SciShow Tangents - Mucus

Episode Date: January 22, 2019

Mucus grosses people out. Whether it’s coming out of your nose or slime oozing from an animal, it’s not really a pleasant substance. But scientifically, mucus is super cool—it can be used for protection, hunting, lubrication, or plain old stickiness. Why do some cephalopods spew out specialized mucus? Does slathering snail slime on your face actually do anything to your skin? And could eating boogers be… good? Sources:[Truth or Fail]http://science.sciencemag.org/content/328/5979/704https://www.mbari.org/mbari-researchers-discover-what-vampire-squids-eat-its-not-what-you-think/https://pdfs.semanticscholar.org/b94c/447075249a39cac514cbb3c6bf24c4e8306c.pdfhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4052311/[Fact Off]Snail mucus:Parasitic worms:http://blogs.discovermagazine.com/discoblog/2010/12/02/a-new-treatment-for-bowel-problems-eating-1000-parasitic-worm-eggs/#.W-ICt3pKgW8https://www.ecco-ibd.eu/index.php/publications/congress-abstract-s/abstracts-2015/item/p389-a-double-blind-clinical-trial-on-trichuris-suis.html[Ask the Science Couch]https://www.ncbi.nlm.nih.gov/pubmed/11465519https://aem.asm.org/content/81/1/332.longhttps://www.ncbi.nlm.nih.gov/gene/727897https://virologyj.biomedcentral.com/articles/10.1186/1743-422X-3-99[Butt One More Thing]https://www.nationalgeographic.com/science/phenomena/2016/05/10/how-this-fish-survives-in-a-sea-cucumbers-bum/

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. Joining me today, as always, are Stefan Chin, producer of SciShow. Stefan, what's your tagline? Stay a while and listen. Guaranteed that that's what's going to happen, because otherwise it will be an unsatisfying podcast experience. We're also joined by Sam Schultz.

Hello. You're up. I don't even know what your title is. Producer at large. Is that a thing? What's your tagline? Pow, pow, power wheels. Thanks.

And Sari Riley is here as well. Hello. Editor and writer of various things. Sari, what's your tagline? Spilled water on my computer today. Did you really? Yeah. It still works, though.

It didn't for 10 minutes. Oh, no. That's a long time. I once poured beer into the back of a computer. It didn't for 10 minutes. Oh, no. That's a long time. I once poured beer into the back of a computer. It wasn't even my computer. It was Catherine's. And it was a really scary evening as I kept going back to check and see if it would work and eventually just turned right back on.

And I'm Hank Green. My tagline is bunny nuggets. So every week here on SciShow Tangents, we get together to try and one-up, amaze, and delight each other with science facts. We're playing for glory, but we're also keeping score and awarding Hank Bucks to the people

who impress us with their poetry or their science facts. Whichever it happens to be. We do everything we can to stay on topic here at Tangents, but the podcast is after after all, called SciShow Tangents. So if somebody on the podcast goes on a tangent and we all deem it unworthy, we will force you to pay up one of your hank bucks.

Now, as always, we're going to introduce this week's topic with the traditional science poem this week by me. The largest protein in your body is a massive giant in your muscles. It binds them together, strength and power, yanking your bones, bearing the weight of your water and flesh, ripping your feet over soil, crushing the bones of your food. That ultimate protein, power beyond measure, a good story to tell, and that is what we say. But it's a lie. The largest protein in your body might be nothing except MUC5AC, not Titan, that giant, that beautiful thing.

It might not be the best story, but it's the one we've got. The largest protein, my friends, I think is in your snot. That's cool. Titan, I've always heard, is the largest protein, my friends, I think is in your snot. That's cool. Titan, I've always heard, is the largest protein over and over again. And these glycoproteins, they're oligomers. So they're polymers, basically. But they're oligomers, which is a different kind of polymer, which means it's not the same unit over and over again. It's different units.

But Titan is like, it's huge. So what is Titan? Titan is one of the proteins that makes your muscles work. And I'm not going to get super into it because this podcast is about mucus, which is what we've just introduced with the science poem. I think it's like four megadaltons. And that's very big. Usually molecules are measured in kilodaltons. It's a unit of mass. So this is this big old biggest protein in your body.

