A ‘Fitbit for the Gut’ May Aid in Detection of GI Disorders

An artificial-intelligence (AI)-enabled system of wearable coils and ingestible “smart” pills shows promise for identifying and tracking gasses in the gastrointestinal (GI) tract associated with digestive disorders, new research revealed.

Traditional methods for locating, measuring, and monitoring gasses associated with such disorders as irritable bowel syndrome, inflammatory bowel disease, food intolerances, and gastric cancers are often invasive and typically require hospital-based procedures. 

This experimental system, developed by a team at the University of Southern California’s Viterbi School of Engineering, Los Angeles, represents “a significant step forward in ingestible technology,” according to principal investigator Yasser Khan, PhD, and colleagues.

The novel ingestible could someday serve as a “Fitbit for the gut” and aid in early disease detection, Khan said. 

The team’s work was published online in Cell Reports Physical Science.

Real-time Tracking

While wearables with sensors are a promising way to monitor body functions, the ability to track ingestible devices once they are inside the body has been limited.

To solve this problem, the researchers developed a system that includes a wearable coil (placed on a t-shirt for this study) and an ingestible pill with a 3D-printed shell made from a biocompatible resin.

The pill is equipped with a gas-permeable membrane, an optical gas-sensing membrane, an optical filter, and a printed circuit board that houses its electronic components. The gas sensor can detect oxygen in the 0%-20% range and ammonia in the 0-100 ppm concentration range.

The researchers developed various algorithms and conducted experiments to test the system’s ability to decode the pill’s location in a human gut model and in an ex vivo animal intestine. To simulate the in vivo environment, they tested the system in an agar phantom solution, which enabled them to track the pill’s movement.

So, how does it work? 

Simply put, once the patient ingests the pill, a phone application connects to the pill over Bluetooth and sends a command to initiate the target gas and magnetic field measurements.

Next, the wearable coil generates a magnetic field, which is captured by a magnetic sensor on the pill, enabling the pill’s location to be decoded in real time.

Then, using optical absorption spectroscopy with a light-emitting diode, a photodiode, and the pill’s gas-sensing membrane, gasses such as oxygen and ammonia can be measured and mapped in 3D while the pill is in the gut.

Notably, elevated levels of ammonia, which is produced by Helicobacter pylori, could serve as a signal for peptic ulcers, gastric cancer, or irritable bowel syndrome, Khan said.

“The ingestible system with the wearable coil is both compact and practical, offering a clear path for application in human health,” he said. The work also could “empower patients to conveniently assess their GI gas profiles from home and manage their digestive health.”

The next step is to test the wearable in animal models to assess, among other factors, whether the gas-sensing system “will operate properly in biological tissue and whether clogging or coating with GI liquids and food particles causes sensor fouling and affects the measurement accuracy,” Khan and colleagues noted.

Khan acknowledges support from USC Viterbi School of Engineering. A provisional patent application has been filed based on the technology described in this work. During the preparation of this work, the authors used ChatGPT to check for grammatical errors in the writing. After using this tool, the authors reviewed and edited the content as needed and take full responsibility for the content of the publication.

Marilynn Larkin, MA, is an award-winning medical writer and editor whose work has appeared in numerous publications, including Medscape Medical News and its sister publication MDedge, The Lancet (where she was a contributing editor), and Reuters Health.