0:00

This is the BBC. This

0:03

podcast is supported by advertising outside

0:05

the UK. Hey,

0:13

I'm Ryan Reynolds. Recently, I asked Mint

0:15

Mobile's legal team if big wireless companies

0:17

are allowed to raise prices due to

0:19

inflation. They said yes. And then when

0:21

I asked if raising prices technically violates

0:23

those onerous two-year contracts, they said, what

0:25

the f*** are you talking about, you

0:27

insane Hollywood a*****e? So to recap, we're

0:30

cutting the price of Mint Unlimited from $30 a month to

0:32

just $15 a month. Give it a try

0:34

at mintmobile.com/switch. Give it a try at

0:36

mintmobile.com/switch. $45 up front for three months

0:38

plus taxes and fees. Promote for new customers for limited time. Unlimited

0:40

more than 40 gigabytes per month. Mint Unlimited slows. A

1:00

great kitchen. And when we were sitting around

1:02

the table, we're all thinking we're in someone

1:04

else's house. Someone could be in all of

1:06

our homes as well. If you

1:08

have a home, but you're not always at home,

1:11

you have an Airbnb. Your

1:14

home might be worth more

1:16

than you think. Find out

1:18

how much at airbnb.com/host. Hello.

1:30

Welcome to Inside Science with me, Liz

1:32

Bonin. This week, what

1:34

species in the animal kingdom is

1:36

the most fearsome? And

1:39

we answer one of your questions about the

1:41

benefits or perils of

1:43

eating suspect food on your travels.

1:46

But first, we all know that sleep is

1:48

important and we regularly get

1:50

new information about how much we need, how

1:52

to make sure we get enough of it,

1:54

what happens to your body if we don't.

1:57

It can be a lot. Enough

1:59

to make you so anxious. to get to

2:01

sleep, you can't. No? Just

2:03

me then. But what exactly happens

2:05

to our bodies when we sleep? New

2:08

research from Imperial College London has

2:10

suggested that one of the leading

2:12

theories may actually be wrong. Science

2:14

journalist and neuroscience expert Ginny Smith is here

2:17

to explain all. Ginny, it's really good to

2:19

see you. How are you? I'm well, thanks.

2:21

Thank you for having me on. It's great

2:23

to have you on. So one

2:25

of the leading theories about the function of

2:27

sleep is all about brain clearance.

2:30

So exactly what is that? Yes. So

2:32

this is some fantastic work that's been

2:34

around for sort of 10 years. And one of the

2:36

leading researchers in this area is Mike

2:38

and Nedegard. And she had a paper out in 2013

2:40

that basically showed

2:43

that when mice were asleep,

2:46

the cerebrospinal fluid that bathes

2:48

our brain flowed faster around

2:50

the brain. And

2:52

she also showed that the cells of the

2:54

brain shrank to kind of create more space

2:58

for the brain to flow faster. So the idea

3:00

of this theory is that while we're sleeping, this

3:02

fluid can move around the brain, basically washing

3:06

away any byproducts that have built up during

3:09

the day as our brains have been really,

3:11

really active. They're using energy. They're creating toxins

3:13

basically. So her argument was

3:17

that sleep was vital because we need to wash

3:20

these toxins away. And it's during the night time

3:23

when we're asleep that is when that happens. Okay,

3:25

good. And there's a fascinating link with Alzheimer's, isn't

3:27

there? Yes. So one of these toxic

3:29

byproducts that can build up, a couple

3:32

of them are linked with Alzheimer's. So

3:34

there's the amyloid plaques and the beta

3:36

tangles. And we think that

3:38

these might be part of that

3:40

process. So these build up during the day, but if

3:42

they can be washed away, cleared

3:45

away, then they don't build up over time

3:47

and you're less likely to develop Alzheimer's. Now,

3:49

there is a huge amount we don't know

3:52

about Alzheimer's. It has been

3:54

linked to these molecules in

3:56

the brain, but there are also a huge

3:58

amount of questions still surrounding that. that

4:00

because in some cases people can have

4:02

these molecules in the brain and not

4:05

develop Alzheimer's and there've been lots of

4:07

drugs that have aimed to break them

4:09

down that haven't helped with the symptoms

4:11

of Alzheimer's so that's another huge question

4:13

that we still don't fully understand. But

4:16

the idea is we know

4:18

there's a link between sleep and Alzheimer's,

4:20

maybe this was the mediator, maybe this

4:22

clearing of the build-up of

4:25

proteins that can damage the brain

4:27

was why sleep is so important

4:29

for your brain and why sleep

4:31

seems to be protective against Alzheimer's.

