Everyone farts. The question is how often? And how much gas is too much gas to pass?
These are questions born out of frustration with laboratory equipment.
To see the fart sensor in action, be sure to watch the video at the end!
Microbiologist Brantley Hall of the University of Maryland in College Park and his colleagues study the metabolism of gut microbes. They tried unsuccessfully to measure hydrogen production from gut microbes with a sensor placed in an oxygen-free chamber. Frustrated, “we took the sensor out of the room and said, ‘Fuck off. We’re going to try to measure a fart.’” So Hall stuck the device in his own pants and let it rip. “And the signal was huge.”
Inspired by this incident, the team designed “Smart underwear” that can track babiesespecially the hydrogen part of farts. Hall and his colleagues described their device – a small hydrogen sensor about the size of a coin that clips onto people’s regular underwear – in December 2025. Biosensors and bioelectronics:.
In a test of the device, healthy college-aged volunteers who wore sensors farted an average of 32 times a day. But that figure varied from a low of four bouts of flatulence per day to a high of 59. Eating the fiber-rich gumdrops caused 36 of the 38 participants to get wind more often, the researchers found.
Hall now wants to expand the study to a much larger, more diverse group to find out how often people fart normally – and whether this changes with age, diet or other circumstances. No one really knows because until now, no one has measured flatulence in people’s daily lives.
“We know what the normal heart rate is, we know what the normal cholesterol level is, but if you go to the doctor, they don’t know the normal number of farts,” Hall says. “If you tell them, ‘I fart 50 times a day,’ they don’t really have a baseline to compare that to.”
The team was “shocked by the lack of intestinal gas measurements,” says Hall. For example, no one knows how much people fart at night, because most studies have used rectal probes in medical settings or relied on people to record their own farts, which they can’t do in their sleep. “Basically, because of the limitations of fart measurement [there is a] There’s a complete gap in our understanding,” he says. “We really don’t know. Isn’t that funny? [In] In 2026, we don’t know if people fart at night or not.
Hall’s team launched the Atlas of human respiration in February to build on the pilot study and identify the normal range. For Project Atlas, researchers are asking volunteers to wear the sensors in their underwear 24 hours a day (minus 15 minutes of charging time while showering) for at least three days and up to 30 days. Volunteers also agree to photograph their food with an app on their phone.
Most people don’t even feel the device once they locate the right place to attach it, Hall says. In the pilot study, people were more likely to lose or wash the device than to think it was uncomfortable and drop out of the study. And people can wear the sensor for almost any activity.
“We’ve seen people play rugby, run a 5K, practice volleyball for hours, without any problems,” Hall says. But “there is one activity that we cannot do, and that is cycling. Cycling is prohibited. No cycling.” Bike seats hit where the sensors are attached.
The previous study suggested that people fall into three main categories. For a group, the playground rhyme “beans, beans, musical fruit, the more you eat, the more you cheat” doesn’t hold up. These “zen digesters” rarely fart even when they eat a lot of fiber.
At the other end of the scale are the “hyperhydrogen producers” who fart a lot. In between are what Hall’s group calls “normal people,” although researchers don’t yet know the true normal range. The most and least prolific participants in the Atlas project will achieve 3D printed plate marking status.
Like the cheese cutting that started it all, interest in the Atlas has been enormous. The first batch of 800 sensors was shipped in just a few days and more than 3,500 people expressed interest. Enrollments are currently on hold while researchers build more devices, but they may soon reopen to accept people already on the waitlist and perhaps others who will join them in the future.
Hall and his colleagues also launched a startup called Ventoscity to help companies that make fiber supplements detect flatulence caused by their products.
The enthusiasm for the Atlas project surprised Hall. With stigma and taboos against discussing bodily functions, “you would think it’s kind of a topic that people don’t want to talk about, but almost people want to talk to me about it too much,” he says. “People are very excited about measuring farts.”