Small intestinal bacterial overgrowth (SIBO) disrupts the normal balance of bacteria in the small intestine. Research suggests the balance of microorganisms in the gut may link to endometriosis, although there is currently a lack of evidence directly linking endometriosis and SIBO.

Endometriosis, or endo, occurs when tissue similar to the endometrium, which is the tissue lining the uterus, grows outside of the uterus. SIBO occurs when there is excess bacteria in the small intestine.

Research suggests a link between gut health and endometriosis. This article looks at the potential link between endometriosis and SIBO.

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According to a 2021 study, people with endometriosis may have changes in their gut microbiota. The gut microbiota is the term for bacteria and other microorganisms in the gastrointestinal (GI) tract.

Research suggests the gut microbiota may play an important role in maintaining good health and may contribute to the development of various diseases.

The gut microbiota helps to regulate inflammation outside of the GI tract. Inflammatory processes may contribute to the development of endometriosis.

Gut dysbiosis is a key feature of SIBO, and endometriosis may also be linked to it. Gut dysbiosis is a change or imbalance in the microorganisms in the GI tract.

SIBO may lead to the development of irritable bowel syndrome (IBS). Excess bacteria in the small intestine can interfere with the normal function of the intestines and may cause IBS symptoms. Researchers do not yet fully understand the link between SIBO and IBS, though.

Around 20% of people with endometriosis also have symptoms suggesting IBS. Research suggests that the gut microbiota may play an important role in both conditions.

Endometriosis and SIBO may share overlapping symptoms and factors involved in the disease process, such as gut and immune health, inflammation, and hormone imbalances.

Endometriosis and SIBO may share similar gastrointestinal symptoms. People may experience the following digestive symptoms with endometriosis, particularly during their menstrual period:

Symptoms of SIBO include:

A 2021 study found that people with endometriosis may have changes to their gut microbiota. The researchers found that people without endometriosis had a much higher variety of microbes in the gut compared to people with endometriosis.

A balanced gut microbiota helps to control disease-causing microorganisms, minimize inflammation, and regulate the immune system.

Gut dysbiosis causes significant changes to the barrier function of the intestines, which can encourage inflammation and lead to various symptoms and diseases.

If invasive types of bacteria are present with SIBO, it can lead to inflammation and cause symptoms. Certain strains of bacteria may injure the tissue lining the gut and cause inflammation of the intestines.

According to a 2023 review, SIBO may cause changes to the immune system and result in chronic inflammation. Imbalances in the gut microbiota change the immune system response, which promotes inflammation.

Gut dysbiosis can reduce the barrier function of the intestinal walls. This can increase the chance of toxins and infectious agents entering the gut or bloodstream, which may create an inflammatory response in the body.

Many studies looking at the link between SIBO, inflammation, and systemic diseases are animal studies, so further research in humans is necessary to better understand the link.

A balanced gut microbiota is an essential part of maintaining a healthy immune system, and gut dysbiosis may cause changes to the immune system.

Poor immune function may also play a role in the development of SIBO. Immunodeficiency disorders, which are conditions in which the immune system is impaired, may increase the risk of SIBO.

The gut microbiota may impact estrogen levels in males and postmenopausal females, and may play a role in estrogen-dependent diseases.

Increased estrogen levels promote the growth of cells lining the female reproductive tract and may contribute to conditions such as endometriosis and endometrial cancer.

In addition to talking with a healthcare professional, people may find the following organizations helpful for resources and support for endometriosis and SIBO:

Many functional doctors and nutritional health professionals also offer support and treatment plans for SIBO. People may also want to search for online SIBO support groups through social media platforms.

Can endometriosis cause gastrointestinal issues?

Endometriosis can cause gastrointestinal issues, including bloating, diarrhea, constipation, and nausea.

Is endometriosis linked to gut health?

Research suggests endometriosis may be linked to gut health. People with endometriosis may have changes to their gut microbiota that are not present in people without endometriosis.

What conditions are linked to SIBO?

Research suggests SIBO may link to many different, systemic diseases, including endocrine, digestive, cardiovascular, and neurological conditions.

Endometriosis and SIBO may have links, although there is currently a lack of evidence directly linking the two conditions.

Research suggests an imbalance in the gut microbiota may play a role in endometriosis. SIBO may also cause changes in the immune system and promote inflammation, and may be link to many systemic diseases.

Further research may help experts better understand the possible link between gut health and endometriosis, and specifically any link between SIBO and endometriosis.