UK trials saliva and gut tests for endometriosis

A saliva tube and a set of sensor pads on the abdomen are being tested against a problem that can consume years: diagnosing endometriosis. In the United Kingdom, two noninvasive tests—Endotest and EndoSure—will be used with general-practice patients over the next three years to see whether they can identify the disease sooner.

Endotest looks for patterns in microRNAs, tiny molecules involved in controlling how genes behave. A French study spanning 971 patients reported high accuracy, but most participants had endometriosis. That differs from ordinary general-practice patients with pelvic pain, who may have bowel, bladder, muscular or other conditions instead. The test’s performance in that real-world mix is still unknown.

EndoSure takes 45 minutes and measures electrical signals in the gut through sensor pads placed on the abdomen. One study of 154 women reported 95% sensitivity—correctly detecting people with endometriosis—and 96% specificity—correctly ruling it out in people without it. But many controls were not surgically confirmed as free of the disease. Preliminary later work involved just 25 women with confirmed endometriosis and 25 controls, and the researchers could not establish whether other conditions, including adenomyosis, might interfere.

The warning became sharper in unpublished findings presented at a scientific meeting: EndoSure detected everyone with endometriosis, but its reported specificity was only 5%. In that result, 95% of people without endometriosis still tested positive. Larger studies would need to confirm which figure reflects the test’s performance in general practice.

For patients, an effective early test could raise suspicion and help them reach specialist ultrasound sooner. It would not replace imaging, which shows where the disease is and how extensive it is, or assessment of adhesions—scar-like tissue that can stick pelvic organs together. A negative result should not dismiss persistent symptoms unless the test reliably rules out endometriosis in the population being tested; pelvic pain still needs investigation even when endometriosis is absent.