“It all started with an enquiry from a nurse,” said Dr Karl Kruszelnicki during his science show on the Triple J radio station in Brisbane, Australia. “She wanted to know whether she was contaminating the operating theatre she worked in by quietly farting in the sterile environment during operations, and I realised that I didn’t know. But I was determined to find out.”
According to the Seriously, Science blog at Discover Magazine, Kruszelnicki investigated the question by getting in contact with Canberra-based microbiologist, Luke Tennent, who helped him design and carry out an experiment. The aim was to discover whether or not the wind emitted from a human was filled with germs or just simply smelt bad.
“[Tennent] asked a colleague to break wind directly onto two Petri dishes from a distance of 5 centimetres, first fully clothed, then with his trousers down. Then he observed what happened. Overnight, the second Petri dish sprouted visible lumps of two types of bacteria that are usually found only in the gut and on the skin. But the flatus [gas] which had passed through clothing caused no bacteria to sprout, which suggests that clothing acts as a filter.”
Kruszelnicki and Tennent noticed two types of bacteria in the second Petri dish - in the centre were the bacteria caused by the subject’s fart gas, they said, and a ring of different bacteria around the edge of the Petri dish "was caused by the sheer velocity of the fart, which blew skin bacteria from the cheeks and blasted it onto the dish”, reports Seriously, Science.
The good news? The bacteria that grew was not in any way harmful. The other good news? Scientific evidence for why you should never, ever get naked and fart near your food. You're welcome.