How can a microbe responsible for ulcers be either beneficial or harmful to you depending on your genetic background and at what time in life you are infected? And why are fewer Danish children today infected and what does that mean for the future of our health? Associate Professor Sandra Breum Andersen will answer all of these fascinating questions in this episode of Microbial Connections on her field Evolutionary Medicine.
Your hosts are PhD Christina Lehmkuhl Noer and Professor Tom Gilbert. Sound and recording by Christian Grimes Schmidt from Centre for Online and Blended Learning and editing by Christina Lehmkuhl Noer and Ella Zoe Lattenkamp.
The Center for Evolutionary Hologenomics and this podcast are generously funded by the Danish National Research Foundation.
00:00:00 Sandra Breum Andersen
So one of the neat things about Helicobacter is when you do the phylogeny of the bacteria, you can track our movement out of Africa.
00:00:09 Tom Gilbert
Well, hello and welcome to another episode of Microbial Connections, a podcast where my co-host Christina and I talk to experts about the fascinating new research field of holobiont biology, where host organisms and their associated microbes are viewed as one intertwined.
00:00:27 Tom Gilbert
My name is Tom Gilbert.
00:00:29 Christina Lehmkuhl Noer
And hi my name is Christina Noer and we both work at Center for Evolutionary Hologenomics at University of Copenhagen.
00:00:36 Christina Lehmkuhl Noer
And today our guest is our dear colleague, associate Professor Sandra Breum Andersen, also from Center for Evolutionary Hologenomics.
00:00:46 Sandra Breum Andersen
Thank you for having me.
00:00:49 Christina Lehmkuhl Noer
So Sandra, your research field is called evolutionary medicine, which we're very excited to hear about and, we asked you to bring something that represents your research.
00:01:02 Christina Lehmkuhl Noer
What did you bring?
00:01:05 Sandra Breum Andersen
You can maybe hear it but you can't see it, but I brought this plastic dish. It's a 24 well plate. And in each of these wells, we can grow miniature stomachs that we can then expose to microbes and other things and see how they respond.
00:01:25 Tom Gilbert
And these miniature stomachs, these are organoids?
00:01:28 Sandra Breum Andersen
They are organoids, yes.
00:01:30 Christina Lehmkuhl Noer
So how do they? Can you explain like how does such a miniature stomach look like?
00:01:35 Sandra Breum Andersen
Yes, I certainly can.
00:01:38 Sandra Breum Andersen
So in the stomach and the other intestinal tissue, there are stem cells. And when we take the tissue from sacrificed mouse, we can coax these stem cells into growing into stomachs in the lab by giving them a cocktail of growth factors.
00:02:00 Sandra Breum Andersen
They grow into these little spheres and so a round shape, which is the organoid.
00:02:07 Sandra Breum Andersen
The advantage of these is that they still have the different cell types that are found in the stomach, so they resemble the stomach to some degree.
00:02:17 Sandra Breum Andersen
So that means we can avoid using live animals for our experiments.
00:02:23 Tom Gilbert
So they kind of resembled the stomach at the cellular level.
00:02:25 Tom Gilbert
If not, it's not just like a big bag sitting there, but all the parts are there, ready to go.
00:02:29 Sandra Breum Andersen
Exactly.
00:02:30 Tom Gilbert
And so why do you, as an evolutionary biologist who is also into your microbes, like to play with these organoids?
00:02:38 Sandra Breum Andersen
I like to look at the interaction between the microbes and the host at different levels.
00:02:43 Sandra Breum Andersen
So we do mouse experiments as well, where we have the whole complex organism with a working immune system and lots of other microbes in the gut.
00:02:54 Sandra Breum Andersen
There we can do some types of experiments.
00:02:59 Sandra Breum Andersen
We also work with the human samples that our collaborators have collected for other purposes.
00:03:05 Sandra Breum Andersen
But growing these organoids allow us to go really on a much smaller scale to look at some of these interactions between host and microbes.
00:03:16 Sandra Breum Andersen
For me, the benefit is really that we can scale from the complex living humans with all of the noise that come from our environment and then really go zoom in to the cellular level.
00:03:28 Tom Gilbert
And so again, I think for many people who have not really experienced an organoid, maybe just the scale is worth asking.
00:03:34 Tom Gilbert
How big is one of these stomach organoids when it's ready to be played with?
00:03:37 Sandra Breum Andersen
Oh good. I actually don't remember.
