Normal Vaginal Flora - Probiotics of the Vagina

Did you know that a community of bacteria exists in the vagina? Normally the vagina is occupied by various Lactobacillus species of bacteria. These known, good, and beneficial microorganisms are called probiotics. Once established within the vagina, these friendly bacteria protect your body against several vaginal infections. They do so by producing natural substances that disinfect the vagina and help maintain an optimal pH level in the vagina. A healthy balance of microflora also prevents the build-up of harmful bacteria and other pathogens.

The presence of probiotics in the vagina helps to compete against any potential bad microorganisms that get introduced to the vagina. For example, some Lactobacillus strains produce substances such as hydrogen peroxide, lactic acid, and bacteriocins that inhibit the growth of E. coli (a cause of UTIs), Candida yeast (the main cause of yeast infections), and Gardnerella vaginalis (a cause of bacterial vaginosis). 

Although these problems are usually addressed with antifungals or antibiotics, taking a probiotic supplement or eating probiotic-rich foods may help to reduce symptoms while maintaining a healthy vaginal microflora. What is the best probiotic to prevent yeast infection? Let's take a look at the clinical evidence.

Best Probiotics for Vaginal Yeast Infections

Generally, the best probiotic for yeast infection, bacterial vaginosis, and general vaginal health is Lactobacillus bacteria. This is because the normal vaginal flora comprises of many Lactobacillus probiotics.¹ Lactobacillus species work to acidify and protect the vagina from harmful organisms. These acid-making bacteria can inhibit harmful or otherwise foreign fungi from adhering to the lining of the vagina.

Lactobacilli probiotics create lactic acid, which helps to decrease the pH in the vaginal tract and create a more acidic environment. Maintaining an acidic environment makes the vagina inhospitable to many pathogenic bacteria and fungi. These acid-making bacteria can inhibit harmful or otherwise foreign fungi from adhering to the lining of the vagina. Disrupting the balance between Lactobacilli and gram-negative anaerobes in the vagina may result in bacterial vaginosis.¹

Will probiotics help yeast infection? One study of 30 women examined the rates of reoccurring yeast infections in women that had yeast infections. They were instructed to use anti-fungal medications for 10 days and were instructed to douche with different milk products or placebo control for 2 weeks. The study found that the application of milk products to the vagina reduced the number of yeast reinfections in 3 months of follow up.

Within 3 months of the treatment regimen 1 woman in the Lactobacillus containing milk group, 1 woman in yogurt treat group, and no women in low fat milk treat group got yeast infections. 3 women treated by a placebo developed yeast infections.² The authors reasoned that the reason why probiotic-free low fat milk worked as well was that the lactose content of the milk acted as a prebiotic for existing Lactobacilli.

Another study featuring 32 women compared the rates of yeast infections in women that consumed Lactobacillus probiotic containing yogurt daily with women that did not. The average number of yeast infections per 6 months was 2.54 ± 1.66 in the control group and 0.38 ± 0.51 per 6 months in the yogurt arm (P = 0.001). This means that the group that consumed yogurt had less yeast infections than the control group and that the result was statistically significant.³

The interesting thing to note is that probiotics consumed orally can colonize the vagina. Although it may be gross, bacteria found in the rectum can end up in the vagina.⁴ This is one of the reasons why women get urinary tract infections more often than men and why it is important for them to maintain healthy Lactobacillus populations by consuming prebiotics and probiotics.

Do Probiotics Cause Yeast Infections?

Considering probiotics comprise various strains of bacteria, you may be asking yourself, “do probiotics cause yeast infections?” The answer is no. The vast majority of yeast infections are caused by overgrowths of the fungus Candida. The most common strain of Candida that causes yeast infections is Candida albicans. Bacterial vaginosis is typically caused by a strain of bacteria known as Gardnerella vaginalis. Considering probiotic supplements do not contain strains of Candida or Gardnerella vaginalis, you don’t have anything to worry about. Simply put, probiotics do not cause yeast infections.⁷

The best probiotic to prevent yeast infection will usually contain varying strains of Lactobacilli. Your vaginal microflora should naturally be rich in Lactobacilli, which helps to maintain a healthy pH to prevent yeast infections, bacterial vaginosis, trichomoniasis, and other common urogenital issues.⁸

 

Best Natural Sources of Lactobacillus Probiotics for Yeast Infections

Probiotics can be found in many foods, mainly those that have been fermented. Some of the best Lactobacillus probiotic-rich foods are:

• Kefir – A fermented milk drink made from cow or goat milk combined with numerous cultures of yeast or lactic acid bacteria.
• Yogurt – Milk fermented with lactic acid bacteria and Bifidobacteria
• Kimchi – Lactobacilli are normally present on napa cabbage.⁵ Fermenting the cabbage allows these populations to grow. The cabbage also acts as a good prebiotic and supports the growth of probiotics in your gastrointestinal tract.

Kefir tends to have more probiotics than yogurt so we recommend kefir more than yogurt.

You can also get a high dose of probiotics from probiotic supplements. When choosing a probiotic for a yeast infection, look for a supplement that offers a diverse range of Lactobacilli strains. The more diverse the probiotics, the greater the potential benefits to your health. Furthermore, pay attention to the CFUs (colony forming units). The CFUs are a measure of how many live organisms are in one serving. While the exact number can vary based on your needs, you should generally aim for a probiotic containing at least 10 billion CFUs. Furthermore, the best probiotic supplement for yeast infections should feature a coating that protects it from harsh stomach acids. While some strains of bacteria are resistant, most are not, and you won’t get the benefits of the probiotic if they can’t survive past your stomach.

 

Probiotic supplements can deliver a high dose of probiotics and can utilize a delayed-release delivery mechanism to protect the probiotics inside from stomach acid, such as Nexabiotic® for Women. Each serving of Nexabiotic® for Women contains 17.25 billion Colony Forming Units (CFUs) of probiotics and 23 different strains of probiotics including:

Lactobacillus helveticus
Lactobacillus delbrueckii LE
Lactobacillus rhamnosus LB3
Lactobacillus plantarum LM
Lactobacillus acidophilus
Lactobacillus rhamnosus
Lactobacillus brevis
Lactobacillus casei
Lactobacillus salivarius
Lactobacillus paracasei
Lactobacillus plantarum

Sources:

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC120688/
2. https://www.sciencedirect.com/science/article/pii/S002203028083013X
3. https://annals.org/aim/article-abstract/705341/ingestion-yogurt-containing-lactobacillus-acidophilus-prophylaxis-candidal-vaginitis
4. https://academic.oup.com/jid/article/192/3/394/833707
5. https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2672.2009.04648.x
6. https://www.ncbi.nlm.nih.gov/pubmed/16762934
7. https://www.healthline.com/health/yeast-infection-probiotics
8. https://www.healthline.com/health/vaginal-health/probiotic-vaginal-health