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The Microbial Majority · Luke's English Podcast

0:07
Speaker 1: Hi, Simon. So another Science of the Times podcast. I
0:11
Speaker 1: think we're sort of managing about once a fortnight at
0:13
Speaker 1: the moment, but hopefully people are still tuning in.
0:17
Speaker 2: Yeah, I'm sure they are. The numbers suggest they are,
0:19
Speaker 2: so that's great. And today's one is very close to
0:23
Speaker 2: my heart. So it's all about bugs, bacteria.
0:27
Speaker 1: I know. But a different kind of take on bacteria
0:32
Speaker 1: in a way to you, right? You're kind of more
0:34
Speaker 1: interested in membranes and whatever, but this is about whole
0:37
Speaker 1: ecosystems of bacteria.
0:39
Speaker 2: Yeah, it's kind of a hybrid of you and me
0:42
Speaker 2: in a way, right?
0:43
Speaker 1: No, I suppose that's right. And actually, I'm really excited
0:47
Speaker 1: to get these two on because they're two early career researchers.
0:51
Speaker 1: You know, they're both postdocs, they've both recently finished their PhDs,
0:55
Speaker 1: and they're both super enthusiastic about... the microbiome do you
1:00
Speaker 1: want to explain what that is a little bit i
1:01
Speaker 1: mean now go into more detail.
1:02
Speaker 2: Obviously yeah sure so um microbiome is basically the um
1:09
Speaker 2: the population of bacteria in any given sort of so
1:13
Speaker 2: it could be on our skin the gut microbiome is
1:16
Speaker 2: the bacteria that live in our gut for example and
1:18
Speaker 2: it's not the exciting thing is that it's not just
1:21
Speaker 2: one species it's a whole sort of world of bacteria
1:25
Speaker 2: and how they live and interact with each other as
1:28
Speaker 2: large communities.
1:30
Speaker 1: And it turns out they're quite important.
1:32
Speaker 2: Enormously important. Yes, absolutely. And it turns out our relationship
1:37
Speaker 2: with them is possibly, well, is for sure more complex
1:40
Speaker 2: than we initially thought.
1:42
Speaker 1: So I remember hearing a story years ago when I
1:45
Speaker 1: kind of came up with the microbiome was sort of
1:47
Speaker 1: becoming popular in biology. And someone had done this study.
1:50
Speaker 1: They was born, and it got passed around between lots
1:57
Speaker 1: of relatives, whether those relatives, you know, started to get
2:00
Speaker 1: a more similar microbiome. And they did this big analyses
2:04
Speaker 1: where they kind of, you know, worked out how many
2:07
Speaker 1: people lived in each house, how many people they saw,
2:10
Speaker 1: whether they had any dogs as pets, all of this
2:13
Speaker 1: sort of stuff in the analyses. And they came to
2:16
Speaker 1: the conclusion from this study that no, actually having a
2:19
Speaker 1: baby didn't have any impact on the microbiome. But what
2:22
Speaker 1: they did find is any family that got a dog
2:26
Speaker 1: within six weeks, everyone had the dog's microbiome.
2:32
Speaker 2: That's amazing.
2:35
Speaker 1: Anyway, should we get them on?
2:36
Speaker 2: Yeah, absolutely.
2:37
Speaker 1: Yeah. Okay. So we have two guests today who are
2:42
Speaker 1: both from Finland, no less, but not in Finland at
2:46
Speaker 1: the moment. Evelina, would you like to start by introducing
2:49
Speaker 1: yourself a little and saying where you are at the moment?
2:52
Speaker 3: Yes, thank you for having me here. So I'm Evelina
2:56
Speaker 3: and I'm currently in Zurich. I've moved here just a
3:00
Speaker 3: couple of months ago after many years in Oxford and
3:02
Speaker 3: started an early career fellowship here.
3:06
Speaker 1: Well, congratulations. I hope you're enjoying it. And Aura, how
3:10
Speaker 1: about you?
3:11
Speaker 4: Well, hello and thanks for having me too. I am
3:15
Speaker 4: Aura and... I'm a fellow at Oxford and also a
3:20
Speaker 4: longtime collaborator of Evelina's and we study the same things.
3:25
Speaker 1: And you two both love something called the microbiome, don't you?
3:31
Speaker 2: Absolutely.
3:32
Speaker 1: I wonder, I don't mind which one of you, who
3:34
Speaker 1: wants to start off by telling our listeners what the
3:38
Speaker 1: microbiome is and why we should, why don't one of
3:41
Speaker 1: you tell us what it is and then the other
3:43
Speaker 1: one can tell us why we should be interested in it.
3:46
Speaker 3: Okay, well, I can go ahead. So the microbiome, specifically
3:52
Speaker 3: the gut microbiome, what we work on, that is a
3:55
Speaker 3: collection of microbes that live in the gut. And it
3:59
Speaker 3: consists of bacteria, viruses, and more. And I'll hand over
4:03
Speaker 3: to Aura to explain why we should study the microbiome
4:06
Speaker 3: to begin with. Yeah, so microbiome is really cool.
