Not only are colonoscopies invasive and uncomfortable, they can also miss biomarkers related to intestinal problems, which are only present in the body for a short period of time. A new "smart pill" uses live glowing bacteria to address these deficiencies.
The prototype device, described as "the size of a blueberry," was developed by scientists from MIT, Boston University, the University of Chicago, biotech company Analog Devices and Harvard-affiliated Brigham and Women's Hospital. It was based on a previously developed capsule that was much larger and therefore difficult to swallow.
The new pill measures less than 1.4 cubic centimeters (0.09 cubic inches) and contains genetically engineered probiotics, electronic components and micro-batteries.
After the device is swallowed and passed into the large intestine, the bacteria inside glow when exposed to biomolecules associated with certain intestinal diseases. Onboard electronics detect these lights and respond by emitting wireless signals that can be picked up by a doctor's smartphone or computer located outside the body.
Because the procedure is so simple and non-invasive, it can easily be done multiple times (with a new tablet each time). That means it has a greater chance of detecting short-acting biomarkers that might be missed in just one or two colonoscopies. The tablets are eventually passed out of the body in the feces.
In tests on pigs, the device was able to detect and report levels of nitric oxide, high concentrations of which have been linked to several forms of inflammatory bowel disease. It is believed that by tweaking the way the bacteria are designed, other types of biomarkers can be detected. In addition, the tablets can facilitate research into the gastrointestinal system.
"The inner workings of the human gut remain one of the last frontiers of science," said MIT associate professor Timothy Lu. "Our new pill could reveal a wealth of information about human body function, the body's relationship with the environment, and the impact of disease and therapeutic intervention."
A paper on this research was recently published in the journal Nature.