It's not just kilodaltons, it's megadaltons. And it's four megadaltons. There are mucins, these mucus proteins. And this is the biggest one I found. 40 megadaltons. How many megadaltons does a French fry weigh? A whole lot. So in grams, this is like 10 to the negative 17th.

Okay. So very small still. What does it do? Makes your boogers boogery? It just makes your slime slimy. Is that why it's so slimy compared to everything else? Because it has the biggest proteins? I think that's kind of the idea of mucus is that you want these very long chains that have lots of hydrogen bonding opportunities with each other.

And so they stick together in the same way that like a rubber band is also made of long chain polymers that sort of stick together. And they're really high molecular weight molecules that intertwine with each other. And then they can stretch and bend and stuff. We're doing real science now. Oh, yeah. Mucus is super science-y. Oh, it's great. So the reason I say maybe is that like I don't actually know how they weighed these proteins.

And so were there water molecules that are like bound into the protein that they weigh or what? But like 40 megadaltons is a very big protein. They don't have a cool name though. Mucin is fine. Yeah, Titan is better. So the topic of today's discussion is mucus. Sari, can you explain what mucus is more like a general science answer to that question? Yeah, we already kind of talked about it.

It's in my body right now and coming out of me. So I'm method podcasting. Sarah's got a terrible cold. It's more than halfway through a roll of toilet paper on the day. It's really gross. She's blowing her nose with the toilet paper. Yeah, I got my flu shot. So it's not that.

This is definitely rhinovirus or some sort of cold nose thing. Anyway, mucus. It's in your sinuses. It's in your throat. It's in your lungs. It lines your stomach to protect it from acid. It lines your intestines. You have mucus membranes. So like your eyes, ears, I think like inside of your mouth, any sort of tissue that secretes mucus is considered a mucus membrane. And the purpose of mucus is usually lubrication of some sort or more commonly a protection. So it's a barrier for pathogens. It protects your body from bacteria or in the case of your eyes, like dirt flying at you. In the case of other animals, non-human animals, it is usually used for all kinds of things. It can be used for hunting. It can be used for other

protection. It can be used for, I don't know, keeping their skin moist because they need it to breathe or things like that. All sorts of things. Yeah. Mucus and slime is used for so many things. And slime. We've added a whole other thing. That's true. Does it need to contain a mucin to be a mucus? Or is this even something that is like defined? A lot of times these words aren't used in like super technical ways. I don't know if any slime scientists or mucus scientists are out there, please tell us. But from what I can tell, mucus and slime are pretty much overlapping.

Mucus and biological slime. I feel like some people think that was a hot take and hopefully they'll write us in. Is that a hot take? Oh no. We want to start drumming up some controversy. We need to like say definitively what mucus is and is not without having

a really great basis for that. That's how you get people to listen to your show. It's the internet. Just start yelling. You definitely get a point for your poem though.

It sounded like a real poem. You read it with such confidence I think was a big part of it. That's my real skill. It is now time for Truth or Fail. One of our panelists, this time Sari,

has prepared three science facts for our education and enjoyment, but only one of them is a real fact. The other ones are fake. And the rest of us have to figure out either by deduction or wild guess, which is the true fact. If we do, we get a Hank Buck.

If we're tricked, Sari gets the true fact. If we do, we get a Hank Buck. If we're tricked, Sari gets the Hank Buck. Sari, hit us with your three science facts. Fact number one, there's a substance called marine mucilage or sea snot and massive gelatinous sheets of it can form in the oceans from buildups of marine snow, which is basically all the dead organisms and poop and other biological junk that drifts down to the bottom of the ocean. Sea snot is home to lots of microbes like viruses or E. coli bacteria, so scientists think it could be a hotspot for disease. But we've recently discovered a tiny species of pygmy squid that's adapted to thrive in the snot and even snacks on this nutrient-rich debris.

