Original subtitles

Wow! Oh, who's at the door?

Who's that?

Little baby, hello!

Mwah, mwah, mwah!

Good morning, angel. Mwah!

Right. I'm gonna have a shower.

Enjoy.

Would you mind taking Hugo for me?

Yeah. Come here. Come with me, my baby.

Oh, mwah!

I'll be really quick so you can get on with paella.

- Yeah. - Okay?

Mwah, mwah!

You're gonna go with Granddad.

- Hello, Dad. - Mwah. Morning.

I got everything.

Oh, mwah!

Are you going to help me in a minute?

I cannot do it without you.

Yeah.

Arms up.

Are you going to help Granddad make paella?

Yeah.

- Hugo, smell it. - Don't touch it.

No.

You don't know how good this is, Hugo.

When a baby starts eating with the family,

that's a big moment.

They're embarking on a lifetime of pleasure through food.

But it's not just fun and pleasure.

It also matters what we eat, because it's fundamental

for the development of the body and the mind.

I've never known anyone to make such a mess

like when you cook paella. Look at the floor.

Breast milk isn't what you think it is.

It's not just food.

Some of the most important things in breast milk

are things you'd never imagine were there.

All right. Are we ready?

♪ Hugo, Hugo, Hugo ♪

- Dad, are you ready? - Yeah.

- Hugo, look at that. - Oh, my goodness.

Hugo, look at this.

One day, Hugo, you can have paella.

Over the last ten to 15 years,

what we are beginning to understand is that

what babies ingest impacts the immune system.

This relates to whether they develop disease or not later in childhood.

- Hugo broke it. - What happened?

The questions we as scientists would like to know are,

which are the important nutrients,

what do they do,

how do babies get them,

and how does that shape their lives?

Well, baby's heartbeat, it looks good, doesn't it?

Are you okay? You can't talk?

I feel nauseous.

Don't worry.

Well done, baby.

Well done.

I'm so proud of you.

He's all pink.

Welcome to the world, Nelson.

What's happened to Dr. Brit?

So Nelson's a day and a half...

and all's going really well.

Hello, darling.

He's tired.

Little one munching beautifully.

He's really learned how to take the milk.

He's been rooting around and he can even hold his head up.

It's amazing, even after, like, coming up to two days.

Yummy yummy, Mummy.

As an anthropologist,

I'm really interested in the ways that mothers raise their babies.

I became interested in breast milk in the late '90s

because it was something in my field of anthropology

where we'd known a lot about breastfeeding,

but we didn't really know about

the composition of the milk that they're providing.

It was the missing piece of understanding

how mothers nourish, protect, and guide their offspring

through mother's milk.

In the grocery store, there is an entire aisle

dedicated to dairy milk.

It's so common that we miss

the fact that milk's really special.

I hadn't given much thought to milk

before I was in college.

Uh, all I really spent time thinking about was that people teased me

because I drank it with ice cubes.

When I started looking at the scientific literature

about milk...

I was shocked that there was so little research about this.

I can find out more about coffee or erectile dysfunction

than the first food a mammal is adapted to consume.

How does a mother's milk vary?

How much fat is in it?

How much protein? What's the volume?

If she's on her first baby or her fifth baby,

is the milk the same or is it different?

We should know about this!

Why do we not know about this? Why hasn't this been a priority?

I first began my research on breast milk by studying monkeys

because their milk is very similar to human milk.

And they grow up four times faster than humans.

So we get a snapshot of a developmental trajectory

at a much quicker timeline

than anybody can study when they're working with humans.

Hey, sweetie.

When I do my research to study milk in monkeys,

we try and make sure that we disturb the animals

as little as possible.

They spend almost all of their time with their family,

we just collect milk a couple times during lactation.

I had some wonderful mentors

who tried very hard

to dissuade me from studying breast milk.

They thought I was headed down a dead-end road,

that work that had been done in the '80s

showed that the average composition of milk from human populations

was the same in, you know, London as it was in The Gambia.

There was this idea that milk was pretty standardized

among women...

and on top of that...

they told me,

"You'll never be able to milk a monkey."

