Swallowable Biosensor Pill Tracks Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a chronic condition causing inflammation in the digestive tract, affects millions of people globally, many of whom struggle with the burden of frequent, invasive monitoring. Existing approaches often rely on unpleasant and expensive procedures such as colonoscopies or require patients to send stool samples to laboratories, which can be cumbersome and discourage regular testing. Patients may also miss early warning signs of flare-ups, which could lead to complications and hospital visits. Now, researchers have developed a new low-cost, ingestible device that enables individuals to detect intestinal inflammation by simply checking the color of their stool.

The pill, called PRIM (Pill for ROS-responsive Inflammation Monitoring), was developed by researchers at Mass General Brigham (Somerville, MA, USA) in collaboration with the University of Toronto (Toronto, ON, Canada), is a miniaturized capsule coated with a special polymer that reacts to elevated levels of reactive oxygen species (ROS), a chemical marker of inflammation. When ROS levels are high, the polymer breaks down and releases a blue dye, which becomes visible in the stool and serves as an indication of intestinal inflammation. Designed to be stable in healthy gut conditions, the capsule activates only in the presence of inflammation, offering a simple and non-invasive alternative to current monitoring methods. The device has an estimated production cost of just $0.38 per unit, supporting its potential for widespread, regular at-home use.

In preclinical testing, the PRIM capsule was evaluated using 36 pills in both laboratory settings and a rat model of colitis. In rats with intestinal inflammation, the pill successfully detected inflammation with 78% sensitivity and 72% specificity, while it remained inactive in healthy animals. The visible dye provided a clear signal in stool samples. These findings, published in Device, validate the effectiveness of the approach and underscore its stability and specificity. The research team is now working to adapt the technology for human use by refining its sensitivity and conducting tests in larger animal models. The long-term goal is to develop a reliable, patient-friendly monitoring tool that reduces the need for clinical visits and enhances disease management.

“With further development and testing in humans, this swallowable sensor could help patients and doctors catch flare-ups earlier, adjust treatments more effectively, and ultimately improve quality of life without the hassle of stool handling or hospital visits," said co-senior author Yuhan Lee, PhD.