Does Bacteria Cause Endometriosis?
Hi, Bestie! Welcome back to another chat about endometriosis—something tells me these are going to become commonplace here given the prevalence of the issue and the new research that is being published all the time. If you missed our last chat on the basics of endometriosis, catch up here. Today, I wanted to talk about endometriosis and its potential link to bacteria. A new study was published earlier this year (2023) that demonstrated bacteria as a potential cause for endometriosis. This article caused a complete frenzy because of its implications for the treatment of endometriosis. Let’s talk a bit about it and other similar articles.
To review, endometriosis (sometimes also referred to in brief as “endo”) is the growth of endometrial-like tissue outside of the uterus. The reason endometriosis develops is not well understood. This makes it difficult to diagnose and treat. One commonly accepted hypothesis for the cause of endometriosis is retrograde menstruation. This occurs when menstrual blood flows back through the fallopian tubes and into the pelvic cavity, instead of exiting the body through the vaginal canal. This menstrual blood contains cells from the uterine lining (endometrial cells) and it is thought that these cells may stick to surfaces within the pelvic cavity and cause the development of endometriosis. It is also known that endometriosis is estrogen-dependent. This means its growth is dependent on the presence of estrogen. Since post-menopausal females have decreased levels of estrogen, endometriosis is not commonly an issue in that population.
Endometriosis presence on a fallopian tube, ovary, and uterus
So, what is this study I was going on about earlier? It is an article called Fusobacterium infection facilitates the development of endometriosis through the phenotypic transition of endometrial fibroblasts by Muraoka et. al (1). In this study, researchers searched for bacteria in the endometrial tissue samples of 84 females. Half of these ladies had endometriosis and half did not have endometriosis. They found a bacteria called Fusobacterium Nucleatum in 64% of the females with endometriosis. Contrastingly, they only found this bacterium in 7% of the people without endometriosis. Strangely enough, this is the same type of bacteria associated with periodontal disease, or gum disease. More research will need to be done to understand this connection.
Next, the researchers went a step further to see if they could promote endometrial lesion growth in mice. This was somewhat of a complicated process, but ultimately resulted in more endometrial lesion growth in the infected mice compared with the uninfected mice. In fact, the mice that were infected with the Fusobacterium Nucleatum grew more than twice as many lesions as the uninfected group, and those lesions were five times bigger than the lesions present in the uninfected group of mice.
Finally, the researchers looked at whether antibiotics would help contain the bacterium and therefore reduce the spread of endometrial lesions in the mice. They gave the mice a dose of antibiotics and found that the antibiotics seemed to slow the spread of the endometrial lesions. Further studies will need to be done to test the potential effect of antibiotics on endometriosis in humans.
The reason this study gained so much traction is that it points toward a potential new treatment for endometriosis. Endometriosis is notoriously hard to treat. Because scientists don’t fully understand its cause, it has been difficult to find a solution that combats the root of the issue. Many treatments have been aimed at ameliorating the symptoms of endometriosis in order to make it a more manageable condition. Other treatments, such as surgical removal of endometrial lesions, removes the source of endometriosis pain, but does not tackle the source of the lesions. If antibiotics can reduce the size and spread of endometrial lesions in humans, this will revolutionize the way endometriosis is treated.
In a somewhat similar article from a few years ago, entitled Bacterial contamination hypothesis: a new concept in endometriosis by Khan et al., authors hypothesized that bacteria has a role in endometriosis (2). They specifically looked at lipopolysaccharide (LPS) which is a significant component in gram-negative bacteria. It is also referred to as “endotoxin.” The authors thought that LPS could possibly be involved in the growth of endometriosis. It is presumed that a large amount of LPS (endotoxin) in menstrual fluid could be involved in pelvic inflammation and promote endometrial lesion growth.
To confirm their hypotheses, the authors measured the LPS present in the menstrual blood of females with and without endometriosis. They found the concentration of endotoxin to be four to six times higher in folks with endometriosis compared with those without endometriosis. The authors speculated as to whether bacterial contamination of the menstrual blood is the cause of effect of endometriosis and ultimately determined that it could be either (sort of a chicken-or-the-egg scenario).
To sum things up, speculation regarding the connection between bacteria and endometriosis has been around for quite some time. It is pretty clear now that certain types of bacteria are connected to endometriosis. The ways in which these bacteria cause endometriosis to develop are still being debated and studied. The good news is that endometriosis research is being done all the time, and each new article is one step closer to a potential cure.
XOXO,
Your Pelvic Bestie
References:
1. Muraoka A, Suzuki M, Hamaguchi T, Watanabe S, Iijima K, Murofushi Y, Shinjo K, Osuka S, Hariyama Y, Ito M, Ohno K, Kiyono T, Kyo S, Iwase A, Kikkawa F, Kajiyama H, Kondo Y. Fusobacterium infection facilitates the development of endometriosis through the phenotypic transition of endometrial fibroblasts. Sci Transl Med. 2023 Jun 14;15(700).
2. Khan KN, Fujishita A, Hiraki K, Kitajima M, Nakashima M, Fushiki S, Kitawaki J. Bacterial contamination hypothesis: a new concept in endometriosis. Reprod Med Biol. 2018 Jan 18;17(2):125-133.
*The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a qualified health provider regarding any questions you may have about a medical condition or health objectives.