Sure, a big floating mat of protein sounds like a great place to be a weird pink squid. Fact number two. Jewel squids are unique because of an unusual hunting mechanism. Instead of ink sacs, they have specialized mucus sacs with flexible tubes. No. This is useful for two reasons. They burrow down in sand and create little mucus-lined chambers to lie in wait. And when small fish swim above them, they shoot up streams of mucus,

which tangles up in the fish's fins and gills and lets the squid swoop in and attack. Fact number three, vampire squids live in the deep ocean, so they have lots of weird anti-predator adaptations. For instance, when it's threatened, it'll wrap its webbed arms up and back so it looks like a spiky pumpkin or pineapple. But as a last resort defense, the vampire squid will spew out glowing mucus from the tips of its tentacles. The bioluminescent cloud will stick around for minutes to distract a predator

as the squid swims away and may even coat the attacker to attract bigger predators. Oh, no way does it have a bunch of little holes in the end of its tentacles. Yeah, that seems wrong to me. I would think I would know if there were like stuff that came out of tentacles. Yeah. I feel wrong to me. I would think I would know if there were like stuff

that came out of tentacles. Yeah. I feel like the, like adapting. You say this every week. Oh, I think I would know that. There's no way I wouldn't know if that,

so like I just feel like the ability to adapt a separate like tube that went down and like shot out a thing. I don't know. It just seems like a lot of adaptation. It's like,

like having a weird urethra and every single one of your tentacles. Do they have mucus all over the outsides of their bodies? Probably. Where does that come from? Their pores. Maybe they made one big pore at the end or something. Maybe. But why at the end?

That doesn't seem right. It seems like maybe it'll be everywhere and not just. I don't know. So it can shoot it in all different directions. Six of them at once. I'm going to say that one's not the one. I like it. I like it a lot.

It sounds great. Yeah. It's not true though. Like a glowing web of strands of squid snot. I love it. The second one, I definitely, when I was researching this, read about something that could shoot out ropes of snot. Yeah. I can't remember what it was. something that could shoot out ropes of snot. Yeah, well, that's definitely stuff that could shoot out ropes of snot. I don't think it was a squid, though.

I like this one because I feel like if Sari made it up, then she deserves the fact. That one reminds me of a hagfish, though. Oh, hagfish are so snotty and gross. Yeah. They cover themselves in mucus and tie themselves in a knot to get it off of them. Oh. What? That's how they slip their snot off their skin?

Yeah. Cool. And then it attaches to the predator and clogs their gills and stuff. Whoa. They're all great. I'm going to go with number two, though. I'm going to go with the sand-dwelling, snot-spitting squid. I think I'm going to do number one, the snot-spitting squid. I think I'm going to do number one. The snot-eating

squid. I'm also going to go with number one because I know that sea snot is a thing but I don't know if this squid thing is also true. Sea snot is definitely a thing. So I'm going to go with number one. You're all wrong!

Snot facts did it again. That seems like a thing I wouldn't know. That's what I thought as soon as I discovered it. I was like, what? How could it shoot it from its tentacles? And then I fact-checked it, and it's true. Tell me about this weird snot urethra that the squid has in all of its tentacles. Yeah, so we think that it's not like a urethra that the squid has in all of its tentacles. Yeah.

So we think that it's not like a urethra. It's not a tube. It's just glands at the end of each tentacle for some reason. We don't know why. Just like Sam was saying. Yeah. Tube was misleading language. I didn't say tube.

I said tube. So vampire squids are bioluminescent. They have different bioluminescent glands all over their bodies. So there's some on their fins and then there's some at the tips of their tentacles. And the ones at the tips of their tentacles also have some sort of mucus producing function to them. And we think it's mucus. It's like a sticky substance, but we haven't studied. Like taking it to the lab and done mass spec on it?