I think it speaks to both my overwhelming curiosity

about monkey milk,

but also my hubris that I was like, "Okay, I'm gonna do it anyway,"

and I was able to milk a monkey.

Hugo.

Hi.

Hi!

I absolutely love the breastfeeding,

and once you've nailed it,

once you go through the horrific beginning,

it is just such a joy.

It is so, so, so special.

I said to myself, "I'll stop at six months," but...

like, he got to five months and I was thinking,

"I've only got a month left of this, this isn't long enough.

I think I'll keep going for a little bit more."

It is so unique and it's something that only I can do for him.

And as a parenting tool,

I don't know how to settle him if I'm not putting him on the breast.

Ads and my dad,

they have all these lovely, fantastic ways of calming him down.

I have one. Like, one. That is it.

I don't know what I'm going to do when I don't know that one anymore, like...

Yeah, I have to read up on some books maybe.

In our lab,

I was looking for patterns in the nutrients of milk.

We used hundreds of monkey milk samples.

We've measured how much fat was in the milk,

how much protein was in the milk, how much carbohydrate was in the milk,

the volume of milk that they were producing,

and at different time points of lactations.

What we got really excited about was that

one of the patterns that we saw...

was a richer, more energetically dense milk for sons.

So the mothers were making a different biological recipe of the milk

whether or not they had a son or a daughter.

So I started to look for other differences in the milk.

We're now boiling a very small amount of milk in acid...

so we can measure how much mineral is in the milk.

And one of the things that we found

was that the calcium phosphorus ratio

was higher for daughters than it was for sons.

And this makes a lot of sense

because we know that the calcium phosphorus ratio

is really important

for bone development.

Skeletal development of daughters is faster than it is for sons

because females reach adulthood quicker than males.

This is the first time such a finding has ever been reported.

It's really preliminary,

but it shows us

how many questions remain to be answered.

I wrote an essay on my blog about the biological recipe of milk

for sons and daughters

and tweeted about it.

A few hours later, I got a tweet back

from a dairy scientist,

who said, would I be interested

in investigating this using dairy records from dairy cows?

And because I'm a consummate professional, my first message to this person was,

"Hell yes! I would love to do that."

I was really excited to work with dairy cows

because we know more about dairy cow milk than we know about human milk

and all the other kinds of milks put together.

Hi, Molly.

Their records are so extensive.

We were able to study one and a half million cows

to look at how the amount of milk produced was perhaps influenced

by whether or not the cow had had a son or a daughter.

What we found is that after producing a daughter,

cows produce significantly more milk

than if they produce a son.

We don't know exactly what it is about a fetal daughter

that influences the mammary gland.

We also found by looking at 112,000 cows

having a daughter on the first pregnancy

increased the amount of milk that was produced on both the first

and the second lactation.

It had a long-lasting effect

on what the mammary gland was able to produce.

These differences aren't just in cows.

We're also starting to see evidence of a daughter effect

in the breastfeeding outcomes in humans.

And the finding that the mammary glands' ability

to make more milk with each sequential baby

means that even if moms have a really tough time breastfeeding

on a first baby,

they might be successful if they try again later on.

Oh, hello! Momma's pretty sure you're hungry.

- Feeding's a big deal. - Yes.

People don't realize it's, like,

30% of your parenting endeavors.

I thought I could eat,

but they eat non-stop

from when they are, I would guess, five in the morning...

till bath time, which is 8:30.

At first, I really was hoping to completely

100% breastfeed both children for a year plus.

It didn't happen that way, because I have twins

and my body just wasn't able to produce enough milk for both of them.

It was a big decision to not breastfeed.

- I was really emotional. - There you go.

I remember crying about it.

Um, I remember thinking, like,

maybe I could still try it if I can give them

a little bit of a bottle here and there and still do it a little bit,

but at the same time

I have to make the decision that's best for me

emotionally, and also for, um, the kids.

When breast milk is not available,

when mothers aren't able to produce breast milk for a variety of reasons...

there is no other option that is better

to support a baby than an artificial formula

that is based on the science of human breast milk.

It doesn't replicate breast milk,

but it's not the same as directly feeding a baby cow's milk.

We as a scientific community owe it to parents

to close that gap between breast milk and formula.