00:03:40 Tom Gilbert
Not very big is the answer.
00:03:42 Sandra Breum Andersen
They're tiny.
00:03:43 Christina Lehmkuhl Noer
I think I remember you saying that you could grow hundreds organoids in a small well like and that is what, like essentially a lot.
00:03:45 Sandra Breum Andersen
Yes we can have hundreds in one of these wells, yeah. Exactly yes.
00:03:53 Tom Gilbert
So very, very, very small.
00:03:54 Sandra Breum Andersen
Small.
00:03:54 Tom Gilbert
So it's all work under the microscope.
00:03:55 Sandra Breum Andersen
Tiny.
00:03:56 Sandra Breum Andersen
And that's another thing that the organoidsallow us to do.
00:04:00 Sandra Breum Andersen
So when you when you have a mouse tissue with the microbes.
00:04:07 Sandra Breum Andersen
You can look at some things in the microscope, but it can be tricky to really zoom in, and that's what we can do more easily with these organoids. And the tissue cultures derived from the organoids.
00:04:22 Christina Lehmkuhl Noer
Very cool. But so you say you are growing stomachs.
00:04:25 Christina Lehmkuhl Noer
Why is it stomach's not like other organs that you're interested in?
00:04:30 Sandra Breum Andersen
You can grow all sorts of organoids from the different tissues.
00:04:35 Sandra Breum Andersen
We are interested in stomachs because this inhospitable environment is actually the home of one specialized Helicobacter pylori that has been associated with humans.
00:04:49 Sandra Breum Andersen
Since before we were modern humans.
00:04:51 Christina Lehmkuhl Noer
When you say in hostile environment, is it because it's very acid acidic there in the stomach or yes?
00:04:56 Sandra Breum Andersen
Exactly. The pH is quite low in the human stomach about 1.5 and so not a lot of things can live there.
00:05:04 Sandra Breum Andersen
It's thought that's one of the reasons why we have acidic stomachs.
00:05:08 Sandra Breum Andersen
So that when we ingest something, if there's anything in there that can make us sick, then it gets killed off in the asset and it also helps start the breakdown of the food so that we can get nutrients from it.
00:05:23 Tom Gilbert
So this helicobacter pylori, which is your microbe of choice, it's a famous one.
00:05:27 Tom Gilbert
I believe there was even a Nobel Prize linked to it at some point and you mentioned it's been around humans for a long time, but I guess it was only really discovered in humans fairly recently, and maybe you can tell us more about it and why you find it so fascinating and why it's got that really important relevance for the yeah.
00:05:45 Sandra Breum Andersen
So, so in the 80s, early 80s, it was discovered that there was actually a microbe living in human stomachs and that it was associated with stomach ulcers.
00:05:55 Sandra Breum Andersen
Until then, stomach ulcers had always thought to be caused by stress in a poor diet.
00:06:02 Sandra Breum Andersen
And then two Australians found out that it was actually caused by Helicobacter pylori.
00:06:09 Sandra Breum Andersen
Then at that point, people thought, well, obviously then this is a bad thing. We should get rid of it.
00:06:16 Sandra Breum Andersen
And for some people, yes, that is probably a good idea. But in most people Helicobacter cause mild inflammation that we don't even know that we have Helicobacter.
00:06:28 Sandra Breum Andersen
And about 10% of infected individuals, they develop a stomach ulcer.
00:06:32 Sandra Breum Andersen
Also, and much rarer, but much more seriously is gastric cancer.
00:06:37 Sandra Breum Andersen
Of course, there are definitely some cases where it's a good idea to get rid of Helicobacter.
00:06:44 Sandra Breum Andersen
But not always.
00:06:45 Tom Gilbert
So there's this degree of complexity then that in some people makes you very, very sick.
00:06:50 Tom Gilbert
Where in other people, it doesn't have an effect. Why is that?
00:06:53 Tom Gilbert
It's not, as you said, just a stress related thing, a diet related thing.
00:06:56 Tom Gilbert
Think it's more than that?
00:06:58 Sandra Breum Andersen
So we know that.
00:07:01 Sandra Breum Andersen
Oh, we estimate that about 50% of the world's population are infected with Helicobacter at this time, and this used to be much higher.
00:07:10 Sandra Breum Andersen
So in a recent survey we did of Danish children, we found that about 15% are infected.
00:07:18 Sandra Breum Andersen
Whereas, for example in Colombia, where a lot of interesting studies have been done, it's about 80-90% of the population that are infected with helicobacter.
