The deadliest (curable) infectious disease on Earth, featuring John Green

Tiny Matters

Every year, tuberculosis claims over a million lives despite being curable. Tuberculosis or TB is an infectious disease caused by Mycobacterium tuberculosis. About 5–10% of people infected with TB will eventually get symptoms. In the early stages a TB infection might cause chest pain, a cough, night sweats, and loss of appetite. But eventually it could create holes in the lungs and cause you to cough up blood. And of course, TB can be deadly.

In this episode of Tiny Matters, Sam and Deboki talk with TB researcher Uzma Khan as well as John Green, the author of books including The Anthropocene Reviewed, Paper Towns, The Fault in Our Stars, and Turtles All the Way Down. John is also the co-creator of Crash Course and one half of the vlogbrothers — the other half being his brother Hank Green, who Deboki and Sam chatted with on the show last year.

Although he's best known as an author and YouTuber, last summer John made headlines for something else: fighting for more equitable access to tuberculosis treatments, particularly bedaquiline, an incredibly effective and essential medicine for patients with drug-resistant tuberculosis.

In this episode, Sam and Deboki cover the science and history of this devastating yet treatable disease, the recent public pressure on companies that is leading to increased treatment and testing access, and clinical trials that make John and Uzma hopeful that one day this humanity-plaguing disease could be gone.

Transcript of this Episode

John Green: So I recently met with the head of drug development at a major pharmaceutical company and I said, “tuberculosis is the deadliest infectious disease in the world.” And he said, “is it?” And I said, “yeah.” And he said, “I thought it was malaria.” And malaria is a very dangerous disease, malaria kills about 600,000 people per year… but tuberculosis kills over one and a half million people per year. This year it may be down to 1.3 million, which represents a minor success, but to lose 1.3 million people to a disease we know how to cure is absolutely unacceptable.

Sam Jones: That’s John Green, the author of books like The Anthropocene Reviewed, Paper Towns, The Fault in Our Stars, and Turtles All the Way Down. John is also the co-creator of Crash Course and one half of the vlogbrothers — the other half being his brother Hank Green, who we had on the show last year.

So you might have tuned into this episode because of John’s writing or because he has taught you about world history or literature on YouTube. But in all likelihood, and because of the name of this episode, you’re here because of something else that John is passionate about — the most passionate about: wiping out tuberculosis.

Welcome to Tiny Matters, I’m Sam Jones and I’m joined by my co-host Deboki Chakravarti.

Deboki Chakravarti: We’re really psyched to have John on the podcast today, as well as physician and tuberculosis researcher and advocate Uzma Khan. Today Sam and l, and our guests, are going to cover the science and history of this devastating yet treatable disease and some of the exciting things happening that make John and Uzma hopeful that one day this humanity-plaguing disease could be gone.

Sam: Tuberculosis or TB is an infectious disease caused by Mycobacterium tuberculosis or M. tuberculosis for short. This bacterium spreads through the air by droplets that come from a person with TB who’s likely just coughed or sneezed or talking… you get the picture, it’s a lot like the COVID-19 virus in that way. Because you inhale M. tuberculosis it primarily attacks the lungs, where it multiplies. From the small air sacs in your lungs it can enter your bloodstream and go on to attack other parts of your body like the spine, brain and kidneys.

Deboki: Your body will do its best to keep the M. Tuberculosis bacteria from spreading by throwing white blood cells called macrophages its way, which will engulf and contain the bacteria, giving rise to hard immune-cell clusters called granulomas. With TB, the granulomas are called tubercles. These tubercles usually stop the bacteria from further multiplying and spreading, although it will stick around for years and one day could cause active TB. About 5–10% of people infected with TB will eventually get symptoms.

John Green: If you are one of the 10 million people a year who becomes sick with tuberculosis, who develops what we call active disease, that's potentially very serious.

Deboki: In the early stages a TB infection might cause chest pain, a cough, night sweats, and loss of appetite. But eventually it could create holes in the lungs and cause you to cough up blood. And of course, TB can be deadly.

Sam: Over the course of history, TB has gone by names like “consumption” and “the white plague.” And it hasn’t just been found in ancient texts — it has been pulled from skeletons over four thousand years old.

