You Are What You Eat | Michael Harnish | TEDxIntlSchoolDüsseldorf

this is a gypsy moth caterpillar now

this is a gypsy moth caterpillar now like most caterpillars it leads a very

like most caterpillars it leads a very

like most caterpillars it leads a very simple life in the evening it will climb

simple life in the evening it will climb

simple life in the evening it will climb up to the top of trees and it spends the

up to the top of trees and it spends the

up to the top of trees and it spends the rest of the night feeding as the Sun

rest of the night feeding as the Sun

rest of the night feeding as the Sun rises it will descend into the shade to

rises it will descend into the shade to

rises it will descend into the shade to escape the heat of the daytime on

escape the heat of the daytime on

escape the heat of the daytime on occasion though these caterpillars will

occasion though these caterpillars will

occasion though these caterpillars will reverse this behavior they’ll suddenly

reverse this behavior they’ll suddenly

reverse this behavior they’ll suddenly start declined at the top of the tree

start declined at the top of the tree

start declined at the top of the tree during the midday Sun where they

during the midday Sun where they

during the midday Sun where they essentially overheat they die and they

essentially overheat they die and they

essentially overheat they die and they melt for years scientists wondered why

melt for years scientists wondered why

melt for years scientists wondered why this was occurring and they would notice

this was occurring and they would notice

this was occurring and they would notice that this would occur in specific

that this would occur in specific

that this would occur in specific colonies living in particular trees and

colonies living in particular trees and

colonies living in particular trees and it wasn’t until the discovery of a

it wasn’t until the discovery of a

it wasn’t until the discovery of a single virus that infects all of these

single virus that infects all of these

single virus that infects all of these caterpillars and that changes just a

caterpillars and that changes just a

caterpillars and that changes just a single gene that we aren’t finally

single gene that we aren’t finally

single gene that we aren’t finally understood what was going on so the

understood what was going on so the

understood what was going on so the change in this gene drives these

change in this gene drives these

change in this gene drives these caterpillars to reverse their behavior

caterpillars to reverse their behavior

caterpillars to reverse their behavior and this will then lead to the spread of

and this will then lead to the spread of

and this will then lead to the spread of the virus as the caterpillars melt the

the virus as the caterpillars melt the

the virus as the caterpillars melt the melting caterpillars infect neighboring

melting caterpillars infect neighboring

melting caterpillars infect neighboring caterpillars that are healthy and this

caterpillars that are healthy and this

caterpillars that are healthy and this carries on the virus’s reproduction

carries on the virus’s reproduction

carries on the virus’s reproduction cycle Toxoplasma gondii is a single-cell

cycle Toxoplasma gondii is a single-cell

cycle Toxoplasma gondii is a single-cell parasite that lives and breathes in the

parasite that lives and breathes in the

parasite that lives and breathes in the intestines of cats now the challenge for

intestines of cats now the challenge for

intestines of cats now the challenge for the parasite is how to move from one cat

the parasite is how to move from one cat

the parasite is how to move from one cat to another and it’s developed a rather

to another and it’s developed a rather

to another and it’s developed a rather ingenious method for doing so while it

ingenious method for doing so while it

ingenious method for doing so while it reproduces only in the intestine of a

reproduces only in the intestine of a

reproduces only in the intestine of a cat it can infect other mammals and this

cat it can infect other mammals and this

cat it can infect other mammals and this includes mice mice that are infected by

includes mice mice that are infected by

includes mice mice that are infected by the parasite and really are quite a sum

the parasite and really are quite a sum

the parasite and really are quite a sum is symptomatic with the exception that

is symptomatic with the exception that

is symptomatic with the exception that they develop some odd behaviors whereas

they develop some odd behaviors whereas

they develop some odd behaviors whereas a normal Mouse will avoid the sense of

a normal Mouse will avoid the sense of

a normal Mouse will avoid the sense of cats and avoid wide open spaces infected

cats and avoid wide open spaces infected

cats and avoid wide open spaces infected mice actually approach the sense of cats