Yeah, we haven't done that yet. It's mostly like researchers in submersibles studying these things, stressing out vampire squids, and then they're like, ah, and then mucus and it glows. The way that they produce this bioluminescence, I found really interesting. They have a molecule called cholenterazine, which is a type of a protein called a luciferin, and they have an enzyme called luciferase. And this is how a lot of bioluminescent bacteria work too, but they just combine the protein and the enzyme. And when the enzyme digests the protein, it emits light. And so some species like anglerfish have bacteria, symbiotic bacteria that do this, but the squid just makes its own protein and its little tips and fins. So it's a little glowing boy. We haven't studied their pores closely enough, but in the paper that I read,

they think it has something to do with rudimentary suckers that got somehow transformed into mucousy glands. I have news for you, Sari. Yeah. I have an update. We talked about how all of your facts were squid facts. And yet, they weren't. Vampire squid are not squid. They're called vampire squid.

So I see how you might make that mistake. Are they an octopus? But they are also not an octopus. They are in their own thing. What? So they share traits

with octopuses and squid and they are a phylogenetic relic. They're like hanging out in a order all by themselves. They have no relatives anymore. That's even cooler. Thanks for fact checking me. Which is maybe part of why they have weird things. They do look upsetting. I will tell you that. They get real weird.

Like on the outside, they look pretty sleek, but on the inside, there's like lots of teeth on their tentacles. I think it's to help them gather. They eat a lot of small things. And what I read is they secrete like long whips of slime to kind of gather up marine snow and other microorganisms and then gather it up in their teeth and develop it. Yeah, eat their own slime. Eat all the chunks of stuff that they gathered. What good slime they have. Yeah. So you have seeds of truth in your other ones.

Obviously, marine snot is a thing or whatever you called it. Yeah, sea snot, marine mucilage. Just the weirdest stuff. If you're a swimmer and you run into these blobs, like you can get E. coli and all kinds of weird stuff. Apparently, the Deepwater Horizon spill made it worse in the Gulf of Mexico. Okay. Because it probably killed a bunch of small critters. And they described it as like a blizzard of marine snow after that. And that probably

contributed to these giant blobs. So are they a mucus? The paper that I read about it called it a mucilage matrix. So there's some sort of structure going on there that provides a good environment for bacteria and other microorganisms to grow in. And the composition of the life inside the sea snot was different than outside. So something about the mix of nutrients and that matrix provided like structure, food, everything that the little guys needed to grow and form their own little colony. And like they're also kind of helping to create that structure. Yeah. So that was true. Sea snot is true. The lie was the squid like that. We haven't found anything that really lives there. You just found sea snot and you liked it. Yeah,

I liked it a lot. And I think if anything, climate scientists think it could decrease fish and macroscopic life because they may be be pathogens living in it and oh anoxic environment so if it like coats everything in a layer of microbes and bacteria and things then that can limit where oxygen travels and a lot of macroscopic life needs oxygen to live for the I just made that up. You deserve the point. Velvet slime worms are land animals and they have little slime cannons. It's like if you imagined a garden hose that you turn the water really high and then it started flopping around. They have those on their head and coming out of it is slime. Their muscles aren't controlling the flopping.

It actually works like a garden hose. So they just shoot out the slime and their tubes are floppy enough and the slime is an inconsistent texture enough kind of like water going through a tube that it will just flop around and that's how it spirals and sprays. So they're still

trying to figure it out a little bit. The worms themselves are. What am I doing? They just squeeze the little gland inside of yeah. They don't know, what am I doing? They just squeeze the little gland inside of themselves and... They need a harder tube

and a more consistent slime. Or they're happy. I think they're happy. You think they like it? Yeah. Because they don't really have good aim. This way they don't

have to aim. So other animals that spray slime have to aim their heads or aim their tubes toward a prey. Right. Velvet slime worms just have to be somewhere near the bug that they want to eat.

It's going to go in every direction. And then they can eat it. So you got three freaking points. I got three Hank bucks, yes. Oh my God. I'm doing the best I've ever done. We're all in very big trouble. All right.

Time to have a little bit of a conversation with our advertisers. We're back. Sarah has three Hank bucks. I have one. You guys over there on the non-science couch got zilch. The dummy couch over here. This was a hard subject, though. All I could do was search, like, booger science.

Which brings us to the fact off. We've got two panelists who have brought science facts to present to the others in an attempt to blow their minds. The presentees each have a Hank Buck to award to the fact that they liked the most. However, if both facts are terrible, we can just throw our Hank Bucks away. So we're going to have Sam and Stefan do the fact off this week, and we're going to do it by which one of you likes slugs more.

