01x03 - Fuel

[bunniefuu]

- There's one ritual that happens

in every corner of the world.

Chances are, you did it today.

Over millennia

humans have turned eating

into culture

a way to celebrate

our roots

to bring us together.

But at the end of the day,

when you strip away

everything else

food is really just one thing

Fuel.

It's where you get the power

to live your life.

Even when you're sitting

completely still,

your body needs a lot of energy

to stay on.

But nowhere is the need

for fuel more apparent

than when you push yourself

to the absolute limit.

- As a Navajo distance runner,

we run for very specific things.

It's the celebration of life.

It's a form of prayer.

It's a teacher. It shows us how

to overcome obstacles in life.

And finally,

it's a form of medicine.

It helps heal us.

This is Navajo tea.

It's very hydrating.

On a cold morning like this,

it's the perfect way

to start a cold, long run.

Running in the Navajo culture

and the way that I was raised,

it's a part of life.

Whoo!

We get up, and we run

every morning to the East

to meet the Creator, at that

innocent time of the day,

the birth of that new day.

As we begin our run,

we start with a shout.

When we feel the connection

to the earth and to the sky

and to the Creator, we yell

Whoo!

and announce that we're

thankful for all those deities.

Our breath is breathing in

Father Sky.

The act of running is a prayer.

I'm Shaun Martin, I'm Navajo,

and I'm an ultra-marathon

runner.

- The marathon is considered

the ultimate test

of human endurance.

But an ultra-marathon

is in a whole other league

often upwards of 100 miles,

or four standard marathons

back to back to back to back.

These feats are only for

an elite class of athletes

and they send the body

to the edge of collapse.

See, the human body

is an amazing machine,

capable of feats that seem

impossible to most of us.

But like all machines,

it requires fuel.

Every one of our nearly

40 trillion cells

needs the juice to power on.

And for us, it comes

in one form glucose.

It's a sugar that allows cells

to create energy.

And it's locked inside

every plant and seed on earth.

The trick is extracting it.

Like how crude oil

has to be refined

to make the gas that we pump

our bodies contain a factory

that takes all the raw material

from food

and extracts glucose.

You know it as

the digestive system,

or more commonly, the gut.

It's a series

of connected organs

from your mouth,

through your intestines, and

all the way to the other end.

- When I think of the gut,

I think of three things

I think of an engine,

I think of a tunnel,

and I think of a strainer.

It's the engine because

it really is

where the food comes in,

and it gets processed

and digested,

and then it goes out to feed

all the other parts of the body.

It's a tunnel because

when you think about it,

it's a hollow tube

that divides the body,

so when something

is in your gut,

it's excluded

from the rest of the body.

And I like to think of it

as a strainer.

You dump something

into a strainer,

and the liquid goes through

into your little pot,

whatever you're

collecting it in.

And then all the debris

that's left gets dumped out.

- The liquid that goes through

the strainer is glucose.

And for an ultra-marathon runner

getting that fuel

is all about timing.

- Running, especially

long-distance,

is a really tricky challenge

when it comes to taking in the

right amount of food and water

to make sure you have

the sugar needed

to keep moving

without eating too much to the

point where you start cramping

because you can't

properly digest.

- So, this is what we call

blue corn mush.

In Navajo, it's called

Tóshchíín.

It's like a porridge.

The corn itself is really easy

on the stomach,

and then we add juniper ash

to the roasted corn,

and then with the ash mixed in,

it is a really good source

of energy

that'll last

for quite a long time.

- Starches like corn break down

into glucose in the gut,

and getting that sugar before

a run is crucial for Shaun.

But it doesn't happen instantly.

Luckily, a while ago,

humans discovered

how to jump-start the breakdown

before we ever take a bite.

- We don't know exactly when

hominids started using fire.

You know, it could have been

as long ago

as 2 million years ago,

2 1/2 million years ago,

perhaps longer than that.

But one of the major things

that it did for us

was to allow us to cook our food

and to unlock more nutrients.

