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The Next Frontier of Microbiome Transplants May Be the Vagina
Don’t try this at home
This story was updated on Oct. 7, 2019 to reflect new study data.
There is new research that proposes that the best way to treat a bacterial infection in one woman’s vagina might be to transplant bacteria from another woman’s vagina.
Our bodies are home to a diverse ecosystem of bacteria. Different body parts host different bacterial communities and require a specific balance of microbes to stay healthy. In the vagina, one strain reigns supreme: Lactobacillus. One theory as to why Lactobacilli are beneficial is that they produce lactic acid, keeping the vaginal pH relatively acidic and killing off most of the other types of bacteria. If Lactobacillus is usurped as the dominant strain, a type of inflammation called bacterial vaginosis (BV) sets in, and there’s an overgrowth of other kinds of bacteria.
“High diversity is very healthy in the gut. In the vagina, it’s the total opposite,” says Jacques Ravel, a professor of microbiology and immunology at the University of Maryland. “That’s what defines BV — it’s what they call a polymicrobial disease. That means you have many different microbes that you really don’t want to be there.”
BV is the most common vaginal infection among women, with an estimated prevalence of about 30% among women ages 14–49 in the U.S. It can cause discharge, a fishy odor, itching, or burning in the vagina, although not all women with BV are symptomatic. The condition can also be associated with an increased risk of urinary tract infections. More pressing, in some cases BV can lead to preterm birth in pregnant women and a greater risk for sexually transmitted infections, including HIV and cancer-causing HPV.
The standard treatment for BV is antibiotics that are supposed to eliminate the non- Lactobacillus microbes and allow the good bacteria to regrow. However, in most women the relief is temporary and the infection recurs within two to four weeks. Another approach is to give women a probiotic containing Lactobacillus either vaginally or orally, but so far the results have been mixed. So scientists are searching for alternative treatment options.
