The fart sensor in your underwear and the science behind it
How often do you really fart? A US research team wants to find out using a sensor in your underwear. The technology sounds bizarre, but it is intended to close a gap in gut research.
There are inventions that inevitably make you wonder: does humanity really need this? A sensor in your underwear that counts how many times you fart – at first glance, it sounds absolutely like one of those superfluous ideas. However, a closer look reveals that the device could fill a real research gap.
Why farting can be medically interesting
Anyone who has ever suffered from flatulence or stomach pain due to a bloated abdomen knows how uncomfortable and painful it can be. Gas production depends on factors such as diet, digestion, stress, and the activity of gut microbes. However, the extent to which flatulence actually says anything about gut health remains largely unclear. There is a lack of measurement data and comparative values – the topic is too embarrassing, and the associated experimental setups have been too uncomfortable until now.
And so, to this day, a reliable normal value is missing. How often people actually fart in everyday life has mainly been estimated so far – and is likely to have been underestimated due to incomplete self-reporting, especially at night.
A research team wants to make the taboo measurable
A team led by cell biologist Brantley Hall from the University of Maryland aims to close this gap. Hall and his team have developed a wearable sensor designed to enable long-term measurement of intestinal gases in everyday life. According to the researchers, it is the first wearable specifically for this measurement.
The flatulence researchers want to answer previously unresolved questions: How much do people actually differ in their intestinal gas production? What influence do different meals have? And why can some people tolerate a high-fiber diet with few complaints, while others react quickly with flatulence?
How the fart sensor works
In their feasibility study published at the end of 2025, the team first tested whether the sensor could be reliably worn and evaluated in everyday life. The coin-sized device contains an electrochemical sensor. It detects hydrogen that escapes with intestinal gases and stores the time and intensity of the measurement signals. The gas is produced when gut bacteria ferment certain carbohydrates and dietary fibers. The measured values thus reflect when gut microbes are fermenting and how much this activity increases after a meal.
Source: Botasini et al., Biosensors and Bioelectronics: X (2025), Fig. 1.
19 healthy adults wore the device for an average of more than eleven hours a day for one week. It recorded an average of 32 intestinal gas events per day, although individual values varied widely, ranging from four to 59. Previous estimates assumed significantly fewer (about 14 farts per day on average). In a second trial with 38 people, the measured hydrogen production increased after the subjects were given inulin, a prebiotic fiber. The trial showed that the sensor can make the reactions of gut microbes to diet visible outside of a laboratory.
Source: University of Maryland
Next step: the Fart Atlas
With the «Human Flatus Atlas», the team now wants to transition the small pilot study into a larger everyday study: 500 healthy adults are to wear the sensor for at least twelve hours a day for three days and document their meals. This data is intended to create an initial comparative basis that will help to better classify individual measurement values in the future. Only then can it be reliably tested whether certain patterns occur more frequently in people with flatulence or irritable bowel syndrome.
Not yet a home gut check
For now, the smart underwear is primarily a tool for research. However, the data could one day help doctors to classify certain complaints more accurately. Together with food diaries, symptom logs, and other examinations, it could be possible to track how the gut reacts after certain meals and whether recurring patterns emerge. This would be particularly interesting for people who actually want to eat fiber but react to it with severe flatulence or stomach pain.
Until then, caution is advised regarding big promises. No diagnosis can be derived from the number of flatulence events. A sensor does not detect irritable bowel syndrome, lactose intolerance, celiac disease, or any other cause of digestive complaints. A lot of gas can be completely normal, for example, when gut bacteria process fiber-rich food.
Source: University of Maryland
In any case, the sensor is not yet available for everyday use. The researchers have filed a patent for the technology and co-founded the company Ventoscity, which intends to further develop and market the sensor. Whether this will eventually become a medical product, a tool for nutritional studies, or a wearable for consumers remains to be seen.
Science editor and biologist. I love animals and am fascinated by plants, their abilities and everything you can do with them. That's why my favourite place is always the outdoors - somewhere in nature, preferably in my wild garden.
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