Bacterial vaginosis is the most common condition arising from vaginal dysbiosis. Globally, BV affects an estimated 23%-29% of women of reproductive age. While sexual activity may be a trigger, BV is not usually classed as a sexually transmitted infection.^6,16,17,18

BV is characterised by unusual vaginal discharge often with a strong, fishy smell and a change in appearance to greyish-white and thin and watery. However, half of women with BV may be symptomless, and BV does not usually cause inflammation, itching or soreness.^10,19

Health consequences of BV include adverse effects on pregnancy and birth such as spontaneous abortion, premature births, and low birth weight, as well as increased risk of endometriosis and reduced resistance to STIs including herpes simplex 2 virus, HPV and HIV. Pelvic inflammatory disease (PID) and endometriosis are also more likely.^1,6

Decreased Lactobacillus levels combined with increased levels of Gardnerella vaginalis and Atopobium vaginae are particularly diagnostic for BV, but increased levels of Eggerthella, Prevotella, and Megasphaera are also commonly found.²⁰

Formation of bacterial biofilms, involving virulent strains of G vaginalis in combination with other organisms, contribute to BV formation and persistence.²¹