Science Friday - Your Cheese’s Microbiome, COVID Reinfection Questions, Future Of Meat. Nov 27, 2020, Part 1

Episode Date: November 27, 2020

Can You Get COVID-19 More Than Once? SciFri producer Elah Feder’s friend tested positive for antibodies a few months ago—but last month, she developed COVID-19 symptoms again. So far, only a handful of cases of COVID reinfection have been confirmed, but we don’t yet know the true rates. Cases could be missed if the first or second infection is asymptomatic, and sometimes, what looks like a case of reinfection is something else entirely. Over the past few months, we’ve seen both concerns that antibodies to SARS-CoV-2 fade quickly and reassurances that immunity probably endures. Akiko Iwasaki, an immunobiologist at Yale, along with Alessandro Sette and Shane Crotty of the La Jolla Institute for Immunology, explain what we know about the immune system’s ability to remember this virus, and what cases of reinfection could mean for the efficacy of vaccines. What Is The Future of Meat? More and more people are trying meat alternatives, and for good reason: The meat industry is a major contributor to climate change. Almost 15 percent of greenhouse gas emissions come from livestock, with cattle making up about two-thirds of that. Others avoid meat because of ethical problems with slaughtering animals. Altogether, plant-based meats are having a major moment, making their way onto the shelves of major grocery stores, and the menus of fast food chains. It’s now possible to eat a burger that tastes, looks, and feels like beef—while being entirely made of plants. Some scientists are devoting their careers to creating a future where more meat comes from plants, or even cells grown in a lab. Joining Ira to mull over the future of meat is Pat Brown, CEO of Impossible Foods, and Isha Datar, executive director of New Harvest, a non-profit that promotes the research and development of cell-based animal products.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. Later in the hour, we'll talk about the microbes that make your smelly cheese and will chew over the future of meat. But first, if you've recovered from COVID-19 or tested positive for antibodies, you might be wondering, can I get infected again? You might have seen reports in the news saying antibodies wane within a few months. You might have also heard about cases of reinfection and then skepticism about those claims. So what's the deal? Can you get COVID-19 twice? And if immunity does wane over time, how long would a vaccine protect us? Here to tell us more, Science Friday producer Ella Fedder. Ella, welcome back. Thanks for having me. So you started working on the story after your friend got COVID-19? Yeah. So back in May, my good friend got tested for SARS-CoV-2 antibodies. If you remember, New York had just started offering these antibody tests for free. And so a lot of people were getting them. I tested negative. But my good friend, whose name I'm omitting for privacy, she tested positive. Which was surprising because I hadn't had any symptoms that I knew of. Like I was thankfully very healthy.

She'd actually been training for a half marathon all throughout that spring, just in great health. So she wasn't expecting this result. And just to be sure, she actually got a second test at another facility. And again, she's, she was positive for antibodies. At the same time, she tested negative for the virus, and then negative again for the virus a few months later. So by all accounts, she'd had an asymptomatic COVID infection and cleared it. And I was really excited by this. I thought my friend is probably immune to COVID. You know, she can walk around freely in a way that most of us cannot. I think I even joke that she was immortal. That was incorrect. In October, I get a text from her that says, she has COVID again. Thankfully, it was a mild case. No fever at all, just, you know, a little bit of stuffiness and congestion. I think after about a week of having just a cold, I started to get

leg tightness in the chest, kind of came and went. And that just, that lasted for a few days and then you were completely fine? Yeah. And so she's all better now? Yeah, she's feeling great now. But for a few months, I was operating under the assumption that my friend was probably immune to COVID-19. I was in closer contact with her than I would have been otherwise. And clearly I was wrong. So I wanted to know, first, what do antibody tests really tell us? And what do we know about reinfection cases at this point? Like, are they really happening?

I talked to a few experts, and the answer to that last question is yes. There are confirmed cases of reinfections. Akiko Iwasaki is a professor of immunobiology at Yale, and she recently reviewed four confirmed cases of reinfection in The Lancet. The first case was from Hong Kong, a man who was detected for the reinfection because of airport screening. But this was actually a good result because this man had a mild infection in the first case, and the second infection resulted in asymptomatic infection. But then there are other cases where the second infection actually resulted in worse disease than the first infection.

One case was a 25-year-old man in Nevada who had mild symptoms in April. Six weeks later, he got infected again, and that second time, he was actually hospitalized. So a second infection can be very serious. So how do we know those patients are really getting infected twice? Could something else be happening? Right. So the question is, were these people maybe infected the whole time, you know, and just had a second flare-up of symptoms? Or was there possibly some mistake with the testing?

