Flatulence, often a source of embarrassment or jokes, is nevertheless part of the normal functioning of the human body. A study attempted to precisely measure their number using a device capable of detecting intestinal gas.
Flatulence or “farts” are gases produced when bacteria in the intestinal microbiota ferment certain foods in the digestive tract. Despite their normality and banality, scientists have little precise data on their real frequency. These intestinal gases are mainly made up of hydrogen, methane and carbon dioxide, molecules produced when intestinal bacteria break down fiber and certain sugars that the human body cannot digest on its own.
Researchers have tried to see things more clearly using an original device: a portable sensor capable of detecting gases expelled by the body. In a study published in the scientific journal Biosensors and Bioelectronics, they used a device called “Smart Underwear”, a sensor attached to underwear to continuously measure the hydrogen present in flatulence. The researchers chose to specifically measure hydrogen because this gas is directly produced by bacteria in the microbiota.
To test this technology, the team conducted an initial study with 19 healthy adult volunteers who wore this device for a week. Result: the participants emitted an average of 32 flatulences per day. A person who gets up, for example, at 7 a.m. and goes to bed at 11 p.m. emits 2 flatulences per hour. The study, however, demonstrated strong differences between individuals. Some only produced four in one day, while others released as many as 59! This difference is partly explained by the composition of the intestinal microbiota and by diet. Certain foods rich in fiber or fermentable sugars – such as legumes – promote fermentation in the intestine and therefore the production of gas. The researchers also found that gas production varied throughout the day, particularly after meals, which directly reflects the activity of gut bacteria.
These figures are higher than previous estimates of 10 to 20 flatulences per day, but these data were based on participants’ self-reports. The researchers believe that this type of measurement can lead to an underestimate, because it is difficult to precisely count these events over the course of a day, especially during sleep. Their device makes it possible to record these gas emissions continuously, including at night, thus offering an objective measurement of this physiological phenomenon. In addition, by measuring the hydrogen produced by intestinal bacteria, their tool can help to better understand the activity of the microbiota and the way in which it reacts to food or certain digestive pathologies. It allows the activity of intestinal bacteria to be observed in real time in the intestine.
They emphasize that their study remains preliminary and carried out on a limited number of participants. Further work will be needed to more precisely define what constitutes “normal” gas production in adults. Larger studies will also need to confirm whether this tool can become a reliable way to explore microbiota activity in daily life.
