Diagnosing endometriosis: can the microbiota help?

Is it finally time for endometriosis patients, i.e., one in every 10 women of reproductive age (sidenote: Endometriosis, World Health Organization (2021 March). ) , to come out of the shadows and put an end to diagnostic error? As we enter into Endometriosis Awareness Month and with the announcement by French President Emmanuel Macron on January 11, 2022 of a national strategy (sidenote: https://www.elysee.fr/emmanuel-macron/2022/01/11/strategie-nationale-endometriose ) , the answer is hopefully yes.

Researchers have for some time harbored suspicions about some of our microbiota: not only the vaginal microbiota, which could be a useful predictor of severity, but also, according to one recent Chinese study, the gut microbiota as well as the peritoneal fluid (sidenote: Peritoneal fluid Fluid found in the peritoneal cavity, i.e., inside the membrane surrounding the abdominal organs. It acts as a lubricant, preventing friction between the organs during digestion. DiZerega GS, Rodgers KE, Peritoneal Fluid. The Peritoneum. 1992. pp 26-56 Springer New York ) as tools for confirming the diagnosis.

Peritoneum, gut, and cervix under the microscope 

According to their results, the communities of microbes living in the gut and peritoneum of women with endometriosis differ from those observed in women not affected by this condition. Endometriosis patients have fewer of certain types of protective bacteria (especially Ruminococcus) in the digestive tract, and in contrast an over-representation of pathogenic bacteria (especially Pseudomonas) in the peritoneal fluid. 

On the other hand, the composition of the cervical mucus is relatively similar between women with and without endometriosis.

The gut microbiota, a diagnostic tool? 

Could this difference in the microbiota of the gut and peritoneum in women with endometriosis be used to diagnose the condition earlier? That is the question! Crucially, could this be something thousands of women have until now only dreamed of: a more rapid diagnostic test based on an analysis of the microbiota? In fact, the discovery of an intestinal marker is particularly interesting because a simple stool sample is all that is needed to analyze the gut microbiota. A very promising idea...