And in these four cases, the main line of evidence that this is really, truly reinfection, is that researchers actually sequenced the viruses, and they found that the virus from the first infection and the virus from the second infection were slightly different. Now, even though there are only a handful of confirmed reinfection cases in the whole world, It actually shouldn't totally surprise us that this can happen. In reality, that is very similar or reminiscent of what happens with common cold coronas. That's Alessandro Sete, a professor at the La Jolla Institute for Immunology. And you heard he mentioned common cold coronas. You might know that there are actually seven types of coronaviruses that infect humans.

There's the virus that we've been talking about, SARS-CoV-2. There's the other, older SARS virus. There's MERS, Middle Eastern respiratory syndrome. those are all very serious. And then there are the four coronaviruses that basically give you a regular cold. And we know that with those common cold coronaviruses, immunity is relatively short-lived. Because there are studies where people have actually experimentally infected people in the 90s. Age 90?

No, the 1990s in the UK. Aha, I get it. I didn't know that this was allowed. experimentally infecting people with viruses, but I guess if they're mild enough, you can get approval. But in any case, in this one study, researchers infected a few people with this common cold coronavirus, and then they exposed them again to the virus one year later. And six out of nine subjects did get infected again. But nobody got sick.

So, yes, they could have just enough virus to be detected, but nobody reported. that common cold symptoms. So that's obviously a good thing. But reinfection did happen. So what I'm wondering is, how do our immune systems respond to this coronavirus? We heard him talk about the other cold viruses. What about this coronavirus? Does, do our bodies remember it a few months later? Right. So a few months back, we saw some reports that suggested COVID-19 antibodies were declining pretty quickly, which sounded worrying to a lot of us. But there have been conflicting reports, and I asked Alessandro's colleague, Shane Crotty, who's also an immunologist, about this. So I'd say the area is controversial still. My take on the literature is that most of the

studies are showing antibody is maintained pretty well, actually, and maintained pretty normally compared to other infections. Normally there's some drop after the end of the infection, but not a dramatic loss. And this is important, even if antibodies do. do decline, that doesn't necessarily mean you've lost immunity. One way that I've explained this is actually the hepatitis B vaccine, where it's known that if you have antibodies after the hepatitis B vaccine, you're protected from hepatitis B, and that's great. But those antibodies fade after five to ten years. And actually, the epidemiology has been those people are still protected even though the antibodies are gone. Because when it comes to fighting

and remembering infections, there are other parts of your immune system that are Antibodies are a component from it, but the immune system works in a way that you get infected, you have your immune cells that expand and reproduce, and then they contract, and they remain to a certain level. And so, but if you were to encounter that virus again, even though maybe antibodies have waned, those memory B cells are still there, and they can see. start to make antibodies again on a moment notice. So if I understand what he's saying, he's saying the current presence or absence of antibodies is not a perfect measure of immunity at any given time.

Right, exactly. So reinfection is obviously something we're concerned about. But something that especially worried a lot of people when we heard about these cases is what does it mean for a vaccine? if your body just cannot remember this virus for very long, you know, will your body mount an immune response to that vaccine and then forget a couple of months later? Right. So the type of immune response generated during natural infection with SARS-COVID-2 may be different from those that developed during a vaccine response. And the reason for this is that the coronavirus,

as with any viruses, they employ a lot of evasion mechanism. So an actual virus is trying very hard to hide from your immune system to avoid triggering antibodies or B cells or T cells. Whereas vaccines don't succumb to the same sort of evasion mechanism at all. It's designed to promote the most robust antibody responses by stimulating both innate and adaptive immune responses and longer lasting, hopefully, immune responses. So I don't think any of these reinfection cases should equate to, you know, worries for a vaccine-mediated immunity. Let's hope not. Okay. COVID-reinfection is happening. Now, how common is it? Okay, so it's hard to know exactly. Some cases that look like reinfection might not actually be,

like we mentioned. On the flip side, with cases of real reinfection, a lot of them might be getting missed. Akiko mentioned earlier that case in Hong Kong. The patient got infected a second time, But he didn't know it because he had no symptoms. The only reason that this got caught was because he happened to get tested at an airport. So without a proper epidemiological study, we don't really know how common reinfection is, but Akiko is hopeful. Well, I would think it's fairly rare, even though, like I said, there's a caveat that, you know, reinfections may be occurring a lot more frequently, but because we don't have the viral sequences from the two infections.

it's difficult to prove it. But I have heard of a lot of anecdotes as your friend's case where a person recovers from an infection and then months later test positive. So it's probably occurring, but not very frequently. Great. Let's hope so. But Ira, before we start giving out those antibody passports, remember that there can still be false positives. You know, you think you have antibodies but you do not. And so you could have a significant fraction of the people that think they have a positive test, and thereby we think that they are protected, taking very significant chances. And so that's kind of like driving a car with an airbag that you think it works, but there is no airbag.