4:33

Okay and then to add more

4:35

to this fascinating subject is this

4:37

new study that's just been published

4:39

what has that research found? Yes

4:41

so this was a group led

4:43

by Nicholas Franks and they've done

4:45

a slightly different methodology so rather

4:47

than injecting the molecule that they're

4:49

looking at into the cerebrospinal fluid

4:51

just outside the brain they've

4:53

put it actually into the brain and then measured

4:55

it in a different part of the brain and

4:58

they found sort of the opposite of

5:00

Nedergaard's study so they actually found that

5:02

when the mice were asleep the

5:05

molecule built up

5:07

more in the part of

5:10

the brain that they were looking at and

5:12

when they were awake they saw less of

5:14

the molecule so they're arguing that this molecule

5:16

they're looking at was cleared away by the

5:18

brain when the mice were awake at a

5:20

faster rate than when they were asleep and

5:22

they're saying that the flow that they found

5:24

was the same for both

5:26

cases so you've actually got the

5:29

same speed of flow of the fluid but

5:31

more is being cleared away when the animals

5:33

are awake so it's the exact opposite. The

5:35

exact opposite you're not clearing more toxins when

5:38

you're asleep in fact they're clearing them when

5:40

you're awake. Okay so one paper is just

5:43

the start of the scientific process isn't it you

5:45

need to get a consensus what's the reaction to

5:47

this study being by the wider science community and

5:49

I want to know what you think because you

5:51

know you've really studied this closely

5:53

for quite a while Yeah so it's

5:55

been quite interesting there's there's been a

5:58

little bit of response Matergaard

6:00

is going to write a proper paper

6:02

responding to it, but

6:04

I found a couple of articles where she

6:06

was quoted and her argument is that you

6:09

can't compare the two studies because the methods

6:11

are different. She also

6:13

worries that implanting the cannulas,

6:16

the things you need to get

6:19

the liquids into the brain, straight into

6:21

the brain of the mice might have

6:23

damaged the glymphatic system, that clearance system.

6:25

So she said there's a reason they

6:27

inject the tracer into the cerebrospinal fluid,

6:29

not straight into the brain. So

6:32

that's an interesting point. But

6:35

then Frank's take on her work

6:38

is that actually her findings could

6:40

be explained by less clearance. So

6:43

she saw that during sleep the molecule

6:45

got further into the brain and said

6:47

that that was because it was flowing

6:49

faster, but actually could it be that

6:51

it was flowing at the same speed

6:53

and not being cleared? So he argues

6:57

that her findings could support his

6:59

and she's arguing that his findings

7:02

aren't necessarily methodologically

7:05

appropriate and

7:07

so shouldn't be taken at face value. So

7:09

it would be really interesting to see how

7:11

it develops. I think we

7:14

shouldn't throw out a theory that has 10 years

7:17

of research behind it based on

7:19

one study. And

7:21

I also think the brain is so complicated that

7:23

there's a chance that both could be true. One

7:26

thing that from all my time

7:28

studying the brain is that it's never as simple

7:30

as it seems. Yeah, that's

7:33

definitely true. But if we take a step

7:35

back, right, and we think about why

7:37

sleep would have evolved in the first place, why

7:40

would we be completely wiped

7:43

out, completely unconscious, unaware of any potential

7:45

dangers? I mean, the benefits of sleep

7:47

would have to be huge for that

7:49

to be the case. So what are

7:51

the main contenders? What do we know

7:53

so far? Yeah, so setting

7:55

aside the brain clearance theory, which we're now

7:57

a little bit of a question mark over,

7:59

we know that sleep is absolutely vital for

8:02

learning and memory. So we've probably all experienced

8:04

this, that if you've had a bad night's

8:06

sleep and then you try and do some

8:08

work, you just can't concentrate. Your brain isn't

8:10

in the right state to take in new

8:12

information. But we also need to sleep after

8:14

we've learned new things because that's when our

8:16

brain consolidates the information, takes it from short-term

8:19

storage to long-term storage, fits it in with

8:21

other things we already know. That old

8:23

adage of if you've got a problem sleep on

8:25

it, your brain does actually work on things during

8:28

the night and you can often wake up and

8:30

have solved the problem in your sleep. So all

8:32

of that processing we know is really, really important

8:35

for sleep. Sleep is also vital

8:37

for emotional regulation. So again, I

8:39

don't know about you, I tend

8:41

to get a bit more teary,

8:43

kind of emotional if I've had

8:45

a been sleep deprived. Other people

8:47

get grumpy or snappy or both.