We don’t have a clear idea of exactly when TB first started infecting humans, but the more important point is that it still plagues us. Maybe you didn’t know this — I didn’t — but we still have thousands of cases of TB diagnosed in the U.S. each year. Sounds like a lot, but we used to have many, many more.

John Green: We reduced TB rates in the United States by over 99% in the 1950s and 1960s. And we did it by actively searching for cases. We had mobile X-ray vans that went out into communities and said, “get your free chest X-Ray, find out if you have tuberculosis so that you can get put on curative treatment.” And we identified those cases. We offered every single person who had active disease treatment, and then we offered their close contacts who had TB infections preventative therapy.

Deboki: While we’ve made a lot of progress in identifying and treating TB cases in the US, the TB burden remains high in other parts of the world. According to the WHO, in 2022 an estimated 10.6 million people fell ill with TB worldwide. The disease is most common in South-East Asia followed by Africa and the Western Pacific. More than two-thirds of the global total come from Bangladesh, China, Democratic Republic of the Congo, India, Indonesia, Nigeria, Pakistan and the Philippines.

John Green: My brother and I have worked in global health for 15 years working with organizations like Partners in Health and Save the Children and trying to understand the challenges of global health inequity. And yet somehow TB had completely escaped my attention.

Deboki: In 2019 John was in Sierra Leone with his wife Sarah, to learn about maternal health in the country.  At the time, Sierra Leone had the highest maternal mortality rate in the world, with around 1 in 17 women at risk of dying in pregnancy or childbirth. On the last day, one of the doctors asked John and Sarah if they’d go down to the tuberculosis hospital.

John Green: … And I was like the TB hospital? Like the 19th century British romantic poet disease? And he was like, yeah, that one.

Sam: Tuberculosis is a major plot point in operas, plays, and novels, particularly in the 1800s, and it killed some of the most famous writers and composers. But John soon learned it wasn’t a thing of the past — not by a long shot.

John Green: And we went to the hospital and as soon as we got there, this little kid who has the same name as my son Henry, who looked to me about nine years old, the same age as my son, he grabbed me by the shirt and he just started walking me around the hospital, and he spoke pretty good English, and he was showing me the kitchen and showing me the wards where the patients lived and took me to the laboratory, and I saw where they were diagnosing tuberculosis with microscopy, and he just gave me a whole tour of the place. And then I made my way back to the doctors, and I was like, whose kid is that? He's incredibly precocious and charming. And they said, that's actually one of the patients we're most concerned about.

Sam: And as it turned out, Henry was not nine years old. He was 16. Tuberculosis had wreaked havoc on his body and stopped him from growing normally.

John Green: And in that moment I realized that I didn't understand tuberculosis at all, and there was this huge threat to global health that I'd been completely disengaged from. And so I came home, I started reading about TB, I started following Henry's story, and here we are five years later, and I don't think or talk about anything else.

Sam with John Green: Do you have a moment where you felt like, “I need to dedicate my life to this now?” Or was it sort of a, I don't even want to say gradual, it was only 2019, but was it a somewhat gradual burn as you were learning more?

John Green:
I think the moment I realized I wanted to devote a lot of time to learning about tuberculosis was when I found out that Henry was probably going to die and he was going to die because the drugs that were needed to keep him alive, to cure him of his tuberculosis were difficult to access.

John Green: Knowing that this kid and over a million other people die, not because we need to make innovations or because we need to make discoveries, although we do need more robust TB treatment, of course. But right now, most of those people are dying because we're not getting the cure to them. A cure that exists, a cure that has existed for over 70 years. All of the drugs that most people need to take to be cured of TB are older than my dad. And so it just became untenable to me to just sit by and watch all of this happen and write about it and think about it and not talk about it publicly. And so that's why I started talking about it publicly more.

Deboki: So before we get into /access/, let’s talk about what’s available to treat, test for, and prevent TB.

First off, there is a vaccine for TB called the BCG vaccine, which has actually been around since 1921. It’s recommended for groups of people who are at a higher risk of contracting the disease, mainly children living in areas with high rates of TB. But it’s not very effective for all forms of infection. Today the best options for fighting TB are accurately detecting it and then treating it.

