BV Treatment for Men: Understanding Male Partner Treatment

Bacterial vaginosis (BV) is the most common vaginal condition in women aged 15-44, and sex is its biggest trigger. This begs the question: since it takes two to tango, what is men’s role in bacterial vaginosis? Would treating a male partner for bacterial vaginosis reduce your risk of developing BV over and over again?  

Experts still aren’t exactly sure what causes bacterial vaginosis, but there’s evidence that men play a huge part in transmission to their female sex partners during sex — and new research suggests they’re the missing link to treat BV.

Keep reading to learn more about BV treatment for men, and whether your partner should take antibiotics like metronidazole to reduce your chances of recurrent BV.

What is bacterial vaginosis?

Bacterial vaginosis is a common vaginal infection that occurs when there’s an imbalance in the normal vaginal microbiota. Typically, a healthy vagina has a mix of good and bad bacteria, but when the bad bacteria outnumber the good, bacterial vaginosis can develop.

Bacterial vaginosis is often characterized by a thin, white, or gray vaginal discharge that has a strong fishy odor. When left untreated, bacterial vaginosis can lead to various adverse outcomes, including preterm labor, pelvic inflammatory disease (PID), and an increased risk of HIV transmission.

The link between sex and bacterial vaginosis

Although bacterial vaginosis isn’t officially classified as a sexually transmitted infection, sex — especially unprotected sex — can influence the vaginal microbiome and increase your risk of bacterial vaginosis. Being sexually active and having multiple or new sexual partners are both considered risk factors for bacterial vaginosis.

Studies have shown that sex can change the vaginal pH and introduce foreign bacteria, increasing the likelihood of symptomatic BV. A healthy vaginal pH is slightly acidic to keep bad bacteria or other pathogens from growing. Semen, on the other hand, has an alkaline pH. The presence of semen in the vagina can shift your vaginal pH and allow pathogens to colonize.

Contrary to popular belief, men also have microbiomes — specifically, on their penile skin and semen. Some studies also show that although men can’t have bacterial vaginosis, they can carry BV-associated bacteria (like Gardnerella) and pass it on to people with vaginas during sex. Other research has shown that using a condom not only prevents sexually transmitted infections but also reduces the recurrence of bacterial vaginosis.

Interestingly, the same is true even if you don’t have male sex partners. Women in same-sex relationships can also pass bacterial vaginosis to their female partners. Research even shows that women who have female sex partners are more likely to have bacterial vaginosis compared to women who only have sex with men.

This is to say that both female and male sex partners can play a huge role in recurrent bacterial vaginosis, and a 2022 report by the Centers for Disease Control and Prevention (CDC) recognized that BV can be sexually transmitted. It’s still not technically classed an STI, but this can change the way we think about and treat bacterial vaginosis. So what do we know about male partner treatment to prevent BV recurrence?

Can men be treated for BV?

Although men can't contract BV, they can be treated for it if their female partner is diagnosed with the condition. Research indicates that treating male partners may help lower the chances of BV recurring in women. 

While there isn’t a consensus (yet) on whether men can — or should — be treated for BV, a landmark study recently published in The New England Journal of Medicine (NEJM) provides strong evidence that they should. The study found that BV can be transmitted sexually, and it found that treating male partners significantly reduces the recurrence of BV in women.

Is male partner treatment necessary?

Since research shows that men can spread BV-associated bacteria to women during sex, will male partner treatment prevent bacterial vaginosis in women? Male partner treatment involves treating the sexual partner with antibiotics to prevent reinfection of BV-causing organisms. The evidence was inconclusive for a long time, but the NEJM study confirms what many researchers have long suspected: that male partner treatment may be the solution.

Several previous studies have shown that treating male sexual partners of women with BV can potentially reduce the recurrence of the infection in their female partners. It’s important to note that studies conducted in the last few decades have shown mixed results when it comes to reducing bacterial vaginosis in women through male partner treatment alone.

