I had a microbiology professor who had our lab do almost this exact experiment, but with hand washing. We were all shook when we saw the petri dishes. She said that soap brings our natural flora to the surface of our pores and thats why the petri dishes grew so many more microbes. It’d be interesting if you could test the colonies to see what’s actually growing.
Yeah, this is a really important part of the question. You can't always tell how clean something is by looking at a petri dish. What microbes are there is just as important as how many. I did my science fair project on swabbing animal mouths and the human mouth and putting it on petri dishes, and while the petri dish from the human mouth looked worse, the research I did showed that the microbes from the animals would be more dangerous for humans.
This is so important!! They are assuming all bacteria is bad when that's not the case at all. We have colonies of bacteria on us that are SUPPOSED to be there; the goal with washing your body should not be to remove ALL microbes from your skin! Which bacteria are growing is significantly more meaningful information than how much bacteria.
I also thought about the differences in bacteria colonies. Because smartphones are notorious for having a bunch of bacterias and yet they're still safer to handle than technically cleaner things, like a toilet seat or a raw chicken.
This channel has made it so that I'm absolutely horrified on any topic that regards hygiene, but on the bright side, having Steph voice an episode was a nice change of pace. We love you, Steph!
As someone with a statistics degree, it can be so frustrating how small their sample sizes are. I like how they are promoting experiments and science, and I very much enjoy their content. It’s bitter sweet lol
Another way to further this experiment with more definitive results would be to test after “towel dry” vs “air dry.” The reason I suggest this is the possibilities of bacteria/viruses living within the towel you used to dry yourself. Maybe the “soap” did work but the towel just transferred the bacteria/viruses back on your legs. (There was no towel drying in the control)
I NEED you guys to test face washes as soaps. I have terrible acne that's really difficult to manage. It's like wrangling a wild beast. Knowing how to keep bacteria from causing breakouts would be a lifesaver.
(not a dermatologist but I am a licensed esthetician) do you mean like using a face wash as a body wash for body acne or testing face washes similar how they tested soaps here :3?
@@Fbih2o um if your using a handwash on your face your not doing it right. look at skin care products specifically for acne. Also if you can try and see a dermatologist, they can help you get your acne under control and also help build a skincare routine. If it is cystic acne then you could possibly need medication to get it under control.
Actually the lufa thing could be its own video! They could do using the same luffa brand new, then after maybe... three days, and then after a week! And see just how much bacteria is growing on those things!
Moisture is the main difference. A Dry swab on dry legs doesn't allow much to transfer to a dish medium, while MatPat peeled up his sweaty jeans for the control sample. A wet swab provides a nice even coat.
I was looking for this comment. It's not a fair comparison at all. And that probably explains MatPat's results, too - he was sweating more in long pants than the others, rather than just being intrinsically dirty.
I was thinking about the same thing. I had to grow bacteria cultures in my cell and molecular bio class a few years back, and I messed up my lab group’s results just by forgetting to wet the swab before collecting my samples.
I HEAVILY believe the rest of the "Soap Saga" should be VO'd by Steph! Her voice is so nice to listen to her amount of knowledge on the topic is fascinating! (Also I'm starting to wonder what a video with Ash as the VO would be like?!)
I've done six years as a microbiologist with expertise in clean rooms and environmental monitoring. The most likely difference in his leg was that it may just have been sweatier wet swabs pick up more stuff, he also may have more dead skin on top for the control. In terms of the experiment you didn't control the water or dryness of the legs. Drying is actually a very big part of washing,
@@WayWardWonderer it will always have a special place in the hearts of Theorists everywhere, especially longtime fans of the GT Live days of a few years ago
i would love to see yall use different exfoliators (ex: loofah, washcloth, net cloth, etc) and use them twice (at least): once fresh out the package, and again after its left drying for a while
Pant cleanliness is a major theory that NEEDS to be tested. I've read from pants aficionados to rarely wash jeans for length of life but I always worry about the cleanliness. I wash jeans after 1-2 uses and demand validation!
I honestly would love a side show with Steff explaining in more detail any scientific data needed to make these episodes, this would be more of a educational video vs the usual Matpat zainyness with sources and stuff for students in college who are interested in science.
That would be great although it probably won't happen. From what they've said dyring streams Steph is usually busy doing behind the scene and legal stuff.
Hi! Biostatistics student here. So, were the soap samples taken while the skin was still wet? If so I suspect that the amount of culture activity found on the gel was increased by the added moisture in the sample. Especially since the control was done while The skin was dry. (Well, for 3 of you, I think the trapped moisture and sweat from wearing long pants was likely a reason why MatPat had "dirtier legs" regardless of how clean the jeans were/are) I suspect that if you did the same test (or a similar one) but waited to swab until the skin was dry, (or dried off with a towel) there would be a significant difference in the results. There may still be more cultures found post-wash then pre-wash, but the culture activity would likely not be as extreme.
I said the same thing, dry skin vs wet skin matters. I didn't study science at all. I have done some reading on the amount of bacteria in our shower heads. Thai may be a factor here.
My first thought without thinking was "you killed off the bacteria there so new bacteria didnt have much resistance from your body's natural defenses and the cultjre already there. Then i remembered how quikly after the washing they took the samples and realized, had to be something else. And how dry they got pre swab completely slipped my mind for a minute. Glad someone else was thinking about that cause i forgot to.
That makes a lot of sense because bacteria mildews very easily, when in wet and warm conditions. If the swabs were done on wet skin and then kept in a warm room, it stands to reason that bacteria would flourish like it did.
...No control petri dish for the attic in order to know what "naturally" lives there that could contaminate. Also, they were talking while doing the sample smear so that could be other bacterias in the end...
I'm just wondering if one of the reasons Matt's leg control is worse is because the others had exposed their skin to sunlight. As pointed out in the laundry detergent episode, sunlight contains UV light and that kills of bacteria
It could be a combination of that and the fact that the space between your skin and clothes is a dark, warm, slightly humid environment, which is exactly the type of environment bacteria thrive in.
im just gonna ignore the results for a moment and give Stephanie the appreciation she deserves. I loved hearing her narrate this episode, and she definitely deserves more recognition and appreciation from everyone, I was literally thinking about this yesterday and i feel like this video was a great opportunity for me to express my appreciation and love for her contribution to the channels.