Sam: In the U.S., there are several treatment regimens recommended. If the TB is drug-susceptible, which is what you hope it will be, the treatment can take 4, 6, or 9 months depending on the regimen. “Drug-susceptible” means that the bacteria will be killed off by the widely accessible drugs available, including the well-known ones rifampin, isoniazid, pyrazinamide, and ethambutol. These drugs work by targeting different aspects of M. tuberculosis biology, blocking it from forming cell walls or proteins or even making new DNA.

But what about TB infections that do /not/ respond to the common drugs? That’s where you come up against multidrug-resistant or extensively drug resistant TB.

Deboki: Multidrug-resistant TB is resistant to at least two of the drugs Sam just mentioned: isoniazid and rifampin, which are also two of the most potent TB drugs.

And /extensively drug-resistant/ TB means that in addition to not responding to those two drugs, the bacterium also doesn’t respond to a group of antibiotics known as fluoroquinolones or one of three injectable second-line drugs. Extensively drug-resistant TB is incredibly rare, but also incredibly dangerous.

These forms of the disease are scary in part because they’re hard to treat but also because many of the drugs needed to treat drug-resistant TB are quite toxic and given in huge amounts over 18 months to 2 years.

John Green: Some TB survivors and cancer survivors have said to me, it's closer to chemotherapy for cancer treatment than it is to taking seven pills for strep throat, but it is curable.

Sam: One of the drugs key to curing drug-resistant TB is bedaquiline.

John Green: Bedaquiline is this miracle drug. It's incredible. Between 1945 and I think 1965, we developed about eight new classes of drugs to treat TB. And then between 1965 and 2012, we developed none. And that's entirely because of the nature of our medical system, the way that we prioritize private development of drugs for profit rather than the development of drugs to serve the public good. But then we developed bedaquiline.

Sam: In 2012, the FDA granted accelerated approval to Johnson and Johnson's drug bedaquiline — brand name Sirturo — to treat drug-resistant TB.

Bedaquiline worked differently than the other drugs on the market, by blocking the bacterium from producing adenosine triphosphate, or ATP, an acronym you may remember from your high school biology class. Simply put, ATP is a cell’s energy source. Without it, M. tuberculosis dies.

Bedaquiline is part of the World Health Organization’s recommended treatment guidelines for drug-resistant TB. Most patients with drug resistant TB /need/ bedaquiline.

Deboki: But bedaquiline is not cheap — or at least it wasn’t. So here’s where we get into the stuff that you may have seen John go viral talking about last summer. Johnson and Johnson, or J&J, had a 20 year patent on bedaquiline set to expire in July, 2023. They had planned to enforce a secondary patent on a salt formulation of bedaquiline. Same drug, just in a different form. A secondary patent would have prevented life-saving, cheaper generic versions from reaching the market.

John Green: They were trying to extend their patent past this 20 year period by patenting something that had very little to do with the drug itself.

Deboki: Although you may have only learned about this plan last summer — I know Sam and I did — John told us the fight to stop J&J from enforcing a secondary patent was in the works years before then.

In 2019, Mumbai journalist Nandita Venkatesan and tuberculosis activist Phumeza Tisle from South Africa filed a petition with the Indian Patent Office to block J&J’s application. Both women had survived severe cases of tuberculosis. Venkatesan endured years of painful injections and operations and lost her hearing. Tisle had extensively drug-resistant TB, which also led to hearing loss and a collapsed lung.

John Green: These two young women sued the Indian government and said, look, this isn't real innovation. They're patenting something that they know and we know isn't really core to what bedaquiline is or does. And the Indian government agreed, and that set up the ability to create generics. And once we had the ability to create generics, it was up to the rest of us to push Johnson and Johnson and other big movers and shakers in the global health world to say, look, this just isn't acceptable. We need to have generics of this drug immediately. And that worked.

Sam: In September, 2023, J&J announced that it would not enforce a secondary patent in 134 low and middle-income countries.

Deboki with John Green:
Is part of the significance that this ruling was in India where I feel like there is a lot of generic manufacturing going on?

