A scientific research has analysed the content of germs through flatulence, to find out whether it is crucial if you wear underwear or not. Dr Karl Kruszelnicki gave the research question of a nurse, who asked what happens if someone in a sterile operating room “lets out air”: is the environment contaminated with germs?

Kruszelnicki realised that he did not have an answer to the question, and so he decided to start a scientific analysis of the problem. With the help of a microbiologist, and a volunteer colleague to act as a guinea pig, he analysed the germ content of farts.

The volunteer was asked to fart from a distance of 5 cm on Petri dishes, an instrument for cell cultures and then identify the bacterial content. The volunteer was asked to fart either dressed normally, or without pants or underpants, so that the fart arrived directly on the plate.

In the case of farts without clothes, the plates have highlighted two types of bacteria: one typical of the intestine and one of the skin. According to the researchers, the explanation is that in addition to the bacteria that come directly from the intestine, the displacement of air carries bacteria with it from the skin of the buttocks.

In the case of the farts passed through the clothes, however, the bacterial culture did not develop at all, thus suggesting that the pants are the “filter” for the bacteria that come out with farting.

It must be said that even in the case of “pure” farts there are no big risks: in fact, the bacteria identified were for the very large part of the “benign” ones, thus not implying a risk to health.