Hey.

Hi. Hey, Mila.

Oh, my God, that bow.

You're funny, girl.

Oh!

Oh, my God, she's blind.

When I dug deeper into milk...

there were other patterns that emerged.

The biggest pattern of all

is the ways in which an individual mom

makes individualized milk

for an individual baby.

Milk is bespoke.

There you go, Nelson.

You happy?

You happy now, my son?

He's exclusively breastfed,

and I plan to breastfeed for about a year.

Yeah.

He drinks... on average

every two and a half hours

unless there's something wrong:

he's poorly or there's a heat wave or something,

and then he's feeding a lot more.

I wonder how many ounces

he takes in every time he drinks from my breast.

All that exercise has tired him out.

One of the ways in which milk is bespoke

is the way it changes across time.

As a mother goes about her day,

as she experiences different things in her life,

we can see, sometimes,

the signature of those experiences in the milk she's producing.

We wish you a very pleasant flight with us today.

You know, the amount of fat, protein,

carbohydrates, the amount of water, the total volume of the milk.

When the baby gets fussy and changes their nursing pattern,

it affects the milk that's being produced.

When the mother's body detects that the baby is fighting an illness,

her own immune system upregulates the production of antibodies,

and those go into milk

to help the baby fight those viruses and bacteria and pathogens.

Seems so happy.

There are also hormones in breast milk

that go from the mother's body into her milk.

And we are more and more convinced that this is an important signal

that communicates things from mother to baby

that influence the baby's development

from their brain, to their metabolism, to their behavior.

In this way, milk is a physiological conversation

that's responsive to the baby's needs.

Yeah!

My own curiosity about milk is what started me on this research track

but understanding that moms and babies really need this information

to improve human health

is what keeps me going.

All right, I think our next one is down here.

Mm-hmm.

All right, Miss Mya.

You think overnight with her?

- I think overnight. - All right.

We're just kinda working on

feedings and getting her ready to go home today.

Okay.

But that heart sounds good.

I'm going to get you over to Mom. Where's Mom?

Yeah.

Do you realize now she's exactly at what a term baby would be at this point?

Those chubby cheeks.

In my career, both as a pediatrician,

but also as a nutritional scientist,

I've really come to understand how nutrition

shapes our lives across the lifespan.

All right. Listen, good luck with her. That's great.

- Thank you. - Yeah, and we'll see you in clinic.

Hey, should we see how big you are? Huh?

Should we see how big you are?

And you are ready.

You look like you're ready to take off in a little space capsule.

Okay?

Here we go.

Feeding is the biggest concern that families have with their babies.

They want to be absolutely sure

that their babies are getting enough milk,

and they're going to grow and thrive on it.

But not only do parents get it wrong about what is growth,

physicians and scientists do as well.

I hear all the time,

"The baby's growth was this." What do you mean the baby's growth?

"Well, the baby gained this amount of weight."

Weight gain is only one component of growth.

What you really want is proportional growth.

So weight, length,

brain growth, all moving along together.

Yeah.

Were you saying something in here?

We missed you out here.

Yes.

- Oh! - Ta-da!

So here are her numbers, and they look really good.

So 20.4 percent fat

- and 80% fat free mass. - That's amazing.

And that's the part that we think correlates with brain development.

So the more advanced a baby is,

tends to correlate with lots of muscle, good, strong muscle.

So we're real excited about that.

In the last ten years, we've developed new techniques to find out

what babies should be eating

to maintain their growth and development.

- Hey there. - You're so good.

And it might surprise you

what they need to sustain their body and their mind.

I wonder whether Nelson knows

he's about to have his very first food ever.

I love breastfeeding. I really do.

but, um, I think that Nelson is showing signs

that he's ready to start with solid food.

Let me just have a look first.

Oh, yeah, I think it's fine.

- You're about to get a real surprise. - What is that, Nelson? What's that?

'Cause every time we eat something

he's always reaching out to eat

and you can see he's really curious.

Look, he's already going for it.

He's like, "What's all that noise?"

The day will come

when I have to fully wean him and not give him breast milk anymore.

Selfishly, as a mum...

I'm really going to miss our feeds.

