Swallowable sensor unfurls in stomach to monitor gut health

A swallowable sensor can unfurl in the stomach, non-invasively recording nervous system signals to decipher a person’s digestion and gut health.

The pill-size capsule contains a long, skinny sensor that expands to align with the stomach’s inside wall. In an experiment with pigs, the device accurately measured the electrical activity of stomach cells that control smooth muscle contractions to digest food. Ultimately, this device could help diagnose gastrointestinal disorders such as gastroparesis, or paralysis of the stomach, and chronic indigestion.

“We have tools that are pretty good to measure our heart, but we don’t have great tools to measure the gastrointestinal tract,” says Giovanni Traverso at the Massachusetts Institute of Technology. He compares the innovation to an electrocardiogram, which tracks the heart’s electrical activity.

No electrocardiogram equivalent exists for the gut, so doctors must implant electrodes via surgery or endoscopically insert electrodes through the body opening of a sedated patient, says Adam Gierlach, also at MIT and part of the research team.

Traverso and his colleagues developed the ingestible “MiGUT” device to monitor the gut’s nervous system, which consists of hundreds of millions of neurons, without invasive surgery. The device’s 25-centimeter-long ribbon-like sensor contains a line of gold electrodes and is housed inside a 3D-printed resin capsule. Water-soluble tape covers a hole in the capsule. When the tape comes in contact with the stomach’s gastric fluid, it dissolves and the sensor unfurls.

“I always like to think about how one day we could just Amazon-ship it to you same day – this pill that you take – and you don’t even have to come to the hospital,” says Gierlach.

The MiGUT pill is not at that stage yet. The researchers sedated live pigs to endoscopically insert the MiGUT for precise placement in the stomach. This initial testing showed that the capsule and unfolded ribbon could pass through the pigs’ gastrointestinal system without causing any blockage.

The team also clipped the device to a pig’s stomach wall for several days. There, the MiGUT successfully monitored the stomach’s electrical activity during sleep and waking periods, along with mealtimes.

Eventually, the futuristic device could provide treatments for gut illnesses through electrical stimulation via additional electrodes embedded in the sensor, says Traverso. His MIT team recently received more than $65 million in US government funding to develop medical therapies delivered by ingestible devices.

The versatile device’s potential “marks a significant stride forward in both the diagnosis and treatment of gastrointestinal disorders”, says Bozhi Tian at the University of Chicago.

It could also one day aid in the study of neurodegenerative disorders like Parkinson’s, the paper notes. Changes in gut function can appear up to around 10 years before other symptoms emerge.