Watch: Ingestible Bacteria-on-a-Chip Tracks GI Health
S. Himmelstein | May 28, 2018Why would anyone swallow a capsule packed with electronics and genetically engineered E. coli? The device was developed at MIT to diagnose bleeding in the stomach or other gastrointestinal problems.
The tool combines sensors made from living cells with ultra-low-power electronics that convert the bacterial The ingestible sensor is equipped with bacteria programmed to sense environmental conditions and relay the information to an electronic circuit. Source: Lillie Paquette/MITresponse into a wireless signal that can be read by a smartphone. Sensors designed to respond to heme, a blood component, were successfully demonstrated in pig models. Detectors were also designed to respond to a molecule that is a marker of inflammation.
The 1.5-inch-long cylindrical sensor requires about 13 microwatts of power, and is equipped with a 2.7-V battery that could power the device for about 1.5 months of continuous use.
The initial trial used an engineered probiotic strain of E. coli to express a genetic circuit that causes the bacteria to emit light on exposure to heme. The living cells were housed in four wells inside the sensor and covered by a semipermeable membrane that allows small molecules from the surrounding environment to diffuse through. A phototransistor underneath each well measures the amount of light produced by the bacterial cells and relays the information to a microprocessor that sends a wireless signal to a nearby computer or smartphone. A new Android app can be used to analyze the data.
This type of sensor could be deployed for one-time use or designed to remain in the digestive tract for several days or weeks, sending continuous signals. The sensors could be designed to carry multiple strains of bacteria in order to diagnose a variety of conditions, and its use could also eliminate the need for endoscopies for diagnosis.
The research is published in Science.