John Green: Absolutely. That's a huge part of the significance of that ruling that it was in India, which is the pharmacy to the world as they like to say, and I think say correctly. And so to have that ruling in the pharmacy of the world made a huge difference because there were so many generic manufacturers ready to start producing bedaquiline immediately. And in fact, as soon as Johnson and Johnson announced that they wouldn't enforce these secondary patents, almost immediately those generic manufacturers were up and running. And so within a matter of weeks, there was generic bedaquiline available in lots of countries beginning in India, but also now spreading to the whole world.

Deboki with John Green: They were just ready to go.

John Green: Yeah, it was pretty awesome. And India, because it has such a high burden of tuberculosis itself — it’s the leading country in terms of number of TB deaths — it's especially important to have generic bedaquiline available there.

John Green: I'd love to be the hero of this story, but there are too many heroes of the story, and I'm not one of them. Pretty late in the game, our community joined in the fight and started pressuring Johnson and Johnson quite publicly to live up to their credo and put patients first and allow for generic bedaquiline to become available worldwide. And at first in many countries, and then eventually in all countries, they’ve done just that. A few months ago, they announced that they would no longer seek to enforce any secondary patents on bedaquiline, which is what the global health community has been asking for years.

And that represents a really significant shift. We're talking about a reduction in price of between 30 and 60 percent in the cost of this drug, which means that tens of thousands, maybe hundreds of thousands of people can get access to bedaquiline this year and every year moving forward. So it's not just that maybe 50,000 people get bedaquiline this year, who wouldn't have gotten it. It's also true next year and the year after that and the year after that. And as the price continues to drop, which is what we're seeing, more and more people will be able to access bedaquiline, and it's going to be something that saves tens of thousands of lives, maybe hundreds of thousands of lives.

Sam: One of the lives saved was Henry’s. After receiving a bedaquiline-based treatment he improved dramatically, and so quickly.

So this is an enormous win. But like we mentioned earlier, even with bedaquiline, the treatments for multidrug resistant and extensively drug resistant TB are brutal and long, with patients needing to take thousands of pills and enduring months of injections, and these treatments can cause awful side effects including deafness.

To address this, in 2017 a phase III clinical trial called endTB began.

Uzma Khan: The endTB trial was designed to basically find effective, shorter, safer regimens. And this was based on the fact that we were having these two year long lengthy treatments that potentially were not just not effective, but they were also not safe.

Sam: That’s Uzma Khan, who we mentioned at the start of the episode. In addition to working as a physician and implementing and conducting drug-resistant TB research, she is part of the endTB leadership and a co-investigator for their phase III clinical trial that enrolled a diverse group of 754 patients from seven countries — Georgia, India, Kazakhstan, Lesotho, Pakistan, Peru, and South Africa. In the trial they evaluated five nine-month treatment regimens with already available TB drugs and compared that to the current standard of care.

When the trial came to a close in November, 2023, they had some very exciting results.  

Uzma Khan: We found that three of those five regimens were actually similar in terms of performance to the current standard of care.

So having options in this area, especially with this kind of group for drug resistant TB, I think it's excellent.

Deboki: Uzma told us that the data’s now being reviewed by the WHO and the hope is that once these alternative treatment regimens are endorsed we will see their global use. This could be a huge step forward in terms of making drug-resistant treatments safer, cheaper, and faster. And people, including John, are anxious to see us get to that next step.

John Green: I do really strongly believe that we're not going to end tuberculosis without speeding up the pace at which we implement the innovations that we come across. We found the same thing with HIV. We spent way, way, way too long having HIV antiretroviral therapy that worked very effectively and didn't get to people in the poorest countries in the world. Tens of millions of people died because of that delay. And with 1.5 million people dying every year of tuberculosis, we know that this is also an emergency. And so I hope we can treat it like an emergency.

Deboki: Cheaper bedaquiline and more efficient, less toxic treatments are both big, important steps in the right direction. But there’s something else we haven’t really touched on when it comes to TB that is equally as important: diagnosis.