4:09
Speaker 4: I've completely fallen in love with this study topic, because
4:12
Speaker 4: it's not just the kind of part of our body
4:15
Speaker 4: like an organ but it's also an ecosystem it's like
4:18
Speaker 4: an ecosystem inside of you and actually is one of
4:21
Speaker 4: the most diverse ecosystems on earth uh only more diverse
4:26
Speaker 4: ecosystems are soil microbiomes but still uh it's very very
4:31
Speaker 4: strange organ because it's kind of like very influential for
4:36
Speaker 4: our body it influences our immunity and our brain and
4:39
Speaker 4: our behavior and the foods we can eat our digestion
4:43
Speaker 4: really plays a big part as part of our body
4:45
Speaker 4: but unlike other organs in our body it can spread
4:49
Speaker 4: between us it doesn't kind of stay in one individual
4:51
Speaker 4: but in a social contact when we hug and kiss
4:54
Speaker 4: and talk to each other we we exchange microbes and
4:57
Speaker 4: that makes it kind of a leaky part of ourselves
5:00
Speaker 4: and i think that's very fascinating and we should be
5:03
Speaker 4: very much studying it Because of that, and also because
5:07
Speaker 4: of this reason, it is not just a biomedically valuable
5:12
Speaker 4: thing to study because it links to a lot of
5:14
Speaker 4: our health and disease, but it is also a way
5:18
Speaker 4: of bringing ecological perspective into medicine and biomedical sciences.
5:23
Speaker 1: Very cool. Saima, how's your microbiome? Is it pickled? Yeah.
5:29
Speaker 2: Possibly less pickle than yours, Tim. So just for our
5:38
Speaker 2: listeners and viewers, so not only do we have this,
5:42
Speaker 2: as you said, this ecosystem that lives within us, but
5:45
Speaker 2: we actually can't survive without it, right?
5:47
Speaker 4: Yeah, it's really like a very crucial part of us
5:51
Speaker 4: and they can't survive much without us either. So we
5:54
Speaker 4: are really like tied together to the extent that I
5:56
Speaker 4: would even consider that cells of our body, almost like
5:59
Speaker 4: our own cells.
6:01
Speaker 1: And Evelina, is it just like chance that you're both
6:05
Speaker 1: Finnish or did you grow up, do you have very
6:07
Speaker 1: strange microbiomes in Finland because all you eat is fish
6:11
Speaker 1: and no vegetables?
6:13
Speaker 3: Well, that's actually not quite true. We do eat a
6:16
Speaker 3: lot of root vegetables. But yeah, maybe we have a
6:19
Speaker 3: very root vegetable heavy microbiome. No, it's, yeah, it's just
6:23
Speaker 3: by chance.
6:24
Speaker 4: It's sad, sad, sad. Yeah, but actually something that Evelina's
6:31
Speaker 4: research really much kind of circulates around is that Finnish
6:34
Speaker 4: microbiomes are kind of interesting for science because here in
6:39
Speaker 4: Finland is suffering from a lot of allergy and autoimmune disease.
6:42
Speaker 4: And there's been research on Finnish microbiomes and how to
6:46
Speaker 4: make them richer, how to enhance the microbiome health of children,
6:49
Speaker 4: especially because that would make them less allergic. And there's
6:54
Speaker 4: been really cool research showing that it's contact with nature,
6:57
Speaker 4: with ecosystems around you and contact with other people that
7:01
Speaker 4: really influences your health through these microbes.
7:06
Speaker 2: So what I guess I don't have a real feeling
7:09
Speaker 2: for is... How diverse are the microbiomes between individuals and
7:15
Speaker 2: how far away do you have to go before you
7:17
Speaker 2: see a difference? So for example, would my microbiome be
7:21
Speaker 2: the same as someone who I share a house with,
7:25
Speaker 2: or would it be completely different?
7:27
Speaker 4: Well, I mean, it's a mixture.
7:29
Speaker 3: Actually, our microbiomes are very individualized. So if we look
7:34
Speaker 3: at your microbiome over time, it will sort of have
7:38
Speaker 3: a signature of But actually, even within individual microbiomes will
7:43
Speaker 3: be changing all the time. And this is most drastic
7:46
Speaker 3: in early life when the microbiome develops in the first place.
7:49
Speaker 3: But even during adulthood, even when nothing really changes, many
7:54
Speaker 3: things still seem to change in the microbiome. So, yeah,
7:58
Speaker 3: no two microbiomes will ever be the same.
8:00
Speaker 4: Yeah, and it's true that with whom you live, you
8:03
Speaker 4: do have more similar microbiome.
8:05
Speaker 2: Yeah, for sure.
8:06
Speaker 4: It's more than your genes or your diet or your background.
8:10
Speaker 4: Even more than your lifestyle, it really influences your microbiome
8:13
Speaker 4: with whom you are in contact with.
8:16
Speaker 1: But how do you study it? I mean, do you
8:17
Speaker 1: cut open stomachs to like hoik it out? Or do
8:20
Speaker 1: you go down the throat? Or do you collect feces?
8:24
Speaker 1: I mean, what's because, you know, it's kind of inside us.
8:27
Speaker 1: It's a kind of key part of it. You don't
8:28
Speaker 1: want to disturb it too much either, do you?
8:31
Speaker 4: Well, me and Evelina both have this cutest ever study systems.
8:35
Speaker 4: We've been studying wild mice and their microbiome where we
8:40
Speaker 4: can kind of profile the bacterial communities living in their
8:44
Speaker 4: gut by just sequencing DNA from their poo. So we
8:46
Speaker 4: don't have to cut open the mice. We can just
8:49
Speaker 4: collect poo and then we can measure other things about
8:52
Speaker 4: the mice. We even track their behavior and the social
8:55
Speaker 4: interactions or Evelina follows baby mice from when they first
8:59
Speaker 4: emerge from their holes and and then see how their
9:03
Speaker 4: microbiome changes with them growing up.
