Australian researchers are running human trials of a gas-sensing swallowable capsule.

The ingestible capsule (the size of a vitamin pill) detects and measures gut gases – hydrogen, carbon dioxides and oxygen – in real time. 

Trials by researchers at RMIT University have already uncovered mechanisms in the human body that have never been seen before, including a potentially new immune system.

Professor Kourosh Kalantar-zadeh, study lead and capsule co-inventor, said human tests showed that the stomach uses an oxidiser to fight foreign bodies in the gut.

“We found that the stomach releases oxidising chemicals to break down and beat foreign compounds that are staying in the stomach for longer than usual,” Dr Kalantar-zadeh said.

“This could represent a gastric protection system against foreign bodies. Such an immune mechanism has never been reported before.”

Another never-before-seen observation from the trial was that the colon may contain oxygen.

“Trials showed the presence of high concentrations of oxygen in the colon under an extremely high-fibre diet,” Kalantar-zadeh said. “This contradicts the old belief that the colon is always oxygen free.

“This new information could help us better understand how debilitating diseases like colon cancer occur.”

The trials were conducted on seven healthy individuals on low- and high-fibre diets. Results showed that the capsule accurately shows the onset of food fermentation, highlighting their potential to clinically monitor digestion and normal gut health.

The trials also demonstrated that the capsule could offer a much more effective way of measuring microbiome activities in the stomach, a critical way of determining gut health.

“Previously, we have had to rely on faecal samples or surgery to sample and analyse microbes in the gut,” Kalantar-zadeh said.

“But this meant measuring them when they are not a true reflection of the gut microbiota at that time. Our capsule will offer a non-invasive method to measure microbiome activity.”

Now that the capsule has successfully passed human trials, the research team is seeking to commercialise the technology.

The findings are published in the inaugural volume of Nature Electronics.