For decades, bacterial vaginosis (BV) has been classified squarely as a “women’s health issue.” Affecting nearly 30% of people with vaginas in the United States, it’s long been understood as an imbalance in vaginal flora, marked by unpleasant discharge and odor. But a groundbreaking study recently published in the New England Journal of Medicine challenges this framework—and may forever change how we understand the vaginal condition.
A Quick Refresher: What Is BV?

Bacterial vaginosis (BV) occurs when there’s an imbalance in the vaginal microbiome—specifically, when healthy lactobacilli (good bacteria that help keep the vagina acidic) are reduced and replaced by an overgrowth of anaerobic bacteria, such as Gardnerella vaginalis. This disruption leads to inflammation and symptoms like discharge and odor, although many people don’t experience noticeable symptoms. It’s important to note that BV isn’t caused by a single bacterium or a classic infection, and it’s not considered a sexually transmitted infection (STI)—Still, sexual activity such as not using condoms and having new or multiple sex partners can often trigger or worsen the condition.
BV can cause symptoms such as:
- Thin, grayish-white discharge
- Fishy vaginal odor
- Vaginal irritation or burning
- Pain during urination
However, many people with BV are asymptomatic. Left untreated, BV can raise the risk of preterm birth, pelvic inflammatory disease, and increased susceptibility to STIs like HIV.
The Big Shift: What the New Study Found
The randomized, controlled trial studied the effect of treating both men and women when one partner had bacterial vaginosis (BV). In the trial, male partners were given oral metronidazole and topical clindamycin (applied to the penis), while the female partners underwent standard BV treatment.
After 12 weeks, research concluded that only 35% of women who were treated along with their male partners had a BV recurrence. On the other hand, 63% of women who were treated alone experienced a recurrence of the infection.
Why is this a big deal?
Traditionally, BV has been seen as a microbiological issue isolated to the vagina. Treatment guidelines haven’t included male partners, mainly because men don’t show symptoms. However, this study suggests that male partners can act as a reservoir for BV-associated bacteria, unknowingly reintroducing them during sex.
CEO & Founder of PherDal, Dr. Jennifer Hintzsche, agrees, saying, “This study confirms what many women and clinicians have long suspected: BV isn’t just about the vaginal microbiome, it can also be a shared condition between partners.
BV often occurs shortly after intercourse, which is why it has been suspected to be a sexually transmitted infection (STI). But until now, studies that treated both partners with antibiotics hadn’t shown the expected drop in recurrence rates. This is the first study to combine both oral and topical antibiotics for male partners. This combined approach can target BV bacteria species that can survive inside the urethra and on the penile skin.”
Rethinking the Sexual Health Conversation
This research has significant implications for how we approach BV, not just in clinical care but also in addressing social stigma. For too long, women have had to deal with the worry of recurrent infections, often feeling frustrated or even ashamed. Many report treating BV over and over, only to have it return within weeks or months due to an untreated male partner. Hintzsche explains, “With all antibiotic treatment, it’s important for the patient to follow the medication guidelines and take their full dose. If you only kill 99% of the bacteria with an antibiotic, that means 1% of bacteria that remain have now survived the first dose of antibiotics and can develop resistance.” She also notes that the go-to treatments for BV are antibiotics, such as metronidazole or clindamycin, which are typically prescribed for women only; however, the study focuses on treatment for both partners.
Now, there’s solid evidence suggesting that involving male partners in treatment could significantly reduce these recurrences. This could lead to:
- Updates to BV treatment protocols
- Broader education on the shared nature of BV risk
- Reduction in stigma for those repeatedly affected
How to Help Prevent BV in the First Place
While these findings are a game-changer for treatment, they also shine a light on prevention. Understanding that BV isn’t just about individual hygiene but about a shared microbial environment means that prevention efforts can go beyond the basics. From supporting the vaginal microbiome to making informed choices about sex, there are simple, proactive steps people can take to reduce the risk of developing or re-developing BV.
Ways to support BV prevention include:
- Avoid douching: It disrupts the vagina’s natural bacterial balance and can make you more vulnerable to infection.
- Use condoms consistently: Barrier protection can reduce the introduction of semen and bacteria that may disturb vaginal pH.
- Practice good genital hygiene (without over-cleaning): Stick to warm water and fragrance-free products designed for your vaginal area. (Hintzsche also recommends men practice good hygiene to prevent BV from recurring)
- Using harsh soaps can irritate and disrupt the microbiome.
- Limit sexual partners and discuss any symptoms: New or multiple partners can introduce unfamiliar bacteria.
- Avoid smoking: Smoking has been linked to reduced levels of protective lactobacilli in the vagina.
- Support overall vaginal health: Incorporating vaginal probiotics such as HUM’s Private Party can help maintain a healthy bacterial environment. This daily supplement contains three clinically studied strains of Lactobacillus that work to maintain optimal pH levels, balances the vaginal microbiome, and supports healthy function of the urinary tract.
- Stay in tune with your body: If symptoms appear, early treatment can help prevent full-blown infections or recurrences.
These steps won’t guarantee you’ll never get BV, but they can help create a healthier environment where beneficial bacteria thrive—and that’s the best line of defense.