Many women with Endometriosis also report issues with their gut health, usually in the form of chronic IBS symptoms such as abdominal pain, bloating, constipation and/or diarrhoea. The links between endometriosis and gut health are many, owing both to the proximity between typical organs affected by endometriosis, the ability of endometriosis lesions to be present almost anywhere and also the role that the gut plays in immune function.
What is endometriosis?
Endometriosis is a chronic inflammatory condition affecting women, believed to be present in around 1 in 9 women. The condition is believed to be caused by a combination of genetics and biological dysfunction involving the hormone oestrogen and immune function dysfunction which triggers inflammation. Currently, there is some debate as to whether it's an autoimmune condition or not.
The condition involves endometrial-like tissue growing outside of the uterus where we normally will find a healthy endometrial lining. Typical symptoms include menstrual pain - often severe - other types of pain, fatigue, digestive complaints and infertility.
I've previously written in depth about the myths surrounding endometriosis.
The links between Endometriosis and gut health
The links between endometriosis and gut health span two main areas: symptoms and causes. Many women with endometriosis report experiencing digestive symptoms that are part of their endometriosis picture. This article will instead be focused on the causes of endometriosis relating to how well an individual's gut is functioning from an immune and hormonal perspective.
The gut microbiome, the estrobolome and oestrogen
Did you know that approximately 70% of our immune cells are located in the gut? Well, now you do! The immune system in the gut is comprised of various specialist cells and physical barriers. The microbiome plays a fundamental role in educating the immune system so that it tolerates foods and friendly bacteria, instead of inappropriately reacting to those. So, the microbiome is essential for correct functioning of the immune system which affects many aspects of health.
What can go wrong here is that the makeup of an individual's microbiome may contain high levels of pro-inflammatory bacterial species that affect immune function AND specific types of bacteria can also interfere with correct oestrogen metabolism and detox.
The estrobolome is defined as the collective genes of the microbes in the gut that can metabolise oestrogen. Oestrogens are metabolised by the enzyme β-glucuronidase which is produced by specific species of gut bacteria. The oestrogens are converted from their conjugate forms to their deconjugated forms to become the "active" oestrogens that enter the bloodstream and exert their effects. A high level of β-glucuronidase is something seen in gut dysbiosis and this can lead to a recirculation of high levels of oestrogen which can be harmful. It's believed that opportunistic bacteria are the ones that can produce this enzyme, so an individual's gut microbiome makeup is very relevant here.
Prior research has shown that dysbiosis leads to increased estrogen levels in the circulation. Increased oestrogen exposure can stimulate growth of endometriosis lesions via proliferation and increase the inflammatory activity in them.
As mentioned already, most of the immune system is located in the gut. This means that any disturbances in that environment filter out to affect potentially every other body system via immune function. The microbiome plays a key immunoregulatory function which can lead to systemic inflammatory responses.
In endometriosis research, the most common sampling sites for microbiome assessment are the gastrointestinal tract (via stool) and the endometrium, although the cervix and vagina have also been assessed in some studies.
A systematic review is like an overview of the research to date on a particular topic and helps to make more high quality conclusions because there is more information to work with compared to just one study.
A 2019 systematic review found clear differences between the gut microbiomes of women with endometriosis and those without the condition. Endometriosis is associated with higher levels of Proteobacteria, Streptococcus, E.coli, Enterobacteriaceae. Firmicutes phylum and Gardnerella also appear to be associated.
One of the most significant, repeated findings in seven studies was that the nine detected taxa belonging to the phylum Proteobacteria were all reported to be significantly increased in endometriosis patients, compared with those without endometriosis. Proteobacteria is considered a highly pro-inflammatory grouping of species due to their cell wall containing endotoxin/lipopolysaccharide (LPS).
Microbiome research using samples from the vagina and peritoneal fluid have also been conducted. Endotoxin or lipopolysaccharide (LPS) is found in the types of bacteria found in greater amounts in women with endometriosis. It triggers a harmful immune response which promotes the onset and progression of endometriosis lesions. In one study, the level of LPS was found to be 4-6 times higher in women with endometriosis compared to those without it.
It’s believed that the combination of estrogen and LPS can promote pelvic inflammation and growth of endometriosis in a greater way than either of those factors alone.
Oestrogen that's ready to be excreted from the body needs healthy bile flow in order to do so, along with regular bowel movements. Those with bile sludge (too thick) and/or constipation - note, these often go together - will end up not excreting oestrogen effectively meaning it will be re-absorbed in to the body.
How I treat women with endometriosis
- An anti-inflammatory, nutrient dense diet is essential for treating endometriosis to help reduce overall inflammation and support various biological processes that support oestrogen metabolism
- Microbiome work to restore balance (eubiosis) is a fundamental part of treatment for endometriosis. This includes diet changes to feed beneficial bacteria and discourage the growth of more harmful bacteria
- If there's an overgrowth of harmful bacteria (as is often found in SIBO), then treating this is very important
- Digestive support may also be needed to ensure adequate excretion of oestrogen