Admit it. You've always wanted to know whether farts can carry germs.

Photo Credit: John Sibley | CC BY-NC 2.0

1. Farts can probably carry germs, but you don't really need to worry about it unless you're naked

A brief entry in the British Medical Journal's 2001 holiday issue recounts how one Dr Karl Kruszelnicki "established whether human flatus was germ-laden, or merely malodorous":

I contacted Luke Tennent, a microbiologist in Canberra, and together we devised an experiment. He 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 which had passed through clothing caused no bacteria to sprout, which suggests that clothing acts as a filter.

Our deduction is that the enteric zone in the second Petri dish was caused by the flatus itself, and the splatter ring around that was caused by the sheer velocity of the fart, which blew skin bacteria from the cheeks and blasted it onto the dish. It seems, therefore, that flatus can cause infection if the emitter is naked, but not if he or she is clothed. But the results of the experiment should not be considered alarming, because neither type of bacterium is harmful. In fact, they're similar to the 'friendly' bacteria found in yoghurt.

Our final conclusion? Don't fart naked near food. All right, it's not rocket science. But then again, maybe it is?

2. Herring (yes, the fish) may use farts to communicate with one another

About a decade ago, researchers led by marine biologist Ben Wilson discovered that Atlantic and Pacific herring can create high-frequency sounds by releasing air from their anuses. Wilson and his colleagues named the distinctive bursts of pulses "Fast Repetitive Tick" (aka FRT) sounds, after the noise they make.


Because darkness and high densities of fish seem to trigger the farts, Wilson and his colleagues suspect herring may use the FRT sounds to help them form protective shoals at night.

3. Some people are sexually aroused by farts

(The official term is "eproctophilia.")


4. According to master satirist Jonathan Swift, there are five types of farts

To our knowledge, there is no official classification system for farts, but the tradition of categorizing them predates by several hundred years, at least. Jonathan Swift, for his part, maintained in his notorious treatise "The Benefit of Farting Explain'd," that there exist at least five "different species of farts, and which are perfectly distinct from each other, both in weight and smell. First, the sonorous and full-toned, or rousing fart; Second, the double fart; Third, the soft fizzing fart; fourth, the wet fart; and Fifth, the sullen wind-bound fart."

5. One of the most famous depictions of farts in the Italian literary canon comes from Canto XXI of Dante's Inferno

The passage describes a scene in which a band of demons gathers to escort Dante and Virgil through the fifth pocket of Malebolge:

Per l'argine sinistro volta dienno;

ma prima avea ciascuna la lingua stretta

coi denta, verso lor duca, per cenno;

ed elli avea del cul fatto trombetta. (XXI, 136–9)

[They made left face on the bank; but first each had bit his tongue toward their leader, as a salute, and he of his ass had made a trumpet.]

These demons were clearly just having some harmless, farty fun, though, right? Maybe not:

6. "In medieval Italy the demonic anus functioned as a locus for the generation of sinners' souls."

So says Suzanne Magnanini, an associate professor in the Department of French and Italian at the University of Colorado at Boulder and author of the book Fairy-Tale Science, in which she contextualizes Dante's infamous fart-scene:

If we consider the iconography of devils and hell contemporary with Dante's poem, it becomes clear that in medieval Italy the demonic anus functioned as a locus for the generation of sinners' souls. In the Scrovegni chapel in Padua, Giotto depicted the devil as eating sinners while defecating others into hell. Similar images could be found ion the walls of churches and abbeys in Bologna, Modena, Pisa, and San Gimignano. Camporesi locates the origins of such depicctions of Lucifer and devils in a figure associated with ancient agrarian festials, stating, 'nel corpo gigantesco e villoso di Lucifero rimane sottesa l'arcaica immagine del'orso padre dai cui peti nascevano le nuove anima, il gigantesco mostro delle feste agrarie, l'orso carnevalesco, una bestia pelosa e peteggiante' [in the gigantic and furry body of Lucifer there remains underneath the archaic image of the father bear from whose farts were born new souls, the gigantic monster of agrarian festivals, the carnivalesque bear, a hairy and farting beast.]

7. In Japanese folklore, flatulence can serve as a form of defense

In Japanese folklore, the kappa is a mischievous water sprite with a penchant for reaching up people's butts in pursuit of their shirikodama, a magical, soul-bearing orb. That said, it is said that kappa can be repelled by blasting them with powerful bursts of flatulence. The technique is immortalized in Tsukioka Yoshitoshi's (1839-1892) ukiyo-e work "Farting at a kappa at the lumber yard in Fukagawa" (above), and elsewhere.

