Can probiotics restore the vaginal microbiota? Promising treatment for HPV infection

HPV stands for Human Papillomavirus, and this is the main cause of cervical cancer. An interesting fact is that nearly every sexually active person catches it! However, our immune system can clear most of the HPV infections without any complications within 6-18 months. Only a small part of infections will progress to precancer and, ultimately, to Cervical Intraepithelial Neoplasia (NIC) and cervical cancer.


What are the factors involved in the development of cervical cancer?


The role of vaginal Microbiota

Surprisingly, women without cervical abnormalities have different vaginal microbiota than women with precancer and cervical cancer. Research shows that vaginal microbiota plays a big role in the persistence or clearance of HPV.1, 2

Scientists have classified the vaginal microbiota in five different “community state types” (CSTs):


As a summary, healthier vaginal states are associated with:


Lactobacillus, a promising probiotic candidate for HPV infections

Vaginal Lactobacillus species have different mechanisms that fight bad bacteria:

  1. Produce lactic acid which lowers the pH and inhibits the growth of other bacteria.9
  2. Produce bacteriocins, proteins with antibacterial activity.
  3. Compete for adhesion sites to the vaginal epithelial cells.1, 10


Research is ongoing with a focus on L. gasseri, L. crispatus, L. jensenii and L. casei. In vitro studies have shown the inhibitory effects of these strains on cervical cancer cells.9

In a study, 65 HIV-infected women with an aberrant microbiota took a daily probiotic containing Lactobacillus rhamnosus GR-1 and L. reuteri RC-14 for 6 months. In the probiotic group, prevalence of Lactobacillus in the vaginal microbiota was observed.11

In another study, 54 women with HPV infection, took the commercial probiotic Yakult (L. casei Shirota) for 6 months. Probiotic users had double the chance of clearance of cytological abnormalities (60% vs 31%).12

L. crispatus seems to be a promising probiotic candidate. While bacterial communities in CSTs can change into CST IV and cause persistence of HPV virus, L. crispatus is the least likely to make this transition.13 This strain produces a specific protein which helps in the attachment to the intestinal and vaginal mucosa, thereby competing for space with other bacteria.8


Limitations of recent research in the “Oncobiome” (microbiota associated with cancer development)

Studies are observational, which means that it is only possible to associate bacteria with the disease, but causality can’t be demonstrated.


Here are my top tips to increase good bacteria in your vaginal microbiota!