At the beginning Steph talked about how soap frees up the bacteria on the skin so it can be rinsed off. Maybe the bacteria being brought to the surface but not properly rinsed played a roll in the results.
Considering Dove is known for moisturizing I think it leaves a layer of soap that might also be trapping bacteria.but I know I'm never buying dove again.
Yes, that's the main purpose of soap, trapping grime so that it can be washed down the drain. If you don't wash it off, it doesn't do anything. As someone else pointed out, they didn't wet the swabs in the control, which is probably why Matt's sweaty legs that had been in pants had more bacteria since they were probably somewhat moist, while the others were dry swabs.
It's important to remember that not all skin bacteria are necessarily bad for you! Some help protect from dangerous ones,most just hang out and do nothing. The dangerous ones are rather rare and can only harm you through open cuts
@@journeytoamillion4572 I don't know if they did research about the harm that skin bacteria does,but just from watching the video its pretty clear the experiment was about how much bacteria are left after each type of cleaning rather than the type.
Absolutely! You actually do wanna have a healthy microbiome of different, non-dangerous bacteria (e.g. different strains of lactic acid bacteria) which are compeletely harmless to you, but provide a viable defense system against pathogenic bacteria by simply being a food and space competitor. The last thing you want is a sterile skin
Im pretty sure that’s the reason that the soapy ones appear dirtier, because the soap gets rid of your moisture barrier and releases your natural bacteria
suggestions for any future experiments: When the control swabs were taken, that was on dry skin. Mud swabs were taken with the moisture from the mud, rinse swabs were taken while still wet, and soaped swabs were taken while just out of the shower still moist (as far as I could tell). The added moisture from taking the sample may have made for an increased humidity environment which may have been a contributing factor as to why so much bacteria grew compared to the control. If you were to repeat this experiment, I suggest taking the samples all dry or all wet to alleviate the added variable of added moisture. fun video tho. heherawrxD
Your comment helped me remember that water is a great transfer medium for microbes. To a microbe, moist is hardly any different from wet, but both are far different from dry.
Yes that is a huge potential for error. To mitigate the external variables, they should have maintained one swabing style instead of switching from dry swabing to wet swabing. The needed to let the area dry after each step to maintain consistent variables.
It's amazing how much your voice changes doing voiceover vs in front of the camera. I'm so used to it with MatPat that I stopped noticing, but hearing the difference with Steph's VO made it easier to hear it with MatPat again.
@@Lord_Vile29i mean as one comment said apperently a wet swab is better than a dry one which is why the controls except mats(which was sweaty) were very clean
In all of your swab after the control you give em extra moisture to grow because you didnt dry it first and your jeans cover feet also have sweat moisture. .
I know this might be harder, but I think it would actually be interesting to know what kind of bacteria there are before/after. Because you can get a worse looking petri dish, but with actual beneficial bacteria where there were only bad bacteria before.
Very true. I had this thought too, but I'm not sure if anyone on the team is qualified to identify the cultures. (I don't know if Stephanie has the tools currently to do it herself, as she seems to be the only one qualified) I wonder if these silly little internet videos will spark a new strain of thorough, unbiased investigations by professionals, because I'd read a whole scientific paper just to see what their results are. They sure have made me curious.
A microscope wouldn’t be enough. They could buy the necessary materials and do it themselves (it’s not actually a terribly complex process). A few simple tests can narrow down a bacteria but a few more can almost positively ID it. Or they could send it to a lab, of course. (I wish I could teach them how to ID bacteria. This is my favorite field of my job.)
You should do an episode on why you shouldn't necessarily use antibacterial soap because it has not been found to be any more effective than normal soap! You could do a test like you did in this episode and see if you see a difference. And not all bacteria is bad and needs to be removed. That should be touched on!
Yes! And I have a theory that dish soap is the most effective soap if you’re trying to get rid of bacteria (or grease stains) because of its decreasing effects but that doesn’t mean it’s the most appropriate for every situation.
@@cristinbuskard9250I’ve actually had grease splatter on my shirt while cooking, and after research, the best way I found to remove the grease was with dish soap, not any “stain remover” or detergent. So I completely agree with this.
I am seriously loving having steph do the voice over. She is doing a great job and you should definitely let steph do it once in a while if she is excited about a topic! Go Steph!
It’s also worth mentioning that not all of that may be bacteria. We grow hundreds of Petri dishes every week in the museum I work at, so I can tell the difference between bacteria (which we keep to show to guests for the experiment) and mold (which we have to toss out because it ruins our dishes). Based on what I’m seeing on the relatively small sample size you have there, I am seeing some fungal colonies. While your legs aren’t growing mushrooms anytime soon, it’s worth knowing that we have cultures of fungi (such as naturally occurring yeast) on and in our bodies, and a lot that can live in soil. And how can we grow a lot of mold too? A dark, warm, humid environment, just like the attic.
Yeah, but they wrapped the samples and they are pretty hermatically sealed....so they kinda reduced the humidity in the environment... All samples are kept in darkness at a relatively warm temperature as far as I know...
I'm definitely interested in a look at the shampoo or how often should you wash your hair episode. I've done some research on it, but I'd like to see some others experience with it.
I think you have an obligation to society to do a second episode as soon as possible. This series is suddenly _far_ more important than a simple learning experience!
i really like the idea of having hosts other than matpat for these theory videos, like Steph and Dan. i hope they do this every so often, especially if Matt needs more breaks like this.
Not gonna lie as much as I love Matt's voice overs in theory videos, Steph has a really nice voice too. I'd love to hear more videos voiced by her in the future, only if she wants to of course.
Maybe the reason Matt had so much bacteria was because he showered with soap closer to the experiment then the rest of the team. When you guys took the swab right after washing you had similar colonies as matpat did in the first swab
@@dreamchaser7177 True, but it is still rather concerning that the soap caused more bacteria of likely both symbiotic bacteria and illness causing bacteria.
@@systematicpastelsYes, when you wash yourself, your body has to rebuild its bacterial cultures again, and rebuild to a balanced nature. Which is why we saw so many cultures right after washing, but fewer before.
@@dreamchaser7177 True, but we don't know if it was symbiotic bacteria that overtook the colonies, or if it was illness causing bacteria, since it didn't look any different and there's no real way of saying if the soap actually got rid of the bad bacteria or not.
The water content of the swab matters a lot! The jeans caused more sweat, and therefore more moisture for the bacteria to live in, then after the wet mud, and the clean swabs were with legs still wet!
