Nobel Prizes 2026: brain switches, ‘ghost’ particle hunter, and 'the chemistry of life'

Nobel prize in physiology and medicine

0:00Welcome back to the Nature Podcast. This week, rounding up the 2026 Nobel science winners and hints of the ancient human gut microbiome. I'm Nick Perchichow, and I'm Benjamin

0:36Thompson. The start of October is always a big moment in the science calendar, as it's the announcement of the Nobel Prizes. I caught up with one of my colleagues each day this week to learn more about the winners. It is Monday, and Monday is, of course, the Nobel Prize in Physiology or Medicine. And here to talk to me about it today is Miriam Nadav. Miriam, thank you so much for being

1:07here. Thank you, Ben. So everyone is talking about optogenetics today because the folk who won it, the three researchers who won it, won four working on optogenetics. Now, let's have a quick 101 on what optogenetics is. Yeah, so optogenetics is this very cool technique that uses light to control the activity of neurons. So imagine that this room is a brain cell, and on that wall, there is a light switch. And using that light switch, I can control what happens in the room. So if I switch on the

1:37light, we all start working and recording the podcast. But if I switch off the light, then we all go to sleep. And this is basically how optogenetics work. And in the lab, researchers use this technique to dial the activity of neurons up or down and study what happens in real time. And it's been in use for about, what, 20 years or so now. And it has made a big impact on the field of neuroscience. Yes, it has definitely revolutionised neuroscience, especially basic science. And there's been an explosion of papers using optogenetics over the past 20 years to study

2:13brain function and brain circuits in conditions like schizophrenia, autism, Parkinson's disease, and depression. So we have to talk about the winners of the prize, right? And I think the story starts with two of them, Peter Hageman at Humboldt University of Berlin, and Georg Nagel at the University of Würzburg, also in Germany. What was the starting point for this field? So the starting point was a type of green algae in Hageman's lab. Hageman was very curious to know how this single cell algae swims towards light. And he and his colleagues identified two DNA sequences

2:50that encode a particular type of protein. And this protein, which is called channelrhodopsin, is an ion channel. And when blue light is shone upon it, it creates an electrical signal. Right. And that's where the third winner comes on the scene, then. Carl Dyseroth from Stanford University in the US. He took this protein and this light-sensing protein and put it into neurons, essentially. Exactly. So Dyseroth and his colleagues used this technique in rodents, and they managed to control the activity of neurons in the brains of these animals.

3:22And this is basically how optogenetics moved from algae into neuroscience labs all over the world. And you've been reporting on this story all day. The announcement was this morning. You've spoken to scientists around the world. What have they told you about this win? Many people thought that this was a long time coming, including myself. So yesterday, I was talking to a friend over WhatsApp, and I envisioned this happening. And I thought to myself, what if optogenetics wins this year? We say this every year, and it doesn't happen. But

3:54it happened. Well, Miriam, could I add the lottery numbers for this week as well? That'd be very, very helpful. Miriam Nadav, thank you so much for being here. Thank you, Ben.

Nobel prize in physics

4:04It's Tuesday, and that's the day that the Physics Prize is awarded. And joining me to talk about it is Lizzie Gibney. Lizzie, hi. Hello, Ben. So right now, then, we are surrounded by ghosts. They're coming through the walls. They're coming through us. Billions upon billions of them. But we can't see them. And these spectres, which are subatomic particles called neutrinos, are central to this year's Nobel win. That's right. Neutrinos are millions of times lighter than an electron. They interact almost never. But when they do, they can tell us something really incredible, because the fact

4:35that they don't interact means they're a direct source. They go straight back to where they came from. And in this case, we're looking at cosmic neutrinos. Neutrinos created outside our solar system. That means that we can figure out what's going on in supermassive black holes or blazars or other kinds of supernovae, incredible things that are happening out there in the universe. So they don't really do a huge amount then. And yet, they can be used as an arrow to kind of point towards these apocalyptically huge cosmic events. That's right. So as you said, there are billions passing through us every second. But very,

5:08very rarely, these are the high energy neutrinos that come from deep space. And even more rarely do we actually detect them. So to detect them, you need to have this very, very rare chance that they hit into an atom and you kind of get the flashes of light that are created. And detecting these neutrinos then is very central to this year's prize. And the winner is physicist Francis Housen. And his win is related to this Ice Cube Neutrino Observatory. Now, this is a telescope of sorts, I suppose, but not in the way that you might imagine one with a sort

