How Probiotics Can Improve Fertility & Help Prevent Infections


Probiotics aren’t just for gut health. Probiotics can improve fertility and help prevent infections, too. Here is what you should know.   

How Probiotics Improve Fertility

There are many factors that affect fertility, and one of them is the health of the vaginal microbiome (and for men, their sperm microbes). Here is what we know so far about the connection between the microbiome and fertility and how probiotics improve fertility:

An Unbalanced Vaginal Microbiome May Prevent Pregnancy

Research suggests that abnormal vaginal microbiota may negatively affect the clinical pregnancy rate in both natural birth and IVF patients.

Study 1: In a Danish study of 130 women undergoing in vitro fertilization (IVF), researchers found that those who had abnormal vaginal microbiota had a harder time getting pregnant.

Of the eighty-four patients who completed IVF treatment, twenty-nine got pregnant. Those who did not have abnormal vaginal microbiota were more likely to get pregnant (44% or 27 out of 62 women), whereas for those with abnormal vaginal microbiota, only 9% (2/22) obtained a clinical pregnancy. (1)

Study 2: In a prospective cohort study of 1,950 women in Philadelphia, a diagnosis of a common infection, bacterial vaginosis, in the first trimester more than doubled the risk of spontaneous pregnancy loss in the second.  That same study also noted the absence of or low levels of the friendly Lactobacillus bacteria in the first trimester also significantly increased the risk of second trimester pregnancy loss. (2)

Study 3: Another study published in BJOG: An International Journal of Obstetrics & Gynaecology, with over 700 pregnant participants, found that women with abnormal vaginal flora – characterized as lacking lactobacilli bacteria – were 75% more likely to have a preterm birth. Abnormal flora also significantly increased the risk of miscarriage.  (3).

Probiotics can help reduce Inflammation which improves fertility

Bacterial infections have high incidence among the female population at reproductive age and are widely known to cause infertility due to inflammation. (4)

Chronic inflammation is associated with a wide range of health concerns. When a woman experiences chronic inflammation, it can affect her cycles and immune system, which can make it more difficult to conceive.

A number of probiotic strains have been found to help reduce inflammation – particularly certain strains of Lactobacillus and Bifidobacterium.

A small animal study looking at the role of probiotics in reducing inflammation-induced infertility found that Lactobacillus plantarum did indeed reduce inflammation and increase fertility in mice. (5)

Probiotics improve sperm health & increase chance of pregnancy

Fertility is not just a woman’s issue…it’s a man’s issue too. Research suggests that in 40-50% of cases in which a couple is having trouble getting pregnant, it’s due to male infertility. Luckily, fertility and sperm health can be improved.

A team of Chinese researchers examined the bacterial breakdown of 96 sperm samples. They found that lactobacillus bacteria (the same type of bacteria/probiotic that is beneficial for women’s fertility and health) was generally high in healthy, fertile sperm samples, and lower in unhealthy/un-fertile samples. (6)

A separate animal study conducted with mice found that orally taking the probiotic L. reuteri (again, the same that is beneficial for women’s health) led to increased sperm count and testicular mass, and improved overall reproductive organ health. (7)

Probiotics vs Bacterial Vaginosis

Bacterial vaginosis (BV) is the most prevalent vaginal infection worldwide and is characterized by depletion of the indigenous lactobacilli.

Women are often unaware that they have BV as about 50% of cases are asymptomatic. If symptoms are present these usually include a thin, white, homogenous discharge and an unpleasant, ’fishy’ odor. If left untreated it can lead to other complications such as reduced fertility, and reduced birth-weights (when pregnancy does occur).

Study 1: In a 2009 randomized, double-blind placebo-controlled study published in the Canadian Journal of Microbiology, researchers compared the results of women with BV who were offered a combination of the standard antimicrobial – tinidazole with either a placebo or a probiotic containing L. rhamnosus and L. reuteri.

They found that at the end of the 4-week treatment period, the women who took the antibiotic and the probiotics had a significantly higher cure rate of BV (87.5%) than the placebo group (50%). Additionally, the women who took the probiotic with the medication were more likely to have “normal” vaginal microbiota by the end of the study, compared to the placebo groups (75% vs. 34.4%). (8)

Study 2: In another randomized, double-blind, placebo controlled study, 125 women were divided in to two groups. One group received a 7 day course of antibiotics, and the second group received both the antibiotics and a probiotic containing the strains Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14®.

The probiotic supplementation was continued for a further 3 weeks after the end of the antibiotic therapy. Those who received just the probiotics alone had a treatment success rate of 40%, while those who used both the antibiotic and the probiotics more than doubled their success rate, with 88% successfully eliminating BV. (9)

The Probiotic Strains Noted For Their Reproductive Health Benefits

While our health is ultimately a reflection of many factors – including diet and lifestyle factors – research suggests adding in the right probiotic strains can be beneficial.

