Today, you’ll learn about how your brushing routine may not be the biggest factor in whether or not you get cavities, how a new method of building pharmaceutical production facilities may bring medical access to previously underserved regions, and how the discovery of a plastic-eating bacteria could revolutionize the recycling industry.
Today, you’ll learn about how your brushing routine may not be the biggest factor in whether or not you get cavities, how a new method of building pharmaceutical production facilities may bring medical access to previously underserved regions, and how the discovery of a plastic-eating bacteria could revolutionize the recycling industry.
Brush but STILL get cavities? You’re not alone (and brushing isn’t enough).
“Why People Who Brush Still Get Cavities” by Maggie Koerth
“How Can You Get Cavities If You Brush Your Teeth?” by davis & Beyer Dental Health Professionals
“History of Sugar” from Wikipedia
BioNTech is now making vaccines on the go.
“BioNTech plans to make vaccines in shipping containers” by The Economist
“BioNTech Covid vaccine plan to ship container labs to Africa” By Jenny Hill
“____-Eating Bacteria” is now nothing to fear! It could be the future of recycling.
“The Future of Recycling May Be in Microbes” by Ula Chrobak
“Scientists uncover the secrets of a plastic-destroying enzyme” by Abe Musselman
“Plastic-eating bacteria: Genetic engineering and environmental impact” by Scott Dutfield
"Endlessly recyclable materials could fix our plastic waste crisis" by Katharine Sanderson
Follow Curiosity Daily on your favorite podcast app to get smarter with Calli and Nate — for free! Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/the-true-cavity-culprit-modular-meds-enzymes-vs-plastic
TITLE:
THE TRUE CAVITY CULPRIT, MODULAR MEDS, ENZYMES v. PLASTIC
Follow Curiosity Daily on your favorite podcast app to get smarter with Calli and Nate — for free! Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
NATE BONHAM: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from Discovery. Time flies when you’re learnin’ super cool stuff. I’m Nate.
CALLI GADE: And I’m Calli. If you’re dropping in for the first time, welcome to Curiosity, where we aim to blow your mind by helping you to grow your mind. If you’re a loyal listener, welcome back!
NATE: Today, you’ll learn about how your brushing routine may not be the biggest factor in whether or not you get cavities, how a new method of building pharmaceutical production facilities may bring medical access to previously underserved regions, and how the discovery of a plastic-eating bacteria could revolutionize the recycling industry.
CALLI: Without further adieu, let’s satisfy some curiosity!
[SFX: Whoosh]
CALLI: Nate, do you want some of this toffee?
NATE: Ah, you know I love the stuff, but I’ve been trying to stay off of the sticky stuff. Avoid the cavities.
CALLI: That's a good plan, but did you know that while diet and oral hygiene play a big role in getting cavities, the bacteria that live in our mouth might be responsible for how sensitive we are to tooth decay?
NATE: That's wild, but the thing I always wonder is, why do we get cavities at all? I would have figured that evolution would have selected for those of us who are more resistant to getting cavities?
CALLI: That's such a good question. You might be surprised to learn that cavities are kind of a new phenomenon. Ancient humans didn’t really get cavities. In fact, when we find an ancient skull that does have a cavity, it causes quite the stir.
NATE: When I was a kid my cavities raised a stir too, it just wasn’t a very good one. And usually came with being forced to drink less soda.
CALLI: (Laughs) Well it might not all be your fault Nate. Cavities started becoming more common as our diet transitioned from being hunter-gatherers. As we started farming, our diet included more carbs and sugars, and our teeth started to decay. This trend really took off in the 19th century when we kicked our refining of sugar and grain into overdrive. For example, Great Britain’s consumption of sugar increased fivefold between 1710 and 1770.
NATE: So the boom in food production may have come at the cost of a little tooth pain?
CALLI: Exactly. But interestingly, researchers think it's not just what we ate, but what else was in our mouths.
NATE: What else was in our mouths? A tongue? A good tune? The whispered name of a former lover?