9:08
Speaker 3: But the microbiome that we do get in the poo samples,
9:11
Speaker 3: we do know that it's not exactly one-to-one representation of
9:15
Speaker 3: what we have in the gut. And maybe we should
9:17
Speaker 3: be talking of fecal microbiome studies. But yeah, the fecal-based
9:25
Speaker 3: studies are the most common one in the field of microbiome.
9:28
Speaker 3: And this is because, of course, this sample type is common.
9:31
Speaker 3: completely non-invasive really. And yeah, anything beyond that gets, gets
9:37
Speaker 3: complicated very quickly.
9:40
Speaker 2: And so you kind of build up this picture of
9:43
Speaker 2: individuals having these bacteria basically living in, inside our guts,
9:50
Speaker 2: inside us, different species, different types. And I guess from
9:55
Speaker 2: what you're saying, there's a great deal of heterogeneity in them. I,
10:00
Speaker 2: also study bacteria from a very different scale. And I'd
10:05
Speaker 2: always thought they were pretty aggressive and were always in
10:08
Speaker 2: constant battle with each other. So in the microbiome, have
10:11
Speaker 2: they found a kind of a peace and a way
10:13
Speaker 2: to live in sort of, you know, under some kind
10:15
Speaker 2: of truce? Or are they still fighting?
10:21
Speaker 4: I think they're not at all in peace. They're fighting
10:24
Speaker 4: a lot. Don't you agree, Evaluna?
10:26
Speaker 5: Yeah, absolutely.
10:26
Speaker 4: It's a highly competitive system. But that's actually good for us.
10:30
Speaker 4: Because what matters for us is that our microbiome is
10:33
Speaker 4: kind of diverse and stable. And actually, these kind of
10:37
Speaker 4: competitive ecosystems tend to be more stable than ones where
10:41
Speaker 4: everybody cooperates. Because then they can kind of... take over
10:46
Speaker 4: each other's roles and do things for it that the other,
10:49
Speaker 4: if someone goes extinct, someone else will take over their
10:51
Speaker 4: ecological niche immediately. And they do battle, they do compete.
10:55
Speaker 4: But the thing that they are most influenced by is
10:59
Speaker 4: like control mechanisms influenced that are like imposed by the
11:03
Speaker 4: host organism, like our own immune system, for example, picks
11:07
Speaker 4: and chooses and selects a little bit who gets to
11:09
Speaker 4: thrive there. So there's a strong police force kind of
11:14
Speaker 4: controlling this system.
11:17
Speaker 1: And in your mice, how important is the microbiome? So
11:21
Speaker 1: you said it might affect behavior. Does it kind of
11:24
Speaker 1: affect how kind of bold or shy you are? Does
11:28
Speaker 1: it affect who you hang out with, how social you are,
11:32
Speaker 1: if mice are in fact social? Does it influence how
11:34
Speaker 1: long you live for? I mean, what.
11:38
Speaker 1: What can you tell from these wild mice that you're
11:41
Speaker 1: looking at, both of you?
11:44
Speaker 4: I think this is more like your research because Evelyn
11:48
Speaker 4: is really studying the consequences of microbiome barrier.
11:53
Speaker 3: Yeah, I just wanted to hand over to you regarding
11:55
Speaker 3: the sort of behavior part. I suppose when it comes
11:58
Speaker 3: to behavior, there's a lot of sort of sexy research
12:02
Speaker 3: out there looking at links between microbiome and behavior, but
12:06
Speaker 3: not always can we... kind of distinguish who's actually influencing who.
12:12
Speaker 3: But yeah, I mean, the microbiome is certainly important to
12:16
Speaker 3: really all aspects of our existence.
12:19
Speaker 1: Give us an example then. Let's have some concrete. Because
12:22
Speaker 1: people like to say that, yeah, yeah, it's really important.
12:24
Speaker 4: Yeah, yeah, exactly.
12:26
Speaker 3: So I mean, the easiest examples come from these lab
12:29
Speaker 3: mouse studies where we have mice without any kind of microbes,
12:32
Speaker 3: where we can really show coarsely that the microbiome is important.
12:37
Speaker 3: So for example, mice born without microbes, they will have
12:41
Speaker 3: a hyperreactive stress response system. So the way they respond
12:48
Speaker 3: to various different stresses will be sort of hyperactive. And interestingly,
12:52
Speaker 3: if we colonize these mice in early life in a
12:56
Speaker 3: very specific time window, then we can sort of fine-tuned
12:59
Speaker 3: the stress response system so that it's.
13:01
Speaker 2: Not so hyperactive.
13:03
Speaker 3: So this clearly shows that the microbiome is involved in
13:07
Speaker 3: how something like our stress response system works.
13:10
Speaker 4: Yes, and then by extension also our behavior and personality.
13:13
Speaker 4: There's these very fresh studies coming out just now showing
13:16
Speaker 4: that if you take one of these empty germ-free mice
13:19
Speaker 4: that don't have a microbiome and then you give them
13:21
Speaker 4: a microbiome of a very active mouse or very passive mouse,
13:27
Speaker 4: then their personality also changes accordingly. They will become more
13:30
Speaker 4: active personalities. So it's quite sci-fi, in my opinion, that
13:35
Speaker 4: you can change someone's personality by just giving them a
13:38
Speaker 4: gut transplant.