John Green: In 1882, when Robert Koch identified the bacteria that causes tuberculosis, he identified it by looking in a microscope and seeing the squiggly little rods that are TB bacteria. And that's a great way to diagnose tuberculosis in 1882 —  it was the state of the art. The problem with microscopy as a diagnostic tool is that it misses about half of cases, and it is especially likely to miss cases in kids and people who have severe immunocompromised immune systems… Well, beginning about 15 years ago, we started to have this amazing, I would say, genuinely miraculous test.

Deboki: The test John’s talking about is called the Xpert test — that’s spelled x-p-e-r-t — and it’s manufactured by the company Danaher. The test detects M. tuberculosis as well as resistance to rifampin which, remember, is a major first-line drug for treating TB.  

The Xpert test uses a sputum sample, which is a mix of saliva plus mucus coughed up from the respiratory tract. Within two hours you’ll know whether or not you have tuberculosis and if it’s resistant to rifampin. A follow-up test from the same company can then say whether there are additional drugs the TB is resistant to.

Sam: When Deboki and I chatted with John he called this a miraculous test in part because it’s so fast. Standard bacterial cultures take weeks to grow, not a couple hours. This allows for treatment regimens to be decided on quickly and accurately.

John Green: And so within a day, a person living with active tuberculosis can be put on the exact right treatment regimen for them that gives them the maximum chance of cure. That's game changing. For context, my friend Henry, who I mentioned earlier, Henry took between 20 and 30,000 pills during his treatment for tuberculosis because for over a year he was being treated for a form of tuberculosis he didn't have. And the reason he was being treated for that form of tuberculosis was because he didn't have access to this miraculous test.

Sam: Why didn’t Henry have access? The test is expensive.

John Green: It used to cost $10 for the standard TB test and $15 for the drug resistant test. Now it costs $8 for the standard test, but it still costs $15 for the drug resistant test.

Sam: You’ll notice there’s a slight price drop there. Right around the same time J&J was pumping the brakes on their secondary patent for bedaquiline, Danaher folded — a little bit — after receiving pressure from USAID, Stop TB, and other organizations as well as — you guessed it — John. They agreed to reduce the price of their TB test from $9.98 to $7.97, which it says is what it costs the company to make. But they also said they’d allow a third-party organization to validate that cost. Doctors Without Borders did, and they reported it should only cost about $5 per test.

And by now we all know that, when it comes to diagnosing, treating, and preventing the spread of TB, every cent matters.

Deboki with John Green: So obviously you have a very public following, which makes it so that when you talk about tuberculosis, it feels like there are people listening. But for a lot of people who don't have that kind of following, do you have advice on the ways that they can bring awareness to tuberculosis or some other neglected but curable disease that people are dying of?

John Green: Yeah, that's a great question. You're right that it's different for me because I have a megaphone. But one thing I've learned through this process is that we all at times underestimate our power. And it never crossed my mind that a multi-billion dollar corporation would care that a YouTuber who writes young adult novels isn't happy with their pricing structure. It seemed like that was something that they could probably overcome, but they did care. And the reason they cared wasn't because of me. It was because of thousands of people who had kind of become a constituency for tuberculosis. When I first started this work, I went around and I would talk to anyone who would talk to me. And what I heard over and over again from public health authorities was, well, tuberculosis doesn't have a constituency. HIV has a constituency. Magic Johnson lives with HIV, famous rich people live with HIV.

And this drove me mad when I first heard it because I was like, of course, TB has a constituency. There's tens of millions of TB survivors who are absolutely the constituency and who are in their communities doing everything they can to reduce the burden of tuberculosis in their communities. There's people who've been shouting from the rooftops for decades that we have to do something about this crisis. But what I realized eventually is that what they meant was TB doesn't have a constituency among rich communities like in the rich world, in the global North, because it just has a much lower prevalence here. And so it reminds me of something Tina Rosenberg, I think, said about malaria: “Probably the worst thing to happen to malaria in poor countries was its elimination in rich countries.”