8:50

And that's because we have sort of

8:52

two emotional systems in our brain. There's

8:54

the deeper limbic system, which is a

8:57

bit more reactive. And then there's the

8:59

system that our prefrontal cortex just behind

9:01

our forehead is kind of in charge

9:03

of. And normally your prefrontal cortex can

9:05

kind of damp down your reactive limbic

9:07

system and you can keep check of

9:09

your emotions. But we know from brain

9:11

scanning studies that when people are sleep

9:13

deprived, those links between the two don't

9:16

work as well. So you get more

9:18

of that limbic system response with your

9:20

prefrontal cortex less able to control it.

9:22

And that's why we get grumpy, tearful,

9:24

irritable, whatever. Yeah, fascinating. We know enough

9:26

about what happens to us if we

9:28

don't sleep well for long periods of

9:30

time, right? How much it affects pretty

9:32

much all our organs in our body.

9:35

So can that help us to better understand

9:38

all the important roles of sleep?

9:40

Why it's so incredibly important? We

9:42

know all the outcomes. So we

9:44

know that if you have chronic

9:46

sleep deprivation, you're at higher risk

9:49

of diabetes, of cardiovascular disease, of

9:51

cancers, of the common cold, but

9:53

exactly why that is, is still

9:55

a little bit of a mystery.

9:57

So sleep deprivation is

10:00

a of stress and we know

10:02

that when you are stressed your

10:04

sort of fight-or-flight response is activated

10:06

and that causes all these changes

10:08

in your body that focus on

10:10

immediate survival over long-term health. But

10:12

if we are chronically stressed, money

10:15

worries or a stressful job or something

10:17

that's going on forever or life in

10:19

general, chronic sleep deprivation that's causing that

10:21

level of stress, then you might constantly

10:23

have a damp down immune system which

10:25

can then lead to all these

10:28

knock-on problems. Oh it's so fascinating Jenny, I could

10:30

speak to you for hours on this but for

10:32

now thank you so much for that. You're welcome.

10:34

Really really interesting. Now on the

10:37

periodic table there are 17 metals

10:39

known as rare earth elements all

10:41

originating from the earth's crust and

10:44

they're used in high-tech devices like

10:46

lasers and telescope lenses. They're

10:49

all pretty well understood except for

10:51

one, an extremely rare element called

10:53

promethium. Its chemical secrets have remained

10:55

a mystery for almost a century

10:57

but all that changed last week and

11:00

Andrea Seller, Professor of Chemistry at University

11:02

College London, is here to tell me

11:04

more. Andrea it's so good to see

11:07

you, how are you? It's

11:09

great to talk about these rare earth

11:11

elements which certainly I spent many years

11:13

obsessing about and one of the

11:15

things about them is that it really took

11:17

almost 150 years to untangle

11:20

and to sort of discover

11:22

what was an element and what wasn't which

11:24

were mixtures and in a way

11:27

this whole shaggy dog story is telling us

11:29

about the fact that these

11:32

elements are so incredibly chemically

11:34

similar and so separating

11:36

one from the rest is really

11:38

quite tricky. That's why it

11:40

was so hard to isolate them and

11:42

there was this one exception, promethium

11:45

and the reason is because

11:47

it's highly radioactive and so there are

11:49

very few labs where you

11:51

can actually go and do that kind of

11:53

work and typically people have said A, I

11:56

can't get hold of it, you can't buy

11:58

it in the shops or anything. But

12:00

secondly, it's just a pain to work

12:02

with. It's a pain to work with.

12:04

It's radioactive. It's probably very similar to

12:07

all the others. All that contributed to

12:09

us not studying it properly. Until now,

12:11

what's changed? What's allowed researchers to get

12:13

stuck into promethium now? Well, one

12:16

of the things is that there's

12:18

a growing interest in some of

12:20

these highly radioactive elements because, you

12:22

know, we are still talking about

12:24

nuclear energy, about reprocessing, that kind of thing. And

12:27

so the chemistry of these things and being able

12:29

to handle these highly

12:31

radioactive materials really matters. And

12:34

so here is a report in which

12:36

what they've done is they've gone and

12:38

they've isolated a beautiful compound of promethium.