So that's a little scary. So, Ira, do not make the mistake that I did. Do not assume because your good friend has antibodies that they are definitely immune. They could be harboring, lingering virus. They might have gotten a false positive. They might get reinfected. So my final message is to stay vigilant. Good words of advice, Ella.

I think so. Thanks, Ira. And I want to thank our guests. Akiko Iwasaki is a professor of immunobiology at the Yale University School of Medicine. Alessandro Sete and Shane Crotty are professors of immunology at the La Jolla Institute for Immunology. And I also want to thank Neil Dunhollander, a retired immunologist in Mississauga, Ontario, for helping me with my research. And thank you, Ella. Ella Fetter, development producer at Science Friday. Great report. We're going to take a break, and when we come back, we're going to talk about stinky cheeses, the microbiome living

in your camembert. And what that smell is? All coming up after the break. Stay with us. This is Science Friday. I'm Ira Flato. What's your favorite holiday smell? Is it the aroma of nicely brown turkey, the scent of cookies in the oven, or the wafting fumes of mulled wine? Well, for some people, when it comes to a unique aroma, the cheese stands alone. If you're a cheese lover, perhaps you prefer the inviting smelly odor of a bloomy rind brie or camember. Enjoy by the fire. That's certainly true if you're a microbe, because new research suggests that the bacteria living on the cheese rind love those funky fumes as much as we do, and we'll gobble them up. My next guest will talk about why that's important and about a surprising discovery about the

wild blue fungi found on the walls of French cheese caves. Dr. Benjamin Wolfe is an associate professor in the Department of Biology at Tufts University. Dr. Casey Cassetta is a postdoctoral research at Tufts and first author on some of this new research. Welcome to Science Friday. Thank you. It's exciting to be here. Hi, thanks for having me. Nice to have you. Ben, let's start with the microbes that live on cheese rinds. Tell us what is the cheese microbiome made out of? So the typical cheese that you would see in a artisan or gourmet cheese market would be something like a camember or brie. And so that white, fuzzy surface that you see is a community of microbes. that includes mold, so the fuzzy white surface, as well as yeast and bacteria. So it's a mix of many

different types of species. It could be anything from two species all the way up to 15 or 20 different species of microbes living together in what we call microbial playgrounds on the surface of cheese. Playgrounds, I like that. What benefit does this fungi and bacteria give the cheese? So one of the main reasons that cheesemakers would grow a rind on the surface is to add additional flavor to really bring out aromas, to bring out various tastes when you bite into that cheese that you wouldn't get from something like a standard plastic wrapped cheddar. So the rind is doing essentially what you see when a log is rotting in a forest. It's decomposition. But in this case, it's delicious rot. The cheese maker is controlling the rotting process as

those microbes break up the proteins, the fats, and the other components of the cheese, the curd, the milk. They release all these flavors that we smell and that we taste. Casey, let's talk about these smelly cheeses. I love the breeze, the camemberes, the blue cheeses, because you discovered that one of the bacteria on cheese is actually attracted to the smelly stuff, or released into the air by the fungi. Is that true? So when these fungi are breaking down these components of the cheeses, they're releasing what we call volatile organic compounds, and those are the smells and the taste that they release into the cheese and into the air. And that's what some bacteria on cheese

are actually attracted to or eating up in a sense. So the fungi are actually feeding the bacteria then? Yeah, yeah. So the cheeses aren't just, you know, tasty for us. They can be tasty for the bacteria. And so why is that important for the bacteria? It's really important for one bacteria in particular called fibrio, and that's because volatile compounds that the fungi are producing, that's the major source of nutrients that this bacterium vibrio uses to grow, and without it, it grows very little. And what happens to the bacteria after they eat the smelly compounds? Did they ingested, and it's really, as you say, food for them? Yeah, so we think that they're somehow taking it up and metabolizing these compounds, using it as a source of carbon, and then really,

taking off and blooming. They're not only taking up food for themselves, but they're taking over the whole rinds, the whole microbial community. So if you can control the release of the smelly compounds, then you can control the growth of the bacteria and perhaps the flavor of the cheese? In theory, yes. That would be like an application of what we've learned here is that if we can kind of use these smells as a means of control or as a means of flavor, That would definitely be very important for some people like cheesemakers or even cheesemakers at home. So some other work in our lab shows that the types of bacteria and fungi that you have in a community living on the Rhine can dramatically impact the aromas that are coming from that cheese. And so what this study shows is that these volatile organic compounds are a way for cheesemakers to dial up or dial down certain microbial members and then impact the overall quality of the cheese.

