University of Maryland scientists have created a device, known as "smart underwear," to continuously measure intestinal gases in humans.
This innovation is the first wearable device to accurately record flatulence and track intestinal gases, allowing for a reassessment of old assumptions about how often humans pass gas and opening up prospects for studying gut microbiome metabolism in everyday life.
For decades, doctors have struggled to diagnose intestinal gas problems, as it is almost impossible to document them objectively using available tests.
To meet this challenge, a team led by Brantly Hall, an assistant professor in the Department of Cell Biology and Molecular Genetics at the University of Maryland, developed a small device that easily attaches to any underwear and uses electrochemical sensors to track intestinal gas production around the clock.
In a recent study published in the journal Sensors and Actuators: B. Chemical X, scientists found that healthy adults produce gas an average of 32 times a day, nearly double the rate previously reported in medical literature. Significant individual variations were also observed, ranging from four to 59 times a day.
The study explained that previous estimates were low because they relied on surgical techniques in small samples or on self-reporting, leading to inaccuracy and the impossibility of recording gases during sleep. Furthermore, intestinal sensitivity varies between individuals; two people may produce similar amounts of gas but experience it very differently.
The Hall team is currently recruiting participants from several groups to broaden the scope of the study, including:
"Quiet digestion": People who eat a high-fiber diet yet produce little gas.
Hydrogen producers in excess: People who suffer from excessive gas.
Normal people: those whose gas levels fall between the two previous categories.
In most people, gas is primarily composed of hydrogen, carbon dioxide, and nitrogen, although some individuals also contain methane. Since hydrogen is produced exclusively by gut microbes, its continuous monitoring provides a direct indicator of microbiome activity in food fermentation.
Hall added: "Imagine it as a continuous glucose monitor, but for intestinal gases."
Experiments showed that the device accurately detected an increase in hydrogen production after inulin, a type of soluble fiber, was consumed, with a sensitivity of 94.7%.
To bridge the knowledge gap regarding natural gas levels, Hall's team launched the "Human Gas Atlas" project, which aims to objectively measure gas patterns in hundreds of participants and link them to diet and microbiome composition.
Hall said: "We have learned a lot about the types of microbes in the gut, but we have not learned much about their actual functions at any given moment. The project will establish objective criteria for gut microbial fermentation, which is a necessary basis for assessing the impact of dietary, probiotic, or prebiotic interventions on microbiome activity."
