A new swallowable pill may soon replace painful colonoscopies. Learn how these tiny sensors with engineered bacteria can non-invasively diagnose gut diseases.
Scientists have created a tiny, swallowable pill that may soon make diagnosing gut issues much easier and far less painful than a colonoscopy. The study, published in ACS Sensors, introduces microscopic spheres filled with specially designed bacteria. These bacteria are capable of detecting blood in the gut, which can be an early sign of disease. The spheres also include magnetic particles that allow them to be collected from stool samples using a magnet.
In tests with mice suffering from colitis, the spheres were able to detect internal bleeding within minutes. Co-author Ying Zhou said the technology represents a new approach for fast and non-invasive detection of gastrointestinal diseases. In simple terms, this could offer a faster and simpler way to check what’s happening inside the gut without the need for cameras or surgery.
Why Simpler Gut Tests Are Needed
Millions of people in the United States alone live with colorectal cancer, inflammatory bowel disease (IBD), or conditions like colitis. These illnesses can cause bleeding in the gut, diarrhoea, stomach pain, and long-term inflammation. Currently, doctors rely on colonoscopies to diagnose these problems. Although colonoscopies provide detailed images of the bowel, the procedure can be uncomfortable and requires careful preparation.
For these reasons, Zhou, Bang-Ce Ye, Zhen-Ping Zou, and their colleagues have been searching for gentler alternatives. Their idea focuses on bacteria that can respond to specific biomarkers, chemical signals that indicate what’s going on inside the body. One such marker is heme, a compound found in red blood cells. If heme appears in the gut, it could signal internal bleeding.
Creating Bacteria That Survive the Digestive Process
The team had previously made bacteria that glow when they come into contact with heme. However, these bacteria often died as they moved through the harsh, acidic environment of the digestive system. They were also hard to recover from stool samples.
To address this, the researchers placed the bacteria inside tiny hydrogel spheres made from sodium alginate, a commonly used food thickening agent. The spheres function like protective bubbles, keeping the bacteria safe as they pass through the gut. Magnetic particles were added so the spheres could be easily retrieved from stool using a magnet. Lab tests showed that the hydrogel coating kept the bacteria alive while still allowing heme to pass through and trigger their glowing response.
Testing Spheres in Mice
Next, the scientists gave the spheres to mice with varying degrees of colitis, from healthy to severely inflamed. After the spheres had moved through the mice, the team collected them using a magnet and measured the light signals.
They found three important results:
• The entire process took around 25 minutes, like collecting the spheres and analyzing their glow.
• The worse the colitis, the brighter the light signal, indicating more heme was present in more sick animals.
• The spheres were safe and did not harm healthy mice.
What This Could Mean for Future Patients
Although this technology has not yet been tested in humans, the researchers believe it could eventually lead to simple, non-invasive tests for gut diseases. In the future, a patient might swallow a capsule, wait as it passes through their system, and then return a stool sample for analysis. Doctors could then use this information to diagnose conditions, monitor the effectiveness of treatments, or track disease over time. If successful, this small pill could represent a major advancement in understanding and managing gut health.