5:39of a tube with a glass lens on it. Exactly. It doesn't look like your average telescope. And that's because it's not trying to bring in light. It's not detecting photons. What you need to find something very, very rare is a very, very large volume. He had the amazing idea to use a huge hunk of ice in Antarctica. It's a cubic kilometer of ice, one and a half kilometers down. And within that space, when you have these very, very rare events, when a neutrino actually does interact with something, you can then actually detect it. So we had this idea back in the 80s, and then kind of pitched it in

6:13the 90s. And nobody really knew if it actually was possible, if you would get enough interactions, if you'd be able to capture this very, very rare event when a neutrino actually did hit an atom. He sounds like he really was a kind of a force of nature in bringing this about and pushing it forward. And he's been called the father of this field, which is now neutrino astronomy, or even multi-messenger astronomy. So a worthy winner then, according to the community, would you say? Absolutely. We've been talking to people today, and everybody seems to be absolutely thrilled that he's won. And he really is beyond doubt, like the driving force of this whole field.

6:44And when this announcement was made, I have to say that you and our colleague, Davide Castelvecchi, both sort of punched the air and went, neutrinos, right, let's go. I love neutrinos. Neutrinos, they were discovered later than some of the other particles people might be more familiar with, you know, the proton and the neutron electron. And because of these very strange properties that they have, that they're just so light and they interact so rarely, we often call them ghostly because of these properties. But it also just makes them really interesting. And because they are so relatively undiscovered, they probably are going to be key

7:14to some really important discoveries in the future. You know, there's a lot more that physicists have to learn about neutrinos. And so it's just a whole new area that's opening up. And one that excites me every time I get to write about neutrinos. And so Davide and I have been kind of like fighting to write the story today, because we both love a good neutrino story.

Nobel prize in chemistry

7:31It's Wednesday lunchtime, just a few hours before the podcast goes live. We're going to talk about today's chemistry Nobel. And joining me to do so for what is what the seventh, eighth year in a row, I'm not even sure, is Flora Graham. Flora, hi. Hi, thanks for having me. So much like your, well, your hands, molecules can be left or right handed. And that's the subject of today's chemistry prize. We're talking about things that are mirror images of each other, molecules that are mirror images of each other. Almost every molecule of life is actually only one version of the

8:07possible to mirror image molecules out there. Right. Because amino acids, the building blocks of proteins can be left or right handed. But yet life has gone for the left handed version. Right. And it's been a big mystery, I would say. Not only why this has happened this way, but how, when all the chemistry that we do in the lab ends up with pretty much fairly equal amounts of one and the other, how did natural processes somehow create this massive asymmetry in one direction? Right. And that brings us to today's winner's den. Henri Kagan from the University of Paris

8:39Sud in France and Kenzo Soai from Tokyo University in Japan. That's right. They came up with processes that were kind of the missing piece in this explanation of how a spontaneous chemical system could end up with this one handed nature. So there's actually been a couple chemistry nobels linked to this topic in the past. So you might be thinking, why is this new? Well, these are kind of the last piece of the puzzle. Right. And so their discoveries essentially changed the game then in terms of making these handed molecules. What do they actually do?

9:10So what Kagan did is he figured out how by using a catalyst, you could end up with more of a certain handed molecule, more than we thought was possible. And then Soai came up with a reaction that has his name on it now. And what he did is he figured out how to make that reaction self-sustaining. So you add some catalysts and a big bucket of stuff and that continuously creates more and more and more of one version until you end up with basically a big bucket that's almost purely this one kind.

9:41And of course, this is super useful for things like the pharmaceutical industry, because a molecule can have, say, two different hands. But when it comes to drugs, one can be very useful and have one effect, but the other has a different effect, for example. I think the example that the Nobel Committee, Dave, which is if you're a locksmith and you're making keys for a lock and every time you make a key, you get a mirror image version and you don't know which one works, but one breaks the lock. It's pretty important that you figure out how to determine that you get only the correct key when you need it. And during the announcement then, they actually got hold of Kenzo Soai and he was out shopping

10:14when he heard the news and he was obviously delighted. I mean, it's funny to hear who thinks that they might, you know, take a break to the shops and not really worry about getting the call from Sweden. And I have heard actually that a few people do keep a bottle of champagne on ice. So, you know, good luck to those people for next year. But of course, you've been on the podcast for many, many years with me, Flora, and it seems like we have this conversation again and again, all today's winners. And in fact, all the winners for the past three days have all been men. It's a trend that a lot of people had hoped would not continue. In this case, there have been many mentions of a scientist called Donna Blackmond, who did some very, very pivotal work

10:47in this field, who is very well respected and might have been, according to observers, equally worthy of one of the spots. But that's not said with any disrespect for the people who did win. And let me just add that the very first thing that most, if not all of the winners emphasise, I think, especially with the physics prizes here, is that this is a huge, huge group enterprise. And really, you know, we always talk about how picking out individuals is a bit of an impossible mission. And I would say in all my years covering the Nobels, there's been never to my recollection a case where the winner did not immediately

11:21start talking about the, you know, essential input of other people in the field. So it's never far from winners' minds, from everyone's minds. Well, Flora, looking forward to meeting you next year. Flora Graham, thank you for being here. Thank you very much.

