Speaker 1: Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff,
Speaker 1: I'm Lauren bog Obam, and I've got another classic episode
Speaker 1: for you today. In it, our former host Christian Sagar
Speaker 1: answers a basic yet nonetheless burning question, why do we fart? Hey,
Speaker 1: brain Stuff? It's Christian Sager. So in the late eighteen hundreds,
Speaker 1: there was this French guy and his name was Le
Speaker 1: Peto Man, and he was one of the stars of
Speaker 1: Mulan Rouge. People would come from far and wide just
Speaker 1: to watch this guy fart, Yeah, to watch him fart. Lepetumn,
Speaker 1: you see, was a professional flat glist, which, as it
Speaker 1: turns out, is still sort of a thing, and certainly
Speaker 1: it's a dream job for some. But if you want
Speaker 1: to move out of the ranks of amateur windbreakers and
Speaker 1: into those stinking, hallowed halls of the professionally flatulent, you
Speaker 1: will need to know a thing or two about farts,
Speaker 1: like what are they, why do they happen? And why
Speaker 1: do they smell so bad? Well, first things first, everyone farts,
Speaker 1: every single person. Yes you two listening to this, you
Speaker 1: do too. To not fart would be medically fascinating and
Speaker 1: probably dangerous. On average, most people are passing about one
Speaker 1: leader of gas a day, spread out over thirteen to
Speaker 1: wait for it, twenty one incidents. That's twenty one separate
Speaker 1: times in one day. The composition of a fart varies widely,
Speaker 1: but usually what we're smelling is something that's mostly nitrogen,
Speaker 1: along with oxygen, carbon dioxide, and even methane. This gas
Speaker 1: itself comes from several sources, the air, you swallow, gas
Speaker 1: that enters your intestines, from your bloodstream, and so on.
Speaker 1: But about seventy five of your farts are created in
Speaker 1: your lower intestine, and unfortunately not by you. See the
Speaker 1: bacteria living inside you right now. They comprise a microbiome
Speaker 1: all all of their own. And when we say it's intricate,
Speaker 1: we mean it's so intricate that David Attenborough could make
Speaker 1: a documentary about it. These bacteria form this thriving empire
Speaker 1: with billions of tiny, separate organisms living inside their host,
Speaker 1: and that's you. They're living with you in symbiosis. Now,
Speaker 1: flatulence occurs when food passes through your stomach and small
Speaker 1: intestine without fully breaking down. So what does this mean.
Speaker 1: This means that the food hits the large intestine in
Speaker 1: an undigested state. So For example, let's look at lactose,
Speaker 1: which is present in dairy products like milk and cheese.
Speaker 1: If you're lactose intolerant, then you lack the enzyme that
Speaker 1: breaks lactose into sugar molecules for the bloodstream. Without this,
Speaker 1: lactose just breezes through your stomach and small intestine into
Speaker 1: your large intestine, where it becomes the special of the
Speaker 1: day for billions of hungary bacteria. Those guys love lactose,
Speaker 1: and if you're not going to dudge just it, they will.
Speaker 1: As they digest this lactose, they emit a number of gases,
Speaker 1: including methane, hydrogen, carbon dioxide, and hydrogen sulfide, which is
Speaker 1: responsible for the unpleasant aroma. This process is similar to
Speaker 1: how yeast produces carbon dioxide to leaven bread. And speaking
Speaker 1: of food, it's true that some foods do produce more flatulence,
Speaker 1: primarily because they contain more indigestible carbohydrates. I'm looking at you. Beans,
Speaker 1: nutrient dense vegetables, and fiber rich foods all have a
Speaker 1: reputation for enabling flatulence. That's not necessarily a bad thing.
Speaker 1: See as scientists learn more about the relationship between diet,
Speaker 1: health and a person's microbiome. They're discovering that these flatulent
Speaker 1: foods may encourage the growth of beneficial bacteria in your gut.
Speaker 1: When they're producing that next embarrassing puff of gas, they're
Speaker 1: also making molecules to protect your intestinal lining and prevent infections.
Speaker 1: So remember, the next time your silent crime accidentally ends
Speaker 1: up sounding like a stuttering trumpet, your intestinal bacteria are
Speaker 1: the real culprits. They are the ones actually farting. And look,
Speaker 1: I want to emphasize this, they are farting inside of you,
Speaker 1: and then you fart their farts out. Are we clear
Speaker 1: on that part? Which leads us to the bigger question
Speaker 1: of the day, who are we farting inside of? Today's
Speaker 1: episode was written by Ben Bollen and produced by Tyler Clang.
Speaker 1: To hear more weird and funny true stories from men,
Speaker 1: check out his show Ridiculous History, available wherever you get
Speaker 1: your podcasts, And of course, for more on this and
Speaker 1: lots of other easily digestible topics, visit our home planet,
Speaker 1: how Stuff Works dot com.