All language subtitles for How Bacteria Rule Over Your Body – The Microbiome

Microbes are everywhere,

on your phone,

in your water bottle,

on your hands before you wash them,

on your hands after you wash them,

and literally everywhere else on top of you too.

Microbes are omnipresent at any moment,
and there is nothing we can do about it

So, millions of years ago we made a pact,

we give them shelter and food,

and in turn they work for us.

But the more we learn about this partnership,
the more it looks like a cold war

Inside our mother's womb,
humans start out sterile

When we are born and traveling
through the birth canal,

billions of our mother's bacteria cover
every single part of our bodies.

This is an essential part of human health.

Children born via C-section have a
higher rate of asthma,

immune diseases and even leukemia.

So our bodies do not only accept the invasion
of microorganisms, they welcome it.

Over millions of years, we co-evolved to
make the best of our relationship.

Mother's milk for example,

contains special sugars that are
meant to feed and support

certain groups of microbes,

work as a decoy for others,

and help to modulate the
immune system.

It takes up to two years, until a healthy
microbe community has formed.

Every human has their own unique microbiome,
made up of bacteria,

viruses, fungi and other organisms.

We have three categories of guests,
on and in our bodies.

One:

Quiet passengers that do their own thing,
and are politely ignored.

By being there, they take up space and keep
more aggressive intruders in check.

Two:

Guests that harm us,

But with whom we've learned to live,

for example, bacteria that literally create
acid that melts our teeth,

if we don't brush enough.

They want to take up as much
space as they can,

and we don't want them to.

But, we can't get rid of them entirely.

Three:

Friendly fellows that our bodies
want to have around,

most of them are a community of
380,000 billion bacteria,

from up to 5,000 different species,
that live in our gut.

These gut microorganisms help us digest food,

and pull additional calories from things
that we can't digest ourselves.

Unfortunately, our gut is also the
perfect point of attack for intruders,

so it's guarded by an aggressive army,

our immune system.

To survive here, our microbiome
co-evolved with us

to be able to communicate
with our body.

The most important part of that is to ask
the immune system to not kill them.

But, they also have a real motivation
to keep our gut healthy,

so some of them produce a
messenger substances,

that help to educate the immune system,

and others stimulate the gut cells
to regenerate faster.

But, over the last few years.

Evidence has emerged that the
influence of our gut microbiome,

goes much much further.

It might even talk directly to our brain.

We've observed a few curious things,

90% of our body's serotonin,

an important messenger substance
for nerve cells,

is produced in the gut.

Some scientists think the
microbiome does this,

to communicate with the vagus nerve.

The information highway of our nervous system.

Other examples are bacteria that
stimulate immune cells in the gut,

so they send a kind of alarm
signal to the brain.

Here, it activates immune cells that help
the brain recover from injuries.

Since the brain decides what we eat,

the microbiome is interested
in a healthy brain.

A new field of science is
opening up here,

and we're just on the verge of
understanding how these

complex systems inside our bodies interact.

But we are starting to see how
much our microbiome

actually influences us and our behavior.

Take depression for example,

Healthy rats fed microbes from the
guts of depressed people,

began showing anxiety-like behavior,

and symptoms that look like depression.

And in early 2017, a study linked the
microbiome to intelligence,

by connecting a certain set up
of bacteria in newborns,

with better motor and language skills.

But it might also influence our daily lives.

Tests with fruit flies,

showed that their microbiome, influenced
what kinds of food they craved.

This could mean your microbes are
able to tell your brain,

which food it should get them.

Although, this is not a one-way street

The seed for our microbiome
comes from our mother,

but how it develops and changes, is
determined by what we eat.

the organisms in our gut feed
on different things,

some like fibers and leafy greens,

others go for sugars and starches,

and some love greasy fries and butter.

Our gut is like a garden in which
we constantly decide,

what will grow and blossom.

If we eat healthily, we breed bacteria
that like healthy food.

If we eat a lot of fast food, then we
breed fast food loving bacteria.

Life is hard, so we can get trapped
in a vicious circle.

You have a stressful time, and eat lots
of burgers and fries and pizza.

This is awesome for fast food bacteria,

they multiply and multiply, and take up space
from vegetable loving bacteria.

But even worse, they send signals to the
brain to continue what it's doing.

this makes you want more
fast food.

Which breeds more fast
food bacteria,

which makes you crave fast food,
and so on.

This kind of self-reinforcing cycle,

could play a huge role in obesity.

But, it's important to stress that you
can fight this process,

and reverse it, by eating healthily and
breeding more good bacteria.

Beyond weight gain, our microbiome
has also been linked to other

serious diseases like autism,

schizophrenia, and cancer.

One of the earliest symptoms of Parkinson's,
is actually gut problems.

If your body is overrun with
bacteria that harm you,

there is often only one solution.

You bring in an army of good guys.

That's very easy,

You just transplant some healthy poop.

You do that by literally transferring poop,
from a healthy person,

into your gut.

This method is already used,
to cure diarrhea

that's caused when C. difficile bacteria,
take over a gut microbiome.

But we just don't know enough about
the complex interplay at work here yet.

For example, a transplant from an overweight
donor cured a woman's diarrhea,

but contributed to her obesity down the line.

This caused some ways and another
study tried to reverse the effect.

Poop transplants from slim people
to obese ones,

gave them a more diverse microbiome,

and made them less sensitive to insulin.

Both things that also happen when
people lose weight

We need to do a lot more science,
to really understand

how our microbes make us
healthy or sick.

But, whether we like it or not.

We need our microbiome, and it needs us.

We'll never have our bodies to ourselves.

But we have gained a powerful ally,

if we can just keep the peace.