October 25, 2024, 12:50 pm | Read time: 5 minutes
Many women have to deal with a bacterial vaginal infection – also known as vaginosis – at least once in their lives. Until now, antibiotics have been used for treatment, but this, in turn, often unbalances the vaginal flora and encourages further infections. A new study has now uncovered an alternative that could be used to treat recurring bacterial vaginosis. FITBOOK editor Janine Riedle explains what the researchers have discovered.
Bacterial vaginal infections are among the most common infections of the female reproductive organs. It is estimated to affect around five in 100 women.1 In around a third of women, the disease is asymptomatic or only causes mild symptoms. In these cases, the infection usually subsides on its own. However, if symptoms such as itching and unpleasant smelling and gray-white vaginal discharge occur, vaginosis must be treated. This is usually done with a suitable antibiotic. As many women want to avoid antibiotics due to the sensitive vaginal environment, the following news should raise hopes. Researchers found that a certain fatty acid could be suitable for treating or preventing bacterial vaginosis.
Overview
Why bacterial vaginal infections often recur
Bacterial vaginosis can occur when there is an imbalance of naturally occurring microbes in the vagina. If the infection is left untreated, it can cause problems with pregnancy, lead to an increased risk of sexually transmitted infections and promote painful vaginal inflammation (vaginitis).
Healthy, intact vaginal flora is, therefore, essential to prevent diseases in the female genital tract. Put simply, this consists largely of lactic acid bacteria, also known as Lactobacillus. The sex hormone estrogen is responsible for their multiplication, which is why a balanced hormonal state positively affects vaginal health. The lactic acid bacteria create an acidic environment. This ensures that fungi, viruses, and bacteria cannot multiply within the mucous membranes. The ideal pH value of the vaginal environment is around 4.5.2
Taking antibiotics can lead to an excess of lactobacilli, or more precisely, Lactobacillus iners, and thus upset the balance. This, in turn, promotes recurrent vaginosis after taking the medication.
Oleic acid promotes the growth of healthy lactic acid bacteria
A team of researchers led by Dr. Meilin Zhu investigated the extent to which the proliferation of Lactobacillus crispatus, which is important for the balance of the vaginal environment, can be promoted.3 In the laboratory, the scientists, therefore, planned a large-scale screening to analyze the effects of various compounds on the bacteria.
Initially, the team began cultivating the lactobacilli in the laboratory. However, an important component of the culture medium interfered with the screening tool. During troubleshooting, it was discovered that the lactobacilli needed oleic acid in order to grow. The researchers then cultivated the lactobacilli strains with oleic acid.
Using RNA sequencing, the scientific team then attempted to identify genes that positively influence oleic acid and unsaturated long-chain fatty acids. This step served to understand the extent to which the production of the body’s own fatty acids could be stimulated.
Link between oleic acid and bacterial vaginosis
The scientists also wanted to know how oleic acid affects the vaginal flora in the presence of bacterial vaginosis. For this reason, the bacteria responsible for the vaginal infection were cultivated with the lactobacilli iners and crispatus.
Results
After cultivating the lactobacilli strains with oleic acid, the scientists observed that the growth of Lactobacillus iners, the harmful lactic acid bacteria, was inhibited. In contrast, the growth of healthy lactic acid bacteria, including Lactobacillus crispatus, was promoted. The same inhibitory effect on harmful bacteria was also observed during co-cultivation with bacteria that typically promote vaginal infections. In addition, oleic acid also inhibited the growth of some strains that were resistant to standard antibiotic treatments. These results show that oleic acid can protect against and prevent recurring bacterial vaginosis.
Furthermore, RNA sequencing was used to identify a gene that codes for the so-called oleate hydratase enzyme. This is responsible for converting unsaturated, long-chain fatty acids in such a way that only bacteria with this enzyme can use it. Another gene identified encodes the fatty acid efflux pump, which is necessary for bacteria to withstand high concentrations of oleic acid.
Study from the USA Eating fish during pregnancy can reduce the baby’s risk of autism
Good to know Why fiber is so important for the body
Study shows By 2050, 39 million deaths are expected to be attributable to antibiotic resistance
Classification of the study
“This study is an important example of how understanding the basic metabolic requirements and functions of important bacteria can lead directly to new therapies that allow us to modify the microbiome for improved health,” said co-senior author Seth Bloom, lecturer in infectious diseases at Massachusetts General Hospital, emphasizing the importance of the study results.4 The research provides important clues as to how bacterial vaginosis could possibly be treated completely without antibiotics or how the vaginal environment could be rebalanced after treatment of the infection.
However, the results of the study currently only represent the first step in the right direction. As this is an in-vitro study, i.e., purely laboratory tests, additional research must be carried out on humans in order to confirm the initial exciting indications. The first step is to investigate the extent to which oleic acid production can be stimulated in humans, e.g., in the form of a drug. “We believe there is great potential to apply these findings to permanently alter the vaginal microbiome, improve the treatment of bacterial vaginosis and reduce negative health outcomes for women worldwide,” says Doug Kwon, Professor of Medicine at Harvard Medical School.