8. Basically, flatulence plays an important role in the folklore, myths, and fairy tales of many cultures

In Innu mythology, one of the most powerful spirits is called Matshishkapeu, which translates to "The Fart Man." The Greeks were also partial to farts. Folklore scholar D.L. Ashliman lists a handful of legendary farts on his website, though his account is by no means exhaustive.

If you decide to seek out more examples of flatulence in myths and fables, keep an eye out for common motifs. One of the more interesting similarities I've found between seemingly disparate folk tales and belief systems is the association of farts with the giving and taking of life. Two examples: In Viola, a tale by 16C Italian storyteller Giambattista Basile, an ogre believes his flatulence to have reproductive, i.e. life-giving powers. In Maya tradition, the god of death is occasionally referred to as "the flatulent one."

In his book Death and the Classic Maya Kings, mesoamerican archaeologist James L. Fitzsimmons writes that the biological associations of flatulence with death are "obvious." I admit, this had not previously been obvious to me, but as it turns out...

9. Dead bodies fart

In fact, according to Caleb Wilde (a sixth-generation mortician and creator of the hugely popular blog Confessions Of A Funeral Director), "some dead bodies fart a bunch."

10. You can thank the microbes in your intestine for your death-farts

Your large intestine is home to hundreds of species of beneficial bacteria that help digest whatever food your small intestine misses. In doing so, these bacteria generate a variety of gases, including carbon dioxide, oxygen, nitrogen, hydrogen and methane, to name a few. It is here where farts are born – not just in life, but in death (just because you've kicked the bucket doesn't mean your microbes need to stop doing their thing.)

Another source of death farts is putrefaction. As the body decomposes, it releases noxious gasses. Occasionally, these gasses are released in the form of a postmortem toot. When these gasses have nowhere to go they can accumulate, sometimes with explosive results.

11. The same microbes responsible human farts are occasionally responsible for explosive colonoscopies

The medical literature contains a record of at least 20 instances of a colonoscopy resulting of "colonic gas explosion" between 1952 and October 2006. One of these was fatal.

12. Wait, I know farts are flammable – but people explode during colonoscopies? How?

Image via Shutterstock

Yep. It's interesting, actually – a lot of people think farts are flammable due to their methane content. While this is technically true, most human farts are actually flammable due to the hydrogen, which is also produced, and typically in greater volumes. Some people's guts produce both both gasses, in which case they burn together.

ANYWAY, according to researchers led by gastroenterologist Emmanuel Ben-Soussan, an explosion of colonic gasses requires three things: The presence of combustible gases (hydrogen and/or methane); the presence of combustive gas (oxygen); and the application of a heat source. As we previously reported:

Your bacteria provide the first two; electrocautery — a technique that uses heat to remove potentially cancerous intestinal growths known as polyps — provides the third. The perfect colonic storm would comprise a high concentration of hydrogen and/or methane (greater than 4% or 5%, respectively), plenty of oxygen and a piping-hot electrocautery tool. Concentrations of hydrogen and methane in the colon can vary considerably (0.06%—47% and 0%—26%, respectively, according to this study). Taking these thresholds into consideration, it is estimated that almost half of colonoscopy patients with unprepared large intestines harbor potentially explosive concentrations of hydrogen and methane in their bowels.

13. In the late 60s, scientists studied the farts of NASA astronauts

The purpose of the study? To quantify the potential buildup of hydrogen and methane in people on a "space diet," namely the one followed by astronauts on the early Gemini missions. It was thought that these gasses "could constitute a fire hazard in a closed chamber." Say, a spacecraft. Or a space suit.

You can read the details behind the experiment here, but the results basically showed that astronauts fed a Gemini-style diet produced a lot more flammable gas than those fed a "bland" formula. "Computed from 12-hour values, maximum potential daily H2 and CH4 are per man: for S, 730 ml and 382 ml; for F, 80 and 222 ml," write the researchers, though they note that these "volumes would be larger at reduced spacecraft and suit pressures."

14. Apollo 16 astronaut John Young, by his own admission, farted prolifically while on the moon

He's even known to have described his flatulence during a mission briefing.

15. The marginalia of illuminated manuscripts are loaded with visual fart jokes.

Poop jokes, too.