Study suggests commonly-found bacteria in the mouth can cause bacterial vaginosis; indicates need for safe oral sex

Bacterial vaginosis is one of the most common causes of abnormal vaginal discharge in women in their reproductive age. The common signs of bacterial vaginosis are grey, white or green vaginal discharge which usually has a fishy odour, vaginal itching and a burning sensation during urination. Bacterial vaginosis increases the risk of preterm labour and amniotic fluid infections during pregnancy. The most common cause of bacterial vaginosis is the excess or reduced growth of Lactobacillus bacteria, which leads to the change in the pH of the vagina. However, a research published in the journal PLOS Biology on 25 August, scientists found that oral sex may also result in bacterial vaginosis. Study: The presence of F nucleatum bacteria in the vagina  Bacteria benefit from each other and usually live in a mutually beneficial relationship. In the study, Dr Amanda Lewis along with other colleagues at the University of California, San Diego, stated that the growth of potentially harmful microorganisms, such as Fusobacterium nucleatum, can not only be seen in the absence of healthy bacteria but also due to the mutual relationship between the bacteria. Fusobacterium nucleatum is a bacteria usually found in the oral cavity and is associated with various gum diseases. It has also been responsible for intrauterine infection and preterm birth in pregnant women. The scientists firstly inoculated F nucleatum bacteria in the vagina of the female mice and found that there was a change in the biochemical activities of their vagina. The scientists found the presence of enzyme sialidase in the vagina which is associated with bacterial vaginosis. The scientists then conducted the experiment on vaginal swabs taken from twenty-one women. The scientists incubated a few vaginal samples with F nucleatum bacteria and incubated others with no bacteria in it. The results of the study showed that the samples that were incubated with Fusobacterium had higher levels of indicators which resulted in bacterial vaginosis as compared to the samples incubated without Fusobacterium. Conclusion: Oral sex may result in bacterial vaginosis The scientists concluded that the enzyme sialidase helps Fusobacterium to consume sialic acids from the mucus produced by the host, thus allowing it to grow. They further stated that since Fusobacterium is mostly found in the oral cavity (especially found in those with an excess of dental plaque), it can spread to the vagina during oral sex, increasing the risk of bacterial vaginosis. By indulging in safe sexual practices , such as using dental dams during oral sex, the transmission of such infection-causing bacteria can be avoided completely. Frequent use of antimicrobials can alter the bacteria in the mouth It is not only the presence of dental plaque but also the overuse of antibiotics that can change the microbiota of the oral cavity. In the ‘Finnish Health in Teens’ (Fin-HIT) study published in the journal Microbiome, scientists found that out of 11,000 Finnish adolescents, those who consumed antimicrobials such as azithromycin and amoxicillin during the first decade of their lives showed less diversity of bacteria in their mouth. Scientists stated that it made them prone to antibiotic resistance and obesity later in life. For more information, read our article on Bacterial Vaginosis. Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.