CALLI: (laughs) Nate it's just ... bacteria. Unfortunately, the biome of our modern mouth is often dominated by bacteria that cause tooth decay. Our ancient ancestors had mouths full of a wide scope of bacteria. All kinds were in there. But, as our diets changed, the bacteria in our mouths became a lot less diverse. Not all of these bacteria are bad, but some of them, like Streptococcus mutans can cause tooth decay and cavities.
NATE: I can understand sugary and acidic foods causing cavities, but how would bacteria cause a cavity?
CALLI: These specific, cavity-causing bacteria eat the sugar and carbs that build up on our teeth. Rather than cleaning it off, though, their digestion ... creates byproducts, which ferment to make natural acids. Those acids sit on our teeth and dissolve the enamel.
NATE: Ahh, like acid rain melting away marble statues. But then why do some people who brush away those acids on the regular get cavities, while others who barely pay attention to their oral hygiene don’t?
CALLI: Nobody said life was fair, Nate. Our oral biomes are complex, and some folks have more of the cavity-causing bacteria in their biomes than others. What’s wilder is that research is showing that in animals, if you put a cavity-resistant individual with other animals who are more susceptible to cavities, the animal who was resistant will start to form cavities as well!
NATE: You mean ... they are kind of passing this bad bacteria along? Oh man, is that true for family units then? Am I impacting my friends’ and family’s oral health just by being around them?
CALLI: In this way, cavities aren’t just a hygiene thing, they’re sort of like a transmissible infectious disease. Research shows that knowing how susceptible to cavities the parents and daycare providers are can give us a good idea of how likely a child is to get cavities themselves.
NATE: Well if we can “catch” cavities, can we treat them and beat them too?
CALLI: Some researchers and scientists have wondered about rebooting our mouth biome with a “spit transfer,” from someone whose mouth has less of the cavity causing bacteria. But we don't know enough about mouth biomes to know if it would work ... or ... potentially make things worse.
NATE: Spit transfer is even less romantic than swapping spit.
CALLI: It’s not a kiss, Nate. It’s a medical procedure.
NATE: If you do it wrong, it kinda feels like one.
CALLI: Plus, our biomes are constantly changing. We don't know exactly how it works yet. Right now, we have these correlations between the bacteria and cavities, but it’s possible they’re both caused by another thing entirely.
NATE: If my doctor can’t spit in my mouth for science, what can I do?
CALLI: Well…brush twice a day, floss, use mouthwash, and avoid refined sugars and carbs.
NATE: So, what I have been doing?
CALLI: It's still good advice that will make your mouth less acidic, and a less friendly environment for cavity-related bacteria like Streptococcus mutans, even if it doesn’t reset your oral biome.
NATE: I’m going to go brush again now.
CALLI: Good, you’ve had something in your teeth the last hour.
NATE: What?!
[SFX: Whoosh]
NATE: Calli, I’ve been thinking about this restaurant I went to in New York. I’m craving their soup dumplings.
CALLI: So, why don’t you order them?
NATE: You see, that’s the thing. I live thousands of miles away. The cost of getting them to me in good quality, the work, the resources used. It’s no small task.
CALLI: So, get other soup dumplings.
NATE: Clearly you’ve never had these soup dumplings. There’s no replacement. Anyway, I’ve got a feeling the scientists at BioNTech were craving soup dumplings when they came up with a new idea in vaccine manufacturing.
CALLI: What do you mean?
NATE: Well, BioNTech—you know, the company that created the first mRNA vaccine—has developed a system to create mRNA vaccines in modular shipping containers. If the idea works, these vaccine facilities could be shipped around the world and make millions of vaccines in under-served areas each year.
CALLI: Ah, so they’d be easier to get to the places that need them. Like your dumpling place...
NATE: Grand Sichuan.
CALLI: Right, like Grand Sichuan opening a second location on your corner.
NATE: Yes! I’d have a much easier time getting what I need. And, there's SO much disparity in vaccine access and THIS could be the solution. Only eleven percent of Africa’s population is fully vaccinated. Creating vaccines on the continent would make the supply easier to distribute, which would possibly help raise those numbers.
CALLI: So how do you go from making vaccines in a dedicated lab to making them in something normally used to ship Nintendo Switches, cheap t-shirts, and crowd-funded table games around the world?
