Causes of Bacterial Vaginosis (BV)
The vagina is home to a diverse ecosystem of bacteria, but upsetting the balance in this ecosystem may result in a condition known as bacterial vaginosis (BV). While this imbalance may be caused by various factors, many wonder if it can come as a result of oral sex. Can BV be transmitted orally? Read on to learn more.
Symptoms of Bacterial Vaginosis
Bacterial vaginosis most often affects women during their reproductive years, but it can realistically occur at any point in a woman’s life. Many women with bacterial vaginosis show no signs or symptoms of the disease. For those that do, some of the most common symptoms include:
- Vaginal discharge appearing as thin, grey, green, or white
- Vaginal itching
- Fishy odor
- Burning sensation when urinating8
While these symptoms on their own may not pose serious issues, studies have linked bacterial vaginosis to more serious issues, including ascending genital tract infection, certain sexually transmitted infections, and birth issues.10
Causes of Bacterial Vaginosis (BV
BV is commonly attributed to the microorganism Garnerella vaginalis. It is the most virulent of the BV-associated anaerobic organisms. However, it has been found that Gardnerella vaginalis is present in only 40-50% of the vaginas of women with BV. Furthermore, pure cultures of G. vaginalis do not always lead to bacterial vaginosis, while those with asymptomatic forms of the disease may be colonized with low numbers of the bacteria. Further research is necessary to determine if G. vaginalis is the causative agent of BV or if BV is a result of several different microbes in an altered vaginal microflora.1G. vaginalis is also found in the vaginas of women who have been cured of BV. Other causes of BV are mycoplasma and anaerobic organisms, such as bacteroides, Peptostreptococcus fusobacteria, and those of genus Mobiluncus.2
BV is characterized by a dysbiosis, or imbalance, of normal vaginal microbes. The normal, healthy vagina contains many Lactobacilli species. With bacterial vaginosis, you experience a partial loss of Lactobacilli indigenous to the vagina, along with the overgrowth of several anaerobic microbes within the vaginal mucosa. In a cross-sectional study, researchers evaluated a population of 531 women for vaginal and rectal bacterial colonies. Results showed that Lactobacillus crispatus, L. jensenii, and L. gasseri were the most prevalent bacterial strains. Only 13 of 147 women who had vaginal or rectal colonies of L. jensenii or L. crispatus were found to have bacterial vaginosis. By comparison, 12 of 27 women with other Lactobacilli strains had bacterial vaginosis. This suggests that being colonized by the normal vaginal microbes, such as Lactobacillus crispatus and Lactobacillus jensenii, is associated with a lower risk of BV.3 These and other hydrogen-peroxide producing Lactobacilli help defend the vagina by making the environment more acidic and hostile against pathogenic organisms.
While you may be wondering, “Can BV be transmitted orally?” it is important to understand that bacterial vaginosis is not strictly a sexually transmitted disease as it can be contracted without having sexual intercourse. However, some studies do show that sex has the potential to cause bacterial vaginosis. Frequency of sexual intercourse is a critical factor in the epidemiology of bacterial vaginosis, suggesting that it may be a “sexually enhanced disease”.7
Could having receptive oral cunnilingus disrupt the normal vaginal flora by introducing microbes that are likely to cause BV? Can BV be transmitted orally?
Possibly. Studies do show that women who receive oral cunnilingus have a higher chance of BV in both women who have sex with men as well as women who have sex with women. In one study, a group of 17 lesbians was evaluated for bacterial vaginosis. Nine of these women had received oral sex in the previous four weeks, and six of these had bacterial vaginosis. The other eight women who had not partaken in oral sex were found to have no signs of BV. In parallel, 256 straight women were studied, and 55 were diagnosed with bacterial vaginosis. Of this group, 111 women had received cunnilingus in the previous four weeks, 41 of whom had BV. Only 14 of the 145 women who had not received oral sex had bacterial vaginosis.
While further research is necessary, particularly regarding bacterial vaginosis in women who sleep with women, the results in both groups suggest a link between oral sex and symptoms of bacterial vaginosis.4
Common Risk Factors for Bacterial Vaginosis
Multiple Sexual Partners
As mentioned, sex may have an effect on bacterial vaginosis. Research is still shaky on the direct influence of sex on bacterial vaginosis, but women who have multiple sexual partners or a new partner tend to have cases of bacterial vaginosis more often. BV is also more common in women who sleep with other women.8
Natural Lack of Bacteria
Some women naturally produce less Lactobacilli, resulting in a lack of beneficial bacteria in their vaginas, which makes them more potentially vulnerable to bacterial vaginosis.8
Rinsing the vagina out with water or a cleansing agent has been shown to upset the natural microbial balance in the vagina. This can potentially result in an overgrowth of anaerobic bacteria, resulting in bacterial vaginosis.8
In a 20-week pilot study, 39 women who used douching products were enrolled in a regimen comprising four weeks of douching followed by 12 weeks of douching cessation. In the last four weeks, participants could choose whether to continue douching or maintain cessation. Using self-collected vaginal samples, results of the study found that cases of bacterial vaginosis were significantly reduced in those women who stopped douching.9 The vagina can clean itself naturally, so douching and other forms of vaginal washing are unnecessary.
Can Normal Oral Flora Cause BV?
While oral sex may contribute to bacterial vaginosis, further research is necessary to understand if specific bacteria in the mouth result in dysbiosis or if the act of cunnilingus itself causes dysbiosis. The normal flora of the oral cavity consists of many organisms including fusobacterium which can cause BV.5 BV in the mouth can come from anaerobic organisms, which are associated with BV.
Anaerobic organisms break down proteins and other organic matter and release sulfurous, malodorous compounds called volatile sulfur compounds.6 An overgrowth of anaerobic organisms in the mouth can cause bad breath or halitosis.
Peridontal disease and gingivitis, caused by an overgrowth of microorganisms along the gums, can also cause halitosis. Therefore, receiving cunnilingus from a person with dental disease could increase your risk of BV more than from someone without dental disease.
Can BV be transmitted orally? Concerned about bacterial vaginosis? Read about BV Home Remedies and Prevention here.
Probiotics for Vaginal Health