He's growing up, you know?

I have to adapt to his growing needs.

Who's going to love carrot?

Carrots today,

prime beef steak tomorrow.

Once he knows what solids taste like,

the door's gonna be open.

Nelson!

What is that?

What's that?

Is that yummy?

Another one?

That's so cute.

Supper time for this family is more than just...

you know, sitting down and having a meal, it's more of a social thing.

So, yeah, we'd like Nelson to be part of that

even though he doesn't speak very much at the moment.

The swallowing is epic.

I think every family gets very excited when babies transition to solid food.

- Look at that face! - Open less.

Look.

We know that

food is social.

Food gives us energy,

but food is not always exactly what you think.

In 1983,

I moved to Minnesota and I was studying proteins in babies.

And we found that there were these proteins

that were telling us that our babies were iron-deficient.

That was a problem, because...

the unsung heroes for food are these micronutrients.

We're talking about tiny amounts of metals

like iron, zinc, and copper.

All of those metals affect the complexity of the brain...

and we know that it's critically important for learning and memory.

One way Mother Nature ensures that a baby will have plenty of iron

is to stockpile it in the womb...

so that the baby is born with all the iron that it needs

for the first four or so months.

It was a total shock and surprise...

because based on what we knew,

there should not be any iron-deficient babies.

And we discovered that moms with high blood pressure,

moms with diabetes, moms who smoked cigarettes,

they were the ones where the iron was not completely getting across...

from the mom

to the fetus.

We knew that older children

who have iron-deficiency,

that they had some memory issues.

And so we wanted to know, "Well,

do we have the same problem in the babies or not?

Wow!

That's great!

We got a precocious one.

Oh, nice.

Um, this doesn't hurt,

but if she is upset and we can't calm her down, we'll stop.

- It's completely fine. - Sure.

So, since I can't ask a newborn

to do a memory task for me,

we have to use a cunning technique...

to trick the baby to show us that it can actually do a cognitive task.

Okay.

We do that with EEG.

The EEGNet measures electrical activity that is coming from the brain.

And we're ready to go.

We're just gonna measure her...

One of the remarkable things that a baby does

and has to be able to do is to recognize its mother's voice

from a stranger's voice.

That memory system needs a fair amount of iron to develop.

All right. We're gonna get started.

We play the sound of Mom saying "baby."

Baby.

Baby.

Baby.

Then we play a stranger's voice.

Baby.

Baby.

Baby.

And we can see if the baby has a different EEG pattern to Mom

as opposed to a stranger.

All right. That's great.

You're all done. You did it.

You did it. Good work.

When we analyzed the results,

they were dramatic.

In the iron-sufficient baby,

the response to the mother here in black

is a very different shaped curve

than the response to the stranger.

This tells us that the baby has in some way memorized

and differentiated between those two.

So here's a baby who's got great memory.

The iron-deficient baby

doesn't show any discrimination

between the mom's voice and the stranger's voice.

And that would suggest to us that that baby's hippocampus,

the area that's involved in learning and memory,

is not functioning adequately

due to the iron-deficiency.

This was completely game-changing.

It was absolutely shocking to me.

Nobody even thought babies were iron-deficient,

much less that there would be a neuro-developmental consequence.

One of the most amazing things about these micronutrient deficiencies

is how common they are.

Two billion people in this world are iron-deficient,

but it's not just iron

that is critically important for the development of the brain.

One point eight billion are zinc-deficient,

another 900 million are iodine-deficient,

and if we could get rid of those deficiencies...

we would shift the world's IQ positively by ten points.

That's a big one. It's a big one.

Yes!

What we learned in 2000

turned the public health conversation from postnatal to prenatal.

And making sure that moms were getting adequate iron during pregnancy

to stockpile it in the womb,

and that they're taking care of any conditions

that might limit how the iron goes to the baby.

We think about these lesser-known nutrients

as building blocks for the brain.

We gotta realize that what we're building in there

are the pieces that go into temperament and personality.

So really the nutrients are building your person.

This looks good,

or this looks good,

or this looks good.

Do you think we should get a green bowl?

It would be probably, like, more chopped up.

- Okay. Do you want to try that too? - You know, like smaller, bite-sized?