I love when Steph and Amy do some voice over :) I love Matt's voice of course, but it's obvious how much Amy and Steph care about this content :) it's awesome!
at the beggining of the episode it was said that soap makes germs not adhere to your skin, so what may have happened is that when you swabbed the legs after using soap there was more loose bacteria that stuck to the swab than when using just water
There should be another set of negative controls (perhaps with the other leg) in which you DON'T muddy up the leg at all. This would help show if the soap was really making the leg dirtier.
@@jason200912 I think they meant washing a leg that never got muddied to see if the soap was exacerbating the mud bacteria or if it would have a similar effect on more standard skin bacteria levels.
The 10 second dip into lawn care was full tilt dad mode for Matpat. I’m over here like, 👏👏 “you gotta have a mix to provide stabilization and irrigation”! 👏👏
As someone who exclusively wears jeans/sweatpants/etc and who has the bad habit of falling into the “if it passes the sniff test it’s fine” trap, MatPat’s results are horrifying.
Don't worry about it. This video is scientifically bunk. Not all bacteria is the same. Yes there more, but it's it benign or dangerous? They didn't bother to check.
I am literally required to wear jeans as part of my work uniform so I'll be washing my jeans in hot water or drying them in the sun because jeans hate hot water I guess haha
You need to remember that the dishes are the super cultivated bacteria, yes you have more in your jeans but that doesn't mean you have as much as in a dish made for that result. Also the world is full of bacteria, trust your immune system and remember a lot of bacteria are not harmful
I enjoy all these things. A year later, I'm sure this has already been mentioned or considered, but.. If petris are ever used in the future (likely), boy would I like to see a few more controls put in place. Like, not breathing all over the open bacteria food dishes, and not waving the open dishes around through the air. At a minimum, face mask for the person swabbing, and leave the top on until the *very brief moment* when you apply the swab to it, and in a proper swabbing technique. I'm not even slightly surprised that he dishes were consistent disaster zones. :( I did swabs around school for a science fair years ago, and I play with petris as a hobby now, technique is invaluable.
I'd love to see an episode talking about makeup removers! Ive struggled to find a makeup remover that actually does what it says it does and doesnt leave my skin red from having to scrub, and I'm super curious as to whether its the product, my methods, or my makeup!
Any of those things you listed can make a big difference. Plus different people's skin reacts differently to different methods and product ingredients.
In the Laundry episode it was mentioned hanging clothes outside to dry helped kill bacteria (If I remember right it was the ultra violet radiation). Could those who's legs were exposed to the sun be cleaner than Matt's whose legs were protected from the sun by his jeans?
I just got on before bed to suggest the same thing. It makes sense that Matt's legs being protected from the sun would result in him having more living bacteria on his legs. Wearing shorts or a dress and having your legs in the sun should kill a lot of that bacteria.
I came here to comment something along these lines. Because I realized that they forgot to take into account that three out of 4 were exposed to the sun in those areas on the control.
18:55 I feel like you should have also tested a plain swab of just the dirt, just the soap, and just the shower water to see if it might be bacteria from the shower or the soap, etc. It could be because the shower head needs to be cleaned and no one thinks about that, I didn’t even think about that until right now and my family uses a filtered shower head that we need to change every once in a while. Maybe Matpat’s control was only worse because he showered only a couple hours before the control swab
i have a theory, perhaps the fact your legs were wet may have helped with bacterial growth since bacteria love hot, humid environments and in your control you started with dry legs
One thing to keep in mind is that our micro biome serves an important purpose. When they redo this experiment I’d love to see if the antibacterial soap kills too much and what too much (or too little bacteria) even looks like. Kind of ties in with how often you should shower really.
This would, unfortunately, be really hard for them to do. Lab analysis to get the strain count for each type would be prohibitively expensive. The only way I can possibly see them pulling it off would be to find a stain or reagent that can test for the presence of the most onerous skin bacteria (staph, etc...) along with a few of the expected less disease-causing bacteria. Even then, it would be a hell of a production.
@@da-be-ju Yeah, they did seem to try to address that with the "changing opinions on what defines dirty" bit, but they definitely lacked a clear "Hey, you need some of these guys."
I'd always heard that Dove is more of a gentle, lotion bar for hydrating the skin more than anything else. It shocked me that the team was using it to test cleaning/removing bacteria unless the episode had been sponsored by Dove. It would definitely be interesting to see the experiment repeated with a soap meant for cleaning and breaking up oils instead.
Agreed, I made a similar comment/observation, but I feel like after they've found a brand of soap that functions as advertised/expected, maybe they could re-visit this experiment to see if different styles of soap are more or less effective.
I'm glad I didn't have to go that far to see this. I didn't think Dove was actually soap. It's clearly marketed as a cleanser and moisturizing bar. If it was really soap, wouldn't it be marketed as "soap"?
There is something to be said also about not overly pushing soaps that would completely clean us. Doing so beyond medical need would lead to further development of resistant bacteria as a natural consequence. We make too many of them resistant and we lose treatments to things that used to be fatal and are now commonplace, like strep throat and other bacterial infections.
This is also a factor! I know that before the pandemic, the general rule was not to over-use antibacterial products which tends to evolve resistant strains, but that kind of all went out the window in the past years.
I would love to see you do a test that compares natural/small batch soaps against mass produced soap bars. For fun you could even try making some homemade soap yourself to toss into the comparison.
I love y'all's content, and I am very attached to Mat's voiceovers but... Steph's voiceover was a breath of fresh air!! So glad to see Steph involved on camera more and y'all having so much fun!!!
I wonder if the soap upset the balance of microorganisms in the mud, killing one side and thus allowing the others to propagate, like killing the predators in an environment doesn't lead to an over all reduction of the animal population but to an explosion in the number of prey animals, it's the only thing I could think of that would explain more bacteria AFTER the soap. Great work as always from the whole team.
It might not be that MatPat's jeans are particularly dirty. It might be that everyone else's legs were exposed to sunlight, and the UV was killing the bacteria.
One potential descreptency I noticed when considering the swabs is that the control swab was seemingly done on dry skin. The other leg swabs all had some added moisture element which would simingly encourage more growth. I'd be interested in seeing this test done again testing different brands and other variables but adding another petri dish sample pre mud with just a simple quick rinse before taking the swab. Just to see how large of a role the added moisture caused. Not that it changes the end result much but it would make the drastic difrences between the first two samples more clear on what elements (moisture vs mud) caused varrying growth.