00:07:27 Sandra Breum Andersen
So our association with this microbe is changing and when we look at the causes of like who gets sick, when so many people have this bacteria, that's where the helicobacter comes in.
00:07:42 Sandra Breum Andersen
Because it turns out that at least part of what determines whether you get sick or not is the match between the microbe and the host.
00:07:53 Tom Gilbert
The match between the microbe and the host.
00:07:55 Tom Gilbert
So you have a certain genetic background in the host, and that means you're compatible with a certain kind of microbes that will give you symptoms or not symptoms.
00:08:03 Sandra Breum Andersen
So one of the neat things about helicobacter is when you do the phylogeny of the bacteria, you can track our movement out of Africa.
00:08:13 Sandra Breum Andersen
And so we have different strains of helicobacter that are most commonly found in certain air parts of the world.
00:08:19 Sandra Breum Andersen
And then, of course, there's been a lot of mixing in recent and past movement of humans, and so rarely you have a Helicobacter that's completely African.
00:08:31 Sandra Breum Andersen
A completely European, but they will often be a mix.
00:08:34 Sandra Breum Andersen
And so, of course, will the human genetic background to some degree.
00:08:39 Sandra Breum Andersen
And what was found in Colombia exactly, was that if you had a mismatch between the ancestry of Helicobacter and the host, then you are more likely to develop stomach cancer.
00:08:51 Christina Lehmkuhl Noer
So is that why your field is called evolutionary medicine?
00:08:54 Christina Lehmkuhl Noer
Because you can look at it back in time and like follow evolution?
00:08:58 Sandra Breum Andersen
Evolutionary medicine is a is a lot of things. It's how our evolutionary history contributes to our health and disease today.
00:09:10 Sandra Breum Andersen
And I am particularly interested in the microbial part.
00:09:13 Sandra Breum Andersen
So this is also for example related to our gut microbiomes, how they are changing over time because of our diet, because of the antibiotics we use.
00:09:25 Sandra Breum Andersen
And how that can give us a mismatch to the world that we are living in.
00:09:30 Christina Lehmkuhl Noer
You mentioned that it's only around 15% of Danish children. Who has it? So do we know why or how we lost all of this Helicobacter?
00:09:41 Sandra Breum Andersen
So the a part of it is probably less transmission, so transmission primarily happens from mother to child and it's thought to be the gastro oral route or the fecal oral route.
00:09:59 Sandra Breum Andersen
And so as we live in a more hygienic way, then there's probably less transmission from mother to child.
00:10:07 Sandra Breum Andersen
Adults probably also have lower loads of Helicobacter, maybe because they're using antibiotics.
00:10:14 Sandra Breum Andersen
And so there's less microbes to pass.
00:10:17 Sandra Breum Andersen
And so you can kind of see it as in for each generation there's less transmission.
00:10:23 Sandra Breum Andersen
And more eradication. And in in that way, the lower the prevalence drops.
00:10:29 Tom Gilbert
So I guess this raises the obvious question. Should we just get rid of it completely?
00:10:35 Sandra Breum Andersen
Yeah. So, so that was long the thought and still is for many in the clinical world that the only good Helicobacter is a is a dead Helicobacter.
00:10:44 Sandra Breum Andersen
And but what we see is that Helicobacter likely hasbeneficial effects, especially early in life.
00:10:51 Sandra Breum Andersen
So this could be one good reason to not get rid of Helicobacter.
00:10:56 Tom Gilbert
Beneficial in which way?
00:10:57 Christina Lehmkuhl Noer
Yeah. What benefits?
00:10:59 Sandra Breum Andersen
So if you are infected with Helicobacter, you are less likely to develop asthma and allergies later in life.
00:11:08 Sandra Breum Andersen
Life. And so this is thought to be a part of our old associates in the microbiome world. And so the microbes that we meet.
00:11:18 Sandra Breum Andersen
Early in life helped train our immune system so that we react in an appropriate way later in life to the challenges we meet.
00:11:28 Sandra Breum Andersen
And so this has been shown in humans through correlation that you're less likely to develop a range of diseases if you have Helicobacter.
00:11:37 Sandra Breum Andersen
And there's beautiful work done in mice showing that if you expose the mice early in life to Helicobacter, they are less prone to develop disease later in life. And so in this sense, the human and the animal studies support each other beautifully.
