When you eat beans, you are never eating alone. Some very small guests want a bite.
What is special about beans?
Beans contain special sugars that your body cannot break down. So they reach your large intestine without being digested.
Who makes the gas?
That is where huge numbers of tiny bacteria live. They feast on those sugars and give off gas. Much of that gas leaves your body as a fart.
Why do farts smell?
The smell comes mostly from gases that contain sulfur. The main one smells like rotten eggs.
Should you skip beans?
Beans are still great for you, full of fiber and protein. Soaking dried beans and pouring off the water can mean less gas.
One more thing
Even better, your body can get used to beans. Eat them often, and the extra gas usually fades within a few weeks.
Sources
- NIDDK: Symptoms & Causes of Gas in the Digestive Tract
- NIDDK: Definition & Facts for Gas in the Digestive Tract
- Harvard Health Publishing, 2012: Recipe for health: cheap, nutritious beans
- Harvard Health Publishing: Gas (flatulence)
- Harvard T.H. Chan School of Public Health, The Nutrition Source: Legumes and Pulses
- Nutrition Journal, 2011: Perceptions of flatulence from bean consumption among adults in 3 feeding studies (Winham and Hutchins)
- Cleveland Clinic Health Essentials, 2023: Why Beans Make You Fart and How To Prevent It
- Cleveland Clinic Health Essentials, 2025: 6 Big Benefits of Beans
- Gut, 1998: Identification of gases responsible for the odour of human flatus and evaluation of a device purported to reduce this odour (Suarez, Springfield and Levitt)
- BBC Science Focus, 2025: What your farts say about your health
- Cleveland Clinic Health Essentials, 2022: Why Do Farts Smell and What Does That Say About Your Health?
- Merck Manual Professional Version: Gas-Related Symptoms
- Harvard Health Publishing
- MedlinePlus: MedlinePlus (NIH)