12:41

It's not got tremendous chemical

12:44

surprises. But the beauty of this

12:46

paper is that, first of all, for

12:48

the first time, I've seen a photograph

12:50

of a promethium compound, right? It's got

12:52

a beautiful pink color. But

12:55

because it's so radioactive, they can't

12:57

use many of the classical tools,

13:00

things like X-ray crystallography. So

13:02

they've inferred the structure using

13:05

other X-ray techniques. And

13:07

so they know what the structure is. And

13:09

then what they did was they went and

13:11

made all the others around it and gone,

13:13

yeah, it fits exactly where you would expect.

13:16

And so it's a beautiful little piece of

13:18

science. It's a little bit like

13:20

the idea of having jigsaw puzzles where

13:22

you've always got one piece missing. And

13:24

I love the fact that here, finally,

13:26

we've got the piece in the jigsaw.

13:28

And what this is doing is saying,

13:30

okay, well, now we can really go

13:32

ahead and go and take a look

13:34

at the chemistry of promethium. Fabulous. And

13:36

so what does this mean for the

13:38

future of the science of promethium, the

13:40

chemistry of it? What's the potential here?

13:45

The sad thing is that I

13:47

think promethium's promise is relatively limited

13:49

just because it is so radioactive.

13:52

And so the chances of it

13:55

actually finding real world applications are

13:57

fairly limited. That said, I mean, these

13:59

are... artificial elements to give you

14:01

one example, amorecium, which was a synthetic

14:03

element. Well, we have it at home

14:06

in all of our smoke detectors. And

14:08

so it turns out that actually having

14:11

something quite radioactive can be quite useful.

14:14

And so one might imagine power

14:16

sources for spacecraft, but I have to

14:18

say, I kind of love

14:21

permethium. I love its pink color, but I'm

14:23

not holding my breath. Andrea, thank you so

14:25

much. Now, time to play

14:27

you sounds of some of the

14:30

planet's most fearsome predators. Which of

14:32

these make the hairs on the

14:34

back of your neck stand on end? What

14:41

had just happened? As if it was a kind of

14:43

mystery that needed to be solved. If

14:56

it wasn't the humans, guess what? You

14:58

are an outlier in the animal kingdom.

15:01

Wildlife biologist Dr. Liana Zanett studies the

15:04

ecology of fear in wild animals, and

15:06

she's joined me to tell us why.

15:08

Liana, thanks a million for joining me.

15:11

We've been playing back the sounds of

15:13

predators in wild environments all around the

15:15

world. Tell me, what

15:17

were you trying to find out?

15:19

Well, like you say, we've done

15:22

many experiments on different continents, on

15:24

Africa, Europe, North America. And

15:26

what we find on all

15:28

of these continents is that

15:30

fear of humans pervades everywhere.