My theory(more accurately hypothesis) would be that moisure is the reason for the diffence. Bacteria grows better in moist areas. Tight clothes like jeans will make the skin build up moisture. This can explain matpat's control. Meanwhile during the showers I presume moisture built up in the room. This would allow more bacteria to grow on surfaces in the room. It is also possible that more moisture ended up in the petri dish. Because the soap was tested last the moisture would have been highest during their swabbs.
Exposed legs also would be exposed to UV radiation (sunlight) which kills bacteria. So if they were in direct sunlight, even for a few minutes, it could have a disinfecting effect o those with exposed legs.
You are 100% true, because bacterias can not survive without water, that is why salt is deadly for bacterias, because it removes water from their body.
The crew subbing in for Matt that know him well enough to mimic his intonations and vocal rhythm is everything! Love it. Dan and Steph are doing a great job! As a Dove consumer, I’m SHOOK.😳HAAAAALP
I remember being told that Dove was a “beauty bar” and isn’t actually soap, did no research for this comment, but i was told that it has a small amount of lye and then a bunch of moisturizers.
Yeah, that’s why it doesn’t dry skin out. The only way to get off bacteria is to strip the oil off the skin, which dries it out. That’s why you shouldn’t shower every day and you should put on lotion afterwards to protect it until it can oil up again
All soap is made with lye. Soap is generally created through a process called soaponification in which lye chemically bonds with fat. During that process the lye changes at a chemical level and becomes soap. After that process it is no longer lye, nor does it have the same properties as lye. It's kind of like how table salt is made up of the chemical chlorine but it acts nothing like chlorine because it's sodium chloride and not just clorine.
My thought for why Matt's leg was dirtiest to start with was not necessarily the jeans themselves leaving things on his skin, but it being summer, It's possible that Matt's legs had a bit more accumulated sweat that could cause a more active culture.
I would say that each of the named factors plays a role but I would say the sun light with UV light seams too play a big factor in reducing bacteria on bare skin compared to covered skin
I just got to them showing the petri dishes, and I'm wishing they had thought to do another culture maybe 6 hours after shower. Considering how clean Amy and Josiah's control samples were. I wonder if they would have seen a significant difference from just waiting a few hours.
Honestly I think this just shows that our bodies are more resilient than we think. Yes, soap should do what is says, it's scary if you buy a product thinking it will do one thing and does another. But also our skin is a barrier that does a great job at protecting our body. Excited to see what other videos come off of this
Big props to Stephanie for HER EPISODE since she did everything. Unsung hero of many an episode, hopefully getting the attention she so rightfully deserves!!
Steph is so great yeeeessss~! Her VO sounds like she lost a bit of her voice at VidCon too but girl has done so much for this channel behind the scenes so I love it when she gets to be on camera! She always has such great chemistry with Mat and they're such a great couple. I've missed her on GTLive to bounce off of, so her being in the live action segments of episodes is just so amazing.
I was surprised when Steph said "soap actually kills viruses" because I thought viruses weren't living things (or at least I remember that being a very debated topic when i last heard of it), but when she explained it firther, yeah, even if they aren't alive in the first place, they're neutralized
It’s kind of fun and interesting to have some other crew do VO’s. Definitely still gotta have MattPatt for 99% of them 😂 but it’s nice to shake things up.
I don't care what anyone else says. This theory channel is my hands down favorite now. This episode just helped me have a breakthrough with my OCD. It helped me realize that it wasn't germs and bacteria triggering the response, because NONE of this upsets me, none of it triggers compulsive behaviors in me, or even much more of a response than: ew, gross. I literally have to sit washing dishes over and over at the sink, but now I know WHY I'm doing it. Which means I might be able to fix it, or at least moderate it! Thank you SO SO much for making this video. This one was more than just fun to watch.
I would love to hear Steph's opinion in Dr. Squatch soaps if possible. They say they have real ingredients that don't need a science degree to understand. I feel it would be interesting since it's different from all other soaps.
Agree with others in saying that Dove, to me, never classified as a soap. That may just be bc I always look for exfoliaters and other “cleansing” soaps, but I always was of the opinion that Dove left a weird layer of oily thickness on my skin. That may just be my personal anecdote though. Definitely would love another episode where you test out different brands of soap though!
The bar they used isn’t even really soap, but a “beauty bar”, and the oily residue you feel is probably the 1/4 moisturiser which was their popular selling point.
One absolutely massive point of contamination that i'm honestly shocked no one on this project considered after seeing just how much difference Mat's jeans did is that Y'ALL WERE SHOWERING WITH CLOTHES ON. Clothes that not only hadn't been properly sterilized beforehand but were also part of the mud bath. Your water rinse was just that, a quick rinse with water really only touching your exposed leg and barely anything else where as while using the soap y'all got fully in there and let the bacteria stuck in your clothes run all over your body.
I like the take but I personally don't think it makes much of a difference. When they rinse their shirt and shorts with water, all that bacteria is running down to their legs. But because they're washing their legs really thoroughly, they should already be getting bacteria down there.
@@arsongamer1510 it makes a huge difference bacteria in cloths is way harder to get out and when they did the bacteria could've been dripping down their legs not getting washed away because they would've been "finished" by then
So a quick correction on agar from my microbiology professor: it is not food for bacteria or any other microorganism. If it were you wouldn't see things growing on it, but it would have holes or it would be visibly smaller in size. It is more of a media from which microbes could get nutrients and their actual food if you put it in with the agar, kind off like dirt with plants.
I feel that the reason everyone else's legs were cleaner than Mat's is because of the exposure to both sun and air they all had, while Mat's jeans made it a better environment for bacteria to grow in. Also, here are some suggestions for future episodes: - Does the "rinse lather and repeat" actually work better than just a single scrubbing of shampoo? - Would using a scrub help get rid of bacteria when showering and are they really "clean" before each use? - Is showering before bed better for you (health or otherwise) than showering after waking up? - Would you be "dirtier" if you don't shower for quite a while as opposed to having daily showers?
Do shampoo bottles really say rinse lather and repeat in the US? Cause after that last episode about washing your legs I checked if it really says repeat and at least in my country it doesn't.
