(Baroque string music) (chalk scratching)
- So, in the late 1800s,
there was this French guy named Le Pétomane,
and he was one of the stars of Moulin Rouge.
People would come from far and wide
to watch this guy fart.
Yes.
To watch him fart.
Le Pétomane, you see, was a professional flatulist,
which, as it turns out, is still sort of a thing.
And, certainly, it's a dream job for some.
But if you want to move out of the ranks
of amateur wind-breakers, and into those stinking
hallowed halls of the professionally flatulent,
you will need to know a thing or two about farts.
What are they?
Why do they happen?
And why the hell do they smell so so bad?
First things first.
Everyone farts.
Every single person.
Yes, you too.
To not fart would be medically fascinating,
and probably dangerous.
On average, most people are passing about one liter
of gas a day, spread out over 13 to, wait for it,
21 incidents.
21 separate farts.
The composition of a fart varies widely,
but usually we're smelling something that's mostly nitrogen,
along with oxygen, carbon dioxide, and even methane.
This gas itself comes from several sources.
The air you swallow, gas that enters your intestines
from your bloodstream and so on, but about 75% of your farts
are created in your lower intestine, and not by you.
See, the bacteria living inside you right now
comprise a microbiome all their own,
and when we say it's intricate,
we mean it's so intricate that David Attenborough
could make a documentary about it.
These bacteria form this thriving empire,
with billions of tiny separate organisms
living inside their host, that's you, in symbiosis.
Now, flatulence occurs when food passes through your stomach
and small intestine without fully breaking down.
So what does this mean?
This means that the food hits the large intestine
in an undigested state.
Okay, for an example, let's look at lactose,
which is present in dairy products like milk and cheese.
If you're lactose-intolerant,
then you lack the enzyme that breaks lactose
into sugar molecules for the bloodstream.
Without this, lactose just breezes through your stomach
and small intestine, into your large intestine,
where it becomes the special of the day
for billions of hungry bacteria.
Those guys love lactose,
and if you're not going to digest it, they will.
As they digest this lactose, they emit a number of gases,
including methane, hydrogen, carbon dioxide,
and hydrogen sulfide, which is responsible
for the unpleasant aroma of farts.
This process is similar to how yeast produces carbon dioxide
to leaven bread, which we have a video about,
and it's probably gonna pop up here.
And speaking of food, it's true that some foods
do produce more flatulence, primarily because
they contain more indigestible carbohydrates.
I'm looking at you, beans.
I'm making eye contact with you.
Nutrient-dense vegetables and fiber-rich foods
all have a reputation for enabling flatulence.
That's not necessarily a bad thing.
See, as scientists learn more about the relationship
between diet, health, and a person's microbiome,
they're discovering that these flatulent foods
may encourage the growth of beneficial bacteria in your gut.
When they're producing that next embarrassing puff
of ass-gas, they're also making molecules
to protect your intestinal lining, and prevent infections.
So remember, the next time your "silent crime"
accidentally ends up sounding like a stuttering trumpet,
your intestinal bacteria are the real culprits.
They are the ones actually farting.
I want to emphasize this.
They're farting inside of you,
and then you fart their farts out.
Are we clear on that part?
Which leads us to the biggest question of the day:
Who are we farting inside of?
(jaunty jazz music)