11:35Flora Graham there. Also talking with me was Lizzie Gibney and Miriam Nadaff. To read all of Nature's Nobel coverage, look for links in the show notes. Coming up, how humans may have once shared a similar gut microbiome. Right now, though, it's time for the Research Highlights with Dan Fox.

Research highlights

11:52Watching sports on YouTube doesn't necessarily inspire people to engage in physical activity in real life, according to new research. Scientists surveyed more than 300 university students in their 20s who consume sports content on YouTube, including live game coverage, videos on exercise and sports variety programs. But while the students watch these videos for a variety of reasons, the researchers found no significant relationship between motivation to watch sports

12:25content and how much the respondents actually participated in exercise. The researchers also studied attitudes towards YouTube sports videos and found that the more motivated the students were to consume the content, the more positively they perceived the technology, rating it as useful and easy to use. This positive attitude, however, did not translate into more physical activity, but merely into a stronger intention to continue watching the programs. Run over to Performance Enhancement and Health to read more.

12:57Researchers have found evidence that the supermassive black holes at the centre of most galaxies help to regulate the pace of star formation in their host systems. A team studied 324 galaxies, each with a central black hole that is going through a growth spurt, heating the gas in its immediate vicinity. This process can also cause black holes to spew jets of plasma out of the galaxy in opposite directions. Such jets are thought to heat up gas in the halo that surround galaxies, a mixture that might otherwise have cooled and fallen

13:31towards the galaxy, helping to form new stars. It is also proposed that jets, partially ionise hydrogen in the halo. To confirm this, the team analysed the spectrum of light from different regions of the galactic halos. In the regions crossed by a black hole's jet, the researchers observed the signature of ionised hydrogen. By contrast, other regions did not have that signature, confirming that the jets had the expected effect on the gas in the galaxy's halo. Read that research in full in Astrophysical Journal Letters.

Ancient human gut microbiomes

14:06How healthy is your microbiome? And what does that even mean? Now, if you're familiar at all with the gut microbiome, the collection of microorganisms that inhabit our guts, you'll know that it's associated with various health conditions. There's evidence that the presence or absence of certain bacteria can contribute to inflammatory bowel diseases, diabetes, and even some cancers.

14:36So, there's an idea that changing or improving our microbiomes could treat or prevent some of these conditions and improve our health. But what does a healthier microbiome actually look like? A major part of the gut microbiome field has been interested in kind of this holy grail question of what is a healthy gut microbiome. This is Justin Sonnenberg, a microbiologist and one of the authors of a new paper in Nature that's been looking back in time to try and answer that question.

15:07Because there's been quite a bit of evidence that historically, human gut microbiomes were more diverse than they are now. And that the less diverse microbiomes now present in most of us in the industrialised world could be having negative effects on our health. For instance, some research suggests that humans living in less industrialised societies today have lower incidences of inflammatory bowel diseases. And that really led to this question of, is there something more fundamental going on here? Are these

15:39microbes that are associated with populations living non-industrialised lifestyles, are those microbes really part of our ancient history? Microbes that perhaps we transmitted across generations over a long period of time? Many researchers have been interested in studying the microbiomes of non-industrialised populations. hunter-gatherer groups or others who don't live with easy access to healthcare, antibiotics and other comforts that most of the world now enjoys. But Justin is specifically interested in whether their

16:12microbiomes are closer to what could have been thought of as our ancestral state, and whether he could trace the specific microorganisms they carry backwards in time to figure out what species might have been present in ancient humans. This was a big challenge. Testing that is a little bit tricky because of the unique ways that microbes evolve. They, unlike human genomes, they can get transmitted between us. This is Ben Good, another one of the authors of the new paper. The thing is, microorganisms love swapping genes between each other. While in humans you can look at

16:48our genomes over time and get a sense of how things were changing, in microorganisms they do a lot of horizontal gene transfer, meaning that it's hard to trace their history. If the genes keep moving, then it's tricky to keep track of what mutations have been accumulated and where.

