A team of researchers at MIT has created a pill-sized ingestible sensor that is essentially a group of genetically engineered “bacteria on a chip” which can detect intestinal bleeding and diagnoses several diseases.
A strain of E. coli bacteria was genetically modified to respond to the presence of a chemical compound called “heme” found in red blood cells. Upon detecting the presence of heme, the engineered bacteria starts glowing.
In the next step, they created a capsule that can contain the bacteria and allow molecules from the body to permeate into the capsule through a membrane. Here the bacteria can interact with bodily fluids, and in case of internal bleeding, the presence of heme would result in the emission of light from the bacteria.
A phototransistor inside the capsule measures this light and relays the data wirelessly to a smartphone or a computer. Currently, the chip is placed inside a capsule that is 1.5 inches (3.8 cm) long, but the researchers are looking into ways to reduce the size of capsule sensor.
Their goal is to devise a method to store these sensors inside a person’s digestive tract for weeks and send continuous signals that would enable doctors to monitor the gut.
In future, patients could swallow the capsule to scan for early signs of cancer instead of getting a colonoscopy. It would also help in screening the tricky-to-reach parts of the small intestine in people suffering from Crohn’s disease or study the balance of microbes in the gut.