NATE: Well vaccine production is a really complicated and specific process. Things like local temperature and atmospheric pressure all have effects on the production and machine functions. Each of these things has to be accounted for and adjusted to create a high quality vaccine. So ... you have to tweak the fifty-thousand-step mRNA vaccine recipe to fit in this new environment. It’s important to note that pharmaceutical companies already do this whenever they open a new, traditional, vaccine production facility.
CALLI: But, isn’t that even more challenging in a container?
NATE: Yes and no. You see, these new facilities would be more standardized. Shipping containers are reliable, and the build-outs could be repeatable. They could clone facility after facility into new shipping container setups, without having to worry about different dimensions or layouts. Updates would be easier to roll out as well.
CALLI: But is speed the biggest concern? How do we know these facilities ... which look so unimpressive, by the way, maybe unrelated ... How do we know they'll make the same quality vaccines? I’m not interested in soup dumplings on my corner if they’re not as good as the original.
NATE: Well, this isn’t dumplings. This is pharmaceutical manufacturing. If they can’t keep the standards up, you’ll never even see them.
CALLI: Right. It’s not up to the kitchen. These vaccine facilities will have to be given the stamp of approval by the local government.
NATE: Exactly. Now, if all goes well, it could significantly lower the cost of vaccine production, and each container facility could create forty-to-sixty-million doses a year with just four or five operators.
CALLI: Oh man! That's a ton of doses, when could we hope to see the first container produced vaccines?
NATE: About two years from now.
CALLI: Two years from now, will we still need COVID-19 mRNA vaccines?
NATE: We very well might. I hope the pandemic will be far behind us at that point, and if it is, these facilities can be used to make and distribute different drugs and vaccines, like those for malaria and tuberculosis.
CALLI: Ah so this isn’t a shortsighted plan?
NATE: No, BioNTech hopes the system revolutionizes how we create drugs and vaccines ... not just in Africa ... but in areas ... especially underserved ones ... all over the world.
CALLI: Hey, maybe next, BioNTech will get into the dumpling biz, put up container shops all over the place.
NATE: I know vaccines are important and all, but I think they should switch their focus to that, yeah.
[SFX: Whoosh]
CALLI: Nate, are you nervous or something? What’s going on?
NATE: (chewing) I’m recycling.
CALLI: You’re chewing on a water bottle.
NATE: Exactly, I just heard of this thing called enzymatic depolymerization, a process that uses enzymes to break down plastics for recycling.
CALLI: Okay, now I see the connection. You have enzymes in your saliva, so you think your saliva is breaking down the plastic?
NATE: ... I don’t really, but I wish I did. Plastics are a huge environmental concern, and we need better solutions to deal with them.
CALLI: We’re recycling, aren’t we?
NATE: Yes, but sadly, traditional recycling, often called thermomechanical recycling, can only be done a few times before the plastic is no longer usable. Often you only get three times! Then, the plastic gets too brittle to be reused anymore, and it ends up right where it would’ve ended up.
CALLI: In the black bin instead of the blue bin.
NATE: Exactly, in the trash, in the landfill. Or, if you’re a real jerk, just on the street, or in the park, and eventually probably in the ocean. And that’s a problem. Plastics don’t break down easily. They’re made of these things called polymers.
CALLI: Polymers. Many mers?
NATE: Yes! In fact, polymers are long strings of monomers.
CALLI: Polymers, monomers. I’m getting that plastics and “mer” are related. Plastic man? Mer-man. All those plastic ornaments at christmas, they’re made of frankincense-and-mers. Plastics made of hushed words are ... ?
NATE: Murmurs.
CALLI: You got it! Okay so, tell me Nate, how do we solve the mer problem?
NATE: Well, for one, you make and use less plastic in the first place. That’s the biggest one. Reduce, THEN reuse, THEN recycle. That’s the order for a reason.
CALLI: Okay, so assuming we’ve reduced and reused, now we need to recycle. What’s the move?