- Cooking releases about 80%

more energy than raw food.

That's great news

for an endurance runner,

especially because

exercise actually

makes digestion slow down.

- Running and digestion are both

really active processes

in the sense that they both

require a lot of blood flow.

So somebody

who's an endurance runner,

a lot of blood flow

gets diverted away

from other parts of the body

and, in particular,

the digestive system

and gets diverted to

the large muscles in the body.

- One of the things

I had to learn really early

in running these distances

was to be able to eat enough

to have enough energy and fuel

during the long runs,

but at the same time,

not too much

to feel heavy and bogged down.

Scoop in there.

When I have blue corn mush

before a morning run,

I like to have it

at least an hour before

just so my body has time

to digest a little bit

and absorb

some of the nutrients.

Yep. That's what

I was raised on.

- Digestion really consists

of six distinct phases.

The first is ingestion

Just taking the food in.

- When you eat, mouth saliva

breaks food down

and binds it into a single mass,

ready to be swallowed

into the esophagus.

Through a process of relaxing

and contracting muscles,

the esophagus pushes

the food on its way.

The pulses are so powerful

that you could hang upside-down

and still move food against

gravity into the stomach.

The stomach is basically

a vat of acid,

so strong it can dissolve metal.

The juices k*ll off

dangerous bacteria,

and enzymes turn the solid mass

into liquid,

and then it's onto

the small intestine.

It's here where glucose

is finally extracted

and then absorbed

into the gut's lining,

where it then

enters the bloodstream.

Now it is ready

to refuel the body.

But glucose can't reach

hungry cells all by itself.

It needs to be carried

through the blood

by a hormone called insulin.

- Insulin is hugely important

in glucose metabolism.

What do we mean?

When you're eating,

you need insulin to come out

and ferry that sugar

and those carbohydrates

where they're needed

to convert it to energy.

Most of us know someone or have

heard of someone with diabetes.

Those are people

who have problems

with their insulin system,

so they have trouble

controlling their sugar levels.

- But how does glucose

actually become fuel?

Well, your cells have doors,

and insulin opens those doors.

Once the glucose is inside,

it burns into raw energy

and heat.

Usually that requires oxygen.

But some cells, like muscles,

can do it without

which tells us

that this chemical process

evolved even before

the atmosphere had oxygen.

Under normal circumstances,

insulin keeps the amount

of sugar in your blood in range,

and levels drop

as glucose gets burned for gas.

But for a marathon runner,

things work

a little differently.

- During exercise, there is

the suppression of insulin

which lowers blood sugar

so that we see in people

who are doing intense activity,

their sugar levels can rise

to almost diabetic levels,

because their bodies know

that they need that sugar

to do the intense activity.

- And on the flip side, the cells

of elite endurance athletes

are also much more sensitive

to insulin

three times more, in fact.

Glucose floods in

so an ultra-marathoner's body

can get more raw fuel

to cells faster.

During an ultra

is one of those times

muscles have to burn glucose

without oxygen.

When you're out of breath,

you can bet your cells are, too.

The upshot

is that you can keep running,

but there are byproducts.

As you push on, lactic acid

builds up, which means soreness.

At a certain point,

even the most efficient bodies

start to break down.

- As I'm running, I'm paying

attention to overall effort,

how my body's feeling inside,

what the muscles

are feeling like,

little aches and pains,

tightness all over the body.

As you go further

in an ultra-marathon,

those little, tiny

aches and pains

have the potential

to turn into something bigger

that could ultimately

end your race early.

- All runners have felt

muscle aches and exhaustion.

But marathoners have to face

hitting the wall.

It usually happens

at about mile 20.

That's when the body's

natural glucose reserves

are totally dried up.

The gas tank is empty.

A fog settles in,

and focusing becomes

increasingly difficult.

Some runners get cramps,

and others just can't

continue the race

unless they refuel.

- About every 15 to 20 minutes,

I like to take a gel

or blue corn mush.

- Every body is different,

and some people feel

that during the run,

they need to take a small amount

of carbohydrates or sugar

as they're running.

