Could endometriosis be caused by bacteria? Study provides new clues

Infections with certain bacterial groups can be associated with endometriosis, a painful condition that affects up to 10% of women and girls of reproductive age.

A study of 155 Japanese women found that members of the bacterial genus Fusobacterium It was found in about 64% of patients with endometriosis and 7% in the uterus of people without endometriosis.¹.tracking experiments in mice infected with Fusobacterium We showed that antibiotic treatment can reduce the size and frequency of lesions associated with endometriosis.

Researchers will need to do more research before the findings, published June 14 in the journal. scientific translational medicineIt could be used to develop treatments for endometriosis, said Elise Courtois, a genomicist who studies endometriosis at the Jackson Research Institute in Farmington, Connecticut.

However, the results highlight growing interest in the potential role of microbes in endometriosis, a condition with limited treatment options and a poorly understood origin. “There are certainly factors that make us suspect that the microbiome is involved in endometriosis,” says Courtois. “Genetics cannot explain everything.”

painful lesions

Endometriosis is caused by the migration of tissue from the lining of the uterus, called the endometrium, to other parts of the body, most often organs in the pelvic region, where it attaches and grows. It often causes lesions in the reproductive organs, leading to decreased fertility. In addition, people with ovarian involvement have an increased risk of developing ovarian cancer.

The most common symptom of endometriosis is pain, which can be severe. Treatment includes hormone therapy, which also acts as a contraceptive, and surgery to remove the lesion. “We want to find new treatments,” says Yutaka Kondo, a cancer biologist at Nagoya University in Japan and a co-author of the paper. “But first we need to know why people suffer from endometriosis.”

It’s time to expand the definition of ‘women’s health’

Kondo et al. analyzed endometrial tissue from women with and without the disease. They found that samples from patients with endometriosis were likely hosted by bacteria belonging to the genus Endometriosis. Fusobacterium. Fusobacterium It is often found in the mouth, intestines and vagina and is associated with other conditions such as periodontal disease.

to check if Fusobacterium The researchers transplanted endometrial tissue from one set of mice into the peritoneal cavity of another because it could directly affect the course of endometriosis. Within weeks, endometriotic lesions formed in recipient mice. Using this model, researchers found that lesions tended to be more abundant and larger in similarly vaccinated mice. Fusobacterium than what it wasn’t. Vaginal administration of the antibiotics metronidazole or chloramphenicol to mice reduced the development of endometriosis and reduced the number and size of lesions.

Kondo said clinical trials are underway in women with endometriosis to see if antibiotics can alleviate some of the symptoms.

missing part

While the results are compelling, Courtois says the story is still missing some key pieces. For example, it’s useful to test for relationships between: Fusobacterium And endometriosis occurs in more diverse populations, she says. Courtois and his colleagues successfully lobbied the Connecticut state government to establish a repository of endometrial samples for research that included tissues from ethnically diverse populations, transgender and gender diverse people. (This article uses “female” to describe people at risk for endometriosis, but not everyone who identifies as female has a uterus and We also recognize that not everyone with a uterus is female.)

More extensive studies in humans are particularly important because mice, which are amenorrheic and spontaneously form endometrial lesions, are a limited model of symptoms. Kondo’s mouse studies focused on lesions that form in the ovaries, but humans may also develop lesions elsewhere in the body, including the colon and bladder. “These are really interesting and potentially exciting results,” said Krina Zonderban, director of the Nuffield Department of Female Reproductive Medicine, University of Oxford, UK. “But we are still in the early stages of this issue.”