00:11:58 Christina Lehmkuhl Noer
Cool. I have another question.
00:12:00 Christina Lehmkuhl Noer
So you said that it can have like beneficial effects if you have it from very young because it can affect the immune system and protect against asthma and allergies.
00:12:12 Christina Lehmkuhl Noer
You know anything about how the bacteria because you said it's in the stomach, like how can it? How can it infect?
00:12:18 Sandra Breum Andersen
Yeah. So it it while it's in the stomach, the immune cells are constantly sampling who is there and is in that encounter.
00:12:30 Sandra Breum Andersen
That they tell the immune system to chill.
00:12:34 Sandra Breum Andersen
And take it easy and that these are good.
00:12:37 Sandra Breum Andersen
So we know that the timing is important here because early in life there's this window of opportunity.
00:12:44 Sandra Breum Andersen
Where you can.
00:12:45 Sandra Breum Andersen
Kind of assume that a lot of the things that you meet for the first time.
00:12:49 Sandra Breum Andersen
Something that you are supposed to be associated with and so it has to be in this period of time that you meet certain microbes and that affects them. How you meet other things later in life.
00:13:05 Christina Lehmkuhl Noer
So the so in the infants, their immune system is more.
00:13:09 Sandra Breum Andersen
Like a blank canvas basically.
00:13:10 Christina Lehmkuhl Noer
Yeah. So it's more open to accept. Yes, new, yes.
00:13:16 Sandra Breum Andersen
And that builds a tolerance to other microbes and other challenges later in life.
00:13:22 Tom Gilbert
So how does the Helicobacter actually lead to the damage?
00:13:27 Tom Gilbert
Caused in stomach ulcers or cancer or so.
00:13:29 Tom Gilbert
Is that the bacteria itself, or is that a body response to it and?
00:13:33 Tom Gilbert
Why does it not do that if it has the right host association?
00:13:37 Sandra Breum Andersen
Yeah, that the details of how the match matters, that is something that's being studied at the moment. So we don't actually know that well.
00:13:48 Sandra Breum Andersen
But it's in part in the response of the host cells to the bacteria.
00:13:53 Sandra Breum Andersen
So the bacteria have different ways of getting nutrients from the host cells and in that process.
00:14:01 Sandra Breum Andersen
They can damage the tissue and then again also the response from the host to these bacteria being present.
00:14:08 Sandra Breum Andersen
So we know that there's much more inflammation in when you're infected later in life because there's a much harsher response for the immune system, whereas early in life you have this tolerance to meaning.
00:14:20 Sandra Breum Andersen
New organisms.
00:14:21 Tom Gilbert
So it's very much partially driven by the host damaging itself in response to it.
00:14:25 Sandra Breum Andersen
Yes, so so yes.
00:14:26 Christina Lehmkuhl Noer
What are the perspectives of this research like?
00:14:29 Christina Lehmkuhl Noer
You think we end up infecting newborns with Helicobacter pylori to make sure that they get it early life or?
00:14:37 Sandra Breum Andersen
So no, I don't think so.
00:14:40 Sandra Breum Andersen
It's one trend we can see not.
00:14:43 Sandra Breum Andersen
But for example, there's a new probiotic with this bacteria called Acamencia, and there you can actually use dead cells and they still that the dead cell material of these bacteria enough to.
00:14:58 Sandra Breum Andersen
The immune response that has the beneficial if.
00:15:02 Sandra Breum Andersen
And so this is something that's also been looked at with Helicobacter.
00:15:08 Sandra Breum Andersen
To see and this has been shown, at least in my that the cell material is enough to elicit the beneficial effect.
00:15:16 Sandra Breum Andersen
I think this is going to be the way forward with many of these things.
00:15:21 Christina Lehmkuhl Noer
So you could infect the newborn children with dead bacteria just to train their immune system?
00:15:28 Christina Lehmkuhl Noer
So a little bit like a vaccine, I guess, but.
00:15:30 Sandra Breum Andersen
Yeah, so not infection, but a treatment, yeah.
00:15:32 Christina Lehmkuhl Noer
Yeah, interesting.
00:15:35 Tom Gilbert
So, given your expertise on Helicobacter pylori, what advice would you have to people who might have it already?
00:15:44 Sandra Breum Andersen
If you don't have any complications, then nothing I would say.
00:15:48 Tom Gilbert
That's good advice.
00:15:51 Sandra Breum Andersen
Of course, the curiosity of knowing, so I did screen myself and I'm not.