Others get cramps from doing it.

Some people get diarrhea.

It all depends on the body.

- It's not about

replacing calories.

It's about getting sugar

into the blood

as quickly as possible to start

reviving those overworked cells.

The trick is to refuel

before

you run out of gas.

Our bodies can be pushed

to extremes

as long as we know

how to support them.

The record for longest run

stands at 350 continuous miles.

- When I finish an ultra,

I usually feel really good.

As a Navajo distance runner,

it's an enormous amount

of connection

thinking about our loved ones,

thinking about our ancestors,

and it's very emotional.

- Chances are you don't eat

with the same precision

as an endurance athlete.

Most of us eat

when we're hungry,

a few times a day.

But is inhaling food

every few hours

actually what's best for us?

- Today, we have access

to foods year-round

that we wouldn't

have had access to

through most of our

evolutionary past.

Our bodies are adapted to

dealing with periodic scarcity

that we don't encounter now.

- We evolved in a world

where sometimes

you just didn't catch dinner,

or frost k*lled the plants.

And obviously, we survived.

Hunger is a part of our DNA.

So while long-term

starvation is bad,

choosing not to eat

sometimes might

actually be good.

- Food is a huge part of my life

in every way.

It's sustenance.

You know, it keeps me going,

and it keeps me alive.

Food is also a part of my work,

and food is also meditation

for me.

My name is Deepti Sharma.

I am a practicing

spiritual Hindu.

Growing up, Hinduism was

a pretty big part of my life,

so I fast as part

of my religious practice.

I've tried to incorporate

those different beliefs

and rituals

into my everyday life today.

Hindus fast for a lot

of different reasons.

It's a form of discipline.

It's a form of cleansing,

to remember family members

that have passed away.

I grew up fasting

for those reasons,

and I continue to

because I believe

it's just a wonderful tradition.

- Fasting is a test of will.

That's probably why

it's part of so many religions.

But it also has powerful

physical effects

inside the body.

- Digestion uses up a lot

of resources from the body,

a lot of blood flow.

So when you fast, you basically

allow your digestive tract

to take a break.

- And it benefits

the rest of the body, too,

because of our

evolutionary past.

- Research actually suggests

that fasting might help

our cognition, memory,

ability to learn,

and be better for our bodies.

- If you're eating

three meals a day,

your body relies on glucose

for energy.

Whatever isn't immediately used

by cells goes to the liver.

It's the body's

energy reservoir.

When you're not eating,

the liver burns that sugar

and releases it into the blood.

But when you fast,

all that changes.

After about eight hours

of no food,

the liver runs out of sugar

to burn,

so you got to tap

into a new resource fat.

Under the skin,

around internal organs,

and in between muscles

are pockets of fat.

Fat cells travel to the liver,

and it breaks them down

into acids called ketones.

Ketones can be used

in the same way as glucose

by the brain, blood,

and muscles to power on.

And they're actually a more

efficient source of energy.

- Fasting seems to promote

an increased production

of a protein called brain-

derived neurotrophic protein,

and this seems to be something

that increases new cells

being laid down,

both in the digestive tract,

as well as in the brain.

- I'm a working mother.

I'm an entrepreneur.

My schedule

is all over the place,

as in each day

is very different for me.

So, a day of fasting for me

is I usually try

to eat one meal a day.

If in between, I feel sluggish

or exhausted,

I try to consume

a piece of fruit,

and I drink water

throughout the day,

because, for me,

it's really hard.

- What Deepti does is called

intermittent fasting,

and it can take

a couple different forms.

Some people don't eat

for a full 24 hours.

Others just seriously

limit their calories

once or twice a week.

- I try to adapt to what works

for me and my lifestyle,

because it's important

to take care of my body,

my health, my sanity,

most importantly.

As I am spending time

with other people

talking to them about work,

what I do, and what they do,

I started a company, FoodtoEat,

where we partner

with immigrant-, women-,

and minority-owned restaurants

in New York City.

