Stool test could provide a simpler way to diagnose endometriosis

Low levels of a specific compound in your stool may be a sign of endometriosis, and supplementing with that compound may even help manage the condition.

Endometriosis occurs when endometrial tissue grows in other parts of the reproductive tract and affects nearly 200 million people worldwide. There is currently no known cure, but once the condition is diagnosed, the lesions can be removed regularly with surgery. However, due largely to a lack of awareness and understanding, endometriosis currently takes on average more than six years to be diagnosed.

Previous research suggests the gut microbiome may play a role in this condition. For further investigation, Ramakrishna Komagani and colleagues at Baylor College of Medicine in Houston, Texas, collected stool samples from 18 women with endometriosis and 31 women without endometriosis. They studied the bacteria in the feces as well as the metabolome – a group of chemicals produced by gut bacteria.

They found that women with endometriosis had lower levels of the metabolite 4-hydroxyindole in their feces, possibly due to changes in the gut microbiome.

Based on this discovery, Kommagani said commercial stool analysis could rapidly screen for this widely “underdiagnosed, understudied and underappreciated” condition, allowing for early and effective treatment.

“Feces is easy to collect and is not as invasive as current diagnostic techniques such as laparoscopy (a type of keyhole surgery),” he said.

To explore whether 4-hydroxyindole might have a protective effect, the team supplemented 4-hydroxyindole with a group of mice that had tissue implanted in their abdomens to induce endometriosis. After 14 days of treatment, these mice had no fewer lesions than control animals, but their lesions were significantly less severe and they were significantly less painful.

Further experiments showed that when mice with endometriosis were treated with 4-hydroxyindole, their lesions improved significantly. The results were similar in mice transplanted with human endometriosis lesions, suggesting that the treatment may also be effective in humans.

“We believe this is a very good treatment option because it’s something that occurs naturally in the body rather than something drugged or synthetic,” Kommagani said.

However, larger studies in humans are needed to confirm whether 4-hydroxyindole can be used to diagnose endometriosis and whether the compound can be an effective treatment.