Endometriosis: Why the Microbiome Is Key To Treatment Success

When you think about endometriosis, what comes to mind?

Is it the pain, the hormone swings, or the constant fatigue? What if I told you that there’s another piece to the puzzle—something smaller than you might expect? I’m talking about the microbes living inside you, like bacteria, viruses and others. Recent research suggests that these tiny organisms have a big impact on endometriosis, affecting both digestive issues and other body systems. So, how do these little microbes fit into the picture? Let’s take a closer look.

It turns out that women with endometriosis are more likely to experience pelvic infections. If a woman has had pelvic inflammatory disease (PID)—which is often (but not exclusively) caused by sexually transmitted infections—she’s at a significantly higher risk of developing endometriosis. In fact, having PID can triple the chances of developing endometriosis within 10 years. And it doesn’t stop there. Studies show that infections in the uterus can even impact the success of in vitro fertilization (IVF). When it comes to viruses, the connection between endometriosis and human papillomavirus (HPV) is one of the best-known. Even if you've been vaccinated against HPV, it’s important to remember that not all strains are covered. Other viruses like herpes, Epstein-Barr, and cytomegalovirus have also been linked to endometriosis. These viruses can cause the cells that normally line the uterus to behave abnormally and form endometrial tissue where it shouldn’t be. And it’s not just viruses—things like pollution, radiation, and stress can also trigger genetic changes that play a role in developing endometriosis.

What about bacteria?

Recent research has revealed that women with endometriosis often have an imbalance of microbes in both their gut and reproductive system. Studies have found higher levels of certain bacteria like E. coli, Shigella, Streptococcus, and Ureaplasma in women with endometriosis. These bacteria can trigger inflammation, which is one of the hallmarks of endometriosis. In particular, E. coli and Shigella are problematic because they release toxins that activate the immune system, making the inflammation even worse. Another type of bacteria—called mollicutes—are also more common in women with endometriosis. These bacteria are unique because they don’t have cell walls, and they can have a sleeper effect on some immune cells. Changing the way the immune system works is a way that microbes can trigger or maintain inflammation in the body.

What’s more, even the bacteria in your mouth might be involved! Researchers have found that women with more severe endometriosis tend to have higher levels of Fusobacterium, a type of bacteria often associated with gum disease. In milder cases of endometriosis, Cardiobacterium appears more frequently. Animal studies have even linked Fusobacterium to the growth of endometriosis lesions. Your oral health could have a bigger impact on your condition than you might think!

There’s one more twist: certain bacteria can actually boost estrogen levels in your body. These microbes are part of what’s called the "estrobolome”, and in an estrogen-sensitive condition like endometriosis, estrogen can act like a growth factor, which is generally not what we’re going for. That’s one more reason why a good balance in our gut bacteria is so important in this condition.

Here's a summary to remember

Research suggests that women with more severe forms of endometriosis have a less diverse microbiome in their gut, as well as overgrowth of certain specific bugs, which can trigger symptoms. Addressing imbalances in gut bacteria — also known as dysbiosis — may play a crucial role in effective treatment.

It’s important to remember that when bacteria die, they release toxins that can make you feel worse. If you want to save the time and trial-and-error of finding effective treatments on your own, work with a naturopathic doctor to navigate this tricky terrain. Together, we can create a plan that works for you – a plan that addresses both your symptoms and root causes.

References

1. Oral, Vaginal, and Stool Microbial Signatures in Patients With Endometriosis as Potential Diagnostic Non-Invasive Biomarkers: A Prospective Cohort Study. Hicks et al. Oct 2024. https://doi.org/10.1111/1471-0528.17979

2. Shan J, Ni Z, Cheng W, Zhou L, Zhai D, Sun S, et al. Gut microbiota imbalance and its correlations with hormone and inflammatory factors in patients with stage 3/4 endometriosis. Arch Gynecol Obstet. 2021;304:1363–73. doi: 10.1007/s00404-021-06057-z.

3. Ata B, Yildiz S, Turkgeldi E, Brocal VP, Dinleyici EC, Moya A, et al. The Endobiota Study: Comparison of Vaginal, Cervical and Gut Microbiota Between Women with Stage 3/4 Endometriosis and Healthy Controls. Sci Rep. 2019;9:2204. doi: 10.1038/s41598-019-39700-6. 

4. Koninckx PR, Ussia A, Tahlak M, Adamyan L, Wattiez A, Martin DC, Gomel V. Infection as a potential cofactor in the genetic-epigenetic pathophysiology of endometriosis: a systematic review. Facts Views Vis Obgyn. 2019 Sep;11(3):209-216. PMID: 32082526; PMCID: PMC7020943.

5. Koninckx PR, Ussia A, Adamyan L, et al. Pathogenesis of endometriosis: the genetic/epigenetic theory. Fertil Steril. 2019;111:327–340. doi: 10.1016/j.fertnstert.2018.10.013.

6. de Ziegler D, Pirtea P, Galliano D, et al. Optimal uterine anatomy and physiology necessary for normal implantation and placentation. Fertil Steril. 2016;105:844–854. doi: 10.1016/j.fertnstert.2016.02.023. 

7. Tai FW, Chang CY, Chiang JH, et al. Association of Pelvic Inflammatory Disease with Risk of Endometriosis: A Nationwide Cohort Study Involving 141,460 Individuals. J Clin Med. 2018;7:379. doi: 10.3390/jcm7110379.