We love coming into restaurants,

getting to know the owners.

Like, where are you guys from?

Like, why did you

start this restaurant?

We essentially

help these local restaurants

be able to book more catering

opportunities

at large corporate offices.

So, our clients

are, like, The Skimm,

Microsoft, Warby Parker.

- Wow.

- We love to get them to think

about diversity and inclusion.

But before we onboard

these restaurants,

we taste their food.

- The first dish

is a soup dumpling.

- Wow. Wow.

- Wow. Look at that.

- That looks amazing.

Those look so good.

But I will not be eating today,

because I'm Hindu,

and I'm actually fasting.

- Wow.

- Yeah.

- The fact that fasting

is mostly mind over matter

is particularly tough,

considering how hardwired

that connection is

between our stomach

and our brain.

- Digestion begins long before

the food actually hits the gut.

In fact, the thought of food

or the smell of food

can actually stimulate the

release of digestive enzymes.

- When we see

something appetizing,

receptors in the brain

fire signals

for the mouth

to start producing saliva

to help break down that food

before we even swallow it.

Within our saliva is an enzyme

that kick-starts

the chemical part of digestion,

preparing the body

for the task ahead.

- So I always bring somebody

along with me

who gets to enjoy the food

more than I do, I guess.

- Give feedback.

- Yeah, give feedback.

- I'm eating for two.

- Okay.

- Where should I start?

- Here you go.

- There you go. Wow.

- I'm so hungry.

I haven't eaten anything.

This is definitely t*rture.

- The stomach is

really fascinating

in how it can tell your brain,

"I'm full," or, "I'm hungry."

Our brains actually get a signal

when our stomach

is stretched out

saying, "Oh, my gosh.

I'm full. Don't eat any more."

And on the other hand,

when our stomachs are empty,

this also triggers our brain

in saying, "Eat and fill me up."

Our guts can directly affect

our moods and vice-a-versa.

- While scientists

have connected fasting

with an increase

in mental flexibility,

they've also found an increase

in hanger,

the irritable,

hot-tempered feeling

that comes along with hunger.

When we aren't eating,

and glucose levels drop,

adrenaline and

cortisol levels rise.

These chemicals in the brain

that trigger for hunger

are the same ones

that trigger for anger, rage,

and other emotions.

- We refer to the gut

as the enteric nervous system,

and we have about five times

as many neurons in the gut

as we have in the spinal cord.

90% of serotonin, the feel-good

hormone, is produced in the gut,

and we know that many

other neurotransmitters

are also produced in the gut.

So it really has a whole

separate system in there

that is helping to regulate mood

and feelings, et cetera.

- I can't wait to come back

and to eat for real,

'cause that looks great.

When I'm fasting, my body

definitely feels it.

There's a difference

than when I'm stuffing my face.

My body does feel

a little sluggish

and a little weaker.

It's a lot of discipline

of, like,

what you're able

to push yourself through.

But there is this energy,

this power

that comes from within.

- The fact that a lack of fuel

might make you healthier

isn't the only irony

lurking in the gut.

It's also home to a giant

population of bacteria

that, instead of

making you sick,

might actually be the key

to a strong immune system.

See, despite being

in the middle of our body,

the gut is our most

direct connection

to the outside world.

Food brings with it

pieces of nature,

and nature makes itself

at home inside us.

There's a symbiotic relationship

between our own cells

and foreign ones,

an alien universe

that runs right through us.

- The microbiome

essentially describes

the bacteria living in our gut.

Scientists estimate we have over

10 trillion bacteria in our gut,

which are playing a great role.

They help us break down food,

reabsorb nutrients and vitamins,

and even play

a really critical role

in keeping out the bad bacteria.

- The gut is a diverse

environment where our own cells,

food from outside,

and the bacteria that live

within us all coexist.

And because bacteria and human

cells are constantly touching,

it's a perfect place for

the body to learn what's safe

and what's dangerous.

- Where is your immune system?

It's in your gut.

- The thin mucus barrier

that protects the gut

is home to 80% of all

the immune cells in the body.

