Your underwear could soon reveal what is happening inside your gut

Everyone farts. But scientists have never had a particularly good way of measuring how often it happens.

That may be changing.

Researchers at the University of Maryland have developed a small wearable sensor that attaches to ordinary underwear and continuously monitors hydrogen in intestinal gas.

The technology, dubbed Smart Underwear, is giving researchers a more accurate look at a bodily function that has long been surprisingly difficult to study.

And the early numbers are challenging a figure that has appeared in medical literature for decades.

A study published in Biosensors and Bioelectronics: X found that 38 healthy volunteers produced an average of 32 flatulence events a day when monitored with the device. Individual results ranged from four to 59 events.

That is considerably higher than the roughly 10 to 14 daily events often cited in older research.

Why scientists are counting farts

The problem is not that doctors have ignored flatulence.

It is that measuring it accurately has been difficult.

Earlier studies relied on small groups, invasive equipment or people remembering and reporting how often they passed wind. That can miss events that happen during sleep or simply be affected by memory.

Brantley Hall, a University of Maryland microbiologist who leads the research, says scientists have had surprisingly little objective data to work with.

“There are a couple of studies, but they were pretty invasive. They involved rectal tubes,” Hall said. “We really haven't advanced our understanding since then.”

Smart Underwear is designed to close that gap.

The device is only a few centimetres across and attaches to the outside of underwear near the perineal area. It uses electrochemical sensors to detect hydrogen in flatus, while other sensors help establish whether the device is being worn.

Hydrogen matters because it is produced by gut microbes as they break down food.

That means the sensor is not simply counting farts. It is also giving researchers a window into when and how actively gut microbes are fermenting food.

The researchers describe the idea as something like a continuous glucose monitor, but for intestinal gas.

The number alone does not tell the whole story

The striking finding from the research is not simply that people may fart more often than previously thought.

It is how different people can be.

Hall has reported seeing an individual produce as many as 175 events in a day in later, unpublished work, while another person on the same diet produced only four.

That huge difference is now one of the questions researchers want to understand.

The current peer-reviewed study also found that the device could detect changes in hydrogen production after participants consumed inulin, a type of prebiotic fibre. It recorded the diet-related increase with 94.7 per cent sensitivity in the 38-person study.

That matters because fibre is often encouraged as part of a healthy diet, yet increasing fibre can also produce more gas in some people.

The gut microbiome may help explain why.

Enter the Human Flatus Atlas

The University of Maryland team is now using the technology in the Human Flatus Atlas, a research project designed to establish a better baseline for human flatulence.

Researchers want to compare gas patterns with people's diets and gut microbiomes.

Participants are being studied across different levels of gas production. One group, called Zen Digesters, consists of people who eat relatively high-fibre diets but produce little gas.

At the other end are the Hydrogen Hyperproducers — people who produce large amounts of gas.

Researchers hope that comparing these groups will reveal why some gut microbiomes appear to handle fibre with relatively little gas while others produce much more.

The study is aimed at adults in the United States, with participants completing the research remotely. The project's website currently says enrolment has been paused because of high demand, with a waiting list available.

Could your farts really say something about your health?

Possibly — but the science is not there yet to diagnose disease from a fart count.

Passing gas is normal. The US National Institute of Diabetes and Digestive and Kidney Diseases says people pass gas an average of eight to 14 times a day, while noting that some people may pass it more often. What matters clinically is also whether the symptoms are troublesome or accompanied by other changes.

Gas can be affected by diet, swallowed air and the activity of bacteria in the large intestine.

Persistent or troublesome gas can also occur alongside conditions such as irritable bowel syndrome, lactose intolerance and coeliac disease.

But that does not mean a person who farts frequently has one of these conditions.

The Smart Underwear itself is a research device, not an approved diagnostic test.

Hall says that distinction is important.

“We don't actually know what normal flatus production looks like,” he said. “Without that baseline, it's hard to know when someone's gas production is truly excessive.”

The next step: more than hydrogen

The current device focuses on hydrogen.

The researchers are interested in expanding its capabilities to detect other gases, including methane. That could provide additional information about gut microbial activity and digestive patterns.

But there is still a long road between a research sensor and something a doctor might routinely use.

For now, the value of the technology is more basic — and perhaps more important.

Scientists are trying to establish what normal looks like.

Once that baseline exists, researchers can begin asking better questions about why one person's gut behaves differently from another's, how diet changes microbial activity and whether long-term changes in gas production can provide useful clues about digestive health.

So the future of gut health may involve something few people would have imagined a decade ago: keeping an eye on what happens in your underwear.

And, for once, science may finally have a way to count it.

Category: Lifestyle

About the Author

Maureen Onyango is a journalist passionate about storytelling, life coaching and spiritual lessons. She studied at the Kenya Institute of Management and enjoys telling stories that inform, inspire and empower communities.