NATE: Basically, you’re hoping to turn the polymers from the plastics into monomers, which you can then build back into new polymers. And those new plastics will be like brand new. If you can do this successfully, you can do that essentially forever. Not just three times and then into the bin. And that’s where enzymatic depolymerization comes in.
CALLI: De-polymer-ization ... I get it. Breaking down plastics. Enzymatic ... using enzymes?
NATE: Bingo. Enzymes are really interesting. Organisms of all kinds use them to break down chemicals into other things. We digest food this way, into energy and other component resources. And in 2016, scientists at the Kyoto Institute of Technology and Keio (KO) University, both in Japan, discovered a bacteria that can digest an incredibly common plastic called P-E-T, down to its monomers, using two enzymes.
CALLI: A bacteria that eats plastic?
NATE: Yes! It was a monumental find, and, though enzymatic depolymerization had been around before then, it really started taking off once they found this special combo of enzymes. And scientists in the field have been improving on the enzymes ever since, through genetic modification. The big goal is to be able to make those old plastics good as new, and eventually eliminate the need to make new plastics at all.
CALLI: Lofty goal.
NATE: Indeed.
CALLI: I mean, it all seems great, in theory. So ... what are the downsides here?
NATE: Well, for one, you’re always competing against making new plastic.
CALLI: That’s easier?
NATE: Yes, way easier. Those methods and technologies have long since been established, made efficient and cost-effective. And there are stores of petroleum just waiting to be used for that very purpose. The price of oil is cheap, too. So, until they can make the actual recycling cheaper than making new stuff, it’s going to be hard to convince companies to do it. Another downside is that it uses more energy.
CALLI: Ah, that’s not great.
NATE: An interesting counter-argument to that comes from the chief science officer at Carbios, a French company working to commercialize enzymatic depolymerization. He says that the traditional methods aren’t even really recycling.
CALLI: How’s that?
NATE: They’re extending the life of the plastic by a couple uses, but, since it’s not infinitely recyclable ... well, it’s like we were saying before.
CALLI: All that stuff ends up in the bin.
NATE: Eventually, yeah. So, more energy, but for something that really works. Also, it does take less energy to recycle this way than it does to make the P-E-T in the first place. Another downside is that there are plastics this may never work for. Like polystyrene, and PVC. They have strong carbon-carbon bonds that enzymes might never be able to break down.
CALLI: So, we’ve still gotta reduce THEN reuse THEN recycle.
NATE: As always.
CALLI: So what’s next for enzymatic depolymerization?
NATE: Develop a process to recycle blended materials. A lot of the P-E-T out in the world is mixed with other materials and, therefore, isn’t easy to break down in this way. Stuff like that isn’t recycled, it’s thrown out. And then of course there are needed policy changes. In Europe, things are beginning to shift. Policies are being enacted that incentivize the use of recycled plastics over virgin plastic.
CALLI: That’s a boon.
NATE: And with oil prices rising, it’s possible the balance will shift, and recycling will be the more viable option even from a capitalistic standpoint.
CALLI: If this doesn’t work out, I think we can all agree it’ll be a major ... plastic made out of the British word for butt.
NATE: Huh?
CALLI: Bum-mer.
NATE: Calli, you’re fired.
CALLI: Yep, I totally get it.
[SFX: Whoosh]
CALLI: Let’s recap what we learned today to wrap up. While brushing, flossing, and watching your diet will help you avoid cavities, new research shows that some might slip through from an unexpected source: bacteria. While our oral biome is full of bacteria, some are more prone to break down our enamel, and cause cavities in, even the most rigorous brushers.
NATE: Vaccine production might soon be going global, and local. Pharmaceutical company BioNTech has developed a new system to ship vaccine production facilities around the world, built inside shipping containers. If it works, the system could vastly increase distribution and lower costs, all while maintaining vaccine quality.
CALLI: Innovation in recycling shows promise for the goal of recycling plastics indefinitely, compared to current methods, which can only recycle a given plastic a few times. Companies like Carbios are using enzymes to break down the plastic polymers into their component parts to be remade anew. Hopefully they will make the need for new plastics obsolete.
NATE: Join us every Monday, Wednesday and Friday to learn something new in just a few minutes.
CALLI: And until then, stay curious!