As we digest, these cells

learn to tell the difference

between friend and foe.

They know that what we eat

is fuel,

even though it comes

from the outside.

And anything that can hurt us

provokes a response.

- An intact intestinal membrane

is really essential

for protecting us from toxins

and keeping us healthy.

- But when these cells

malfunction,

fuel can suddenly become poison.

- Hey, guys.

- Hi.

- Okay, I have some cream cheese

and carrots, your favorite.

- Oh, yay.

- Do I use this for that?

- Mm-hmm, you can dip it.

It's all allergy-friendly.

Is that good?

- The carrots are really hard.

-My name is Ava,

and I'm 11 years old.

I'm allergic to dairy,

wheat, soy,

fish, shellfish,

nuts, tree nuts,

and I don't know if I said egg,

but egg.

It is kind of scary

to have all these allergies,

but, like, as long as you

stay away from them,

they can't really hurt you.

I can be near dairy.

I can be near nuts.

I just can't eat it or touch it.

- For a variety of reasons

we don't quite understand,

some people are more predisposed

to having allergies than others.

What happens in these people

is the immune system

will see certain types of food

as dangerous,

attach onto it,

and trigger this huge cascade.

- Whenever I have dairy

or some other allergens,

then I'll probably

start vomiting,

and I have to stay home

from school,

but I'm anaphylactic to nuts,

so they could

potentially k*ll me

if I didn't get

the right treatment time.

It's really terrible when you go

into anaphylactic shock,

'cause you start, like, grabbing

at your throat.

It's like you're underwater,

but you can't get out.

- The health of the G.I. tract

is one of the main factors

that's involved

in allergic reactions

and why we're seeing

so many people

who are having food allergies

and food sensitivities.

- An allergy is basically a case

of mistaken identity,

where the immune system

sees food as toxic.

There are a lot of different

immune cells

involved in

an allergic reaction,

but there's one special type

of cell that starts it.

They're called dendritic cells.

And they live on the top layer

of the gut's lining.

They're the messengers

of the immune system,

and their job

is to spot threats.

When you eat something,

dendritic cells eat, too,

in a way.

They try a piece

of what's passing through

to find out

whether it's safe or not.

Underneath this outer layer,

deep in the gut's lining,

are other immune cells

that can be activated fast.

Let's say these cells

absorb milk or a nut

and decide it's dangerous.

They raise the alarm

for other cells to go to w*r.

They release chemicals

that attack the food.

One of the most common

is called Immunoglobulin E.

- Now, IgE historically

was used to hunt down

parasites in our body.

But in some people,

for whatever reason,

the IgE will see food

as foreign, which can cause

all the symptoms

we see with food allergies.

- You may throw up

or break out in hives

classic signs of the body

trying to get rid of poison.

When the reaction happens once,

it will likely happen again.

Often, it starts early on.

- When Ava was born, she had

a lot of feeding issues.

She would vomit every thing

that ever went into her mouth.

- We know that one

of the contributors

to developing food allergies

is whether we've been exposed

to a lot of germs early on.

- From the moment we're born,

bacteria starts

putting down roots in the gut.

- Breast milk encompasses

the exact ratio of protein,

carbohydrates, and fat

needed to give Baby nutrition,

but it also contains antibodies

to promote healthy

gut bacteria growth

and to prevent the growth

of some bad bacteria.

- Our infant immune system

interacts with these bacteria,

and if all goes well,

this training makes it easy

for us to process fuel.

But if the body doesn't

get exposed to enough germs,

the immune system may never

learn to fight the right stuff.

And instead, the body

could end up attacking food.

Without the trillions of foreign

organisms living inside us,

we're more susceptible

to disease.

There are other effects, too.

The microbiome is also

directly responsible

for keeping us energized.

- We are completely animated

by our microbes.

We are really just the hive,

but without our microbes,

we are an empty hive.

The microbes are the worker bees

that are doing all the work.

They're synthesizing

the vitamins.

They're breaking down

the toxins.