13:40
Speaker 2: Yeah, so just thinking about that. So this is something
13:44
Speaker 2: that goes beyond our genetics. It's something that we can
13:47
Speaker 2: control then with our environment. So can you, I don't know,
13:50
Speaker 2: sort of all these gut, sort of microbiota foods foods
13:55
Speaker 2: that we have now and encouraged to have to encourage
13:58
Speaker 2: the sort of our healthy gut can having these would
14:01
Speaker 2: these change or have any impact on your personality.
14:06
Speaker 5: Yeah I mean maybe theoretically yeah yeah I mean we
14:09
Speaker 5: know that people also like um have that there's been
14:14
Speaker 5: this long-standing um notions in biology that certain diets make
14:20
Speaker 5: you happier or more like less happy, for example.
14:23
Speaker 1: They may be involved, yes, Simon.
14:27
Speaker 4: Also, there's this longstanding notion that loneliness is related to
14:35
Speaker 4: shorter lifespan. So people who have less social contacts live
14:38
Speaker 4: shorter lives. And then this has been studied by psychologists
14:41
Speaker 4: a lot because we think it's a psychological thing. But
14:43
Speaker 4: there's also a lot to be said about whether some
14:46
Speaker 4: part of it is just a biological thing, because we
14:49
Speaker 4: know that social isolation depletes your microbiome heavily, and then
14:52
Speaker 4: that can also expose you to disease. And then if
14:56
Speaker 4: you're very socially connected, you gain a diverse microbiome. In humans,
15:00
Speaker 4: it's been shown, for example, that the number of social
15:03
Speaker 4: contacts you have is related to your microbiome diversity.
15:08
Speaker 1: So if I was to shift my diet, for example,
15:11
Speaker 1: and start eating lots of salad... Is it possible I've
15:14
Speaker 1: become a real introvert?
15:18
Speaker 4: I suppose so.
15:19
Speaker 3: I think changing salad will just increase the quantity of
15:23
Speaker 3: water in your body, really.
15:24
Speaker 2: Nothing to do with microbiome. It'll dilute you, Tim.
15:29
Speaker 1: Okay, but a bit more seriously, I mean, there have
15:32
Speaker 1: been cases, I think, and I know that you might
15:34
Speaker 1: not be experts on this bit, but perhaps you can
15:37
Speaker 1: comment where people, there's been microbiome transplant plants in in
15:42
Speaker 1: humans actually through fecal transplants and that's actually changed character
15:47
Speaker 1: people's personality but also like factors about their their level
15:51
Speaker 1: of obesity and what.
15:52
Speaker 4: Have you yes yes and importantly also the micro like
15:56
Speaker 4: if you get the microbes you have also influenced what
15:59
Speaker 4: foods you have cravings for so it kind of Like
16:02
Speaker 4: if you, for example, I don't know if you have
16:04
Speaker 4: any friends who have gotten like very much into sourdough baking.
16:08
Speaker 1: I did in the pandemic.
16:11
Speaker 4: There is a little bit of a kind of an
16:12
Speaker 4: addiction forming there because the more sour foods you eat,
16:16
Speaker 4: the more you kind of support these bacteria that thrive
16:20
Speaker 4: in sour conditions. And they also influence your brain and
16:24
Speaker 4: make you crave for more sour foods.
16:26
Speaker 1: Oh, wow. OK, I'm going to cut out that grapefruit juice.
16:34
Speaker 1: And so, yeah, so how, I mean, how accurate can
16:39
Speaker 1: you get? Are the particular species of bacteria that we
16:44
Speaker 1: know play a major role in a microbiome? Because as
16:49
Speaker 1: you said, it's incredibly complicated. There are sort of, you know,
16:52
Speaker 1: tens of thousands, if not more, different species. You know,
16:55
Speaker 1: there's vast numbers of bacteria in our gut. Are we
17:00
Speaker 1: at a point where we can sort of say, okay,
17:03
Speaker 1: these species are good ones. And coming up with some
17:08
Speaker 1: medicine or some inoculants that allow people to develop or
17:12
Speaker 1: to feed or to seed particular species of microbiome in
17:16
Speaker 1: the gut, or these are the ones that tend to
17:19
Speaker 1: be correlated with shorter lives or something, or a craving
17:25
Speaker 1: to eat food that's unhealthy. Are we getting to that
17:27
Speaker 1: point yet?
17:29
Speaker 3: Well, I think the issue is that it seems which
17:33
Speaker 3: microbes are important to you might be quite different from
17:36
Speaker 3: the ones that might be important to me or useful
17:38
Speaker 3: for me. So it's so context dependent and it really
17:41
Speaker 3: does depend on the rest of the community. So just
17:44
Speaker 3: by taking extra, I don't know, lactobacillus doesn't necessarily lead
17:49
Speaker 3: to anything because it really depends on what you already
17:52
Speaker 3: have in your gut microbiome and how you know, with
17:57
Speaker 3: your body sort of intact with the microbiome. So I
18:01
Speaker 3: think this is a big part of the issue in
18:04
Speaker 3: terms of identifying specific microbes. There's certainly some microbial species
18:10
Speaker 3: that kind of pop up in loads of studies as
18:13
Speaker 3: the more sort of beneficial ones, but there's also a
18:17
Speaker 3: good amount of variation and not in all studies do
18:20
Speaker 3: they seem to be so important. And I really do
18:22
Speaker 3: think this is, you know, largely because It's not just
18:26
Speaker 3: one bacterium we're dealing with, we're dealing with the whole community.
