In the area of infertility, any little thing can make a difference. So when researchers found a difference in bacteria in semen, that raises some concerns. Infertile men had higher levels of: “Staphylococcus aureus (16.9%), Staphylococcus saprophyticus (9.2%), Escherichia coli (6.9%), Proteus mirabilis (3.4%),Klebsiella spp (2.3%), Pseudomonas aerouginosa (1.1%), and Proteus vulgaris (2.3%).”
The response was to look at supplementing men with probiotics orally, which doesn’t address the oral/topical split in the microbiome. More importantly, the male population is very likely to reflect the female vaginal population. Doing that follow-up testing would likely increase the effect of the results. If both partners are infected with species that are inflammatory, that’s going to impact fertility. But they then need to use topical probiotics to reverse the situation.