So I understand it's easy to feel like, wow, John has all that power and has such a huge megaphone. And I do, and I try to be conscious of that. I want to use that megaphone as carefully as I can. But we all do, first with where we put our attention, we tend to solve the problems we pay attention to, and we tend to not solve the problems we ignore. Second, the more we learn about tuberculosis, the more we understand that this is an ongoing crisis, not what I always believed it to be a 19th century British romantic poet problem, the more likely we are to be able to address the crisis. And then lastly, I think we all underestimate the amount of power we have if we live in a country where our leaders are elected. I think we all underestimate the power that gives us. It doesn't give us a lot of power as individuals, but it gives us a lot of power as a collective. And so I think there are a lot of ways that we can be involved from activism to writing letters, to making phone calls to donating, and all of those ways matter.

Sam: With any infectious disease, or I guess you could argue disease in general, the goal is eradication. Wipe it out entirely. And when we talked with Uzma, she made a really important point that I think often gets missed. If we’re trying to eradicate TB, not incorporating testing and treatment into a country’s greater health care system, and not taking into account a country’s social and economic conditions is going to make attempts to eliminate TB less effective.

Uzma Khan: It needs to be integrated into primary care.

TB intersects with mental health. TB intersects with climate change. TB is in crisis and wars and malnourished people going under famine. There are outbreaks that can happen in those conditions. I mean, that is the reality. But the intersections of that are embedded under poor infrastructure, poverty, marginalization, and insane inequities.

Deboki: In March of 2024, USAID announced it would partner with the Philippines Department of Health to support comprehensive tuberculosis care in the Philippines, which is in line with what Uzma was just talking about. So they’re not only going to be testing for, treating, and preventing TB, they’re also integrating the testing and treatment of other diseases like HIV, lung disease, and diabetes.

In 2022, the Philippines had around 737,000 estimated new TB cases, making it one of the most affected countries in the world.

John Green: So that's an $85 million program over four years that Hank and I are kicking in about $4 million of. It's only one region, it's only one country. But I think the Philippine Department of Health has shown a real profound mission to end TB in their country and we want to support that in any way that we can.

Sam with John Green: The last thing that I want to ask you is if you think eradication of TB is possible in our lifetime.

John Green: So I've always kind of thought that eradication of TB is not possible in our lifetime. I mean, TB does have some animal carriers that make it difficult to eliminate. That's one thing. Also, we just have so many latent TB infections, but lately I've been talking to TB doctors who are feeling optimistic, really optimistic, and in some cases, feeling optimistic for the first time in decades. And what I'm hearing from them is, why not live in a world where zero people die of TB? I don't know if it's possible to live in a world, in my lifetime anyway, without TB infections happening. But if nobody's dying of TB or experiencing lifelong disability from TB, that's pretty close to TB elimination as far as I'm concerned. And I think that is possible. I think I might live to see that.

Sam with John Green: Yeah. I hope so.

John Green: I hope so too. That would be so fun. I mean, what a great old man thing that would be.

Sam: So, tiny show and tell. I think I went first last time?

Deboki: That sounds maybe right.

Sam: Yeah. Okay.

Deboki: For my tiny show and tell. I am apparently kind of on this funny kick where I have been enjoying stories of people finding things by the water, last time it was sea glass, and this time it's dinosaur fossils. And so I've seen this story in a few places now, and it's just really, really exciting to me. So in 2020, a girl named Ruby Reynolds was out with her family in England, and they were walking along the river Severn. I don't know if that's exactly how you say it. I assume names in England are kind of names in Massachusetts where you think you know how to say it, and then you're like, eh, this pronunciation doesn't make sense. Anyways, back to the story, Ruby and her dad, they have this hobby where they hunt for fossils, and this time they happened to find a fossilized bone, and then they found another even bigger one that was about eight inches long.

And so it turns out that others had actually found similar fragments at a nearby spot, which they thought was the jawbone of something called an ichthyosaur. So the Reynolds family reached out to the scientists who had been working with those fossils and got them to join in on a dig in the area, and they ended up finding what seems to be half of a bone that might be longer than seven feet.

Sam: Whoa.

So yeah, pretty big. Even if you're just finding half of the bone, it seems like a lot. So the shape suggests that it might come from an ichthyosaur jaw. And so then when the researchers looked at the bone under a microscope, they found these collagen fibers that were in a crisscross pattern, which is apparently an ichthyosaur thing. So yeah, they're feeling, I guess, pretty good about this potential identification. So based on these fossils, scientists named the species Ichthyotitan severnensis and they estimate it may have grown as big as like 82 feet long.