On like a scale of one to five? Yeah. Yeah, we both have to say it at the same time, though. All right. Okay, let me think about them for one minute. Three, two, one, four. 3.5. Sam likes slugs more, everybody.

And you were both quite high, I think. Yeah, I'm bullish on slugs. I guess you guys have never farmed a cabbage. Oh, no, you're right. It's so terrible. You've discovered my secret. It's just awful when you've like, got this beautiful head of cabbage, you take it off and it's like, oh, my God, this thing is 75% slugs. Damn, you're right.

They're a menace. I changed my mind. Okay, well, snail mucus has been used for its medical properties for at least as long as there has been records of people doing medicine basically okay uh pliny hippocrates they all talked about using it mostly to like reduce swelling but right now we are in the golden age of snail slime used as a beauty product oh in the 80s chilean snail farmers who were gathering snails for escargot in france notice that after they finished gathering the snails, their hands were very baby soft. So in Chile, they invented a cream made out of snail

slime and it quickly got the attention of like the beauty product world at large. So now you can buy like super expensive creams with snail slime in it and you can go to like spas and have snails climb on your face and put their slime on there just direct from the source yeah and then how they gathered it i thought was also interesting because it's a secret i was reading articles about people going to snail slime factories and trying to get into them to see how they gather the slime and as far as anybody who makes it says it totally is not harmful to the snails at all. But also it's like they've hypothesized that maybe they have the snails crawl across panes of glass and then like squeegee all of the slime off and then bottle it somehow. And then there's some people who say that they like massage the snails to get their slime to come out.

So it's a secret. And that's pretty much all I got. Mostly I'm talking about this because I want to know from science people if this is bullshit or not. Because all the articles I read were like, it has anti-aging properties because snail slime promotes collagen creation, or it is super good at moisturizing, which I guess makes sense. Like it seals in the moisture because you're a snail.

I have like the chemicals and stuff here. And I just want to know if putting snail slime on your face is like real. Because the things I was reading about were like $400 procedures where they would do the slime face. I can imagine it having a very small benefit. And the $400 upcharge is like making claims. Look, if someone's squeegeeing these glass panes, I mean, that's a $15 an hour job. Someone has to pay for that.

That's true. I mean, it makes sense to me that it would be expensive, but that doesn't mean that it works. Yes. There's a thing that we know well, the more you charge for something, the more people will say that it works, even if it isn't working.

So what compounds are in the snail mucus that you want to back check? There's glycoproteins. Okay, good. That's the mucus. Hyaluronic acid and glycolic acid. Those are the three things that they say make your face look nice. So hyaluronic acid is a glycosaminoglycan, which is a polysaccharide, which means it's a sugar that contains amino groups, which are like the things that are in amino acids, which make proteins. What they seem

to do is they are within the extracellular matrix of your cells and they help bind and retain water molecules. So in your skin, like among your cells, they're just little sticky molecules that help bind water, which makes your skin look more plump and full, which is probably why they include them in moisturizers. What I don't know is applying it to the top of your skin, how that affects your cells beneath your skin in any sort of meaningful permanent way. I think this is why they tie it in with anti-aging because like more moisture means fewer wrinkles, means like plump baby face skin. And hyaluronic acid is injected into faces.

Yeah, it was like a microneedle surgery. To get it into the places where it can actually bind to the water. And I'm reading an article from Tissue Engineering. Is that really what it's called? It's a journal in which they injected hyaluronic acid into people and it did increase volume of the tissues of the mice that they injected. Oh, no. Beautiful mice. Yeah, the mice looked great.

