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A New Avenue of Treatment for Endometriosis: the Vaginal Microbiome

The mission of project “LactoBack” is to treat Endometriosis through a less well-known avenue of treatment: the disbalanced vaginal microbiome, which has been linked to the onset and progression of Endometriosis.

The two main problems we hoped to address with our project were the lack of therapies, and the lack of awareness and support.

The Problem

Most of you probably know someone with Endometriosis. Most of us do.

Endometriosis is an incredibly painful disease that affects at least 1 in 10 women. Even though it's so common it still has a very long way to go: diagnosis is so poor that many more women may have the condition without having a diagnosis. Therapeutic options, too, are poor, since they all have strong side-effects and have to be taken repeatedly. And finally, having Endometriosis is difficult socially too since Endometriosis is so painful that it can interfere with women's daily lives.

Knowing people with this ourselves, and fascinated by a topic that affects women's health, we decided to tackle these issues.

The Biology behind Endometriosis

Endometriosis is a disease that affects the female reproductive tract. In Endometriosis, uterine-like cells appear outside of the uterus, but continue to behave as if they were in the uterus. They change and shed with the menstrual cycle, bleeding where they shouldn't and causing scarring, cysts and a lot of pain.

The most prevalent theory is that of retrograde menstruation, also known as Sampson's theory. During menstruation there is a backflow of menstrual blood into the fallopian tubes. In a healthy person the menstrual blood with the endometrial cells gets cleared away by the immune system. However, in patients with Endometriosis the immune system fails to do so and so the cells can transplant themselves and keep growing in the ex-uterine environment. The cells do not only spread in the peritoneal cavity but can travel as far as the lungs and even the brain in very rare cases.

There is also strong evidence towards the role of immune dysfunction in Endometriosis, as many aspects of the immune system seem abnormal, including immune cells like macrophages. The immune system often not only fails to detect and remove the innapropriately implanted cells, but also reacts by creating an inflammatory environment in the tissue, which increases the cells' abilities to nestle into the unwanted environment.

This inflammatory response is also a very important pain-causing factor. During menstruation, the breakdown of the menstrual tissue is highly regulated by the innate immune system, which induces a sterile local inflammation Endometrial lesions outside of the uterus also undergo a shedding process or a “menstruation”. This induces inflammation in the area of the lesion, which leads to inflammatory pain. This is the main pain mechanism of Endometriosis. Yet, pain can also be caused outside of the usual menstrual cycle, as prolonged inflammation leads to the formation of scar tissue and adhesions.

This is only a very basic overview of what goes on in Endometriosis. In fact, the immunology of Endometriosis is extremely complicated, with many minute details and interactions that seem to play a role - no one factor alone explains the condition[1.].

So we decided to focus on an aspect we thought was less known but equally interesting. Indeed, an aspect we knew less research was being done on: the connection of endometriosis to an imbalanced vaginal microbiome.

The Vaginal Microbiome and Endometriosis

The Vaginal Microbiome refers to the bacterial community of the vagina. The healthy microbiome has a low pH and is undiverse, while a Vaginal Dysbiosis is associated with a higher pH and higher diversity of bacteria. This increased diversity means that the same bacteria that dominate in healthy women - e.g. Lactobacillus species - are less present and more pathogens are able to nestle in and make a home there.

The link between Vaginal Dysbiosis and Endometriosis is still fresh territory. However the evidence of a link between dysbiosis and Endometriosis is strong. Dysbiosis causes a dysfunction in the immune system which not only worsens the already painful symptoms of Endometriosis but might also be involved in the onset of the disease.

As mentioned, dysbiosis has been shown to have a disruptive effect on the immune system. A disrupted immune system leads to elevated levels of pro-inflammatory factors, compromised immune surveillance and even alters the behaviour of immune cells. This is due to bacterial endotoxins which are components of the outer membrane of some bacteria. Through these endotoxins our immune system can sense the presence of the unwished bacteria. Contact with the endotoxins activates the macrophages which start secreting pro-inflammatory and pro-nociceptive (pain inducing) factors. Normally this is how we want our immune system to react to intruders. However, since the bacteria are present over a longer time period in dysbiosis the immunoregulation progresses into a state of chronic inflammation. (1) The worse the inflammation the worse the subsequent inflammatory pain.

Social Aspect

Endometriosis is a disease that affects every aspect of a person's life. Our Human Practices tackled this aspect from multiple different perspectives. From interviews with Experts and Patients to Education and Awareness.

Short Team Introduction

We are a team of 12 students across two universities: the University of Zurich (UZH) and the Swiss Federal Institute of Technology in Zürich (ETH). Our interests are varied, ranging from beekeeping to drawing to kayaking, and we come from a variety of university degrees. Come and meet us at Team Page!

Read our Description Page to find out what we're working towards!