Engineered E. coli could color-code your poop to diagnose gut problems

Humans have an uneasy relationship with bacteria – sure, they can make us very sick, but we also couldn't live without the complex society residing in our guts. 

Now, researchers at Rice University have engineered E. coli to help detect inflammation in the colon of mice by infiltrating that microbiome and sending color signals through their feces.

Eventually this could lead to self-diagnosis tests for humans ... and if your poop turns out blue, you should probably see a doctor.

For the study, the Rice team focused on detecting colitis, a condition where the colon becomes inflamed. Previous studies had shown evidence that elevated levels of a molecule known as thiosulfate might be a biomarker for the condition, so the researchers engineered E. coli that could sense thiosulfate and respond by producing proteins that fluoresced green.

To test the system, the team gave billions of the bacteria to two groups of mice: a healthy control group and a group suffering from colitis.

As expected, the feces of the mice with colitis glowed green when viewed under an instrument called a flow cytometer, indicating elevated levels of thiosulfate and, by extension, the presence of colitis. The more inflamed the mouse's colon was, the brighter their poop glowed.