Checking up on the health of your gut and its resident microbes is soon to be as easy as swallowing a gas-sniffing capsule no bigger than a vitamin.
Around 20 percent of people will suffer at least one gastrointestinal disorder
Intestinal gases can paint a picture of gut health and that of the resident microbes
The researchers, from Australia, are planning phase-two clinical trials of the capsules
Previously trialled in pigs, the capsules — which transmit hydrogen, carbon dioxide and oxygen levels to a receiver as they traverse the digestive system — have successfully passed phase-one human trials.
The “exciting homegrown” invention shows most promise for patients suffering irritable bowel syndrome (IBS), according to Adelaide gastroenterologist Dan Worthley.
“Even though IBS is the most common gastroenterological problem, there’s no laboratory diagnostic test for it,” he said.
The swallowable capsule, published today in Nature Electronics, might one day not only help diagnose IBS, but also track whether treatments work and let clinicians give feedback to patients.
“I think psychologically it could be a really valuable tool for managing patients,” said Dr Worthley, who also runs a gastrointestinal biology lab at the South Australian Health and Medical Research Institute.
Bacteria: tiny gas pumps
Like it or not, there’s always gas in your digestive tract: your stomach, small intestine and large intestine.
A little is swallowed air, and some is produced through chemical reactions, but the lion’s share is generated by your gut microbiome: the trillions of microbes that call your gut home.
They do this by fermenting undigested food for energy and, in the process, churn out gases, such as hydrogen.
While having some gas in our gut is beneficial, too much fermenting bacteria, particularly in the small intestine, can lead to bloating and severe pain.
This “small intestine bacteria overgrowth” is thought to be a driving factor in IBS.
Scoping out how much gas is in the gut and where it’s produced can give doctors an idea of what’s going on in there, but that’s easier said than done.
Clinicians use breath tests to calculate gut hydrogen levels. Gas in the digestive system is absorbed into the blood and carried to the lungs, where it’s exhaled.
(That’s right — as you’re reading this, you’re breathing out hydrogen produced in your intestine.)
But these breath tests aren’t great, said RMIT materials scientist and study-co-author Kyle Berean.
“They have an accuracy of less than 70 per cent for many diagnostic procedures,” he said. “It’s pretty much a toss of coin.”
And even if a breath test returns high hydrogen levels, they can’t say where in the metres of intestines a bacterial overgrowth might be located.