Scientists develop smart underwear to track how often people fart – the results are surprising

Scientists have developed a first-of-its-kind smart underwear to track how often people actually fart, an advance that could lead to new insights into human metabolism.

Until now, tracking human farts in studies has mainly relied on participants' self-reporting their flatulence, which has been unreliable as people tend to forget, miscount, or don’t consider tiny gas releases.

Direct measurements in previous research have been via rectal tubes, which can collect gas from the gut, but these are uncomfortable and impractical for long-term studies.

A continuous non-invasive monitoring method has not been possible until now, as sensors are not small enough, requiring low power, and comfortable enough to wear all day.

Now, the new smart underwear enables tracking flatulence by monitoring gut microbiome hydrogen release.

Its developers say the device could have practical applications, such as tracking triggers for serious digestive diseases like irritable bowel syndrome and food intolerance.

The latest study found participants could comfortably wear the smart underwear for more than 11 hours per day with high adherence to protocol.

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Researchers developed a tiny wearable device that snaps discreetly onto underwear and uses sensors to track intestinal gas production around the clock.

Nearly 60 healthy participants took part in the study, whose results were published in the journal Biosensors and Bioelectronics.

Nineteen of them wore the smart underwear during daily activities for seven days to test comfort and continuous gas detection.

Another 38 took part in a controlled diet experiment to test whether the underwear could detect diet-induced changes in gas production.

Overall, scientists found that healthy adults produced flatus an average of 32 times per day, much more than the 14 daily events often reported in medical literature.

There was, however, individual variation ranging from as few as four farts to as many as 59.

"Objective measurement gives us an opportunity to increase scientific rigour in an area that's been difficult to study," said Brantley Hall, an author of the study from the University of Maryland.

The smart underwear tracks users’ release of hydrogen in their farts.

Farts mainly contain the gases hydrogen, carbon dioxide and nitrogen, with some individuals also releasing methane.

Since hydrogen is produced exclusively by gut microbes, continuously tracking it provides a direct readout of when and how actively they are fermenting food.

“Think of it like a continuous glucose monitor, but for intestinal gas,” Dr Hall explained.

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While there are normal ranges for blood glucose, cholesterol, and countless other physiological measures, no such baseline exists for flatulence, scientists say.

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

To address this gap, researchers plan to conduct an experiment using the smart underwear, tracking flatulence patterns, day and night, across hundreds of participants and correlating those patterns with diet and microbiome composition.

"We've learned a tremendous amount about which microbes live in the gut, but less about what they're actually doing at any given moment," Dr Hall said.

"The Human Flatus Atlas will establish objective baselines for gut microbial fermentation, which is essential groundwork for evaluating how dietary, probiotic or prebiotic interventions change microbiome activity,” he explained.