Sam: Whoa.

Deboki: Which would make it apparently the biggest marine reptile that we know of.

Sam: Ichthyosaurs are very interesting too, just like if you Google one to me, they look like a weird dolphin whale hybrid. Because they have this sort of beak. That's so cool. I feel like there's so many people. I mean, some of the earliest fossils that have been found, I think were on the seashore in England.

Deboki: Yep. Yeah.

Sam: Yeah.

Deboki: That sounds right. My high school had a paleontology museum on the campus. Oh, cool. So our freshman year, we got to go on a little paleontology trip where we would go to Barstow California and look for fossils, and I learned very quickly that I am not cut out to be a paleontologist, but it was super cool. I had other friends who got very into it, and they'd go off and hunt for fossils in Montana and stuff.

Sam: That's cool. I feel like I don't have the patience. I think I would do it for a couple hours and be like, I can't. I'm bored.

Deboki: It turns out you have to hike and you have to be outside, it's a lot. So shout out to all the paleontologists who have infinitely more patience than I do.

Sam: Yeah. Thank you for your service. So Deboki, I'm going to tell you, I have, I think, kind of a cute tiny show and tell today I'm going to tell you about fruit flies on tiny treadmills. Oh, I guess before I tell you why they're on treadmills, let me tell you a little bit about fruit flies in general. So the fruit flies that you've probably heard about or seen or researchers talk about all the time, are the Drosophila Melanogaster species. Fruit flies might seem like it's a fly, how much can we learn from it?

But evolution is amazing, and we can actually learn a lot from other species like fruit flies. They're a huge model organism in neuroscience and actually a lot of fields, but neuroscience in particular because you have this kind of simplified, very simplified, I guess compared to human nervous system where you can kind of interrogate really basic questions for how things link up in the brain and body. Anyone who studied biology in college, and maybe some high schools did this too. You probably did something with a fruit fly at some point. So these little treadmills, they were very cute. They were about four times the length of a fruit fly, which is still really tiny, so tiny. The average fruit fly is maybe a couple millimeters. So this is eight millimeters. They're really small. So the idea here was really just to provide insight on movement.

Deboki: And that you can put fruit flies on a treadmill.

Sam: Yes, yes. Right, so there wasn't a ton of wild insight that was gleaned from this yet. These are kind of the baseline studies where it's like, so now how can we incorporate some sort of brain recording while this is happening to be able to learn even more? In addition to learning about how these flies were moving, how they were sort of modifying where their bodies were in space as they were walking.

It also led to some competitions apparently, between the scientists who are running these experiments, which fly is really good at walking on the treadmill. And apparently they even did a side project where they tested endurance training in flies. So it's just so funny. I mean, I feel like I've heard and seen videos of people getting their dogs to walk or run on treadmills, especially dogs who love to run. I feel like my dogs would just sit on a treadmill and be like, what are you? This is weird. No thanks. But it's cool that you can do this with flies because it provides the basis for other research and including things like recording neural activity. So the video is on YouTube, and so I'll just send it to you really quick right now Deboki so you can see it.

Deboki: That's so fascinating.

Sam: It's kind of cute, right?

Deboki: Yeah. That's very delightful. Thank you. I'm going to be thinking about fruit flies on treadmills all day.

Sam: Yeah. When I saw that story, I was like, I can't not talk about this.

Deboki: Thanks for tuning in to this week’s episode of Tiny Matters, a production of the American Chemical Society. This week’s script was written by Sam, who is also our executive producer, and was edited by me and by Michael David. It was fact-checked by Michelle Boucher. The Tiny Matters theme and episode sound design are by Michael Simonelli and the Charts & Leisure team.

Sam: Thanks so much to Uzma Khan and John Green for joining us. If you’d like to learn more, go to You can also subscribe to John’s newsletter: Have ideas for episodes? Science-y things you just need to share? Email us: If you want another way to support the show, buy one of our coffee mugs! We’ve left a link in the episode description. You can find me on social at samjscience.

Deboki: And you can find me at okidokiboki. See you next time.