Diagnosing gut disorders such as lactose intolerance or even life-threatening health problems could become as simple as swallowing a pill.
Australian researchers say that a new gas-sensing swallowable capsule sensor detects gases that can indicate gut disorders and diseases.
“Our ingestible sensors offer a potential diagnostic tool for many disorders of the gut, from food nutrient malabsorption to colon cancer,” said Kyle Berean, the device’s co-inventor and a research fellow in the department of electronic and telecommunication engineering at RMIT University in Australia.
Such diseases are currently diagnosed through a variety of other methods.
These include breath tests and invasive procedures such as endoscopies and colonoscopies. Both these procedures involve feeding a wired camera through sections of the digestive system.
The researchers’ study was in the inaugural edition of Nature Electronics.
How the capsule works
The RMIT-developed capsule is about the size of a vitamin pill.
It’s powered by three internal silver-oxide batteries. It can transmit data wirelessly to a Bluetooth-enabled phone or other device.
Onboard sensors detect hydrogen, carbon dioxide, and oxygen gases.
“Gases of the gut are associated with the gut disorders,” Kourosh Kalantar-zadeh, a RMIT professor study leader and capsule co-inventor, told Dr.China.
“For instance, if someone has lactose intolerance, lactose cannot be absorbed by the human body and instead reaches the microbiota of the gut and colon that feed on it and produce excessive amounts of hydrogen. As such, a spike in hydrogen production is a sign of lactose intolerance,” he said.
The pill takes about the same time to move through the digestive system as food — 24 to 48 hours.
A preliminary study found that the capsule safely moved through the digestive system of study participants and was able to detect the onset of food fermentation in the gut.
“Previously, we have had to rely on fecal samples or surgery to sample and analyze microbes in the gut,” said Kalantar-zadeh. “But this meant measuring them when they are not a true reflection of the gut microbiota at that time. Our capsule will offer a noninvasive method to measure microbiome activity.”
A breath test alternative
Initially, Kalantar-zadeh was approached by gastroenterologists seeking an improved breath test, since such tests are often only 60 to 70 percent effective.
“The inaccuracy of breath testing is due to it being an indirect measurement. Gases are produced in the gastrointestinal tract, absorbed onto the gut walls, enter the blood recirculation, and some are released into the lungs and then exhaled,” he explained. “The problem is that during this natural process, the gases are interfered with by the metabolism of the body and also diluted.”
These limitations led to the development of the capsule sensor, which can sample gases directly in the gut, beginning in 2011.
Initial testing of the capsule may have uncovered a previously unknown immune function in the stomach. Data from the sensor found that the human stomach uses an oxidizer to break down foreign bodies that linger too long.
“This could represent a gastric protection system against foreign bodies,” said Kalantar-zadeh. “Such an immune mechanism has never been reported before.”
The capsule also detected the presence of oxygen in the colon of patients with a diet high in fiber.
“This contradicts the old belief that the colon is always oxygen-free,” said Kalantar-zadeh. “This new information could help us better understand how debilitating diseases like colon cancer occur.”
What the future could hold
Researchers are currently seeking funding for phase II testing of the capsule sensor, which could be modified in the future to detect a greater variety of gases.
At some point during their lifetime, 1 in 5 people worldwide will experience a gastrointestinal disorder.
Capsule-like devices are already in widespread use in gastroenterology.
With capsule endoscopy, for example, the “pill” contains a camera that takes thousands of pictures as it passes through the small intestine.
Capsule endoscopy is used as an alternative to traditional endoscopy in the more restrictive spaces of the small bowel. It can detect symptoms of Crohn’s disease, celiac disease, and ulcerative colitis, as well as gastrointestinal bleeding and tumors.
Researchers at Caltech are also working on a “” that could use MRI-like technology to deliver medication to precise locations in the body.
And a company called Proteus Digital Health has developed a sensor that essentially uses the patient’s own body as a battery, powering a device that transmits health data to a wearable patch.