18:29
Speaker 3: And so it's a complex system. And just by changing
18:35
Speaker 3: one thing, we can't actually change the whole thing, if
18:37
Speaker 3: that makes sense.
18:38
Speaker 4: Yeah, you notice when you go backpacking in India, if
18:41
Speaker 4: it's any one of us here living in Europe, you'll
18:44
Speaker 4: probably get sick quite quickly. And it's not because you're
18:46
Speaker 4: infected necessarily by pathogenic bacteria. It's just because you're not
18:50
Speaker 4: used to the local symbionts. Like they might be very
18:53
Speaker 4: healthy bacteria for the local people there, but it's just
18:55
Speaker 4: your system can't deal with them because your immune system
18:57
Speaker 4: didn't develop with this bacteria. And there's also, that is
19:02
Speaker 4: why we are interested in this kind of what we
19:04
Speaker 4: call emergent community properties of the microbiome. That means not
19:09
Speaker 4: just who is there, but rather things like diversity, stability,
19:13
Speaker 4: the similarity of microbiome between individuals because those things are
19:18
Speaker 4: linked to health and those we can control even without
19:21
Speaker 4: knowing who exactly which exact bacterial species you have so i.
19:26
Speaker 2: Wonder if you know thinking of what you're saying like
19:29
Speaker 2: at the moment you know we sort of genomically profile
19:33
Speaker 2: people we try and get an understanding of our our
19:37
Speaker 2: hereditary characteristics i'm wondering in the future if this could
19:41
Speaker 2: also be a profiling of people is done through a
19:44
Speaker 2: microbiome it's another way It's not hereditary or anything, but
19:48
Speaker 2: it's characterized someone's microbiome can tell you additional things about
19:54
Speaker 2: their personality or or or indeed their health do you
19:58
Speaker 2: think that's a possibility.
20:00
Speaker 4: Yeah i think that already you think yeah that's like
20:03
Speaker 4: a risk assessment like you can predict someone's risk for
20:07
Speaker 4: colorectal cancer or something from a microbiome?
20:11
Speaker 3: Yeah, they're already being used, as Otto was saying. And
20:17
Speaker 3: I mean, currently, I think it's predominantly in the commercial
20:21
Speaker 3: side of things, but more increasingly also in the healthcare
20:25
Speaker 3: systems as well.
20:28
Speaker 1: So I can... I used to just blame my genes
20:31
Speaker 1: if I did anything wrong. Now I can blame my
20:34
Speaker 1: genes and my microbiome.
20:36
Speaker 2: And your friends from whom you'll be getting the microbes.
20:38
Speaker 1: So Syma actually is responsible for all my bad behavior
20:42
Speaker 1: because I got some of her microbiome by sharing a
20:46
Speaker 1: pint with her in a pub once.
20:49
Speaker 2: I think you managed to put yourself in China recently,
20:52
Speaker 2: no Tim?
20:53
Speaker 1: Yeah, actually it's really interesting. So I was in China
20:55
Speaker 1: and I was eating a very different diet to the
20:58
Speaker 1: diet I I ate here. And I kind of did
21:01
Speaker 1: get an upset stomach, but it didn't, I wasn't really ill,
21:05
Speaker 1: if you know what I mean. It was like, it
21:07
Speaker 1: was probably just the chicken foot and snail soup, which
21:12
Speaker 1: was delicious, which I had, which I think probably tipped
21:15
Speaker 1: me over the edge there. But I want to come
21:17
Speaker 1: back to the mice, right? So you can, you know,
21:21
Speaker 1: you can wander around woods, you can collect mouse poo.
21:25
Speaker 1: I know you put out traps, actually quite clever traps
21:28
Speaker 1: to catch mice and collect the fecal samples from them
21:32
Speaker 1: and then you you you you kind of genotype those
21:36
Speaker 1: to look for though you look for the bacteria the
21:37
Speaker 1: genomes that you've got in that that fecal stuff but
21:41
Speaker 1: surely all mice are like the same how you know
21:43
Speaker 1: you're you telling me there's like outgoing mice and the
21:45
Speaker 1: shy mice and there's like social mice and asocial.
21:49
Speaker 4: Mice Oh, yeah.
21:51
Speaker 2: They come in all kinds of varieties.
21:54
Speaker 4: They have very different personalities. And actually, what's interesting about
21:57
Speaker 4: these mice I study here in Oxford, they're wood mice,
22:01
Speaker 4: the brown ones living in the woods, is that they
22:04
Speaker 4: have such strong social preference patterns that they actually sometimes
22:07
Speaker 4: actively avoid their neighbors and then actively hang out with
22:11
Speaker 4: someone else who lives otherwise a bit further away. And
22:14
Speaker 4: that's pretty important for us because that allows us to
22:17
Speaker 4: build social networks for mice which are not completely just
22:21
Speaker 4: who is where in space. It's not just like you're
22:25
Speaker 4: connected to your neighbor because you live nearby, but it's
22:28
Speaker 4: like you have friends who live further away from you,
22:32
Speaker 4: but you still sometimes meet them. And that's important because
22:35
Speaker 4: that allows us to see which bacteria actually transmit through
22:38
Speaker 4: direct social contact and which through by just sharing space
22:42
Speaker 4: and hanging out in the same places.
22:43
Speaker 1: So some mice are more social than others.