mice actually approach the sense of cats

mice actually approach the sense of cats and will move readily into wide open

and will move readily into wide open

and will move readily into wide open spaces which leads to situations

spaces which leads to situations

spaces which leads to situations something akin to this which most of us

something akin to this which most of us

something akin to this which most of us would expect would lead to this

would expect would lead to this

would expect would lead to this mice that are infected by the parasite

mice that are infected by the parasite

mice that are infected by the parasite are much more likely to be eaten by cats

are much more likely to be eaten by cats

are much more likely to be eaten by cats therefore or thereby transporting the

therefore or thereby transporting the

therefore or thereby transporting the parasite into the gut of its next host

parasite into the gut of its next host

parasite into the gut of its next host and continuing its lifecycle so these

and continuing its lifecycle so these

and continuing its lifecycle so these are just two examples of many many

are just two examples of many many

are just two examples of many many situations in which single-cell

situations in which single-cell

situations in which single-cell organisms can directly influence or even

organisms can directly influence or even

organisms can directly influence or even control the behavior of more complex

control the behavior of more complex

control the behavior of more complex animals however the ability for of

animals however the ability for of

animals however the ability for of microorganisms to alter behavior is not

microorganisms to alter behavior is not

microorganisms to alter behavior is not confined to simple animals like

confined to simple animals like

confined to simple animals like caterpillars and mice anyone who has

caterpillars and mice anyone who has

caterpillars and mice anyone who has ever experienced a cold or food

ever experienced a cold or food

ever experienced a cold or food poisoning will appreciate that some of

poisoning will appreciate that some of

poisoning will appreciate that some of the symptoms associated with these

the symptoms associated with these

the symptoms associated with these illnesses like sneezing or vomiting may

illnesses like sneezing or vomiting may

illnesses like sneezing or vomiting may be a sign that our body is actually

be a sign that our body is actually

be a sign that our body is actually trying to get rid of the toxins however

trying to get rid of the toxins however

trying to get rid of the toxins however there are also very efficient methods

there are also very efficient methods

there are also very efficient methods for spreading the infectious agent the

for spreading the infectious agent the

for spreading the infectious agent the single sneeze can contain as many as

single sneeze can contain as many as

single sneeze can contain as many as 100,000 germs each of which is capable

100,000 germs each of which is capable

100,000 germs each of which is capable of infecting another person which brings

of infecting another person which brings

of infecting another person which brings me to the human GI tract we know that

me to the human GI tract we know that

me to the human GI tract we know that there are more than 500 species of

there are more than 500 species of

there are more than 500 species of microorganisms that inhabit the GI tract

microorganisms that inhabit the GI tract

microorganisms that inhabit the GI tract now estimates are that this accounts for

now estimates are that this accounts for

now estimates are that this accounts for about two kilograms of microorganisms in