They are digesting the food.

- They also play a role

in fat storage

and helping us

with our blood sugar.

So any alteration

in our microbiome

can actually increase our risk

of obesity or diabetes,

and we can alter

our gut bacteria

through lifestyle changes,

diseases, antibiotics.

Research is still out on

how we can go backwards, then,

and fix our gut bacteria

to make ourselves healthy.

- Alright, so, eat, homework,

and then off

to basketball practice.

- We kind of live through life

feeling like

there's this monster out there

that could get her.

So in order to make life normal,

we make sure that Ava

has all the safe alternatives.

Take the flaxseed milk and

mix it in with the rice flour.

- Whether allergies

can be completely reversed

is a question

we have yet to answer.

But it's no surprise

that the solution might lie

in restoring balance

to the microbiome.

But let's rewind.

Now that we know allergies

and the gut are connected,

here's another question

What hurts the gut

in the first place?

- We're seeing so many people

who are having food allergies,

and one of the main factors

is we're exposed

to so many things that really

are microbial disruptors,

that can affect our G.I. system

and that healthy ecosystem

of bacteria.

We are exposed to so many

pesticides and chemicals

through our food supply.

The average American child will

have 18 courses of antibiotics

before their 18th birthday.

That's a time when we should be

really stuffing our kids

full of vegetables

and trying to get them

to avoid antibiotics.

Our microbiome ages with us

as we age,

but the good news is

that it becomes more resilient.

- Oh, that looks so good!

I hope they make

more foods for me,

like coconut whipped cream.

It's delicious.

- Oh, that's a big bite.

What makes me hopeful

is that she's capable.

As much as she's tempted,

she won't try food

that may make her sick.

- I double-check the labels

for all the food

and just make all safe stuff.

That way, I'm not hurt at all.

- Most broad-spectrum antibiotics

will remove 1/3

of your gut bacteria.

So it's such a balancing act

trying to figure out

how can we establish practices

that can keep us safe

from diseases,

but at the same time,

not going too far

so that we're endangering

our health and our microbiome

because we have

super-sanitized ourselves.

- But a sanitized environment

doesn't totally decide

your gut's fate.

We're also learning

that it's much more dynamic

than other parts of the body.

- Based on a variety of factors,

from environmental

and lifestyle factors

to genetics,

our gut microbiome is changing

constantly, all day, every day.

- It's like a microbial

impression of your past

and present,

more unique than a fingerprint.

And it's not just bacteria.

There might be upwards

of a trillion viruses

roaming through our bodies

at any given time.

The microbiome is a living,

breathing organism,

much like a garden,

which means

that we can cultivate it.

- There are definitely

some negative processes

in the outside world

that I think parallel

what's going on

in our digestive systems.

Just as we're destroying

the external environment,

we're destroying

our internal environment

by being over-medicated

and not paying attention

to the food we're eating.

- The microbiome is like a moss

that sits on top of the lining

that separates the gut

from the rest of the body.

It's one of the most

diverse ecosystems on Earth,

controlled by more than

300,000 genes.

Human DNA by comparison

comes from a pool

of only 20,000 genes.

But if we deprive our microbes

for too long,

the moss goes barren

and bad bacteria spread.

That makes it easier for other

toxins to slip into the body.

The same goes for farmland.

When the soil is depleted

by deforestation

and pesticides,

disease creeps in.

- So how do we restore

a landscape that's been damaged?

- The really optimistic message

about the microbiome

is we can change it.

I like to think about gut health

as sort of threefold

remove, replace, and restore.

Remove all the things that are

potentially causing problems,

and that would be

a lot of medications

that are not

absolutely necessary.

Replace What can we do

to replace gut bacteria?

We could eat fermented food.

We can roll in the dirt.

We can get a dog.

We can open a window.

We can be exposed to nature.

And lastly, restore How can

we restore our microbiome?

We really get most of our gut

bacteria from the food we eat.

In conservation ecology,

rewilding means

reintroducing species

into a landscape

where they've become extinct,

and we can apply those

same principles to our gut.

