Most people pass gas 5 to 15 times daily, expelling between 0.6 and 1.8 liters of gas, according to health experts. Flatulence consists of swallowed air and gases produced when gut bacteria break down food. While oxygen and nitrogen from air are odorless, sulphur-containing gases created during protein breakdown give farts their distinctive smell. Sulphur-rich foods including dairy, grains, legumes, fish and meat contribute to eggy or rotten-cabbage odors.
Carbohydrates also produce gas when fermented by gut bacteria. Fiber, while essential for digestion, feeds beneficial gut bacteria but breaks down into fatty acids that contribute to flatulence odor. Sugars and sugar substitutes create gas when they reach the large intestine undigested. People with lactose intolerance experience bloating and flatulence because undigested milk sugar ferments in the gut rather than being absorbed in the small intestine.
Normal flatulence varies widely among individuals, but certain symptoms warrant medical attention. “When they’re accompanied by other symptoms like painful bloating, constipation, diarrhoea or unexplained weight loss, they could be a sign of gastrointestinal issues,” health experts warn. Conditions may include food intolerances, irritable bowel syndrome, inflammatory bowel diseases, coeliac disease and bowel cancer. A 2023 meta-analysis found analyzing fart compounds shows promise for diagnosing gastrointestinal conditions.
The NHS recommends eating smaller meals, chewing slowly, exercising regularly and avoiding carbonated drinks to reduce gas production. “The bottom line is that farting is usually a good thing: a sign that our gut microbes are doing their job and aiding the rest of our digestive system,” according to the article. However, changes in flatulence accompanied by other symptoms should prompt a doctor’s visit to rule out serious conditions.