15:33

The animals, wildlife are far

15:35

more afraid of humans than

15:38

the next most fearsome large carnivore

15:40

in each system. Like what's more

15:43

scary than a lion, but

15:45

still humans are more feared. Also,

15:48

interestingly, it's thought that

15:50

in Australia there's a

15:53

distinctive absence of fearsome

15:55

large carnivores. And because

15:57

of this, the animals

15:59

are thought. be distinctively

16:02

fearless. But what's interesting

16:04

is that there is a

16:07

large mammalian predator that's present

16:09

in Australia. And what our

16:11

marsupials tell us is that

16:13

they absolutely fully recognize

16:16

how dangerous this predator is,

16:18

and they respond appropriately and

16:20

entirely consistently with how all

16:22

of the other mammals and

16:24

all of those other continents

16:26

respond. And that is, as

16:28

you say, that's humans. It's

16:31

a sobering thought, isn't it, to

16:33

think that no matter where you've

16:35

carried out this research, even in

16:37

a place where we presumed animals

16:40

just wouldn't have any anti-predator

16:42

behaviors, humans are

16:45

the most fearsome predator. Is that true to

16:47

say we are the most fearsome predator for

16:49

wild animals on the planet? That's

16:52

right. You know, we don't

16:54

often think of ourselves as

16:56

a major predator, let alone

16:58

the most dangerous predator on

17:00

the planet. But wildlife clearly

17:02

think differently. And this is

17:04

why we are sometimes called

17:06

a super predator. A super

17:08

predator? Wow. Yeah, because we

17:10

are super lethal. It's so

17:12

thought-provoking, so important, clearly, and

17:14

actually quite humbling in a

17:16

way too. What I

17:18

find really interesting as well in your

17:21

research, Liana, is how

17:23

the fear of predators impacts the lives

17:25

of animals. I think we've underestimated that

17:27

as well, haven't we? That's

17:29

true, yes. And so

17:31

I think that one thing this

17:34

research points to is that just

17:36

being out there on the landscape,

17:38

we are causing all of these

17:40

really dramatic behavioral changes. So like

17:42

what? What's happening to wildlife populations?

17:44

How badly can the presence of

17:48

a super predator like ourselves be?

17:51

Well, there's a very strong cost of

17:53

fear. So on the one hand, these

17:55

fearful responses, like running away and such,

17:57

you know, enormously beneficial to keep you

18:00

alive. right? But on the

18:02

other hand it does carry costs

18:04

mostly because scared prey really don't

18:06

eat much, right? And so we've

18:09

shown in other manipulations that fear

18:11

itself can reduce wildlife

18:14

population numbers and

18:16

it can have cascading effects down the

18:18

food chain. Now that we're beginning to

18:20

realise just how much we can impact

18:22

the survival and the success of

18:25

wildlife, are there practical applications

18:27

for conservation based on your

18:29

research? Yeah sure, I mean

18:32

we're very interested in determining whether

18:34

or not we can actually use

18:36

the fear of humans as a

18:38

conservation tool. For example we're doing

18:40

a study in Florida right now

18:42

where we're using the fear of

18:45

humans as a virtual fence. So

18:47

coyotes for example, they like to go

18:50

on to shorebird nesting habitat and eat

18:52

the shorebird nest. Well what

18:54

we're doing currently is we broadcast

18:57

humans playing towards coyote habitat to

18:59

see whether or not we can

19:01

turn those intruding predators into retreating

19:04

predators when human sounds are on

19:06

thereby protecting shorebird nests. So it

19:09

could have all kinds of applications.

19:11

Fascinating stuff. I think your research

19:13

also presents a very strong case

19:16

for needing to establish a

19:18

different relationship with wildlife and perhaps working really

19:20

hard at stopping them from being so afraid

19:23

of us. But Leanna that was fascinating. Thank you so

19:25

much for joining me today. Oh it's my pleasure, thank

19:27

you. Hey I'm

19:32

Ryan Reynolds. At Mint Mobile we like to

19:34

do the opposite of what big wireless does.

19:36

They charge you a lot, we charge you

19:38

a little. So naturally when they announced they'd

19:41

be raising their prices due to inflation, we

19:43

decided to deflate our prices due to not

19:45

hating you. That's right, we're cutting the price

19:47

of Mint Unlimited from $30 a month to

19:49

just $15 a month. Give it a try

19:51

at Mint mobile.com/switch.

20:00

gigabytes per month slows. Full terms at mintmobile.com. Hey,

20:03

I'm Ryan Reynolds. At Mint Mobile, we like

20:05

to do the opposite of what Big Wireless

20:07

does. They charge you a lot, we charge

20:09

you a little. So naturally, when they announced

20:12

they'd be raising their prices due to inflation,

20:14

we decided to deflate our prices due to

20:16

not hating you. That's right, we're cutting the

20:18

price of Mint Unlimited from $30 a month

20:20

to just $15 a month. Give

20:24

it a try at mintmobile.com/switch.

20:27

$45 up front for three months plus taxes and fees. Promote it

20:29

for new customers for a limited time. Unlimited more than 40 gigabytes

20:31

per month, slows. Full terms at mintmobile.com. You're

20:36

listening to BBC Inside Science with me,

20:39

Liz Bonnan, now. The gut microbiome is

20:41

a huge area of research at the

20:43

moment. And the more we study it,

20:45

the more vital it seems to be

20:48

for all aspects of our health. It's

20:50

made up of a huge, diverse collection

20:52

of microbes, something in the order of

20:54

10 to 100 trillion

20:57

of them that together make up a

20:59

whole ecosystem of their own. You provide

21:01

them with a home. They return the

21:03

favor by playing a role in metabolic

21:06

processes, in bolstering immunity.