17:07Undeterred, Ben and Justin teamed up for a new nature paper, where they think they've managed to overcome this issue. Their idea was to find two non-industrialised populations that are very isolated from one another. That way, there's less chance of their microorganisms having exchanged genes. And the idea was, maybe in these two populations, which are sort of the furthest apart, this is the Chimani in Bolivia and the Hadza in Tanzania, that their ancestors actually were separated geographically 10,000, 20,000 years ago. And so this was maybe an idea that, okay, that geographic

17:39separation would maybe prevent a little bit of the transmission, at least in ancient historical times. And therefore, we should be able to distinguish these hypotheses by going in and looking at the, not just which species were there, but the statistics of the mutations in their genomes. Throughout most of time, these two groups were continents apart. But despite this geographical separation, the Chimani and the Hadza had a lot of similarities. Here's Justin again. I think the stunning finding initially was how similar their gut microbiomes actually are based on

18:11the species that are present. So we identified about 1,400 different bacterial species in the Chimani microbiomes collectively. And out of those 1,400 species, 1,200 of those are shared with the Hadza in Tanzania. So just a huge amount of overlap in species composition between these two populations. A share of common species, despite the separation, could imply that those microorganisms have a long

18:43history with humans. Despite the tens of thousands of years without any historical contact, those organisms persisted. And more than two thirds of these shared species are rare or absent in industrialised populations. Which may also suggest that we've lost some of the microorganisms we evolved with. But Justin and Ben were curious about the history of these microbiomes. They wanted to see how the genetic changes in these microorganisms lined up with when humans dispersed around the globe.

19:16This would be more telling evidence that these microbes have persisted over time. They found that there was little transfer of species between the Chimani and the Hadza in the last few thousand years. And they appear to have become genetically isolated around 44,000 years ago. That roughly lines up with when humans are thought to have dispersed out of Africa, suggesting that these species of microbes are similar to those that ancient humans would have had. I was generally impressed by the analysis I did.

19:47This is Karina Schliebush, a population geneticist who's been writing a News and Views article about this new work. She too was struck by the finding that the Chimani and the Hadza had so much in common. And she wonders if looking deeper at our connections to microbiomes of the past could tell us more about human migrations themselves. I think of these other microbes now identified in the Hadza and the Chimani populations, all of those then could be studied separately to see if their sort of inheritance history or their history

20:20and their relatedness to each other reflects also the different relatedness between human populations. So I think it could be very nice to study past migrations and also contact between different people because contact in humans, we measure this by admixture, by two populations mixing with each other. But then we can probably also use microorganisms as some evidence for contact between different populations. Justin and Ben were a bit cautious about using microorganisms to infer information about human

20:52migrations, as the problems of horizontal gene transfer do so complicate things. But they think that there were some things that could be learnt, such as how different communities may have interacted. Changes in their diet, for instance, may leave a telltale trace on their microbiomes. Karina would like to see more work with non-industrialised groups to see how persistent these microbes really are. So I think it's important for the few indigenous hunter-gatherer groups that remain to try to

21:22contact them, try to set up a collaboration between the people themselves and the researchers and try to sequence microbiomes so that we can see if this pattern that is between the Timane and the Hadza is repeated. If we also see it in other hunter-gatherer communities, then of course, people are getting more and more industrialised and more westernised by the day. So a lot of this will also disappear in the next few decades. But what does this all mean for that holy grail question? What is a healthy gut microbiome?

21:57The answer is complicated. It kind of depends on how you define healthy. But the study suggests that there was a more diverse gut microbiome in the past, one that persists in non-industrialised populations. And for Justin, that's something to pay attention to. I think it does raise some alarm bells now in terms of what industrialisation and loss of all these species may mean to our biology now. And it's important to note that out of the

22:28approximately 1,200 species that were shared between the Hadza and Chimani, the vast majority of these, 60% of these are either rare or completely missing in industrialised populations. So there's been this sort of mass extinction of microbes that were part of our evolutionary history as humans. And the question now is, what does that mean for our biology? That was Justin Sonnenberg from Stanford University in the US. You also heard from Ben Good,

22:58also from Stanford University, and Karina Schleibusch from Uppsala University in Sweden. For more on that story, check out the show notes for some links. And that's all for this time. If you'd like to stay in touch with us, you can. We're on email, podcast at nature.com, or you can find us on social media, at naturepodcast. I'm Benjamin Thompson. And I'm Nick Petra. Ciao. Thanks for listening. Thanks for listening.