about two kilograms of microorganisms in

about two kilograms of microorganisms in each of us in contrast the human brain

each of us in contrast the human brain

each of us in contrast the human brain only weighs 1.3 kilograms on average now

only weighs 1.3 kilograms on average now

only weighs 1.3 kilograms on average now the brain and GI tract communicate

the brain and GI tract communicate

the brain and GI tract communicate constantly via nerves and hormones this

constantly via nerves and hormones this

constantly via nerves and hormones this is a bi-directional communication the

is a bi-directional communication the

is a bi-directional communication the brain sends signals down to her gut

brain sends signals down to her gut

brain sends signals down to her gut which in tells our stomach and our

which in tells our stomach and our

which in tells our stomach and our intestines how to react in terms of the

intestines how to react in terms of the

intestines how to react in terms of the environmental stimuli so as I stand

environmental stimuli so as I stand

environmental stimuli so as I stand before everyone here tonight and my

before everyone here tonight and my

before everyone here tonight and my stomach those flip-flops and his

stomach those flip-flops and his

stomach those flip-flops and his butterflies I’m acutely aware of my

butterflies I’m acutely aware of my

butterflies I’m acutely aware of my brain sending signals down to signal

brain sending signals down to signal

brain sending signals down to signal that I’m stressed however 90% of all the

that I’m stressed however 90% of all the

that I’m stressed however 90% of all the communication goes in the opposite

communication goes in the opposite

communication goes in the opposite direction it carries information from

direction it carries information from

direction it carries information from the GI tract up to the brain and since

the GI tract up to the brain and since

the GI tract up to the brain and since we know that many of these microbes are

we know that many of these microbes are

we know that many of these microbes are capable of affecting our GI tract and

capable of affecting our GI tract and

capable of affecting our GI tract and are also capable of producing chemicals

are also capable of producing chemicals

are also capable of producing chemicals that may then

that may then

that may then we can detect it’s not that much of a

we can detect it’s not that much of a

we can detect it’s not that much of a stretch to imagine that these microbes

stretch to imagine that these microbes

stretch to imagine that these microbes might be actually influencing our

might be actually influencing our

might be actually influencing our behavior the community of microorganisms

behavior the community of microorganisms

behavior the community of microorganisms inhabiting the human gastrointestinal

inhabiting the human gastrointestinal

inhabiting the human gastrointestinal tract is known as the human gut

tract is known as the human gut

tract is known as the human gut microbiota now what we understand is the

microbiota now what we understand is the

microbiota now what we understand is the number of cells inside our intestines

number of cells inside our intestines

number of cells inside our intestines outnumber the total number of our owns

outnumber the total number of our owns

outnumber the total number of our owns body’s cells by a factor of ten to one

body’s cells by a factor of ten to one

body’s cells by a factor of ten to one the genetic material that contain out

the genetic material that contain out

the genetic material that contain out numbers our own genetic material by

numbers our own genetic material by

numbers our own genetic material by about a hundred to one this gut

about a hundred to one this gut

about a hundred to one this gut microbiota develops over a lifetime and

microbiota develops over a lifetime and

microbiota develops over a lifetime and is unique to each individual it’s like a

is unique to each individual it’s like a

is unique to each individual it’s like a fingerprint

fingerprint

fingerprint we understand that prior to birth the GI

we understand that prior to birth the GI

we understand that prior to birth the GI tract is sterile however during the

tract is sterile however during the

tract is sterile however during the process of birth we’re actually

process of birth we’re actually

process of birth we’re actually colonized by microbes from our mothers

colonized by microbes from our mothers

colonized by microbes from our mothers and so each of us can trace some of

and so each of us can trace some of

and so each of us can trace some of these microbes back to our our mothers

these microbes back to our our mothers

these microbes back to our our mothers once they’ve established a colony this

once they’ve established a colony this

once they’ve established a colony this microbiome then forms a symbiotic

microbiome then forms a symbiotic

microbiome then forms a symbiotic relationship with us and this has

relationship with us and this has

relationship with us and this has numerous benefits so for example a

numerous benefits so for example a

numerous benefits so for example a robust microbiota will compete against

robust microbiota will compete against

robust microbiota will compete against hostile microorganisms that organisms

hostile microorganisms that organisms

hostile microorganisms that organisms that we might ingest

that we might ingest

that we might ingest sometime later in life and so thereby it

sometime later in life and so thereby it

sometime later in life and so thereby it provides a protective factor another

provides a protective factor another

provides a protective factor another benefit of this is the fact that some of

benefit of this is the fact that some of

benefit of this is the fact that some of these microorganisms can break down

these microorganisms can break down

these microorganisms can break down complex carbohydrates or other