21:08

They provide a barrier against pathogens.

21:10

The list goes on and on.

21:13

And listener Mary Evans wrote in to

21:15

ask if eating all sorts of weird

21:18

and wonderful foods on your travels might

21:20

actually improve your gut health and help

21:22

you to ward off a dodgy tummy.

21:25

Thanks very much for your question, Mary.

21:27

And Dr. Megan Rossi, who is a

21:29

nutritionist and leading expert in gut health,

21:31

perfectly placed to answer this question, is

21:34

with me now. Megan, thanks for joining me. Good

21:37

to see you. It's a pleasure. So

21:39

let's tackle the first part of

21:41

Mary's question first. She says, do

21:43

you think it's likely that people

21:45

who are widely traveled and are

21:47

used to eating local food, including

21:49

street food or drinking tap water,

21:52

would have more diverse bacteria in their

21:54

gut? Look, the answer

21:56

is not necessarily, although I totally understand

21:58

the hypothesis around. that right so we

22:01

know that you know people eat more different types

22:03

of plants and more dietary fiber seem to have

22:05

a more diverse range of gut microbes similarly

22:07

people who drink things like well water and

22:09

live more rural you know on

22:12

farms and outside of cities again they

22:14

have a more diverse gut microbiome but

22:16

actually when we look at the evidence out there

22:19

that's been published people who travel

22:21

you know internationally actually it doesn't change

22:23

their gut microbiome in terms of diversity.

22:26

Why is that? I would have thought yes

22:29

Mary you're right you're increasing your gut

22:31

biome diversity that's not the case that's

22:33

not the case according to the studies

22:36

that have been published so far but

22:38

what they have found actually is that

22:40

some you know anti-inflammatory gut bacteria may

22:43

actually reduce when we're traveling abroad and

22:45

again that kind of surprised a lot of

22:47

people but if you think about your own

22:49

scenario like when you are traveling you know

22:52

maybe you drink a little bit more alcohol

22:54

maybe you know the time zone differences again

22:56

we know these can have a negative impact

22:58

on a gut microbiome as well

23:00

as if you're going to places with you

23:02

know poor hygiene standards you know you might

23:04

be more likely to pick up some microbes

23:06

with you know multi drug resistant genes which

23:09

seem to kind of unbalance our

23:11

gut microbiota so actually

23:13

there's quite a lot of different things you

23:16

know at play that could potentially counteract what

23:18

we thought might have a huge benefit on

23:20

a gut microbiome. Okay so I'm going somewhere

23:22

exotic but I'm partying quite a bit I'm

23:24

not really sleeping that well and I'm not

23:26

focusing on eating well I'm just picking up

23:28

like snack food street food it's

23:31

doing my gut more harm than good

23:33

but if I'm going away somewhere exotic

23:35

and making sure that I

23:37

get a lot of sleep that I eat all their lovely

23:39

you know local vegetables and fruit would

23:41

it be argued or could it

23:43

be argued that I'm increasing my

23:46

gut biome diversity with new novel

23:48

microbes in a healthy way would

23:50

that work? Absolutely so that's what my my theory

23:52

would be is that yes it could so although

23:54

there are other studies out there which is suggesting

23:56

you know it's not necessarily good for us you

23:58

know I think on an basis. If

24:00

you're thinking about you know having the street

24:03

food but also having the total amount of

24:05

fiber, I think yes you might be

24:07

trying you know some different street foods, getting some

24:09

different types of phyto chemicals from the plants from

24:11

these, but actually are you still having the same

24:13

volume of fiber that you would be at having

24:15

at home like you know you know the oats

24:17

and the nuts and the seeds and all that.

24:19

So the quantity I think we need to be

24:22

you know cautious of when we are abroad are

24:24

we getting enough fiber and I know myself when

24:26

I'm traveling it's quite tricky to

24:28

get in you know your 30 plus grams

24:30

of fiber a day. Yeah, nigh on impossible

24:32

especially me when I'm working you know 12

24:35

hour days. So it depends on the circumstance.