00:15:59 Christina Lehmkuhl Noer
I guess. Only if like only if you get sick, you'll actually know if you have it or not, right? And yeah.
00:16:06 Sandra Breum Andersen
I think if you are living in a region where there is where there is a high prevalence of gastric cancer, then of course it could be interesting to know before you develop severe disease, because then you could actually get rid of Helicobacter.
00:16:24 Sandra Breum Andersen
And hear something like knowing the match between your strain and yourself could be an indicator of whether you should treat something or not.
00:16:30 Christina Lehmkuhl Noer
Interesting.
00:16:31 Tom Gilbert
I have another fundamental question that may or may not be useful here. To get back to.
00:16:35 Tom Gilbert
Mentioned it can have no effect on you.
00:16:38 Tom Gilbert
It can cause stomach ulcers.
00:16:40 Tom Gilbert
Can cause gastric cancer.
00:16:42 Tom Gilbert
Is there kind of a logical progression from one to the other or can you get the cancer without the ulcers or the ulcers without the cancer?
00:16:49 Sandra Breum Andersen
Yes, there is kind of a. It's called Korea's cascade, so you have some steps along the way to develop cancer. And as I mentioned there at the earlier points, you can intervene and then when you're past a certain point then it's at least no longer beneficial to get rid of Helicobacter.
00:17:10 Tom Gilbert
So we've got this complicated situation where there's a.
00:17:14 Tom Gilbert
Seems like you might need it early in your life and it gives you.
00:17:17 Tom Gilbert
But on the other hand, if you get the wrong kind of it, it makes you sick.
00:17:20 Tom Gilbert
So I guess this is actually a growing observation with other bacteria out there.
00:17:25 Tom Gilbert
We can't view them as a black and white, good or bad thing, and I guess that really does allow you to change how you think about things.
00:17:30 Tom Gilbert
If we can get back to the organoids, I think it would be interesting to hear what you actually do with them on a day-to-day things. So you grow your organized, your little mini guts in a in your little tiny dishes.
00:17:42 Tom Gilbert
Then what happens next?
00:17:43 Sandra Breum Andersen
So one study that we've done is.
00:17:48 Sandra Breum Andersen
Expose mice to Helicobacter when they were young or later in life, and then compare them to mice that were not exposed.
00:17:57 Sandra Breum Andersen
So we take the tissue from the stomachs of these mice and grow them into organoids.
00:18:03 Sandra Breum Andersen
And these organoids never meet Helicobacter bacteria.
00:18:06 Sandra Breum Andersen
Yet we can see that the gene expression and the size of these organoids differ depending on whether the host was infected or not.
00:18:17 Sandra Breum Andersen
So we can see that the bacteria leave a mark on the host because they were there or not, and also depending on at what age the the mice were infected.
00:18:29 Sandra Breum Andersen
One experiment we also preparing to do is is look at the interaction between Helicobacter and so in again in this Hologenomic framework where we take into consideration the interaction between the host and the microbes and the environment. So for the host, this could be the genetic background, the age where it encounters the microbes.
00:18:56 Sandra Breum Andersen
And of course, we have different strains of the bacteria, with or without different products that they produce or mutations, and the environment could be the pH or the availability of of drugs and nutrients and these kind of.
00:19:12 Sandra Breum Andersen
Helicobacter and painkillers are the worst contributors to gastric disease, and so it's interesting to know what's the interaction between the two given that so many people have Helicobacter in the stomach and so we hope to do an organoid model of where we can vary the combinations of the host, so they would have tissue from different host that have genetic different genetic backgrounds. We would have different strains of Helicobacter producing different virulence factors or not, and then the possibility to add a painkillers and then see how these interact.
00:19:54 Christina Lehmkuhl Noer
So maybe it's not completely.
00:19:56 Christina Lehmkuhl Noer
That painkillers are also causing ulcers, but maybe it's like a a combination of the two, but also alone?
00:19:59 Sandra Breum Andersen
Oh, no, no, that's definitely right.
00:20:01 Sandra Breum Andersen
Yeah. Yeah, that's.
00:20:04 Christina Lehmkuhl Noer
OK, OK.
00:20:06 Tom Gilbert
So if you don't take antibiotics, can you naturally clear Helicobacter pylori? Or once you're infected, is it for life?
00:20:12 Sandra Breum Andersen
It looks like it's most often for life, yes, so I don't know this have a have a product called the Pylo Pass that can help you lower the burden of bacteria. They say without.