And this is something that we're learning in cheese, but it's also potentially applicable to other microbiomes where you may want to manipulate or manage the community of microbes. Ben, your previous work discovered how the wild blue fungi found on French cheese caves literally mutates before your eyes to create the creamy white rind we eat and say a camembert. Can you tell us about this? Yeah, so when we look at a wheel of camembert we see this white, fuzzy mold that's really iconic. It creates that amazing appearance and also contributes to the taste of that cheese. And what's fascinating about that microbe is it's domesticated. We think of animals like cows being domesticated and corn being a domesticated plant.

But we don't really think of microbes as being domesticated. And so my lab and also researchers in France are really interested in where did that microbe come from? How did we train that microbe to become the important cheese fungus that it is today? And so through a variety of experiments in my lab, we were able to show that just over a period of a few weeks, you can train this mold from being this blue, musty, sort of also slightly toxic, a microbe that lives out in the wild, maybe you even accidentally have grown it on a piece of cheddar in your fridge, to something that is really tame and white, it produces more mushroom volatile compounds, and is no longer toxic. And so as the fungus is adapting to the cheese substrate, it lets go of some of these wild traits that it has out in nature and is essentially tamed through the process of domestication. Is this the same blue fungus that's found in blue cheese that we eat? And why does that fungus not mutate and turn color white also? It's not the same species, but it's a close relative to penicillium rock four T, which is the blue vein fungus that you find in blue cheese.

So most of the fungi that are used in cheese production are they start from a starter culture, from a microbe that you can actually purchase from a company. And so what these starter cultures are used for is to have stable production of cheese. So essentially to prevent evolution from happening. But what our work is showing is not necessarily what's happening intentionally from cheese makers right now, but historically what may have happened to give us the cheese microbe that is on cam and bear. So we were trying to figure out where did this thing come from historically in the domestication of these molds. Casey, if the bacteria are chowing down on the smelly compounds, does that mean that you won't find this bacteria on the less smelly cheeses? Not necessarily. It's only at a very low concentration where these compounds can have an effect on the growth of these bacteria. So it doesn't have to be a lot of smells and it doesn't necessarily have to be, you know, a particular.

smell. It's really just a whole combination of the smells in general that can allow this bacteria to grow and flourish. So is there a relationship then between the smell and the amount of bacteria? That's a good question. That's not something that we necessarily looked at, but there could be a correlation between the amount of volatiles present or a particular kind of compounds present, and maybe this bacteria vibria that I mentioned that is really responsive to these volatile. there is a correlation that we can find in the lab in terms of concentration in this compound. And we might see that out in real cheeses as well. When you walk into a cheese cave, when you walk into a vault in a cheese cave,

the air is full of all these aromas. And so what we're thinking and what we're going to be testing out in the real world of cheese caves is that even a cheese that's on the other side of the room from another cheese where these volatiles are being produced could be impacted by these volatile compounds. They can travel really far, and in most cheese aging environments, they're at pretty high concentrations. And so we think perhaps cheesemakers are inadvertently creating these feedbacks where they age a cheese in a room. It creates more of the volatiles, and that promotes more of the growth of this bacteria. And you get at this cycle over and over and over again.

And I'll just point out, we sort of started this work being puzzled by this bacterium, Vibrio KCI that Casey's talking about. It's really a marine bacterium, a bacterium that typically lives out. in the ocean. And we have been trying to figure out for a long time, why is it on cheese? Why is it loving cheese so much? And we really do think that this volatile feeding mechanism is one potential explanation for why this marine organism is just loving, living on a wheel of camembert or Limburger. Well, how does a marine organism make its way all away from the ocean into a cave? That's also been a question that keeps us at night. And we don't have all the dots connected yet. but here is our current hypothesis, sea salt.

So when a cheesemaker is making cheese, they add salt. Salt plays an important role in taste, but also in controlling the microbial community that develops on a cheese. And many minimally processed sea salts, you just take the ocean and you dry it out. You just take big buckets of sea salts or salt water, and you dry them out in various conditions, and you get salt. And during that process, any microbes that are present in the water

that can go dormant, can essentially hang out in a bag of salt. And we've plated out sea salts from all around the world in the lab. And we find microbes. We find viable microbes hanging out in the salt. And so what we think happens is using the sea salt that has these microbes, the cheesemakers are inoculating their cheese with these ocean microbes. And we find Vibrio in cheese made in Wisconsin, and in the middle of the continent where it's very far from the ocean.