22:46
Speaker 4: Yes, and some mice also... some are loners and some
22:50
Speaker 4: are social, but even the social ones, some of them
22:52
Speaker 4: are these kind of in the middle of a social
22:55
Speaker 4: cluster mice who all of their friends are friends with
22:57
Speaker 4: each other. You know what I mean? Those kind of.
22:59
Speaker 2: Mouse clique. Mouse clique, you know?
23:03
Speaker 4: And then some mice have friends who are very not
23:07
Speaker 4: friends with each other, like from very different social circles.
23:10
Speaker 4: And that's actually important for the microbiome too, because if
23:13
Speaker 4: you're connected to others who all are... part of the
23:17
Speaker 4: same clique you get the same bacteria from all of
23:19
Speaker 4: them but if you're connected to others from very different
23:22
Speaker 4: parts of the social neighborhood then you get different bacteria
23:25
Speaker 4: from all of.
23:26
Speaker 1: Them but evelina how do you know where a mouse
23:28
Speaker 1: is in the.
23:28
Speaker 2: Woods um in in our system oh.
23:33
Speaker 1: Okay in our system but you spent some time working
23:35
Speaker 1: on that system as well right.
23:37
Speaker 3: Yeah absolutely yeah so i mean in in the woods
23:40
Speaker 3: there are these loggers that um basically take a note
23:45
Speaker 3: of every single mouse that goes past so we.
23:47
Speaker 1: How does it know what mouse.
23:48
Speaker 3: Is yeah yeah so we so all the data that
23:51
Speaker 3: we collect is longitudinal so we capture the mice and
23:54
Speaker 3: eventually we release them but before we release them we
23:57
Speaker 3: put a little uh chip under under the skin just
24:00
Speaker 3: the same you would put on a pet dog or
24:03
Speaker 3: a cat and this chip will then be read by
24:06
Speaker 3: this logger And we have loads of these logos distributed
24:11
Speaker 3: in the woods and you can match this with the
24:13
Speaker 3: time and yeah, with the individual, of course. And then
24:17
Speaker 3: through this, you will know who was where and when.
24:21
Speaker 1: Amazing. Saima.
24:25
Speaker 2: Yeah, I'm just still trying to get my head around
24:27
Speaker 2: these little, inside all of us, these little communities of
24:31
Speaker 2: creatures that are living and sort of carrying out these different,
24:36
Speaker 2: you know, I, This doesn't sound like a really dumb question,
24:39
Speaker 2: but sort of how do we map the space they occupy,
24:45
Speaker 2: the expanse? And I think I was reading somewhere that
24:49
Speaker 2: the microbiome, we have one big advantage they have is
24:52
Speaker 2: they occupy niches, right? Which prevents sort of parasites and
24:57
Speaker 2: things getting in.
24:59
Speaker 3: Yeah.
24:59
Speaker 4: Is that right?
25:00
Speaker 2: What I was wondering is how do we map that?
25:02
Speaker 2: How do we understand to what extent they're sort of,
25:05
Speaker 2: what's their terrain? That makes sense.
25:08
Speaker 4: You mean like within a microbiome?
25:10
Speaker 2: Yeah. Within an organism.
25:14
Speaker 1: Yeah.
25:14
Speaker 4: Well, that's a thousand dollar question because the ecological interactions
25:18
Speaker 4: between bacteria are practically impossible to observe. So there's been
25:23
Speaker 4: a lot of clever nerds trying to develop ways of
25:26
Speaker 4: analyzing who is competing with whom, who is in a
25:29
Speaker 4: more like helpful symbiotic relationship with whom. from basically just
25:34
Speaker 4: data on their co-variation. But then they also do these
25:39
Speaker 4: clever experiments where we can grow these bacteria in the
25:43
Speaker 4: lab on a Petri dish, and then you can grow
25:46
Speaker 4: them alone, and then you can grow them in pairs.
25:48
Speaker 4: And you can see whether they grow better in pairs
25:50
Speaker 4: or alone, and that's where you know whether they're competing
25:53
Speaker 4: from the same resources and limiting each other, or whether
25:56
Speaker 4: they're actually depending on each other.
25:58
Speaker 1: And And is what you find, the sort of patterns
26:02
Speaker 1: that you find in mice, are they similar to the
26:04
Speaker 1: patterns that you're finding in children, for example, Eveline? Is
26:07
Speaker 1: there any generality here at all? Yeah, absolutely.
26:11
Speaker 3: I mean, if we just look at the development of
26:14
Speaker 3: the microbiome. So mammals are essentially born without microbes. This
26:17
Speaker 3: is what we think. And this is certainly what I think.
26:21
Speaker 3: And so in early life, we quickly have to somehow
26:24
Speaker 3: form this microbiome.
26:25
Speaker 2: And this is driven by various processes.
26:28
Speaker 3: And it seems to be, even though we then end
26:30
Speaker 3: up having very different microbiomes between, not just between individuals,
26:33
Speaker 3: but definitely between different species, like us and koalas will
26:37
Speaker 3: have quite different microbiomes, but the process, the sort of
26:41
Speaker 3: different types of changes seem to be quite similar. So obviously,
26:45
Speaker 3: since we start with nothing for example, diversity will increase,
26:50
Speaker 3: but also it seems that we start with quite different
26:53
Speaker 3: microbiomes between individuals within a given species, so human babies,
26:57
Speaker 3: for example, but then as we get a little bit older,
27:00
Speaker 3: we start to look a little bit more similar to
27:02
Speaker 3: each other. So these sort of processes are quite conserved
27:05
Speaker 3: across different species.