00:20:27 Sandra Breum Andersen
Interrupting the rest of the microbiome. So.
00:20:30 Christina Lehmkuhl Noer
The burden of Helicobacter pylori as well.
00:20:35 Christina Lehmkuhl Noer
It should be.
00:20:35 Sandra Breum Andersen
Specific to Helicobacter and in the trials, they see a relief of symptoms. So this could be a way to change your stomach microbiome, but without taking antibiotics.
00:20:50 Christina Lehmkuhl Noer
Hmm. So if you have like say, an ulcer or stomach problems and you think it's related to go back to.
00:20:59 Sandra Breum Andersen
So I think one problem has been that if you a lot of people when they have stomach problems they will get screened for Helicobacter and depending on which part of the world you live there.
00:21:12 Sandra Breum Andersen
A very good chance that you have Helicobacter in your stomach, but it might not be actually the cause of of disease. And then we enter this problem of using a lot of antibiotics that might not be needed and disturbing the rest of the microbiome.
00:21:27 Tom Gilbert
In addition to not being the cause, can it actually be beneficial for you when you're an adult to have it?
00:21:33 Sandra Breum Andersen
I think the benefits are most likely to be seen early in life during this priming of the immune system. What we also know is that.
00:21:44 Sandra Breum Andersen
Once you are on the path to towards developing.
00:21:48 Sandra Breum Andersen
There is a point of no return where even if you eradicate Helicobacter, it's too late, so that you've already seen some of these mutations in the tissue.
00:21:59 Tom Gilbert
It's a really fascinating topic that things can be good and also can be bad.
00:22:02 Tom Gilbert
I guess I'm curious to. I come back to do we have other major examples that affect humans or even non humans, where you have a similar system where depending on who you are.
00:22:14 Tom Gilbert
Or what situation is a microbe might be good for you or for sure over the edge?
00:22:20 Sandra Breum Andersen
I think for a lot of the human microbiome we would, we thought by now we would have identified the good and the bad guys and I think a lot of it comes down to it's a balance of not having too much of one thing.
00:22:35 Sandra Breum Andersen
And again, then also when we look at a much finer scale, not just at the species level, but what's the Max match actually between the host and the micro?
00:22:46 Tom Gilbert
So it's complicated.
00:22:47 Christina Lehmkuhl Noer
Yes, I know some.
00:22:49 Christina Lehmkuhl Noer
They are starting to say that they can, like, look at your microbiome and tell you like what probiotics should you take or like, like what diet?
00:23:00 Christina Lehmkuhl Noer
Or that and what do you think about that?
00:23:03 Christina Lehmkuhl Noer
Do you have anything?
00:23:04 Sandra Breum Andersen
Yeah, I mean, you can't really do that yet.
00:23:07 Sandra Breum Andersen
I know there are some studies in Israel where they're really looking at a lot of parameters, so they are tracking.
00:23:17 Sandra Breum Andersen
Individuals glucose levels after a meal or everything they eat, sampling their microbiome, and there they say that they can use the composition of the microbiome is one factor in predicting, for example, what would be a beneficial diet or not. But to the general person sending in a bit of their poop.
00:23:36 Sandra Breum Andersen
Nope, not unless you have a. Of course, a very clear pathogen of some sort, but other. Not.
00:23:43 Sandra Breum Andersen
Unfortunately, it's too complicated and I think it's good to remember that when you find these patterns in big studies, it's usually thousands, or at least hundreds of individuals where you see.
00:23:54 Sandra Breum Andersen
A pattern in one or the other direction, but that might not mean so much for the individuals.
00:23:59 Christina Lehmkuhl Noer
So speaking of stomach samples, I know that you have this really cool project with the Copenhagen Zoo abou developing new ways of sampling the stomachs.
00:24:10 Sandra Breum Andersen
Yes, we have a new project that I'm very excited about.
00:24:14 Sandra Breum Andersen
It's also in collaboration with with any poisonous group at the DTU where they've developed a device to samples stomach contents.
00:24:23 Sandra Breum Andersen
It's a smart pill that.
00:24:26 Sandra Breum Andersen
And then it takes a sample in the stomach and then you can collect it in the feces.
00:24:32 Sandra Breum Andersen
So this is something that we're going to try out in this.
00:24:34 Tom Gilbert
It's like a mini excavating submarine. You swallow that.
