Endometriosis, an agonizing condition that affects up to one in 10 American women, could be caused by bacteria commonly found in the mouth and gastrointestinal tract, a new study has suggested.
The disorder occurs when tissue similar to the womb’s lining grows in other places, including the ovaries and fallopian tubes.
Researchers at Nagoya University Hospital and Toyota Kosei Hospital in Japan found that a specific bacterial genus was present in most women with endometriosis, compared to a small percentage of women who did not have the condition.
The bacteria, fusobacterium, Fusobacterium is a group of naturally occurring bugs often found in the mouth, gut, and vaginal region that trigger structural changes associated with endometriosis.
The bacteria is also linked to inflammatory conditions such as colorectal cancer and gum infection periodontitis.
Endometriosis affects women of all ages and can lead to pain, heavy periods, nausea and diarrhea. It is also a cause of infertility: 30 to 50 percent of women who struggle to get pregnant have the condition
Published Wednesday in the journal Science Translational Medicine, the study looked at 155 women in Japan.
This included 76 healthy women and 79 women with endometriosis.
The researchers took vaginal swabs from the women and found that 64 percent of those with endometriosis had Fusobacterium in their uterine lining. Just 7 percent of healthy women had this bacteria.
Follow-up treatments in mice with Fusobacterium suggested that antibiotic treatment could reduce the size and frequency of lesions, which are commonly associated with the condition.
In rare cases, endometriosis can grow in areas beyond the pelvic organs, including the rectum, bladder, and stomach.
The condition causes endometrial-like tissue that grows around the uterus to thicken, break down, and bleed during each menstrual cycle. The tissue has no way to escape, so it becomes trapped.
Endometriosis can cause pain, at times debilitating, especially during menstrual cycles.
According to the World Health Organization, the condition affects one in 10 women and girls of reproductive age across the globe.
About 11 percent of women and girls between ages 15 and 44 have the condition in the US.
Symptoms, according to the Mayo Clinic, include painful periods, pain with intercourse, pain with bowel movements or urination, excessive bleeding during or between periods, fatigue, diarrhea, constipation, and bloating.
It can also cause infertility in 30 to 50 percent of affected women, as it damages reproductive organs.
On average, it takes women with the condition more than a decade to get diagnosed.
No one knows exactly what causes endometriosis. Previous research suggests that it could be due to retrograde menstruation, in which menstrual blood containing endometrial cells flows back through the fallopian tubes and into the pelvic cavity instead of outside the body. These cells then stick to the pelvic walls and organs, which allows them to keep thickening and bleeding.
Although research is limited, hormones such as estrogen have also been to blame.
Risk factors include never giving birth, starting your menstrual cycle early, heavy menstrual cycles, short menstrual cycles, low body mass index (BMI), and family history.
Birth control can manage the symptoms, but the only cure for the condition is removing a person’s reproductive organs.
The researchers are still unclear about how Fusobacterium enters endometrial tissue or what makes some people more susceptible to it than others.
The study team has stated that more research is still needed on the topic.