24:37

So Mary also asked, I

24:39

consider myself a traveler and I

24:41

eat almost anything, have never had

24:43

food poisoning and only rarely a

24:46

mildly upset stomach so I wonder if there

24:48

is any correlation. It's kind of what you're

24:50

talking about. Yeah Mary I love that question

24:52

and it's something I often get asked in

24:54

clinic and what actually the science has shown

24:57

is it's not necessarily the travel that's made

24:59

you more resilient to that. It's probably what

25:01

you're doing at home right. So

25:03

actually people who've got more of a

25:05

diverse range of gut microbes at baseline

25:07

pre-holiday when they go abroad there are

25:09

much lower risk of getting travelers diarrhea

25:11

and things like that. So

25:14

actually I think it's really important for listeners

25:16

you know who might be preparing for their

25:18

summer holiday to start thinking about okay well

25:20

how can I bolster my gut microbiota, how

25:22

can I add that diversity in to make

25:24

sure that when I go abroad I had

25:26

that much lower risk of you know getting

25:28

travelers diarrhea which can affect around 50% of

25:30

people in some countries. Oh that's a bit

25:32

scary and also so take a leaf out

25:34

of Mary's book she's clearly taking care of

25:36

her gut microbiome before she travels. Yeah absolutely

25:38

I think Mary's probably hit the nail on

25:40

the head of what she's doing but I

25:42

guess for those who don't know what Mary's

25:44

doing what I would say you know again

25:46

in clinical practice I would recommend pre-holiday

25:48

thinking about that plant diversity. So we've

25:50

seen some observational studies suggesting people eat

25:53

more than 30 different types

25:55

of plants a day have more diverse range of gut

25:57

microbes which sounds like a lot I know you got

25:59

it. It's simple things like don't just

26:01

get your pumpkin seeds get your three seed mix

26:04

You know don't just get one type of grain

26:06

get the you know eight types that come in

26:08

literally the one packet So it's not extra cost

26:10

or effort. It's these simple things. Yeah, but the

26:12

other thing I think when we're talking about diversity

26:14

is thinking about what I call the

26:16

super six Because a lot of people

26:18

I see they say look I'm having loads of

26:20

fruit and plant diversity But actually they're

26:23

forgetting about the fact that we've got the

26:25

whole grain group We've got the legume group

26:27

so things like chickpeas and butter beans herbs

26:29

and spices count to the nuts and the

26:31

seeds are all of that Actually is really

26:33

important when you're trying to get those 30

26:35

plus different plants in I'm feeling quite smug

26:37

I'm ticking things in my head going. I've

26:39

really up to my spices. I Love

26:42

chickpeas and butter beans not to say that

26:44

I don't cheat often too But anyway variety

26:46

is the spice of life as they say

26:48

really it's not just your plants,

26:51

too You know we know that things like if you

26:53

are eating animal products for mentor dairy like kathia Really

26:55

fish all of these things are really

26:58

important can the specific environment you're in

27:01

You know on your travels also affect your

27:03

gut biome. It's not just the food that

27:05

you're eating whilst abroad. Yeah, absolutely We know

27:07

that independent of diet our environment can have

27:09

a big role to play in terms of

27:11

that gut micro I am diversity in terms

27:13

of which is strongest We don't actually know

27:15

but probably another interesting thing is that even

27:17

if we kind of feel like we're eating

27:20

similar foods if we're in A different environment

27:22

actually the types of microbes were ingesting from

27:24

the foods Actually is different and

27:26

therefore that could have an impact so like an

27:28

apple for example contains a hundred million bacteria just

27:31

on a humble Apple right, but if you pick

27:33

the apple from a different country then that potentially

27:35

could change your gut microbiome So there's so

27:37

many interlink factors that makes it quite hard to

27:39

kind of peace out But we do know that

27:42

environment does have a role to play for sure

27:44

okay? And what else plays a role because I'm

27:46

thinking you know travel jet lag lack

27:48

of sleep Your clocks all over the place

27:51

can that affect my gut microbiome it absolutely

27:53

can you know studies out there and humans

27:55

have shown That after just two days of

27:57

sleep deprivation it can change gut microbiome, reducing

28:00

down some of those anti-inflammatory gut bacteria. And