27:07
Speaker 4: Yeah, and also.
27:08
Speaker 1: Sorry, Ara.
27:10
Speaker 4: Yeah, it's just that humans and mammals have this cool
27:12
Speaker 4: thing that they also control their microbiome by at the
27:15
Speaker 4: same time controlling what microbiome they get exposed to in
27:19
Speaker 4: the environment and then inside of their body is controlling
27:22
Speaker 4: who gets to actually establish there. So for example, when
27:25
Speaker 4: you're pregnant, you modify your microbiome to be such that
27:31
Speaker 4: it's beneficial for the baby so that the mother's microbiome
27:34
Speaker 4: shifts to be one that is good to give to
27:37
Speaker 4: the baby. And then when the baby is born, you
27:39
Speaker 4: feed the baby milk and actually a human and mammal
27:42
Speaker 4: milk contains a lot of compounds that are actually feeding
27:47
Speaker 4: the bacteria inside the baby and not.
27:48
Speaker 2: Really the baby.
27:50
Speaker 4: So it's like a selectively trying to modify the microbiome
27:53
Speaker 4: to be good for the baby and to protect it
27:57
Speaker 4: and help immune development.
28:00
Speaker 2: Wow. So you're really building up this picture of us
28:03
Speaker 2: not really being a single entity, right? I'm not just Saima.
28:07
Speaker 2: I'm Saima and my microbiome, right? Yeah, absolutely.
28:12
Speaker 4: That is what I love about microbiome science is it's
28:14
Speaker 4: really kind of challenging our biological ideas of individuality and
28:19
Speaker 4: ecology and what it means to be a species.
28:25
Speaker 1: And actually there's, I mean, you know, one of the
28:27
Speaker 1: things we haven't talked about, there's something called the gut
28:30
Speaker 1: brain axis, isn't it? And the vagus nerve and that,
28:34
Speaker 1: that's a two way thing. So as you say, the, the,
28:37
Speaker 1: the microbiome can influence us and our personalities, but we,
28:41
Speaker 1: and as you kind of say, we, we can influence
28:44
Speaker 1: our microbiome as well through our choice of food and
28:48
Speaker 1: whether we wash our hands and whether I let my
28:50
Speaker 1: dog lick my face, that sort of stuff.
28:52
Speaker 2: Yeah.
28:52
Speaker 4: And whom we interact with. That's the whole thing is
28:55
Speaker 4: that our social choices influence which microbes we have. And
28:59
Speaker 4: then there are microbes that also influence our social behavior
29:01
Speaker 4: and So there can be like feedback loops between sociality
29:05
Speaker 4: and microbiome. And some people have even suggested that this
29:08
Speaker 4: might have been one of the forces driving evolution of
29:10
Speaker 4: sociality in the early stages, like because you get beneficial
29:15
Speaker 4: microbes and then these microbes might enhance your fitness as
29:18
Speaker 4: a species or even just make you more social.
29:23
Speaker 1: We're running out of time. Have you got a kind
29:24
Speaker 1: of a final question or two, Saima? No, no.
29:28
Speaker 2: I mean, just a comment on, I guess, because Because
29:32
Speaker 2: bacteria came first. So we have only always evolved in
29:37
Speaker 2: their presence, right? Yes. And so, yeah, I think that's
29:42
Speaker 2: probably worth pointing out to our listeners that there's this
29:45
Speaker 2: thing goes, this sort of symbiosis, if you like, goes way,
29:49
Speaker 2: way back from our very origins.
29:51
Speaker 1: Yes.
29:51
Speaker 4: And it's part of the development as well.
29:54
Speaker 5: Yeah.
29:54
Speaker 3: And just to point out, the microbiome clearly is super important.
29:58
Speaker 3: Hopefully we've managed to convince that about We do have
30:01
Speaker 3: mice in the lab that are germ-free, you know, they've
30:04
Speaker 3: been germ-free for generations.
30:06
Speaker 2: And they, I mean, they are a little bit weird.
30:09
Speaker 2: They still look like mice.
30:11
Speaker 3: They still have a level of immune system that, you know, they, it's,
30:17
Speaker 3: so it's not all about the microbiome. That's just what
30:20
Speaker 3: I want to say. I don't want to give the
30:22
Speaker 3: impression that, you know, without the microbiome, there was.
30:25
Speaker 1: Nothing, so. and any advice to our listeners I know
30:29
Speaker 1: we're not a self-help help a self-help self-help podcast but
30:34
Speaker 1: any any any kind of having studied it any insights
30:37
Speaker 1: that that you kind of think oh yeah that's kind
30:40
Speaker 1: of cool I'm going to change my behavior.
30:44
Speaker 3: Well so I suppose the current consensus when it comes
30:47
Speaker 3: to for example food choices I mean diet is one
30:49
Speaker 3: of the key if not the key driver of the microbiome.
30:53
Speaker 3: And so when it comes to food choices, what seems
30:56
Speaker 3: to be the consensus is that eating a very diverse
31:00
Speaker 3: plant-based diet, you know, supports the microbiome. But to be honest,
31:05
Speaker 3: I mean, we really don't know. It seems to be
31:07
Speaker 3: it varies a lot between individuals what works for who
31:10
Speaker 3: and who knows what the consequences will be ultimately.
31:13
Speaker 4: Yeah, and I would also like to.