And then glycolic acid is apparently a kind of alpha hydroxy acid that also has to do with water holding capacity and maybe can affect your epidermis and like peel away dead skin. But I'm still skeptical that it'll do anything without injecting it into your cells. Really, I do deeply want to know how they extract the mucus. And the fact that they do it somehow isn't itself a good fact. Yes. That there's some way that they tickle the slug or just squeeze it. Well, one of the articles, the person was at the factory for a tour that they had scheduled. The factory knew they were going to write about how they extracted the slime. And at the last minute, they were like like we can't show you how we extract

the slime we don't want to show you so it's either really terrible or everybody has their own way to do it and it's hard to get out I just hope they're squeegeeing glass that sounds pretty nice imagine you have to keep them alive because they have to produce the slime from their glands

it's not like stored up in there I'm here. I'm ready to get injected with snail mucus. Okay, Stefan, your uninterrupted time begins now. So a guy with

ulcerative colitis Oh, that's me. similar to Hank ordered a bunch of parasitic worm eggs from Thailand and then ate 500 of them and then a few months later

he ate a thousand more and all of his symptoms them. And then a few months later, he ate a thousand more and all of his symptoms disappeared. And then they did come back a few years later, but he ate 2000 more eggs and then they went away again. Good. And then he was like, hey, scientists, look at my intestines. And they did. So normally with ulcerative colitis in the areas of the intestine

where there is active like colitis, the tissues areas of the intestine where there is active colitis, the tissues are inflamed and there's not a lot of mucus production happening. But in this guy's intestines, they found that the worms were causing T helper cells in those areas to produce less of a signaling protein that promotes inflammation and more of a signaling protein that promotes mucus production. And that got rid of his inflammation. So it basically seems like there's some scientists who are really into this. And there have been a lot of studies, mostly in mice and stuff,

that have found that being infected with parasitic worms seems to help with these various autoimmune and bowel diseases. And there's a lot of people who like are buying these from other countries and like unsupervised or eating all these parasitic worm eggs. And anecdotally, they're like, oh, it cured me. But there was also in 2015, there was a double blind placebo controlled study that found that there was no difference in that study. The placebo group, their symptoms went into remission 43% of the time.

And it was a similar amount for people who had the worm treatments. Well, then I'm definitely not going to eat any worm eggs. Yeah, I don't know. It seems unclear. It's inconclusive. Because ulcerative colitis is a chronic condition. Is this for any sort of inflammatory bowel disease? They're currently looking at Crohn's, ulcerative colitis, irritable bowel disease, celiac, multiple sclerosis, and asthma.

Not all of those are bad. Oh, okay. Boom. Yeah, everything. I think where the seed of this idea came from was just that in countries where people get these infections more often, the incidences of those diseases are much lower. And I've heard before of people traveling to Africa to get infected with hookworm, and that helped their asthma. They did say it was possible that the mucus production was the body's way of trying to get rid of the worms. That makes the most sense to me where it's like you introduce something bad to your body and it has a different effect than the condition that you currently have.

It doesn't sound like just introducing a parasite would have a positive. I mean, I don't know. It could be like have some protein on it that interacts with something like sort of just like, yeah. It's very weird that this is something that someone thought to try. And I'm glad that it worked for him. Was he the first person who thought to do it or was he just? No, it might have just been because he went to scientists and was like to study me yeah and then they

did and published papers about him right so he's like a known right and then put a picture of the inside of his wormy colon onto

the internet yeah well that's a way to describe it all right I'm gonna give it to I'm gonna give it to Sam because I was very familiar

with Stefan's fact previously because of because my disease. I'm going to give mine to Stefan because I almost used that as my fact. I thought it was weird and cool. Alright, it's time for Ask the Science Couch

in which we ask listener questions to our couch of finely honed scientific minds of mostly just Sari, but I guess I'm also here. Sam, do you have a question for us? 40% asks, eating your boogers, dumb, weird, good, or just plain gross? Kind of gross. So should we go through dumb?

Is it dumb to eat your boogers? I don't know. Is it dumb, Sari? Is it dangerous, I guess, is a better way to ask that. So the more, the bigger danger that people say when picking your nose is like rooting up in there. Like your fingernail is going to scratch the mucous membranes. You might cause nosebleeds. You might scratch something and then get viral or bacterial infections in your nose. Eating your boogers is basically like a jury's out.