28:02

again, that might be one of the factors

28:04

at play when we, you know, we spoke

28:06

about earlier about Alzheimer's, right? So we do

28:09

know people with Alzheimer's do have a slightly

28:11

different gut microbiome. But why are the microbes

28:13

affected by jet lag? Are they

28:15

jet lag too? I mean, is that a

28:17

weird thing to ask? They absolutely are. They

28:19

had their own circadian rhythm, just like the

28:21

human cells, gut microbiome and microbes do as

28:23

well. Bacteria have their own

28:26

circadian rhythm. I did not

28:28

know that. That's fabulous. I've always been told

28:30

to help yourself get over the jet lag,

28:32

eat in the new time zone. But is

28:34

that stressing your gut microbiome too much? No,

28:37

absolutely. That's what we recommend. Yes. So

28:39

actually eating to where you are going to be

28:41

locating, even if you start kind of thinking about

28:44

that a few days in advance, you know, does

28:46

start to make sense because we know that the

28:48

flight has a huge impact, not just on your

28:50

gut microbiome, but actually on your gut lining. So

28:52

the cells that line your gut, because, you know,

28:54

when you're up in the air, just like your

28:56

water bottle pops, you know, the air expands.

28:58

Oh, yes, I do get very gassy. I'm

29:01

giving away too much information here. This

29:03

is fascinating stuff. We're running out of time, but

29:05

just one final quick question. What can

29:07

we do if we do have a gut imbalance? You

29:09

know, we've eaten some strange stuff in a street stall.

29:11

We come home. Something's clearly

29:13

not right. We may have Traverse diarrhea as well.

29:16

What can we do? Look, if

29:18

you've got diarrhea for any more than a week, then

29:20

it is important that you go and see your GP

29:22

because what they can do is take a swab and

29:24

check your stool to make sure there's nothing lingering. And

29:26

also if you've got a fever or any blood in

29:28

your stool, then straight away go into your GP. That's

29:31

really important to check. Now, certainly when I see

29:33

people in clinic who, you know, did have a

29:36

bit of a funny tummy and it's starting to

29:38

resolve, what we think it's really important is starting

29:40

to re-fertilize your gut microbiome with that plant diversity.

29:42

So getting in those 30 if you can. Another

29:45

hot tip, if you've got a bit of a vulnerable tummy,

29:47

right, and you are going abroad,

29:50

there is some scientific evidence out there

29:52

that taking a specific probiotic called

29:54

LGG, so Lactobacillus rhammus GG, taking

29:56

that two days before you go and throughout

29:59

your travel. actually can reduce

30:01

your risk of getting troubleous diarrhea.

30:03

Ooh, interesting. Megan, that was

30:05

fascinating. Thank you so much. And to

30:07

all my guests, Ginny Smith, Andrea Sella,

30:09

and Liana Zenett. And if you have

30:12

a question that you'd like us to

30:14

tackle, email us at insidescience at bbc.co.uk,

30:17

and we'll do our best to help. Next

30:21

week, we'll be discussing the future of

30:23

our planet's ocean. Make sure you join

30:25

Marnie Chesterton for that. Goodbye. You've

30:29

been listening to BBC Inside Science

30:32

with me, Liz Bonnan. The producers

30:34

were Hannah Robbins, Ella Hubber, and

30:36

Sophie Ormiston. Technical production

30:39

was by Gail Gordon. The show

30:41

was a BBC Wales and West

30:43

production for Radio 4. BBC

30:47

Sounds, music, radio, podcasts.

30:54

Sooner or later, you'll need to upgrade

30:56

your tech, but you don't have to

30:58

pay full price. We're Back Market, a

31:00

leading online marketplace for refurbished smartphones, laptops,

31:02

tablets, and other tech, all up to

31:04

70% Each

31:07

device sold on BackMarket is tested and

31:09

restored to perfect working condition by industry

31:11

experts, and they all come with a

31:13

one-year warranty and 30 days to change

31:15

your mind. So never pay full price

31:17

for tech again. Visit the BackMarket

31:20

app or backmarket.com to

31:22

save up to 70% on your next device. Welcome

31:25

to the bright side, a new

31:27

kind of daily podcast from Hello

31:29

Sunshine, hosted by me, Danielle Robé.

31:31

And me, Simone Boyce. Every

31:34

weekday, we're bringing you conversations about

31:36

culture, the latest trends, inspiration, and

31:38

so much more. We'll hear from

31:40

celebrities, authors, experts, and listeners like

31:42

you. Bring a little optimism into

31:45

your life with The Bright Side.

31:47

Listen to The Bright Side from

31:49

Hello Sunshine on the iHeartRadio app

31:51

or wherever you get your podcasts.