- Whether they're in your gut

or in the ground,

good bacteria

need fuel to thrive.

On Georges' land, that fuel

comes from an unlikely source.

- The same fundamental building

blocks of the physical world

that make up the food that

ultimately becomes the energy

that fuels our mind and body

are also in our waste products.

- All organic matter can be

turned into energy.

It's a cycle, which means

that waste can become fuel

under the right conditions.

- For most of us,

stool is toxins, waste matter,

passing out of the body,

and it's mostly dead

red blood cells and bacteria.

And it's the dead red blood

cells that tend to give it

that brownish, nice, beautiful,

chocolate color.

- And so what we do at SOIL

is we try to think about,

how can we use

the example of nature

to create a system

whereby the nutrients

that we consume,

instead of going into the water,

where they pollute

aquatic ecosystems,

actually get back onto the soil

so that they can

produce more food?

And we do that

by taking human poop

and turning it into

incredible, fertile soil.

- Even though

it's organic matter,

if it's not treated properly,

human waste can be deadly.

- 99% of human waste in Haiti

is going untreated

into the environment.

Those pathogens are making

their way into the water

that people use to drink,

and that's why waterborne

disease continues to be

one of the leading

causes of death in Haiti.

But if you know

how to treat it well,

then you can actually

transform it

and harvest the amazing

nutrients that it has within it.

- Human waste on its own

would not reach the temperatures

to treat the pathogens,

but when you mix it

with agricultural waste,

that's when you get

that perfect mixture.

- Over time, the waste

breaks down into compounds

that can be put back

into the ecosystem.

- If you really want

a healthy forest environment,

the best way to do that is to

actually leave the forest alone.

How can we sort of stand back

and allow this ecosystem

to really blossom on its own?

If you want a really healthy

gastrointestinal track,

the best thing to do

is to really limit

what you're putting in there

and limit it to food.

- The health of Georges' crops

is actually more connected

to your own gut

than you might think.

Because just like plants

need good soil to thrive,

the microbiome needs plants.

- Healthy bacteria like

a lot of plant fiber.

And plant fiber

is mostly indigestible,

and it's indigestible

because it's really

not there to feed

us.

It's there to feed

our gut bacteria.

When the fiber gets broken down

by gut bacteria,

it's fermented into substances

that are really important

for the health of the gut.

- After they break down fiber,

gut bacteria release

something called

short-chain fatty acids

basically microbial poop.

Short-chain fatty acids

strengthen the lining

of the colon.

This not only prevents disease,

it helps the departure

of our own waste.

So you could say that the gut

is doing its own recycling.

- What does a healthy gut

look like?

A great example is a bacteria

called

Faecalibacterium

prausnitzii.

It's protective against

colon cancer,

heart disease, and diabetes.

But you can't just sort of

transport them in.

Just like when you're trying

to rewild land,

you have to figure out, how do

I create the right environment

to really encourage a growth

of these indigenous species?

If you're not feeding

the

F. prausnitzii

a high-fiber plant diet,

they're not going to repopulate

and recolonize your gut

in a sufficient number

to be helpful.

- I like to sometimes say

not we are what we eat,

but rather, we are

what our cells eat.

I think it would be healthy

for us as humans

to think about what they need.

When we think about what it

takes to be a good gardener

watering those plants,

giving them sun

we forget that our own bodies

are also like a garden.

- What we know about this system

is changing more rapidly

than any other.

- What excites me about our gut

is that

it's almost a symphony

between a half-dozen organs,

a ton of bacteria,

hormones, and chemicals.

It's more than just breaking

down and digesting food.

If you strip away everything,

we all feel

the exact same thing.

We go through the exact same

physiologic struggles.

- It's more than just an engine.

It's a unique footprint

and an entire universe.

- It is influenced

by so many things

by the food we eat,

by the places we've lived,

the experiences we've had.

In fact, we refer to the gut

as the second brain.

It reflects everything about us.

It's the hub. It's the center.