Quick Fact: What Gas Makes Your Flatulence Smell

Nope, it is not methane. Methane is not smelly. About 99% of human flatus contains non-smelly gases such oxygen, carbon dioxide, nitrogen, hydrogen and methane. Methane makes up to 4% of the volume (in a person with healthy digestive system). Individual ability to produce methane in their flatulence is genetically determined, so some people never produce methane at all. If both your parents produce methane then there is 95% chance that you will also produce it. Also, according to 2009 study conducted by scientists from Arizona State University, it appears that many obese people tend to produce much more methane than average*** - the research found out that some people who produce methane have higher energy harvesting efficiency when it comes to converting methane into fat, which can lead to obesity.

So what makes our gas smell?

Sulfur. Precisely, volatile sulfur compounds or VSC. VSC make up less than 1% of our flatulence, and are product of breaking down of hardly digestible polysaccharides by our microflora bacteria in the colon. These polysaccharides are found in lentils, cabbage, cauliflower or pulses. Another type of food that increases production of smelly flatulence is food rich in protein that includes sulfur-containing amino acids, such as fish, poultry, meats, eggs, nuts and legumes.

*** basically, fat people fart more.

[Traditional "Full English Breakfast" - pride of English cuisine.Picture Source]