, the coronal sulcus microbiome of uncircumcised men was more heterogeneous, while its composition became more stable after circumcision. In a two-year clinical trial, uncircumcised men with HIV had significantly higher genital tract levels of anaerobic bacteria than uncircumcised men without HIV.
3. Relationship between sexual behavior and the reproductive tract microbiome
Men whose partners had bacterial vaginosis (BV) had greater genital microbiome diversity, suggesting that some pathogens may be transmitted through sexual contact.
Treating male partners with antibiotics significantly improved BV symptoms in women, further supporting the role of microorganisms in sexually transmitted infections.
4. Effects of age on the reproductive tract microbiome
The genital microbiome differs significantly between prepubertal boys and postpubertal males.
For example, Enterococcus, Bifidobacterium, and Veillonella were more abundant in young children who were not toilet trained, while Staphylococcus and Corynebacterium spp. were more common after puberty.
5. Relationship between reproductive tract disease and microbial imbalance
In patients with balanoposthitis, the main genital bacteria included Prevotella bivia and Staphylococcus warneri, while Porphyromonas somerae and Ezakiella sp. predominated in healthy men.
The microbiome of patients with male genital lichen sclerosus (MGLSc) was dominated by Fusobacterium, Prevotella, and Enterobacteriaceae.
The review also found that supplementation with the probiotic Lactobacillus salivarius PS116610 may improve genital microbiome imbalance and increase success rates in some infertile couples receiving assisted reproductive treatment.
Future Directions: More Research Is Needed
Although the review provides extensive data on the male reproductive tract microbiome, it has several limitations:
Sample sizes were small, and some studies did not report participant ethnicity.
Lifestyle and age distributions differed across studies, potentially affecting comparisons.
Current research has not addressed the parasitome, virome, or mycobiome of the male reproductive tract, which require further study.
Overall, the review demonstrates the diversity of the male reproductive tract microbiome and its potential effects on health. Future research could clarify how microorganisms affect male fertility, sexually transmitted infections, and chronic genital inflammation and support more precise diagnostic and treatment strategies.
News | Male Reproductive Tract Microbiome: Hidden Effects on Health and Disease
News | Male Reproductive Tract Microbiome: Hidden Effects on Health and Disease
Microbiome research has expanded rapidly in recent years. The human microbiota is closely linked to health and affects disease development and immune balance. However, compared with research on the gut, oral cavity, and female reproductive system, the male reproductive tract microbiome has received limited attention. A systematic review published in Microorganisms summarized the microbial composition of the male genital mucosa, including the foreskin, glans, and coronal sulcus, and examined its potential effects on reproductive health.
Background: Why Is the Male Reproductive Tract Microbiome Important?
The microbiota plays an essential role in maintaining health, regulating the immune system, and influencing disease development. The male reproductive tract microbiome may affect fertility and susceptibility to sexually transmitted infections. Some microorganisms may increase the risk of HIV infection, while others may influence genital tract inflammation or infertility.
This study combined available data on the male reproductive tract microbiome and focused on differences between healthy men and men with reproductive tract disorders.
Methods: A systematic review of microbial diversity
The team searched Google Scholar, Scopus, Web of Science, and PubMed for all relevant studies published through August 2022. Ten eligible studies were included. All used 16S rRNA gene amplicon sequencing, although the amplified regions differed.
The review examined microbiome changes at different male genital sites, including the foreskin, glans, and coronal sulcus, and assessed how age, sexual behavior, and circumcision affected microbial composition.
Key Findings: Complex Diversity in the Male Reproductive Tract Microbiome
1. Microbial communities differ significantly by site
Foreskin: The main genera included Winkia, Mobiluncus, Peptoniphilus, Corynebacterium, Staphylococcus, and Prevotella.
Coronal sulcus: The microbiome was strongly influenced by circumcision and included Porphyromonas, Finegoldia, Prevotella, Peptoniphilus, Anaerococcus, Staphylococcus, and Corynebacterium. Urine samples were dominated by Veillonella, Gardnerella, Lactobacillus, and Streptococcus.
Urethra: The urethral microbiome differed substantially from that of the coronal sulcus, and some bacteria, such as Lactobacillus, were more common in the urethra.
2. Effects of circumcision on microbial composition
Before surgery, the coronal sulcus microbiome of uncircumcised men was more heterogeneous, while its composition became more stable after circumcision. In a two-year clinical trial, uncircumcised men with HIV had significantly higher genital tract levels of anaerobic bacteria than uncircumcised men without HIV.
3. Relationship between sexual behavior and the reproductive tract microbiome
Men whose partners had bacterial vaginosis (BV) had greater genital microbiome diversity, suggesting that some pathogens may be transmitted through sexual contact.
Treating male partners with antibiotics significantly improved BV symptoms in women, further supporting the role of microorganisms in sexually transmitted infections.
4. Effects of age on the reproductive tract microbiome
The genital microbiome differs significantly between prepubertal boys and postpubertal males.
For example, Enterococcus, Bifidobacterium, and Veillonella were more abundant in young children who were not toilet trained, while Staphylococcus and Corynebacterium spp. were more common after puberty.
5. Relationship between reproductive tract disease and microbial imbalance
In patients with balanoposthitis, the main genital bacteria included Prevotella bivia and Staphylococcus warneri, while Porphyromonas somerae and Ezakiella sp. predominated in healthy men.
The microbiome of patients with male genital lichen sclerosus (MGLSc) was dominated by Fusobacterium, Prevotella, and Enterobacteriaceae.
The review also found that supplementation with the probiotic Lactobacillus salivarius PS116610 may improve genital microbiome imbalance and increase success rates in some infertile couples receiving assisted reproductive treatment.
Future Directions: More Research Is Needed
Although the review provides extensive data on the male reproductive tract microbiome, it has several limitations:
Sample sizes were small, and some studies did not report participant ethnicity.
Lifestyle and age distributions differed across studies, potentially affecting comparisons.
Current research has not addressed the parasitome, virome, or mycobiome of the male reproductive tract, which require further study.
Overall, the review demonstrates the diversity of the male reproductive tract microbiome and its potential effects on health. Future research could clarify how microorganisms affect male fertility, sexually transmitted infections, and chronic genital inflammation and support more precise diagnostic and treatment strategies.
Story source:
Collected online