Which one do you think that they would like?

- Okay, they're gonna try all that stuff. - Thank you so much.

That looks so good. Thank you.

That was quick.

Yeah.

What do you think, milk-face?

All right.

We got some foods for you to try

'cause you're a big girl.

It's time for you to start eating big girl food.

Some kale.

You gotta put it in your mouth.

There you go.

Ooh!

That's sweet potato.

You ate a piece of food.

Good girl!

Parents can make sure

that their babies are getting enough iron

by paying attention to what's in the diet.

Cereals that are fortified with iron are a good source,

but then after six months,

we recommend a source of either meat or fish,

um, dark, leafy vegetables.

What about you?

It's a grape.

Lincoln, just be open to it.

Babies will definitely let you know how they feel about foods.

It's experimentation, and it should be fun experimentation.

Most important thing is to follow the baby's cues.

You do not want to force feed a baby who is not ready to take solid foods.

All right, buddy.

Let's see if you'll take this old familiar. Here you go.

Mila's had some egg,

sweet potato, grape, kale,

and Lincoln has yet to try anything else but his cracker.

But he's a fun guy.

But you're a fun guy.

There you go, boy.

Oh, okay.

Okay, calm down.

He's crazy. His blood sugar spiked.

He's just dangerous right now.

You're a cracker killer.

I had an incredible biology teacher in high school

that encouraged me to do a degree in biology.

Even from my earliest days in undergrad,

microbiology was something that really captured my imagination.

We tend to think of microbes as very simple,

single-celled organisms,

but I think what we need to remember are

microbes are the oldest and most successful

life form on this planet.

Have we looked everywhere?

So you're setting the scene, are you?

So, who is this?

Mumma.

- Is that what mummies look like? - Yeah.

Look like a mummy monster. Right.

So, that's Mummy.

Hi, mister. Hi mister, mister.

By six months of age, a baby's putting all kinds of things in their mouth,

toys, food, the dog's tail...

and on those things are microbes,

single-celled organisms,

bacteria or fungi or viruses.

They're ancient. They're adaptable.

They exist in every environment that we know of.

- Red? - Red?

Counter to what you might think,

it's actually really important for a baby to ingest microbes in early life.

Okay. So you have to do a bit more glue then.

Microbes are quite amazing.

We are in fact super-organisms.

We're made up of microbes and human cells,

and the gut, even in a one-month-old baby,

is quite a complex ecosystem

comprised of thousands of distinct bacteria.

We know the gut microbiome really influences our health.

So can we predict,

based on the microbes in their gut microbiome,

which babies will go on to live a healthy life or develop disease.

Aurora is our dog.

She just loves to play. She just wants to play 24/7.

Play, lick the kids...

Mm-hmm. Repeat.

Doggy time.

Eww! Eww!

She loves stealing their crackers right now.

Cleaning up their highchairs when they're done with them.

That's the only good thing she does.

- She entertains the kids. - No, she's a good dog.

Hey.

A few years ago,

our collaborators at Henry Ford Hospital in Detroit

had shown that babies who are exposed to dogs

and to a lesser extent cats in very early life

are actually protected from developing immune diseases, like asthma for example,

in childhood.

They get tired before bed.

And we wanted to know, are microbes the link?

So we decided to look at cats and dogs...

Okay.

...and how that changes the microbiology

of a baby raised in that household.

Our collaborators

went into homes in which babies were present

and collected house dust samples

from over 1,000 homes in Detroit.

And some of those homes had dogs present.

Some had cats.

And some had no pets at all.

They sent us their dust samples.

We extracted DNA

to work out what types of microbial species were present.

The advances in technologies over the last ten or so years

now mean that we can take a few grams of house dust

and interrogate the whole profile of microbes

that are in that sample.

It's opened our eyes to the diversity of microbes that exist

in our environment.

Hi, Dick.

We next analyzed the data.

Yeah, looks pretty good actually.

And what we found was very exciting.

In homes with no pets,

there's less bacterial exposure.

And babies raised in those households

have a greater chance of developing asthma in childhood.

We ate veggies.