Previous efforts to prevent BV recurrence by treating male sexual partners didn’t have much success, which made many experts question whether treating a male partner was needed. However, those earlier studies had some important flaws. They only used oral metronidazole, which didn’t really target the bacteria on the skin of the penis. Plus, they couldn’t ensure that everyone followed through with their treatment, and they just didn’t have enough strength in their findings to show meaningful results. By adding a topical antibiotic cream that specifically targets penile bacteria and treating both partners, the authors of the NEJM research found clear evidence that this approach can really make a difference.

That said, while sex can be a trigger for bacterial vaginosis, other factors can contribute to flare-ups as well. Antibiotic use, smoking, douching, and having had bacterial vaginosis in the past are all risk factors for BV. So while male partner treatment might make post-sex BV less likely, it’s not to say that it’ll get rid of the problem altogether.

Getting male partners on board with antibiotic treatment can also be tricky, as the bacteria associated with BV on the penis often don’t cause symptoms in men, which can make it difficult to convince them to undergo treatment. Acceptance of partner treatment may depend on the dynamics of the relationship, with long-term committed relationships showing higher rates of acceptance.

So, when it comes to bacterial vaginosis, sex, and concurrent male partner treatment, there’s a lot we still don’t know. Previous studies that looked at male partner treatment to prevent recurrent BV had mixed results, but it doesn’t mean that partner-acquired bacterial vaginosis isn’t a real thing. It just means we need more research to figure out what’s going on and how to best treat BV.

In the meantime, one way to reduce your risk of developing bacterial vaginosis after sex is to use a condom or dental dam, and look after the health of your vaginal microbiome overall.

Can a man take metronidazole for BV?

In the NEJM study, women received standard oral or vaginal antibiotic treatment, but their male sexual partners were also treated with a seven-day course of oral metronidazole and a topical clindamycin cream applied to the penis.

63% of women in the control group (whose partners didn’t receive antibiotic treatment) experienced recurrence within 12 weeks. In contrast, only 35% of women in the partner-treatment group had BV return — a nearly 50% reduction in recurrence.

These findings suggest that metronidazole (especially metronidazole gel) in male partners could be a valuable strategy in managing BV, although more research is needed to confirm these results.

How long can a man carry BV?

Bacterial vaginosis is by definition a vaginal infection, so men can't develop it. Since they don't show any signs of infection, it's hard to know whether they're carrying BV-associated bacteria or not — and for how long. Luckily, researchers have looked into this.

A 2023 study published in Cell Reports Medicine looked at 110 urethral swab specimens from men with no urogenital symptoms, no STIs, and no inflammation of the urethra. The researchers found only the men who reported having vaginal sex carried the bacteria often associated with bacterial vaginosis. They also discovered the bacteria was detectable for at least two months after having vaginal sex.

FAQs

Should my boyfriend get treated if I have BV?

Researchers have been looking into whether male partner treatment can reduce BV recurrence in women, and while there isn’t a consensus, recent evidence suggests that male partner treatment could significantly reduce BV recurrence in women. If you find that you keep getting bacterial vaginosis after having sex with your boyfriend, it might be helpful to talk to him about how it’s impacting your well-being and sex life.

Can you tell if a man has BV?

No. Although men can carry BV-causing bacteria on their penile microbiome, they can’t develop a BV infection. This means they won’t show any BV symptoms.

Why do I get BV after sex?

There are a few reasons why you might get bacterial vaginosis after sex. Firstly, sexual activity can introduce new, harmful bacteria into the vaginal microbiome, whether that bacteria comes from the fingers, penis, mouth, sex toy, or another vagina. Research shows that sex with both female and male partners can increase your chances of developing bacterial vaginosis. Secondly, having unprotected sex with male sex partners can alter your natural pH. Normally, a healthy vagina has a slightly acidic pH, but semen is more alkaline, which can make it easier for bad bacteria or fungi to grow, leading to things like yeast infections or bacterial vaginosis. The good news is that using condoms and dental dams can help lower your chance of getting bacterial vaginosis from sex.

Can a man give BV to a woman?

Researchers are still trying to figure out what causes bacterial vaginosis, but evidence shows that bacterial vaginosis can indeed be transmitted during sex. Men can’t get bacterial vaginosis themselves, but they can harbor BV-causing bacteria in their penile and semen microbiomes and spread it to their female partners during sex.