Ben, some cheeses like Stilton, blue cheese, they don't have a rind, but they still smell. Where do they get that odor from? What's the relationship? So all cheeses will have some aromas coming from them. And that's because microbes live in the paste. And these are lactic acid bacteria. They're used during the part of the milk collection process and culturing the milk. When the milk goes from a liquid to a solid. And there's a fermentation process. process there, and those microbes play an important role in releasing aromas as well. And then in a blue cheese, that blue fungus that makes the veins inside of a blue cheese is also decomposing the cheese and releasing aromas, breaking down fats and making free amino acids and free fatty acids from

fats and proteins. And so all cheeses will have an aroma profile to them. But a cheese like Camembert or a funky wash-drying cheese like Limburger will have a lot more volatile organic compounds being released or VOCs being released just because there's so much more microbial activity and decomposition of the cheese. What else do you want to understand? Are there other fungi bacterial interactions you are interested in? Yeah, so a big part of the last five to ten years of research in my lab and others has really just been figuring out the biodiversity of cheese. what microbes are out there. It's been like a natural history survey for us. And now what we're trying to do, once we've figured out who's out there, is trying to understand why are they there and what are they doing? How are they interacting with each other in these microbial playgrounds? So my lab is really interested in understanding how microbes interact in these microbial playgrounds. And a lot of the work that we're doing is looking at how fungi and bacteria interact with each other. And in some cases, we see cooperation. So for example, we've seen that fungi can make these networks, the mold as it creates that fuzzy layer across the cheese,

is essentially laying out a highway that bacteria can use as an HOV lane to spread across the surface of the cheese. In some other studies in our lab, we're finding that fungi can produce antibiotics that can wipe out certain bacteria. So it's both microbial war and piece on these rinds of cheese. And at the end of the day, what we can figure out by understanding how these parts fit together in this microbiome, we can then understand what is the assembly manual? If we can understand the parts and how they fit together, we can have a blueprint for how to better design and control these microbiomes. I'm Ira Flato. This is Science Friday from WNYC studios. In case you're joining us, we're talking about smelly cheeses and why they taste so good.

You mentioned before about the historical significance of cheese making. It seems to me that the cheese mongers of old had no idea of the chemistry that was going on inside, yet they were still making good cheese, weren't they, Ben? Yeah, in many ways, cheese making and a lot of fermented foods are just happy accidents. We happen to get the right types of microbes growing on the right substrate at the right time, and if it didn't kill you, it tasted great, and we kept making that over and over again. And so through the process of these happy accidents, we've figured out what microbes can make delicious cheese, and we've then isolated those microbes and now work with them in a more controlled way to inoculate cheeses. We've also figured out that there are important

parameters like temperature and the right amount of salt that you can add to control that microbiome and develop a delicious and high-quality cheese. But there's still a lot to learn, right? We've only, in the last five or ten years, really discovered that full biodiversity that's there, and now we're still trying to figure out, what are we missing? What are other components of the cheese system that we maybe don't understand? Viruses, for example, there's a lot of viruses that naturally live in these microbial playgrounds that we're beginning to learn can attack bacteria and eat up certain bacteria. And those may play a really important role in these ecosystems. The phages, that week.

Phages, yeah, we're a really big fan of the roles that phages could play in these systems. Casey, are you going to make cheese your research specialty now? I mean, think of food tasting you'll have to submit yourself to. Oh, my goodness. I know. It seems like such a tough job. I'm continuing some cheese research right now in the position that I'm in, but I'm hoping to kind of branch out and translate kind of what I've learned from cheese and the cheese microbes out into other systems as well. Such as, what kind of things can you take from this? There's a lot of things that are very similar in cheese systems to other systems. We see a lot of similar microbes that we find on cheese on our own human skin.