I also believe direct sun light exposure is the cause bacteria on the Body is less prevalent, then the question is how long do you have to remain in the sunlight to take advantage of this effect though I wouldn't want these guys to get sun burns from testing like that
A colleague of mine did her thesis on the effect of detergents on the anaerobic digestion of food waste, and the detergents actually increased the growth rate and production of methane.
I had a microbiology professor who had our lab do almost this exact experiment, but with hand washing. We were all shook when we saw the petri dishes. She said that soap brings our natural flora to the surface of our pores and thats why the petri dishes grew so many more microbes. It’d be interesting if you could test the colonies to see what’s actually growing.
Yeah, this is a really important part of the question. You can't always tell how clean something is by looking at a petri dish. What microbes are there is just as important as how many. I did my science fair project on swabbing animal mouths and the human mouth and putting it on petri dishes, and while the petri dish from the human mouth looked worse, the research I did showed that the microbes from the animals would be more dangerous for humans.
guys get this comment to the threorist's radar, this might be key information. like dis comment
Edit:thanks guys
This is so important!! They are assuming all bacteria is bad when that's not the case at all. We have colonies of bacteria on us that are SUPPOSED to be there; the goal with washing your body should not be to remove ALL microbes from your skin! Which bacteria are growing is significantly more meaningful information than how much bacteria.
Yes, that would be really interesting!
I also thought about the differences in bacteria colonies. Because smartphones are notorious for having a bunch of bacterias and yet they're still safer to handle than technically cleaner things, like a toilet seat or a raw chicken.
This channel has made it so that I'm absolutely horrified on any topic that regards hygiene, but on the bright side, having Steph voice an episode was a nice change of pace. We love you, Steph!
Yes and the sweater is 🤌
The shorts vs dress vs jeans really shows the importance of having larger sample sizes in testing
It could be the jeans and also the bacteria and such from sweat as each person can be different
As someone with a statistics degree, it can be so frustrating how small their sample sizes are. I like how they are promoting experiments and science, and I very much enjoy their content. It’s bitter sweet lol
“larger sample sizes” 🤨
@@lightlingzooma-69bro is not funny
Right? My first thought was that jeans are a more moist, dark environment with less exposure to the UV light from the sun.
Another way to further this experiment with more definitive results would be to test after “towel dry” vs “air dry.” The reason I suggest this is the possibilities of bacteria/viruses living within the towel you used to dry yourself. Maybe the “soap” did work but the towel just transferred the bacteria/viruses back on your legs. (There was no towel drying in the control)
there were no towel when they take the wet sample, because the didnt dry the leg, which actually will led to more bacteria due to the wet enviroment
I'd love to see that!
That's not how viruses work 😂
My towel is full of shaving foam.
I love it when Steph makes surprise appearances. She brings such an awesome energy to the show
Mat and Steph make such an awesome duo, they're so great, also I loved having Stephanie in this episode
I NEED you guys to test face washes as soaps. I have terrible acne that's really difficult to manage. It's like wrangling a wild beast. Knowing how to keep bacteria from causing breakouts would be a lifesaver.
(not a dermatologist but I am a licensed esthetician) do you mean like using a face wash as a body wash for body acne or testing face washes similar how they tested soaps here :3?
I agree!
Yes dude I would love to see if face washes do work
@@SpottedWithini use antibacterial handwash as face wash and baby lotion to try and control my acne. Pls tell me if im doing it right 😭
@@Fbih2o um if your using a handwash on your face your not doing it right. look at skin care products specifically for acne. Also if you can try and see a dermatologist, they can help you get your acne under control and also help build a skincare routine. If it is cystic acne then you could possibly need medication to get it under control.
If you do an episode comparing soaps, please make sure to also test the difference between using just your hands vs. a wash cloth vs. a lufa.
Would need to test the item you wash with too. They could cause contamination like his jeans did.
Actually the lufa thing could be its own video! They could do using the same luffa brand new, then after maybe... three days, and then after a week! And see just how much bacteria is growing on those things!
@@justinekeesee6495 I don't think I want to know the answer to that one though.
types of soap would be cool to experiment with too
@@RotGodKingthen don’t watch the video
Moisture is the main difference. A Dry swab on dry legs doesn't allow much to transfer to a dish medium, while MatPat peeled up his sweaty jeans for the control sample. A wet swab provides a nice even coat.
I think this is probably what explains it. Makes sense.
I was looking for this comment. It's not a fair comparison at all.
And that probably explains MatPat's results, too - he was sweating more in long pants than the others, rather than just being intrinsically dirty.
@extendoduck yes, that is what op said
I was thinking about the same thing. I had to grow bacteria cultures in my cell and molecular bio class a few years back, and I messed up my lab group’s results just by forgetting to wet the swab before collecting my samples.
Yes, they needed sterile saline or at least water for the dry legs.
I HEAVILY believe the rest of the "Soap Saga" should be VO'd by Steph! Her voice is so nice to listen to her amount of knowledge on the topic is fascinating! (Also I'm starting to wonder what a video with Ash as the VO would be like?!)
Agreed wholeheartedly
Yes I concur
i agree! love her voice :D
Who is she?
This is what I was thinking. Steph’s Soap Saga would be great.
I love how Steph is the Lawful Neutral to Matts Chaotic Neutral. She's the balance when he goes too deep into the LORE 😂
I've done six years as a microbiologist with expertise in clean rooms and environmental monitoring. The most likely difference in his leg was that it may just have been sweatier wet swabs pick up more stuff, he also may have more dead skin on top for the control. In terms of the experiment you didn't control the water or dryness of the legs. Drying is actually a very big part of washing,
Think it could be the influence of sunlight as well?
@@vinnie666 That can but in this experiment i don't think so, also it's moisturising soap. which inherently holds water.
Once again Stephanie proves to be an absolutely vital piece to this channel 😅😅 always great to see appearances from other team members 🎉🎉🎉
@its-timebot
Let us never forget her iconic performance as Nugget!
@@WayWardWonderer it will always have a special place in the hearts of Theorists everywhere, especially longtime fans of the GT Live days of a few years ago
*insert the "always has been" meme*
Stephanie should voice all future soap episodes, this can be a decently long series too
i would love to see yall use different exfoliators (ex: loofah, washcloth, net cloth, etc) and use them twice (at least): once fresh out the package, and again after its left drying for a while
This
Me too!
Pant cleanliness is a major theory that NEEDS to be tested. I've read from pants aficionados to rarely wash jeans for length of life but I always worry about the cleanliness. I wash jeans after 1-2 uses and demand validation!