complex carbohydrates or other

complex carbohydrates or other substances that we are normally in

substances that we are normally in

substances that we are normally in capable of digesting as a result we

capable of digesting as a result we

capable of digesting as a result we directly benefit by being able to obtain

directly benefit by being able to obtain

directly benefit by being able to obtain nutrition from foods that we normally

nutrition from foods that we normally

nutrition from foods that we normally couldn’t eat as one would imagine this

couldn’t eat as one would imagine this

couldn’t eat as one would imagine this means that having a healthy microbiota

means that having a healthy microbiota

means that having a healthy microbiota is is very beneficial to humans now

is is very beneficial to humans now

is is very beneficial to humans now these are established through a variety

these are established through a variety

these are established through a variety of childhood experiences and one of the

of childhood experiences and one of the

of childhood experiences and one of the ones I’ve already mentioned is is their

ones I’ve already mentioned is is their

ones I’ve already mentioned is is their childbirth

childbirth

childbirth we understand that natural through

we understand that natural through

we understand that natural through natural childbirth children obtain the

natural childbirth children obtain the

natural childbirth children obtain the initial microbes that set up colonies

initial microbes that set up colonies

initial microbes that set up colonies inside our intestines

inside our intestines

inside our intestines and that children who are born via

and that children who are born via

and that children who are born via natural childbirth end up with much more

natural childbirth end up with much more

natural childbirth end up with much more robust and diverse microbiota than

robust and diverse microbiota than

robust and diverse microbiota than children born via c-section similarly

children born via c-section similarly

children born via c-section similarly children who are breastfed actually have

children who are breastfed actually have

children who are breastfed actually have much more robust colonies and this is

much more robust colonies and this is

much more robust colonies and this is linked to the lower instances of asthma

linked to the lower instances of asthma

linked to the lower instances of asthma and skin allergies as well as food

and skin allergies as well as food

and skin allergies as well as food allergies another factor that affects us

allergies another factor that affects us

allergies another factor that affects us is the diversity of food we ingest

is the diversity of food we ingest

is the diversity of food we ingest especially as an as a child but this

especially as an as a child but this

especially as an as a child but this actually spans our entire lifespan and

actually spans our entire lifespan and

actually spans our entire lifespan and so when we eat a diverse diet that is

so when we eat a diverse diet that is

so when we eat a diverse diet that is rich in whole foods but also has Pro up

rich in whole foods but also has Pro up

rich in whole foods but also has Pro up probiotics like yogurt we actually can

probiotics like yogurt we actually can

probiotics like yogurt we actually can greatly increase the efficiency as well

greatly increase the efficiency as well

greatly increase the efficiency as well as the diversity of this microbiota and

as the diversity of this microbiota and

as the diversity of this microbiota and this gives us real health benefits a

this gives us real health benefits a

this gives us real health benefits a takeaway from this is you are what you

takeaway from this is you are what you

takeaway from this is you are what you eat and what you eat directly impacts

eat and what you eat directly impacts

eat and what you eat directly impacts what you can eat in the future but it

what you can eat in the future but it

what you can eat in the future but it also impacts your health as well as

also impacts your health as well as

also impacts your health as well as potentially your behavior as a result of

potentially your behavior as a result of

potentially your behavior as a result of this seems like this which most parents

this seems like this which most parents

this seems like this which most parents are familiar with aren’t necessarily as

are familiar with aren’t necessarily as

are familiar with aren’t necessarily as bad for her as we one might think as I

bad for her as we one might think as I

bad for her as we one might think as I alluded to earlier there is a growing

alluded to earlier there is a growing

alluded to earlier there is a growing body of evidence that imbalances in the

body of evidence that imbalances in the

body of evidence that imbalances in the microbiota can influence behavior and

microbiota can influence behavior and

microbiota can influence behavior and sometimes in very detrimental ways so

sometimes in very detrimental ways so

sometimes in very detrimental ways so abnormal levels of particular bacteria

abnormal levels of particular bacteria

abnormal levels of particular bacteria or imbalances between the different

or imbalances between the different

or imbalances between the different microbes have been linked to things like

microbes have been linked to things like

microbes have been linked to things like obesity eczema as well as psychiatric

obesity eczema as well as psychiatric

obesity eczema as well as psychiatric disorders like anxiety some of the

disorders like anxiety some of the

disorders like anxiety some of the strongest evidence comes from what are

strongest evidence comes from what are

strongest evidence comes from what are known as nodal biotic mice and these are

known as nodal biotic mice and these are

known as nodal biotic mice and these are mice in which antibiotics are introduced