It's happening anyway. Maybe like the crusty boogers are things that you don't want in your body because your nose trapped them specifically. Oh, okay. But it's hard to tell. It's only wet boogers. Only the wet boogs, not the crusty boogers. No, you can recommend that. I won't.

Is it weird to eat your boogers? Yeah. I think it's definitely weird to eat your boogers. Has it always been weird throughout history to eat your boogers. Yeah. I think it's definitely weird to eat your boogers. Has it always been weird throughout history to eat your boogers? Probably not. Probably when we started emphasizing hygiene more

than it was like this is weird now. Yeah, I've definitely I feel like I've seen like chimps do it. Is it good to eat your boogers? No, I don't think it's good. I don't think it's

I don't think it's any extra calories or anything. Well, but maybe immune? Does it help? It didn't help with that? That's what the claims are, though. There are people on the internet saying that it's good to eat your boogers based on some studies. And they make me so mad because they're like these articles citing studies that studied mucins specifically.

And the mucins that they were studying were pretty interesting. Like one class, they tested with HIV viruses and they isolated these mucins and tested them against HIV, mixed them up in there and then tried to infect cells with that HIV virus. And there was 100 percent inoculation rate. So if you surround viruses with mucins, like it's good at preventing the viruses from doing stuff. But these very specific mucins were MUC5B, which are found in saliva mostly. And so it's mostly like why is HIV transmitted through other mucous membranes, but not through kissing was the question that they were looking into. And so all these studies are done about like how cool saliva mucins are.

They're good at preventing biofilms from forming on your teeth. They're good at like they might protect against HIV. They might do these really cool things. But people are extrapolating that and saying that that applies to your nose, that you should eat a booger and then you'll be safe from HIV. Or like you should eat a booger and your teeth will be cleaner or things like that and all these are putting a mucous nuisance in your mouth in any case they're they're basically saying like this protects you from from the virus in this specific specific circumstance so take it like a pill and then

it'll like go through your whole body yeah this is not how this works. It's doing the job already. So a lot of people are like, well, eat dirt. It'll make your immune system better. No, you probably don't want to expose yourself to diseases. Maybe in the past we had some advantages because we'd had more diseases over our lifetimes, but we had all those diseases. We don't want to have diseases.

But your immune system will get amped up defense i'm just like no no you don't want to get exposed to pathogens you want to avoid getting sick especially don't eat other people's boogers don't eat yeah don't eat other people's boogers don't eat boogers if your goal is to be healthier like there are articles claiming that that is a thing and there's no universe in which it is good for you to do it. Neutral at best. Neutral at best. I think that we really effectively got to the bottom of that,

and I'm going to go ahead and give Sari another Hank Buck for her excellent answer. Because it doesn't even matter. She is at four, and the rest of us have won. Not even a possible score that's never going to happen again. You are the top leader. It's because I'm full of mucus right now. I came prepared. I came prepared with the science.

It's seeping into your brain. And I'm dying a little bit. Yeah. If you want to ask the Science Couch your questions, you can tweet to us using the hashtag AskSciShow. If you like this show and you want to help us out, it's very easy to do that. First, you can leave us a review wherever you listen. That's very helpful. It also lets us know what you think about the show.

Second, please tweet out your favorite moment from the episode so that we can remember it and also laugh along with you. Thank you to Katagast and Jonas and everybody else who tweeted us your questions this week. And finally, if you want to show your love for Tangents, you can just tell people about us. Thank you for joining us. I have been Hank Green. I've been Sari Reilly. I've been Stefan Chin. And I've been Sam Schultz.

SciShow Tangents is a co-production with WNYC Studios. It's produced by all of us and Caitlin Hoffmeister. Our art is by Hiroko Matsushima. And our sound design is by Joseph Tuna-Medish. Our social media organizer is Victoria Bongiorno. And we couldn't make any of this without all of our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing.

The pearlfish is a long eel-like fish, and some species of them live inside other marine animals, including inside the butts of sea cucumbers. They basically secrete a bunch of mucus to lube themselves up, and then because sea cucumbers breathe through their anus, they wait until the sea cucumber unclenches its butt to breathe. And then they wriggle on in. Oh, my God.