I honestly would love a side show with Steff explaining in more detail any scientific data needed to make these episodes, this would be more of a educational video vs the usual Matpat zainyness with sources and stuff for students in college who are interested in science.
Agrer
That would be great although it probably won't happen. From what they've said dyring streams Steph is usually busy doing behind the scene and legal stuff.
I would love this but it seems like Steph is normally the one taking care of Ollie
fr tho i swear i learn more from matpat than in my science class lol
Hi! Biostatistics student here. So, were the soap samples taken while the skin was still wet? If so I suspect that the amount of culture activity found on the gel was increased by the added moisture in the sample. Especially since the control was done while The skin was dry. (Well, for 3 of you, I think the trapped moisture and sweat from wearing long pants was likely a reason why MatPat had "dirtier legs" regardless of how clean the jeans were/are) I suspect that if you did the same test (or a similar one) but waited to swab until the skin was dry, (or dried off with a towel) there would be a significant difference in the results. There may still be more cultures found post-wash then pre-wash, but the culture activity would likely not be as extreme.
I said the same thing, dry skin vs wet skin matters. I didn't study science at all. I have done some reading on the amount of bacteria in our shower heads. Thai may be a factor here.
Finally got an explanation regarding this 🫠👍
My first thought without thinking was "you killed off the bacteria there so new bacteria didnt have much resistance from your body's natural defenses and the cultjre already there.
Then i remembered how quikly after the washing they took the samples and realized, had to be something else. And how dry they got pre swab completely slipped my mind for a minute. Glad someone else was thinking about that cause i forgot to.
That makes a lot of sense because bacteria mildews very easily, when in wet and warm conditions. If the swabs were done on wet skin and then kept in a warm room, it stands to reason that bacteria would flourish like it did.
...No control petri dish for the attic in order to know what "naturally" lives there that could contaminate. Also, they were talking while doing the sample smear so that could be other bacterias in the end...
I'm just wondering if one of the reasons Matt's leg control is worse is because the others had exposed their skin to sunlight. As pointed out in the laundry detergent episode, sunlight contains UV light and that kills of bacteria
It could also be the contained more humid environment since it’s all trapped by the thick denim
It could be a combination of that and the fact that the space between your skin and clothes is a dark, warm, slightly humid environment, which is exactly the type of environment bacteria thrive in.
I was about to say that's likely why they were cleaner controls
you guys should test whether or not using a wash cloth makes you more clean
you are HILARIOUS
im just gonna ignore the results for a moment and give Stephanie the appreciation she deserves. I loved hearing her narrate this episode, and she definitely deserves more recognition and appreciation from everyone, I was literally thinking about this yesterday and i feel like this video was a great opportunity for me to express my appreciation and love for her contribution to the channels.
At the beginning Steph talked about how soap frees up the bacteria on the skin so it can be rinsed off. Maybe the bacteria being brought to the surface but not properly rinsed played a roll in the results.
Considering Dove is known for moisturizing I think it leaves a layer of soap that might also be trapping bacteria.but I know I'm never buying dove again.
@@demonheart13I hate moisturizing soaps... They feel gross
Thanks, was about to comment that
Yes, that's the main purpose of soap, trapping grime so that it can be washed down the drain. If you don't wash it off, it doesn't do anything. As someone else pointed out, they didn't wet the swabs in the control, which is probably why Matt's sweaty legs that had been in pants had more bacteria since they were probably somewhat moist, while the others were dry swabs.
@@demonheart13so basically what you're telling me is if i eat a bar of soap I will be cured from covid
It's important to remember that not all skin bacteria are necessarily bad for you!
Some help protect from dangerous ones,most just hang out and do nothing. The dangerous ones are rather rare and can only harm you through open cuts
I was looking for this comment. Are they doing background research before they release some of these episodes?
@@journeytoamillion4572 I don't know if they did research about the harm that skin bacteria does,but just from watching the video its pretty clear the experiment was about how much bacteria are left after each type of cleaning rather than the type.
Absolutely! You actually do wanna have a healthy microbiome of different, non-dangerous bacteria (e.g. different strains of lactic acid bacteria) which are compeletely harmless to you, but provide a viable defense system against pathogenic bacteria by simply being a food and space competitor. The last thing you want is a sterile skin
@@wilnotnone897yep because that's what soap does
no one is gonna talk about the fact that a lot of bacteria on human bodies are beneficial and important for the skin's health??
I believe therein lies lies answer
Im pretty sure that’s the reason that the soapy ones appear dirtier, because the soap gets rid of your moisture barrier and releases your natural bacteria
I was thinking the same
my wish of stephanie doing a VO for a theory episode has come true
@Officiall834bot
Spoilers bro
@@6darren6 it’s in the first 30 seconds 💀
Does anyone else think Steph also sounds off in this video?
@@directorjakees I thought so too, it sounds like she also had a cold or something.
suggestions for any future experiments: When the control swabs were taken, that was on dry skin. Mud swabs were taken with the moisture from the mud, rinse swabs were taken while still wet, and soaped swabs were taken while just out of the shower still moist (as far as I could tell). The added moisture from taking the sample may have made for an increased humidity environment which may have been a contributing factor as to why so much bacteria grew compared to the control. If you were to repeat this experiment, I suggest taking the samples all dry or all wet to alleviate the added variable of added moisture. fun video tho. heherawrxD
I'm thinking about that, because is know that moisture helps to bacteria proliferate.
Your comment helped me remember that water is a great transfer medium for microbes. To a microbe, moist is hardly any different from wet, but both are far different from dry.
From what I can tell from the video they did wet the swab before taking the dry sample, but I'm not sure
Yes that is a huge potential for error.
To mitigate the external variables, they should have maintained one swabing style instead of switching from dry swabing to wet swabing.
The needed to let the area dry after each step to maintain consistent variables.
That’s what I was thinking that too. Knowing moisture is a factor, I was like… maybe it’s the added water?
It's amazing how much your voice changes doing voiceover vs in front of the camera. I'm so used to it with MatPat that I stopped noticing, but hearing the difference with Steph's VO made it easier to hear it with MatPat again.
Lac mics are not the best thing for accurate vocal reproduction, not like the studio mics they use for VO
Yeah, the live Steph sounds mature, while the voiceover Steph sounds like 16 years old Steph.
steph might also be a bit too close to the mic, which causes the proximity effect on microphones, which might not be ideal, like in this instance
13:05 Oh dang, maybe some of us knew already, but Steph has a nice singing voice!