00:24:38 Christina Lehmkuhl Noer
So what it opens up in the stomach and then it closes again when it's taken.
00:24:40 Sandra Breum Andersen
Yes, exactly.
00:24:42 Christina Lehmkuhl Noer
Exactly. Yeah. Nice.
00:24:44 Christina Lehmkuhl Noer
Can you actually then take these pills and then grow them? In the lab.
00:24:50 Sandra Breum Andersen
We're not growing them, so we're just looking at who's there basically at this point, yeah.
00:24:55 Christina Lehmkuhl Noer
Sequencing everything and looking at it genetic, OK.
00:24:57 Sandra Breum Andersen
Exactly. Exactly.
00:25:01 Christina Lehmkuhl Noer
Interesting. So that might give you a much more diverse view of who is actually inside the stomach.
00:25:07 Sandra Breum Andersen
Yes. And what's the pH of stomachs and all of these questions?
00:25:12 Christina Lehmkuhl Noer
What animals do you sample?
00:25:15 Sandra Breum Andersen
Well, tigers is one that we're very excited to try out.
00:25:20 Sandra Breum Andersen
There's obviously a lot of challenges with sampling the live animals, so it has to be an animal that has a fairly large esophagus.
00:25:29 Sandra Breum Andersen
It cannot be chewing too much on.
00:25:33 Sandra Breum Andersen
So gulping is good.
00:25:36 Sandra Breum Andersen
There's also the challenge of actually finding this device afterwards in the fecal material.
00:25:42 Sandra Breum Andersen
And so the vet had a brilliant idea.
00:25:47 Sandra Breum Andersen
Of adding glitter to the to the meal that goes in with the device so that we know which poop to look for.
00:25:55 Christina Lehmkuhl Noer
That will help the zoo keepers, I'm sure.
00:25:59 Christina Lehmkuhl Noer
So they don't have to go through all of them to find the device.
00:26:02 Tom Gilbert
So I've known you a long time.
00:26:04 Tom Gilbert
I knew when you were a proper evolutionary biologist back in your master's and PhD days, and I'm curious, how did you then transition into this interest in Helicobacter pylori and human health angle?
00:26:15 Sandra Breum Andersen
Yeah, so I started working with at the Centre for Social Evolution where it's about how organism interact with each other when they cooperate. When they start cheating and their relatedness is a big part of it.
00:26:30 Sandra Breum Andersen
You are helping other organisms that you are related with because then you pass on your own genes.
00:26:37 Sandra Breum Andersen
And from there on, I wanted to move into something more related to human health.
00:26:41 Sandra Breum Andersen
And so I worked with social evolution in bacteria causing lung infections.
00:26:48 Sandra Breum Andersen
And so there's been this general thought that when we see pathogens infecting humans over time.
00:26:57 Sandra Breum Andersen
That must be an adaptation to the host that they're in and, for example, antibiotic treatment and so on. And we wanted to test the idea whether some of these changes in the bacteria over long infection times were actually due to the bacteria interacting with each other.
00:27:15 Sandra Breum Andersen
And so we looked at bacteria that started out cooperating.
00:27:19 Sandra Breum Andersen
And what we saw often was that the bacteria stopped cooperating.
00:27:23 Sandra Breum Andersen
And what we could show was that actually they stopped cooperating because they start cheating.
00:27:29 Sandra Breum Andersen
And so this is a strategy that can win out in the beginning.
00:27:34 Sandra Breum Andersen
Don't pay the price of cooperating.
00:27:36 Sandra Breum Andersen
Still get the advantage.
00:27:37 Sandra Breum Andersen
And so we saw that these interactions between bacteria actually matter for evolution in a host.
00:27:44 Sandra Breum Andersen
That was somewhat easy to do in lungs because these toy these were long pathogens and they were the dominant Organism in the lung.
00:27:53 Sandra Breum Andersen
So I wanted another bacteria that was dominant in its environment and that made me drawn to Helicobacter and another thing that I really liked was that it has these both beneficial and harmful effects.
00:28:09 Sandra Breum Andersen
This is something, as an evolutionary biologist and someone working with symbiosis, it's always fun to have.
00:28:16 Sandra Breum Andersen
Scale of interactions and see what's the tipping point that makes it harmful or beneficial.
00:28:22 Christina Lehmkuhl Noer
Thank you so much Sandra for taking your time here today with us and making sure that we are aware that the bacteria are not just good or bad, but it's important to look into all the implications around them.