Fart rate monitor On paper, Brantley Hall’s microbiology lab at the University of Maryland, College Park, studies how the tiny members of our gut microbiome orchestrate countless little reactions that let us digest food. Some of these reactions shove electrons onto stray protons, and a hydrogen molecule is born. Add all those hydrogen molecules together with the other gases created in our digestive tract, and you get flatulence.Hall admits the topic is funny, but his lab is getting serious about farts. They’ve developed Smart Underwear, a sensor for measuring when and how much hydrogen gas comes out of your rear in real-time (Biosens. Bioelectron. :X 2025, DOI: 10.1016/j.biosx.2025.100699).In most people, carbon dioxide and hydrogen—not methane, Hall stresses—make up the bulk of farts. All that hydrogen comes from microbes breaking down beans, greens, and other gassy foods. “If you see hydrogen in flatus, you know that the gut microbes were metabolizing something,” Hall tells Newscripts.The new device is the size of three nickels stacked on top of each other, and it clips onto the outside of the subject’s underwear. The device logs a fart’s time and hydrogen concentration, ultimately reporting the microbial activity in the gut throughout the day via smartphone.Before this study, conventional medical wisdom was that humans pass gas about 15 times a day. Hall’s tests are already bucking that: 10–20% of the 250 people in his study passed gas more than 100 times a day, he says. One person even let loose more than 200 times.The study revealed outliers
Manny I. Fox Morone (Mon,) studied this question.