  • The lactobacillus strains in general, and the
  • Lactobacillus rhamnosus (L, rhamnosus)
  • Lactobacillus reuteri (L. reuteri), and
  • Lactobacillus plantarum (L. planatarum)

in particular, are the strains that come up again and again in the research for supporting reproductive health and aiding in infection prevention and treatment.

All three of these strains can be found in Hyperbiotics Pro-Women and Pro-15 probiotics. I use these personally and recommend them to my clients and family and have found them to be the most effective probiotic I’ve tried.

You would only need one – the Pro-15 is more comprehensive in terms of strains, while Pro-Women is more targeted for women’s reproductive health. So if you’re looking to improve health overall, go for Pro-15, if you’re dealing with specific reproductive concerns, you may want to start with Pro-Women.

And remember – pregnancy takes two. Be sure your partner is nourishing his microbiome with probiotics and a healthy diet and lifestyle, too.

Use the code HYPERMARIA for 25% off your order on of Pro-Women or Pro-15 on (their dental probiotic is great, too!)

You can read about my experience using Hyperbiotics.  You can also listen to my interview with the Founder, Jamie Morea, on my Happier & Healthier podcast, episode 10: Improve Your Microbiome & Gut Health.


1. Haahr, T. (2016). Abnormal vaginal microbiota may be associated with poor reproductive outcomes: A prospective study in IVF patients. Journal of Reproductive Immunology, 115, 47-48. doi:10.1016/j.jri.2016.04.144

2. Nelson DB, Bellamy S, Nachamkin I, Ness RB, Macones GA, Allen-Taylor L. (2007). FIRST TRIMESTER BACTERIAL VAGINOSIS, INDIVIDUAL MICROORGANISM LEVELS AND RISK OF SECOND TRIMESTER PREGNANCY LOSS AMONG URBAN WOMEN. Fertility and sterility.;88(5):1396-1403. doi:10.1016/j.fertnstert.2007.01.035.

3. Donders GG, Van Calsteren K, Bellen G, Reybrouck R, Van den Bosch T, Riphagen I, Van Lierde S. (2009). Predictive value for preterm birth of abnormal vaginal flora, bacterial vaginosis and aerobic vaginitis during the first trimester of pregnancy. BJOG 116(10):1315-24. doi: 10.1111/j.1471-0528.2009.02237.x.

4. Bhandari, P., Rishi, P., & Prabha, V. (2016). Positive effect of probiotic Lactobacillus plantarum in reversing LPS-induced infertility in a mouse model. Journal of Medical Microbiology, 65(5), 345-350. doi:10.1099/jmm.0.000230

5. Weiss, G., Goldsmith, L. T., Taylor, R. N., Bellet, D., & Taylor, H. S. (2009). Inflammation in Reproductive Disorders. Reproductive Sciences, 16(2), 216-229. doi:10.1177/1933719108330087

6. Weng, S., Chiu, C., Lin, F., Huang, W., Liang, C., Yang, T., … Huang, H. (2014). Bacterial Communities in Semen from Men of Infertile Couples: Metagenomic Sequencing Reveals Relationships of Seminal Microbiota to Semen Quality. PLoS ONE, 9(10), e110152. doi:10.1371/journal.pone.0110152

7. Poutahidis, T., Springer, A., Levkovich, T., Qi, P., Varian, B. J., Lakritz, J. R., … Erdman, S. E. (2014). Probiotic Microbes Sustain Youthful Serum Testosterone Levels and Testicular Size in Aging Mice. PLoS ONE, 9(1), e84877. doi:10.1371/journal.pone.0084877

8. Rafael C. R. Martinez, Sílvio A. Franceschini, Maristela C. Patta, Silvana M. Quintana, Bruna C. Gomes, Elaine C. P. De Martinis, Gregor Reid (2009) Improved cure of bacterial vaginosis with single dose of tinidazole (2 g), Lactobacillus rhamnosus GR-1, and Lactobacillus reuteri RC-14: a randomized, double-blind, placebo-controlled trial. Canadian Journal of Microbiology, 55:133-138, doi:10.1139/W08-102

9. Anukam K, Osazuwa E, Ahonkhai I, Ngwu M, Osemene G, Bruce AW, Reid G. (2006) Augmentation of antimicrobial metronidazole therapy of bacterial vaginosis with oral probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14: randomized, double-blind, placebo controlled trial. Microbes and Infection, 8(6):1450-4. DOI: 10.1016/j.micinf.2006.01.003

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