When you all test other soaps I would love to see a home made soap compared to standard big name soap brands.
Still shitty probably
is it just me who doesnt know now if their native or any other b rand soap is safe now?
@@Lord_Vile29i mean as one comment said apperently a wet swab is better than a dry one which is why the controls except mats(which was sweaty) were very clean
welcome back to another "Mat Pat makes us freak out about how clean we actually are" episode
Actually it’s welcome back to another “Stephanie makes us freak out about how clean we really are” episode
Don't worry we didn't knew about this until now(at least probably majority of us didn't)and we are fine
Kinda feel unclean after watching this episode while wearing long pants
☭
I need that jeans episode. I wear mine 2 or 3 times before I wash them... I'm shooketh....
i just wanna say how thankful I am to steph and editor dan for taking over the style and food theory I loved both of these videos. thanks.
In all of your swab after the control you give em extra moisture to grow because you didnt dry it first and your jeans cover feet also have sweat moisture. .
I know this might be harder, but I think it would actually be interesting to know what kind of bacteria there are before/after. Because you can get a worse looking petri dish, but with actual beneficial bacteria where there were only bad bacteria before.
Very true. I had this thought too, but I'm not sure if anyone on the team is qualified to identify the cultures. (I don't know if Stephanie has the tools currently to do it herself, as she seems to be the only one qualified)
I wonder if these silly little internet videos will spark a new strain of thorough, unbiased investigations by professionals, because I'd read a whole scientific paper just to see what their results are. They sure have made me curious.
More trials!
@@SockumsThey'd probably need to send the samples to a lab and pay them to analyze them.
@@Lucky10279 Or they could look at it under a microscope, that's always fun! (you'd be surprised with the amount of yeast we have on us just chilling)
A microscope wouldn’t be enough. They could buy the necessary materials and do it themselves (it’s not actually a terribly complex process). A few simple tests can narrow down a bacteria but a few more can almost positively ID it. Or they could send it to a lab, of course.
(I wish I could teach them how to ID bacteria. This is my favorite field of my job.)
You should do an episode on why you shouldn't necessarily use antibacterial soap because it has not been found to be any more effective than normal soap! You could do a test like you did in this episode and see if you see a difference. And not all bacteria is bad and needs to be removed. That should be touched on!
You’re right
True.
Yes! And I have a theory that dish soap is the most effective soap if you’re trying to get rid of bacteria (or grease stains) because of its decreasing effects but that doesn’t mean it’s the most appropriate for every situation.
@@cristinbuskard9250I’ve actually had grease splatter on my shirt while cooking, and after research, the best way I found to remove the grease was with dish soap, not any “stain remover” or detergent. So I completely agree with this.
@@cristinbuskard9250moke sure to moisturize afterwards cos skin needs oil to be hydrated
I am seriously loving having steph do the voice over. She is doing a great job and you should definitely let steph do it once in a while if she is excited about a topic! Go Steph!
We want steph back!🎉🎉
are you high
sick matt sounds better then her
@@Anarchy_02 also have you seen the comment section? You are the only hater in sight
@@Anarchy_02 boo, team steph!
I think it would be interesting if you guys did a similar experiment but with soaps that claim to be natural, like Dr. Squatch or other ones like it
I genuinely LOVE science Steph! I wouldn’t be mad if she voiced more episodes!
Agree
That mic, really makes her sound different
It’s also worth mentioning that not all of that may be bacteria. We grow hundreds of Petri dishes every week in the museum I work at, so I can tell the difference between bacteria (which we keep to show to guests for the experiment) and mold (which we have to toss out because it ruins our dishes).
Based on what I’m seeing on the relatively small sample size you have there, I am seeing some fungal colonies. While your legs aren’t growing mushrooms anytime soon, it’s worth knowing that we have cultures of fungi (such as naturally occurring yeast) on and in our bodies, and a lot that can live in soil. And how can we grow a lot of mold too? A dark, warm, humid environment, just like the attic.
Yeah, but they wrapped the samples and they are pretty hermatically sealed....so they kinda reduced the humidity in the environment...
All samples are kept in darkness at a relatively warm temperature as far as I know...
There’s also the difference of dry swab vs wet swab.
Steph does have a chemistry degree so I think she considered this too
@@Jellybeansatdusk chemistry and biology/microbiology are very different fields.
Europeans will disagree on the attic description.
Cold, arid, but yes, dark.
I really just want a editors week, where the editors get to choose the theory to subject MattPat to and to the voice over.
oh how the tables will turn.
Oh how the turn tables
oh tables turned
I'm definitely interested in a look at the shampoo or how often should you wash your hair episode. I've done some research on it, but I'd like to see some others experience with it.
I think you have an obligation to society to do a second episode as soon as possible. This series is suddenly _far_ more important than a simple learning experience!
truee
this.
Absolutely agree, this is gone from, “did you know technically this works” to actually, dove is lying to us, they make us dirtier than before
We’re too deep in now
i really like the idea of having hosts other than matpat for these theory videos, like Steph and Dan. i hope they do this every so often, especially if Matt needs more breaks like this.
Steph sounded a little weird like her voice is a little raspy?
Not gonna lie as much as I love Matt's voice overs in theory videos, Steph has a really nice voice too. I'd love to hear more videos voiced by her in the future, only if she wants to of course.
We second this!
13:53 this part of the video, I've got to admit, is my favorite.
It's important to consider that it's dangerous to overkill the bacteria on our skin, since we need them
Maybe the reason Matt had so much bacteria was because he showered with soap closer to the experiment then the rest of the team. When you guys took the swab right after washing you had similar colonies as matpat did in the first swab
Came here to say this. Also, those bacterial culture kits don't differentiate between symbiotic bacteria and illness causing bacteria.
@@dreamchaser7177 True, but it is still rather concerning that the soap caused more bacteria of likely both symbiotic bacteria and illness causing bacteria.
@@systematicpastelsYes, when you wash yourself, your body has to rebuild its bacterial cultures again, and rebuild to a balanced nature. Which is why we saw so many cultures right after washing, but fewer before.
@@dreamchaser7177 True, but we don't know if it was symbiotic bacteria that overtook the colonies, or if it was illness causing bacteria, since it didn't look any different and there's no real way of saying if the soap actually got rid of the bad bacteria or not.
