Fertility & Postpartum

Vaginal microbiome science

Professor Willa Huston is a microbiologist at the University of Technology Sydney. Her research team is committed to understanding how STIs and the vaginal microbiome are involved in infertility and other adverse impacts on women’s reproductive and genital health.

"In the not too distant future you might be encouraged by your doctor to give some thought to your microbial friends in your vagina!"

The research on the vaginal microbiome composition in pregnancy dramatically changes postpartum to become less Lactobacillus spp. dominant independent of ethnicity. Lactobacillus are the good, healthy bugs that help to maintain balance and healthy bacterial populations in the vagina.

Lactobacillus species

The microorganisms that dominate a healthy vagina microbiome and are critical for maintenance of vaginal wellbeing are the Lactobacillus species. Lactobacillus species produce lactic acid, hydrogen peroxide and other directly antimicrobial agents which have essential role in the balancing bacterial organisms and maintaining healthy vaginal microbiome. 

There are around 20 Lactobacillus species that have been detected in the vagina. Recent scientific research has shown that healthy vaginal microflora does not contain high numbers of many different Lactobacillus species. Rather, 1 or 2 Lactobacillus species are dominant (mainly L. crispatus and L. iners but also L. gasseri and L. jensenii), and other species are rare.

Lactobacillus crispatus

The most important of the Lactobacillus species is called Lactobacillus crispatus. In fact we like to call it ‘the queen'. It is the most beneficial healthy bacteria in vaginal microbiome of 65% of all women. If you get back a vaginal microbiome test, and see L. crispatus dominance in the results it will usually indicate that there is a balanced and healthy vaginal microbiome. L. crispatus creates very stable colonies. 

Lactobacillus gasseri

Lactobacillus gasseri is the ‘second in command’ good bug, entirely connected with the healthy and balanced vaginal microbiome. It is present in healthy vaginal microbiome in more than 40% of women. Although it does not create as stable colonies as L. crispatus, certain L. gasseri strains have the ability to release antimicrobial substances that interfere with the ability of bad bugs to survive in the vagina and form a biofilm (a protective layer some bad bugs can create around themselves).