Beans make you fart because they contain carbohydrates that your body cannot fully digest. These carbohydrates reach the large intestine, where gut bacteria ferment them and release gas as a normal part of digestion.
åIf you have ever eaten a bowl of chilli, a bean salad, or a bean-heavy dinner and noticed more gas later on, nothing is wrong with you. This reaction is common and, in many cases, completely normal.
No, beans do not affect everyone in the same way. Some people notice a lot of gas after eating beans, while others barely notice any difference at all.
Studies that have measured intestinal gas production show there is wide variation between individuals, even when people eat the same foods1. Factors like gut bacteria, digestion speed, and whether someone produces methane all play a role. This is why one person can eat beans daily with no issues, while another feels bloated after a single meal.
Beans cause gas because they contain carbohydrates that humans cannot fully break down in the small intestine. These carbohydrates reach the colon, where gut bacteria ferment them and produce gas.
One of the main contributors is a group of short chain carbohydrates called oligosaccharides.
Oligosaccharides such as raffinose and stachyose pass through the digestive system undigested because humans lack the enzyme needed to break them down. Once they reach the large intestine, gut bacteria ferment them and produce gases such as hydrogen and carbon dioxide2.
This fermentation process is actually beneficial for gut health. As gut bacteria break down oligosaccharides and fibre, they produce short chain fatty acids (SCFAs), including butyrate, which help support the gut lining, reduce inflammation, and provide fuel for colon cells. In this context, mild gas is often a sign that gut bacteria are actively doing something useful.
Different beans contain different amounts of these oligosaccharides, which is why some feel easier to digest than others. Research also shows that soaking and cooking beans can significantly reduce oligosaccharide levels, making them gentler on the gut2.
Yes, fibre in beans can also contribute to gas. Fibre feeds beneficial gut bacteria, and when these bacteria ferment fibre, gas is produced as a natural byproduct.
This same process also produces short chain fatty acids (like butyrate) that support gut health. So while fibre can lead to gas, it is also doing something positive behind the scenes!
After you eat beans, fermentation happens mainly in the large intestine, which is why gas often appears hours later rather than immediately.
As gut bacteria break down fibre and oligosaccharides, gas builds up gradually and is released over time. At the same time, short chain fatty acids are absorbed by the gut lining and used as a fuel source for colon cells, supporting gut barrier function and digestive health.
Research shows that most gas produced after eating beans comes from this bacterial fermentation process rather than from swallowed air1.
Some beans cause more gas because they contain higher levels of fermentable carbohydrates and fibre, and because how they are prepared and eaten matters.
Studies where people ate beans daily show that fewer than half reported increased flatulence, and many found symptoms eased over time as their gut adapted3. Portion size, cooking method, and how regularly beans are eaten all influence how the body responds.
Some people notice more gas after eating baked beans in particular, often because of added sugars and sauces. We explain this in more detail in our article on why baked beans make you fart.
Chickpeas can also affect digestion differently from other beans, especially when eaten as hummus or falafel. You can read more about this in our guide on do chickpeas make you fart.
Yes! Farting can be a sign of good gut health (sometimes), because it often reflects active fermentation by beneficial gut bacteria.
When gut bacteria break down fibre and fermentable carbohydrates, such as those found in beans, gas is produced alongside short chain fatty acids that help support the gut lining. Mild gas without pain or discomfort is usually normal, especially after eating fibre rich foods.
However, farting on its own is not a perfect indicator of gut health. Excessive gas combined with bloating, pain, or changes in bowel habits may suggest digestive issues that need attention.
No, beans are not bad for your gut. Although they can cause gas, beans are one of the most gut friendly plant foods you can eat.
The carbohydrates in beans feed beneficial bacteria and support microbial diversity. For many people, eating beans regularly improves tolerance over time and leads to fewer digestive symptoms3.
If you are choosing canned beans in premade sauces, it can help to look for options with no added sugar or excess salt.
You can reduce gas from beans by adjusting how you prepare and eat them, rather than cutting them out altogether:
Research shows that soaking and cooking beans lowers oligosaccharide content, which may reduce gas for people with sensitive digestion2.
Gas may signal a gut health issue if it is severe, painful, or accompanied by ongoing bloating, diarrhoea or abdominal discomfort.
In these cases, conditions such as IBS, food intolerances, or gut dysbiosis may be involved. If gas feels disruptive rather than mildly uncomfortable, it is worth looking at overall gut health patterns rather than avoiding beans completely.
Beans make you fart because gut bacteria ferment carbohydrates that your body cannot digest, producing gas as a byproduct.
No, reactions to beans vary widely depending on individual gut bacteria and digestion speed.
No, farting often reflects normal fermentation and healthy, active gut bacteria.
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