31:17
Speaker 4: Advise people to not isolate themselves from touch too much
31:22
Speaker 4: because a lot of this healthy microbiome diversity comes from
31:26
Speaker 4: like social contact. And sometimes even just talking to someone's
31:30
Speaker 4: face is enough to actually spread microbes, but especially all
31:34
Speaker 4: kinds of touch, hugging and kissing and, and being together
31:38
Speaker 4: really has the power to change your microbiome, to be
31:42
Speaker 4: more diverse and more resilient and do the better. And
31:45
Speaker 4: why that's important. is that this social contact spreads the
31:48
Speaker 4: microbes that cannot tolerate oxygen. And these you can't get
31:52
Speaker 4: from environment. You can only get them from other people
31:56
Speaker 4: and from your dog, probably.
31:57
Speaker 2: So pick your friends carefully.
32:00
Speaker 3: That's our ultimate advice.
32:02
Speaker 1: What a great way to pick your friends carefully. Thank
32:06
Speaker 1: you so much, Evelina and Aura. That's absolutely fascinating. Yeah, brilliant.
32:10
Speaker 5: Thank you very much.
32:11
Speaker 4: Thank you.
32:14
Speaker 2: Wow, Tim, so that was amazing. So now we know
32:16
Speaker 2: all about the intricacies of biomes, or do we?
32:20
Speaker 1: Clearly a lot to learn, clearly incredibly complicated, right? But
32:24
Speaker 1: I mean, fascinating what, you know, fascinating that A, you know,
32:28
Speaker 1: they can tell whether a mouse is like social or asocial,
32:32
Speaker 1: but B, then link it to aspects of the bacteria
32:36
Speaker 1: living in its stomach. I mean, it's just like, it's astonishing,
32:39
Speaker 1: isn't it?
32:40
Speaker 2: Yeah, I mean, it's, It's almost a little bit Star Trek-y,
32:44
Speaker 2: you know, when they'd go off to different planets and
32:47
Speaker 2: something would sort of invade and infect them and start
32:50
Speaker 2: behaving in a different way. But it turns out that
32:52
Speaker 2: actually our microbiomes impact aspects of our personality. I hadn't
32:58
Speaker 2: realized quite to what extent that was, you know, that
33:01
Speaker 2: was a thing. That's incredible.
33:03
Speaker 1: No, it's, I mean, I agree with you. It's kind of,
33:07
Speaker 1: who would have thought that the makeup of bacteria in
33:10
Speaker 1: your stomach can influence things going on in your brains
33:14
Speaker 1: right i mean and uh and influence you know whether
33:18
Speaker 1: you're feeling kind of more outgoing or more introverted and
33:22
Speaker 1: and clearly interacting with our genome clearly changes with age
33:27
Speaker 1: and with life and with diet and what have you
33:29
Speaker 1: it's like yeah it's a little bit like.
33:32
Speaker 2: You know in how is it harry potter or one
33:33
Speaker 2: of these where they have this sort of juice that
33:36
Speaker 2: they drink and it makes them happy or whatever you
33:38
Speaker 2: know you can imagine in the future having the happy bugs.
33:43
Speaker 1: I think a potion is the word you're looking for.
33:45
Speaker 2: Oh that's right the potion juice i think it's called
33:49
Speaker 2: that though honestly.
33:53
Speaker 1: But you can get that what's it called yogurt or
33:55
Speaker 1: something like this you can get products right that are
33:58
Speaker 1: full of bacteria that change i don't know if they're
34:01
Speaker 1: any i don't know if they work or not.
34:03
Speaker 2: Maybe we should do an experiment. You should give up
34:05
Speaker 2: the beer for this. No, maybe not.
34:09
Speaker 1: No, I'd be worried my hair might change colour. Look
34:13
Speaker 1: at that. For those people watching online who are not
34:17
Speaker 1: watching online and listening on Amazon, go and look at
34:22
Speaker 1: your lovely new hairstyle. It's very good. Yeah. Anyway, I
34:27
Speaker 1: should probably stop waffling, but I think it's fascinating, actually.
34:30
Speaker 1: And I think it's going to be a growth area. And,
34:34
Speaker 1: you know, I think it's some science to watch because
34:39
Speaker 1: I think it really is actually quite unexpected what people
34:43
Speaker 1: have found over the last few years, both in animals
34:45
Speaker 1: and people, about the role of bacteria.
34:48
Speaker 2: I think so. I think so. And it's, yeah, I
34:51
Speaker 2: think it'll impact... the way we live and our diets
34:55
Speaker 2: and all sorts of things in the future. So this
34:57
Speaker 2: is going to be something that sort of becomes more
34:59
Speaker 2: and more important, as you said. But OK, so I
35:02
Speaker 2: think on that note, I should say see you for, well,
35:07
Speaker 2: I'm off to Greece next week.
35:09
Speaker 1: Oh, well, have a good trip. And I think we've
35:12
Speaker 1: got a podcast scheduled, certainly for when you get back.
35:17
Speaker 1: And that's with a couple of colleagues of yours, I think.
35:20
Speaker 2: That's right, yeah, and some of the discoveries they've done
35:22
Speaker 2: on pain and pain reception.
35:26
Speaker 1: Wow, I'm going to do some reading up on it,
35:29
Speaker 1: so I look forward to that.
35:30
Speaker 2: Cool. All right, Tim, take care.
35:32
Speaker 1: Yeah, have a good weekend.