mice in which antibiotics are introduced

mice in which antibiotics are introduced that wipe out their native microbiota

that wipe out their native microbiota

that wipe out their native microbiota and then they’re raised in sterile

and then they’re raised in sterile

and then they’re raised in sterile environments what this creates is

environments what this creates is

environments what this creates is essentially a germ-free Mouse now if we

essentially a germ-free Mouse now if we

essentially a germ-free Mouse now if we take these germ-free mice and we inject

take these germ-free mice and we inject

take these germ-free mice and we inject them with gut microbes from a mouse with

them with gut microbes from a mouse with

them with gut microbes from a mouse with a particular characteristic or disorder

a particular characteristic or disorder

a particular characteristic or disorder in this case an obese Mouse the result

in this case an obese Mouse the result

in this case an obese Mouse the result is the germ-free Mouse will develop

is the germ-free Mouse will develop

is the germ-free Mouse will develop obesity even more fascinating

obesity even more fascinating

obesity even more fascinating is if we take gut microbes from a human

is if we take gut microbes from a human

is if we take gut microbes from a human say one with depression the mouse will

say one with depression the mouse will

say one with depression the mouse will develop symptoms of depression and this

develop symptoms of depression and this

develop symptoms of depression and this includes decreases in exploratory

includes decreases in exploratory

includes decreases in exploratory behavior as well as decreases in overall

behavior as well as decreases in overall

behavior as well as decreases in overall activity so there’s two big implications

activity so there’s two big implications

activity so there’s two big implications here first of all it’s that these

here first of all it’s that these

here first of all it’s that these microbes can actually affect behavior

microbes can actually affect behavior

microbes can actually affect behavior across species they’re not limited to

across species they’re not limited to

across species they’re not limited to just one species the other implication

just one species the other implication

just one species the other implication here is that we may be able to develop

here is that we may be able to develop

here is that we may be able to develop very novel treatments for disorders that

very novel treatments for disorders that

very novel treatments for disorders that we thought were brain disorders which

we thought were brain disorders which

we thought were brain disorders which may in fact be because of these

may in fact be because of these

may in fact be because of these imbalances to sum this up in certain

imbalances to sum this up in certain

imbalances to sum this up in certain cases situation can become disposition

cases situation can become disposition

cases situation can become disposition things that we’re exposed to early on in

things that we’re exposed to early on in

things that we’re exposed to early on in childhood can fundamentally change who

childhood can fundamentally change who

childhood can fundamentally change who we are and establish traits that last

we are and establish traits that last

we are and establish traits that last and a lifetime another way of putting

and a lifetime another way of putting

and a lifetime another way of putting this is the smallest little factors in

this is the smallest little factors in

this is the smallest little factors in life may have huge impacts on who we are

life may have huge impacts on who we are

life may have huge impacts on who we are and how we behave and so when we think

and how we behave and so when we think

and how we behave and so when we think about our the wider world we have to

about our the wider world we have to

about our the wider world we have to realize we’re not just part of the

realize we’re not just part of the

realize we’re not just part of the ecosystem we are actually an ecosystem

ecosystem we are actually an ecosystem

ecosystem we are actually an ecosystem unto ourselves and that ultimately this

unto ourselves and that ultimately this

unto ourselves and that ultimately this ecosystem shapes exactly who we are

ecosystem shapes exactly who we are

ecosystem shapes exactly who we are thank you