So some of those interactions or some of those cooperations or competitions that we find on cheese, maybe we can translate to other systems. And it could be a clinical sense. It could be an industrial sense. It's really pretty diverse of what we could potentially translate. Ben, one of our favorite topics is the microbiome on Science Friday. And we're so happy to hear that it's everywhere, even on the cheese. Yeah, and really our lab is a microbiome lab. We happen to study cheese, but we're generally interested in understanding how microbiomes work. And this is a big question right now in many labs that study humans or plants or soil. And we're all trying to figure out these assembly rules, the guidebook to help us figure out how microbiomes come together. And once we can figure out these ways that microbial parts fit together will be much better at managing diseases or,

maybe making probiotics more successful for humans or for agriculture. And this microbiome living on cheese is a great model system to do that. It's relatively simple. We can grow the microbes easily in the lab. And so it's been a great lab rat for the microbiome world to understand basic design principles for microbiomes. We've run out of time. I want to thank my guest, Dr. Benjamin Wolfe, associate professor in the Department of Biology at Tufts University, Dr. Casey Cassetta, postdoctoral researcher at Tufts.

and first author on this new research, thank you both for taking time to be with us today, and happy holiday to you. Thank you so much. Thanks. And if you want to see some of those bacteria cheesing for the camera, we have pictures and videos up on our website at sciencefriety.com slash cheese microbe.

After the break, we're talking about the future of meat, which may not involve animals at all. This is Science Friday. I'm Ira Plato. if you were celebrating Thanksgiving yesterday, I hope you had a happy and safe gathering. Perhaps you were one of the people on Thanksgiving who finds a substitute for eating that iconic turkey. You might be avoiding meat because the meat industry is a huge contributor to climate change. Almost 15% of greenhouse gas emissions come from livestock.

And cattle make up about two-thirds of that. Or maybe you just don't believe in slaughtering animals. Well, you might be a harbinger of the future. which makes us kind of think about what does a future without meat look like. Joining me today as someone who has made it his goal to disrupt the meat industry, Pat Brown, CEO of Impossible Foods, based in Palo Alto, California. Welcome to Science Friday. Thanks, Ira. Now, you were a very accomplished biochemist, I understand, for many years before you found it in possible foods. Tell me a little bit about what inspired you to dive into the plant-based,

meat sphere? So at the time that I decided to do this, I had been a professor in the Medical School of Stanford for 25 years. And I never contemplated going into the business world. And I wasn't actually that interested in food. But when I had a sabbatical about 10 years ago, I basically challenged myself to find the most important problem in the world that I could contribute to solving. And when I did my research, I realized that the use of animals as a food technology is by far the most destructive technology in human history. It is far more destructive to the global environment generally than the fossil fuel industry, for example. And you, I'm sure, know that we're in the advanced stages of a catastrophic global collapse of biodiversity. And it's

almost entirely due to our use of animals as a food technology. Eliminating the use of animals in food production is the way and the only way that I can imagine to actually turn back the clock on climate change. There's very simple math I could take you through, but if I could snap my fingers and make that entire industry disappear in this second, 20 years from now, total atmospheric greenhouse gases would be not higher, but back to where they were in 2015. And so I quit my job at Stanford, which I loved, and dove into solving the problem. And basically, the thesis was, we don't want to get rid of meat. We just want to find a better way to produce it. It's just like 200 years ago, people didn't want to get rid of transportation. They just wanted to find a better

technology than the horse. We're taking the same approach. And I decided that it was a completely solvable scientific problem to understand in molecular terms what creates the sensory experience that meat lovers crave in molecular terms, what's the mechanism underlying the juiciness, the texture, the flavor chemistry, and so forth, and that we ought to be able to reproduce that far more sustainably by finding scalable, sustainable ingredients from plants that can be put together to not only deliver that deliciousness, but actually do a better job. Impossible Foods created the very popular Impossible Burger, made from soy protein, teens. Does Impossible Foods plan to dive into more types of plant-based meat?

Oh, sure. You know, when you look at Impossible Foods from the outside, you know, we look like a food company, it's in our name, but actually behind the scenes, we think of ourselves as sort of a planet technology company that's literally trying to save the planet with science and engineering. And we chose brown beef as our first product, basically because we thought would be the most disruptive product. Our goal is to completely replace the use of animals as food technology by 2035. And part of understanding that goal is our goal is not to be a massive food company. It's to eliminate the incumbent technology as fast as possible.

We chose ground beef because more than half of all the beef produced in the U.S. is sold as ground beef. And our approach is market-based. We felt that if we could make a better version, a version that did a better job of giving meat, what they want from meat, that we could compete in the marketplace and have the biggest disruptive impact. When you say compete in the marketplace, it sounds like you're trying to win over not vegetarians, but meat eaters. Oh, absolutely. Look, I've been vegetarian in my entire adult life. I love vegetarians, okay? But we're not here for vegetarians. We're not interested in making food for vegetarians. We focus relentlessly on how to make meat consumers happier, okay? This

depends on making our product, not just a sad little imitation of meat, but uncompromisingly delicious to hardcore meat lovers. And I think we've succeeded pretty well, actually. And as it turns out, more than 90% of the consumers that buy our products in restaurants or in retail are current meat consumers. And once they try our product, 75% of them become repeat consumers. The fact that most meat today is made from the cadaver of animals is not part of the value proposition to people who love meat. They love meat not because it's made from animals, but in spite of the fact it's made from animals. They love it because it's delicious, nutritious, convenient, affordable. If you can deliver that without using the animal to make it, consumers are wide open to that.

