Scientists are working to better understand what constitutes a “normal” amount of flatulence, a question that has long been hard for both patients and physicians to answer objectively. Researchers at the University of Maryland are tackling this challenge with a modern study utilizing wearable technology to map the full spectrum of human gas production.
The project, called the Human Flatus Atlas, aims to quantify intestinal gas and explore its connection to gut health and the microbiome. According to researchers, current estimates of daily flatulence – often around 10-14 times per day – may be significantly lower than reality. This research is important because understanding normal ranges can help doctors better address patients experiencing digestive discomfort.
“Imagine you proceed to the doctor and you advise them, ‘I think I have a heart problem.’ They would measure your heart rate,” explained Brantley Hall, an assistant professor in the Department of Cell Biology and Molecular Genetics at UMD. “But if you go to the doctor saying, ‘I have a problem with my gut health,’ they’ll respond, ‘It’s all in your head. You just think you’re farting a lot?’”
Hall and his team developed “Smart Underwear,” a small wearable sensor that discreetly attaches to underwear and uses electrochemical sensors to track intestinal gas production around the clock. The device measures hydrogen in flatus, providing a quantifiable metric for gas levels.
The technology, recently detailed in Biosensors and Bioelectronics: X, arose from initial attempts to measure hydrogen production in a sealed chamber. When that approach proved insufficient, researchers moved the sensor closer to the source.
The sensor, about the size of a dollar coin, attaches to the outside of underwear and can be worn comfortably throughout the day—though researchers note it’s not ideal for cycling.
Preliminary testing revealed that participants passed gas an average of 32 times per day, with a range from as few as four to as many as 59 events. Notably, 36 out of 38 participants experienced increased flatulence after starting a fiber supplement.
“We’re measuring the hydrogen content in flatus,” Hall said. “So we can grant you a number, but likewise an estimate of the concentration—the total amount emitted. Basically, we detect if the device is being worn, then the number of events and their volume. And there are other indicators we can deduce from that, like when you ate and how quickly gas production started.”
Researchers have identified three broad categories of participants: those who rarely experience flatulence even with a high-fiber diet; those who produce high levels of hydrogen and experience frequent gas; and those who fall within a “normal” range, the definition of which is still being refined. Understanding these variations could provide valuable insights into gut health.
Significant Benefits
Beyond the inherent humor of the topic, Hall believes the project will address significant gaps in scientific knowledge. While normal heart rates and cholesterol levels are well-established, little is known about typical flatulence patterns.
“If you’re producing 40, 50 events or more per day, your microbiome has a lot to teach us,” researchers stated, addressing those they’ve dubbed “hydrogen hyperproducers.”
Conversely, researchers are also seeking individuals who experience minimal gas production despite a fiber-rich diet. “You eat fiber. You eat beans. And yet, almost nothing happens. If your gut runs silent despite a diet that should produce gas, we want to know why. You might hold clues to microbial efficiency that science hasn’t yet explained,” they said.
The project is particularly timely given the growing interest in the gut microbiome and its links to various aspects of human health.
“We’re very interested in studying the composition of the microbiome, and this gives us a way to monitor its activity in real time,” Hall explained.
This monitoring, Hall added, could eventually play a diagnostic role. “If a cardiologist asks a patient to wear a device for 24 or 48 hours to record their heart rate, why wouldn’t a gastroenterologist do the same with the microbiome?”
High Demand
Interest in the study has been overwhelming, with approximately 9,000 people registering to participate— “we’re completely swamped,” Hall admitted. However, researchers currently have only around 1,800 sensors available, forcing them to temporarily pause enrollment. You can find more information about the Human Flatus Atlas online.
“If I told you my research was about electron flow in the gut microbiome, you probably wouldn’t interview me,” Hall concluded. “But if you want to talk about farts, that’s funny. And so, I don’t mind that it’s amusing.”
“I love fart jokes. Listen, thousands of people are telling me fart jokes right now. It doesn’t bother me that it’s funny, because we’re actually doing very complex science, and so it’s fun. Science is hard, so having fun while doing This proves really important to us.”