Conversely,

in homes in which dogs are present and to a lesser extent cats,

there's a much broader diversity of bacteria in those homes

that the baby is exposed to,

and those babies are actually protected from developing asthma.

Good girl, Aurora.

Aurora, you're being a really good sport.

Nelson, look at Cocoa.

Ah...

Oh, we love Cocoa.

Better be careful that he doesn't put his hands in Cocoa's eyes,

Cocoa would not be impressed.

Nelson...

Be gentle, okay?

Gentle. Gentle.

Nelson.

I think it's been about two or three weeks now

that he's noticed Cocoa.

One day, um, Cocoa came out

and Nelson's face just lit up.

Do you love Cocoa, Nelson?

He couldn't take his eyes off her.

He wants to kiss her!

Do you want to kiss Cocoa?

So we'd found out that pets were protective

and that microbes were associated with that protection.

The next step was to understand

which microbes played a role in preventing disease.

So this is a very difficult study to do

and we were fortunate that our collaborators again

at Henry Ford Hospital had a phenomenal resource.

They had collected stool samples from babies in very early life

and followed those babies right through childhood

and knew if those babies developed allergies and asthma years later.

So we examined the stool samples of 130 babies aged one month of age.

And then we examined the hundreds of different bacteria

found in all of those samples.

This process generated a very large data set.

We used computer algorithms

to identify patterns of microbial colonization in the gut in early life.

What we found was that babies are not all the same

in terms of their gut microbiome at one month of age.

In fact, there's three distinct gut microbiome compositions

that are evident in one-month-old babies.

Two of them, in green and blue,

were associated with a lower risk of developing allergies and asthma,

and the group in red is the group that were

at significantly higher risk of developing disease in childhood.

Yeah. It was by DMM that we had on the paper, yeah.

For the first time, we now can predict

which babies will go on to live a healthy life

or develop immune diseases like asthma

based on the microbes in their gut.

In the future,

this may represent a novel avenue for treatment

and offer the opportunity to intervene early in life

to prevent disease development in childhood.

What color is it?

Bless you.

Do you want to hold a rabbit?

Oh!

- Yeah. - I think he likes it.

little habbit, the little rabbit

He's a bunny!

You like it?

I think he loves me.

You think he loves you?

This relationship between microbes and humans

has been going on since humans first evolved.

Look, a little goat

Baah!

Baah!

- Tash, wash her hands? - Yep.

And over the last several generations,

particularly in Westernized nations

where our lifestyle has changed quite dramatically,

we've really altered our interactions with microbes.

Factors such as more hygienic living conditions

and microbial use really deplete microbes

that are necessary to promote health.

Abby!

Hey!

We eat the baby

Because the field is very new,

it's difficult to make recommendations at this stage

as to what may promote a healthy microbiome in a new baby.

Aah!

Are you trying to bite it off?

Aah! Aah!

Aah!

We don't even know what a healthy microbiome really is

at this stage.

While we know diet influences

the types and activities of microbes in the gut,

the specifics of those interactions have yet to be fully determined.

But what we do know is a sterile environment

is not beneficial to set a baby up for a healthy life.

And though it may seem counterintuitive,

environments that are rich in microbial exposure,

farming environments, homes with cats and dogs,

and even mice and cockroaches in the inner-city environments

are actually protective against development of disease in childhood.

Oh, you're reading! Are you reading?

He's excited about the menu.

Oh, well done.

That's so cool.

- Okay, a toast. Toast. - Lovely.

What is that?

You all right, fellow?

He's loving it.

He loves toast.

This is his first breakfast out with us, isn't it?

Yeah?

Food is a fundamental part of who we are as humans.

What we eat,

how we get our food, how we prepare our food,

how we share our food with other individuals...

this is a core part of human culture.

- What do you think of egg? - D'you like it?

That's gonna help you, make you a big and strong young man.

As babies start to transition to eating some of these foods...

they're joining this part of what it means to be a family.

Hugo.

Hey, babo.

I think we're on the cusp of an explosion of information about

how food is more than just calories.

- Feeds himself. Babo, good job. - Yay! You did it!

Food and especially these micronutrients

are really building your baby.

Well done!

Well done!

It's truly one of the most remarkable processes

in all of life.