And we see that in the market. I want to now bring in our second guest who is also working, on the future of meat in a very different way. Isha Dattar is Executive Director of New Harvest, a nonprofit that promotes the research and development of cell-based animal products. She's based in Edmonton, Alberta. Of course, that's in Canada.

Welcome to Science Friday. Thanks for having me, Aura. Briefly tell me what is cell-based meat? Cell-based meat is the idea or the concept of producing meat from cell cultures rather than from the carcasses of animals. And before I dig too far as the meat side, I think the concept that we are excited about

is the production of all kinds of foods, even beyond meat, such as milk and eggs and perhaps even more products that are produced from cell cultures rather than from whole plants or animals. Where are we in research and development of this type of product? That's a great question. So this is an interesting field

because there is quite a lot of private investment in this space right now, just this past June, we crossed over into over a billion dollars invested into hundreds of companies around the world producing meat, milk, and eggs from cell cultures. But on the other side of things, the public funding side is actually quite underfunded. And I would say the R&D is at the point where we're seeing a lot of companies taste testing prototypes and slowly scaling up. But we don't have a huge understanding behind the fundamental questions of this research,

such as, you know, what constitutes as meat versus cell culture. You know, when does that transition take place? And also, how do we actually produce this at a scale that is cost competitive? Give me an idea of what cell-based meat tastes like. Ooh, I was able to taste a cell-cultured meat product in the form of a chip several years ago. And what was cool is it had the same mouth feel as a potato chip, but it was made entirely from muscle cells. And what was so exciting about that taste test was realizing that by producing foods from cell cultures, we don't have to mimic the meat that we know today.

We actually have this enormous culinary opportunity to apply this technology in ways to make proteins that we've kind of not experienced before. So we're not really very close to going to a burger shop and getting a set. cell-based meat hamburger? Well, that's a tough question. I think what most people think of when we think of a cell culture meat product is a product that is 100% grown from cells, grown in a bioreactor somewhere. But there are several companies who want to put a product on the market within the next five years. I think we just need to readjust our understanding of what that product might be.

And it might be something kind of similar to what Pat is working on, which is largely plant-based. East Burger with some cell cultured elements incorporated or some animal cells incorporated. And that's the kind of product that I think we could see on the market pretty soon. Is that because you think that the plant-based or Pat's product is very competitive at this point and they'll get a bigger audience while you're still a little bit behind? No, I think it's because there's this idea that cell cultured products and plant-based products are these two discrete categories. But instead, we should think of them as two toolbox. that we can access in order to create alternative meat products that address all kinds of

different markets and different tastes and experiences. And I think that, obviously, from a cost perspective, it's going to be a lot more reasonable to introduce something that is plant-based with some self-cultured elements than it will be to introduce something that is 100% self-cultured. So I think it kind of opens the door a little bit. And also from a regulatory perspective, it's probably a lot easier. to introduce something where the cell culture elements are an ingredient rather than kind of the bulk of the product. And I guess you should think of it as slowly opening the door towards

and slowly transitioning towards more cell culture products. That being said, I think our nonprofit has the same goal that Pat does, which is to minimize the impact of animal agriculture today. And the outcome that we're looking for is that positive impact on the world. And we don't No, for sure, if the cell culture product is really the goal, and if the 100% cell culture meat is going to be the thing that causes that change. Pat, I understand that you're not a fan of cell-based meat. No, that's not quite correct. If the cell-based meat could become a product that can compete successfully in the market

against the animal cadaver products, I would be its biggest fan. I just don't think that, from my understanding of the technology, that it really is economically scalable. And when you're making it directly from primary ingredients, distinct sort of proteins and small molecules and so forth, you control all the knobs. And in a way that's a lot harder to do when you're basically stuck with sort of genetically pre-wired animal cells.

