The vaginal microbiome is increasingly being shown to potentially play a key role in protecting against cervical cancer. This protection stems from its ability to maintain a healthy environment that reduces the risk of infections (including HPV), and inflammation. 

With this month being Cervical Cancer Awareness Month, we thought it especially important to highlight some of the ways in which the vaginal microbiome is increasingly thought to potentially impact cervical cancer risk… 

1. Prevent HPV & pathogens

• The ‘good’ bacteria (Lactobacillus species) maintain a balanced environment and acidic pH. This acidic environment inhibits the growth of harmful pathogens, which includes HPV and other STIs.
• These good bacteria therefore reduce your susceptibility to HPV infections.  This is very important, as HPV is the main cause of cervical cancer, being detected in 99% of cervical cancer cases. 

2. HPV Clearance 

• 85% – 90% of high-risk HPV infections are cleared by the vaginal environment. 
• The dominance of Lactobacillus species can eliminate HPV infections, with CST I (dominance of Lactobacillus crisptaus) and CST II (dominance of Lactobacillus gasseri) are the Community State Types most associated with HPV negative women^[1]. While CST II in particular is associated with the fastest clearance of acute HPV infection in women who are HPV-positive^[2]. 
• In comparison, CST III (dominance of Lactobacillus iners) and CST IV (no Lactobacillus dominance) are thought to be less protective and therefore associated with persistent HPV infection^[3]. 
• Research has also indicated that Bifidobacteria may play a potentially protective role, similar to that of Lactobacillus species^[4].

3. Reduce Inflammation

• Inflammation is associated with vaginal dysbiosis. Increased inflammation and infections like BV can increase levels of some cytokines, which can promote cervical cancer development^[5]. 

4. Inhibit Cervical Cancer Cell Proliferation

• Chemicals secreted by Lactobacillus species can reduce the spread of cervical cancer cells and encourage cell apoptosis (process of removing damaged or unneeded cells)^[6]. 

5. Immune System Regulation 

• The vaginal microbiome plays a key role in your immune system. The precise impact on the vaginal microbiome on key aspects of immune system function such as T cells and NK (natural killer cells) is still an area which requires further research in order to fully understand.  

How ScreenMe can help:

• Most accurate – NGS provides results that are 99.9% accurate.
• Most comprehensive – We screen ALL bacteria present (from a database of over 500,000), allowing you to understand your microbiome in depth.
• Most supportive – A free 1:1 consultation with every test allows us to give you the support you require.
• Personalised – individual report, tailored recommendations, and bespoke plan, creates solutions that are catered to you.
• Determine CST – discover which community-state-type you are, so you can make the correct choices for your intimate & general health.

In conclusion, while there is still much more research to be done in this area, it is increasingly thought that the vaginal microbiome may play a significant role in cervical cancer risk via mechanisms including inflammation, immune system impact, HPV prevention and clearance. ScreenMe is committed to helping to eliminate cervical cancer, and so spreading awareness around this topic is so important to us! 

^[1] Chee W, Chew SY, Than L. Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health. Microb Cell Fact. 2020;19(1):203. doi: 10.1186/s12934-020-01464-4.

^[2] Chee W, Chew SY, Than L. Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health. Microb Cell Fact. 2020;19(1):203. doi: 10.1186/s12934-020-01464-4.

^[3] Di Paola M, Sani C, Clemente AM, et al. Characterization of cervico-vaginal microbiota in women developing persistent high-risk human papillomavirus infection. Sci Rep. 2017;7(1):10200. doi: 10.1038/s41598-017-09842-6.

^[4] Freitas AC, Hill JE. Quantification, isolation and characterization of Bifidobacterium from the vaginal microbiomes of reproductive aged women. Anaerobe. 2017;47:145–56. doi: 10.1016/j.anaerobe.2017.05.012.

^[5] Laniewski P, Herbst-Kralovetz MM. Bacterial vaginosis and health-associated bacteria modulate the immunometabolic landscape in 3D model of human cervix. NPJ Biofilms Microbiomes. 2021;7(1):88. doi: 10.1038/s41522-021-00259-8.

^[6] Sungur T, Aslim B, Karaaslan C, et al. Impact of Exopolysaccharides (EPSs) of Lactobacillus gasseri strains isolated from human vagina on cervical tumor cells (HeLa) Anaerobe. 2017;47:137–44. doi: 10.1016/j.anaerobe.2017.05.013.