And that enables something that I think is really interesting, which is that when we have, and I'd say we're close to it right now, a meat product that's as good as the best version from an animal, the next day we can make it better. We can dial in the flavors and textures and juiciness and form factor and so forth with a blank slate. But honestly, I just want to say, Isha, I'm a fan of what you're doing and the companies that are working on cell cultured meat, and I wish them the best. I just don't see it being economically competitive. Before I get an answer for you. from Isha. Let me remind everybody that I'm Ira Flato and this is Science Friday from WNYC

Studios. In case you're just joining us, we're talking about cell-based meat and the impossible burger and a meeting of the minds here. Isha, how do you react to Pat's statement? Pat has very many legitimate concerns about the scale-up of the technology and all the more informed by his background in biogynastry. This is novel science in many respects and I think that's That's why New Harvest approach has been very much about how do we build the field and discipline that continues to ask these questions. I think a lot of us believe that growing various proteins from cell cultures rather than from whole animals can have these enormous benefits.

But there's a lot of fundamental questions we need to ask about scaling up. You know, what does the supply chain look like? Where will the starting materials come from? And, you know, can we make those research quantum leaps that allow us to. mass produce certain types of proteins using these cell culture technologies. Further to his statement about tuneability, I think that's another piece that we're extremely excited about. We had one of our research fellows out of Tuft University recently published on changing the kind of nutritional content of meat that we will soon be able to do if we

introduce these cell cultured ingredients. Pat, I've heard an argument from some people that they'd like to try meat alternatives, but feel that the impossible burger is plant-based, but yeah, but maybe just too processed. Yeah, I think that that's a very unfortunate label. When people think about processed food and the things that are problematic with the foods that are commonly called processed foods, isn't that they were produced through a process. I mean, a loaf of bread is highly processed, You know, everything from harvesting the wheat to, you know, mixing it with yeast and salt and maybe olive oil, which has been processed from an olive, pretty much everything that is food on the table. And just think of it when you're eating your Thanksgiving dinner, what the process was by which it got there.

And don't even get me started about meat from animals comes from a process. The reason that the term has taken on kind of a pejorative meaning is because of tweeter. pinkies and potato chips. The problem with those foods, it's that they were made with no concern for the nutrition of the consumer, that they're full of junk. You know, they're full of sugar and fat and calories and very devoid of valuable nutrients. That's the problem. So what I would say is read what's in the product, read the nutrition facts. That's what should be important. But people who look at that package, if you look at the ingredients on the list, there are a lot of ingredients in that package?

Well, I would say, think about how many ingredients go into making your Thanksgiving dinner. Like, there are people who even will say, you know, like, there's too many syllables in that ingredient. Like, it's nuts. Pay attention to what those ingredients are, what the nutritional facts are, did the producer of this food, whether it's your grandma or impossible foods, produce it with your health and well-being in mind, which we see? certainly do. One last question for you. I know you're a privately held company. You're not traded on the

stock market. Do you feel like if you became publicly traded, you might lose control of the quality of what you're trying to do? That is probably the principal reason why we've held off ongoing public. I didn't found this company because I wanted to found a business because I'm trying to save the planet from environmental catastrophe. And it's critically important for us. to have the ability to stay focused on the long-term mission. Isha, I have one last question for you, and that is my blank check question, because, as you've said, there is still a lot to learn about your technique. If I could give you a blank check, like I have in my back pocket, sorry, I can't give it to you,

you're not here? Yeah, really. What would you do with it? What kind of technology? What kind of resources do you need? How would you spend it? That's a great question, Ira. And I love how Patrick talked about kind of the long view here because what I think we need to see

is cellular agriculture become an established discipline and a area of research that a high school student can enter and want to contribute to producing animal products without animals or producing all kinds of foods in this new way. And I think, you know, the food science field could use this kind of reinvigoration of skills from sciences that were kind of normally focused on medical technologies applied to food science. So if you handed me a blank check, what I would do is create the first Institute of Cellular Agriculture at some university, somewhere in the world, but a university that uniquely brings together excellence in agricultural and meat sciences and excellence in biomedical technologies

and establish kind of the first place for this field to develop. And from there, we can kind of create the scientific infrastructure of the industry that we want to build. That is a great place to end it. That's all the time we have for this hour. I'd like to thank my guests, Pat Brown, CEO of Impossible Foods, based in Palo Alto, California. Isha Dattah, Executive Director of New Harvest, a nonprofit that promotes the research and development of cell-based animal products. She's based in Edmonton, Alberta. Thank you both for taking time to be with us today.

Thanks, Sarah. Thanks so much. Charles Berkowitz is our director. Our producers are Alexa Lim, Christy Taylor, Katie Feather, Kathleen Davis. BJ Leatherman composed our theme music. Have a great holiday weekend. We'll see you next week. I'm Ira Flato.