The water content of the swab matters a lot! The jeans caused more sweat, and therefore more moisture for the bacteria to live in, then after the wet mud, and the clean swabs were with legs still wet!
Exactly!! This is very important. The temperature of the water also matters, but it's not much of a variable for this test.
I love Stephane saying “thats just a theory, a style theory! Keep look-in sharp.” It’s perfect.
yeah
Absolutely
I love when Steph and Amy do some voice over :) I love Matt's voice of course, but it's obvious how much Amy and Steph care about this content :) it's awesome!
The way Steph yelled at MatPat for not realizing soaps kills viruses had me wheezing!
But matpat was still right lol
That moment really encapsulates why the pandemic happened.
Didnt they conclude that soap doesnt necessarily do that tho? Or was it referring to bacteria only
@@shift7808 It was referring to bacteria only.
@@pedrosso0 oh ok. ty
at the beggining of the episode it was said that soap makes germs not adhere to your skin, so what may have happened is that when you swabbed the legs after using soap there was more loose bacteria that stuck to the swab than when using just water
There should be another set of negative controls (perhaps with the other leg) in which you DON'T muddy up the leg at all. This would help show if the soap was really making the leg dirtier.
7:02 they already did that in the video
@@jason200912 I think they meant washing a leg that never got muddied to see if the soap was exacerbating the mud bacteria or if it would have a similar effect on more standard skin bacteria levels.
The 10 second dip into lawn care was full tilt dad mode for Matpat. I’m over here like, 👏👏 “you gotta have a mix to provide stabilization and irrigation”! 👏👏
Matt the science guy and Steph the chemistry gal is the ultimate duo
Chemistry is science
*in Bill Nye theme rhythm*
Matt Pat the science lad
Yeah I feel like Matt is definitely more physics and Steph feels more chemistry and biology
It’s always nice to see someone else narrate today’s Theory.
@TvManskibidi313bot
As someone who exclusively wears jeans/sweatpants/etc and who has the bad habit of falling into the “if it passes the sniff test it’s fine” trap, MatPat’s results are horrifying.
Same here 💀
Don't worry about it. This video is scientifically bunk. Not all bacteria is the same. Yes there more, but it's it benign or dangerous? They didn't bother to check.
I am literally required to wear jeans as part of my work uniform so I'll be washing my jeans in hot water or drying them in the sun because jeans hate hot water I guess haha
You need to remember that the dishes are the super cultivated bacteria, yes you have more in your jeans but that doesn't mean you have as much as in a dish made for that result.
Also the world is full of bacteria, trust your immune system and remember a lot of bacteria are not harmful
Saaaame 🥹
I enjoy all these things.
A year later, I'm sure this has already been mentioned or considered, but..
If petris are ever used in the future (likely), boy would I like to see a few more controls put in place. Like, not breathing all over the open bacteria food dishes, and not waving the open dishes around through the air.
At a minimum, face mask for the person swabbing, and leave the top on until the *very brief moment* when you apply the swab to it, and in a proper swabbing technique.
I'm not even slightly surprised that he dishes were consistent disaster zones. :(
I did swabs around school for a science fair years ago, and I play with petris as a hobby now, technique is invaluable.
I'd love to see an episode talking about makeup removers! Ive struggled to find a makeup remover that actually does what it says it does and doesnt leave my skin red from having to scrub, and I'm super curious as to whether its the product, my methods, or my makeup!
Any of those things you listed can make a big difference. Plus different people's skin reacts differently to different methods and product ingredients.
Coconut oil works well for me
For makeup removing (not cleansing your skin) dermalogica pre cleanse is an amazing product, its basically what coconut oil does but lighter weight
Cleansing balms are WAY better
In the Laundry episode it was mentioned hanging clothes outside to dry helped kill bacteria (If I remember right it was the ultra violet radiation). Could those who's legs were exposed to the sun be cleaner than Matt's whose legs were protected from the sun by his jeans?
I just got on before bed to suggest the same thing. It makes sense that Matt's legs being protected from the sun would result in him having more living bacteria on his legs. Wearing shorts or a dress and having your legs in the sun should kill a lot of that bacteria.
I came here to comment something along these lines. Because I realized that they forgot to take into account that three out of 4 were exposed to the sun in those areas on the control.
Exactly that. The sun kills bacteria too, because of the uv rays.
that is possible
the team should see your comment so that they should take note of this
18:55 I feel like you should have also tested a plain swab of just the dirt, just the soap, and just the shower water to see if it might be bacteria from the shower or the soap, etc. It could be because the shower head needs to be cleaned and no one thinks about that, I didn’t even think about that until right now and my family uses a filtered shower head that we need to change every once in a while. Maybe Matpat’s control was only worse because he showered only a couple hours before the control swab
they should rlly take down this video its full of a bunch of mistakes and terrible errors.
i have a theory, perhaps the fact your legs were wet may have helped with bacterial growth since bacteria love hot, humid environments and in your control you started with dry legs
One thing to keep in mind is that our micro biome serves an important purpose. When they redo this experiment I’d love to see if the antibacterial soap kills too much and what too much (or too little bacteria) even looks like. Kind of ties in with how often you should shower really.
There's so many variables that could be tested for! Maybe they need a new channel called soap theory!
This would, unfortunately, be really hard for them to do. Lab analysis to get the strain count for each type would be prohibitively expensive.
The only way I can possibly see them pulling it off would be to find a stain or reagent that can test for the presence of the most onerous skin bacteria (staph, etc...) along with a few of the expected less disease-causing bacteria.
Even then, it would be a hell of a production.
Yeah, it's actually kind of annoying to hear them refer to bacteria as "dirty". For all the talk about science, this was so unscientific.
Up!!
@@da-be-ju Yeah, they did seem to try to address that with the "changing opinions on what defines dirty" bit, but they definitely lacked a clear "Hey, you need some of these guys."
I'd always heard that Dove is more of a gentle, lotion bar for hydrating the skin more than anything else. It shocked me that the team was using it to test cleaning/removing bacteria unless the episode had been sponsored by Dove. It would definitely be interesting to see the experiment repeated with a soap meant for cleaning and breaking up oils instead.
Soap is soap though, look at the ingredients labels.
Isn't Dove a soap replacement?
Dove even says on its own website that their beauty bar is not “soap”
Agreed, I made a similar comment/observation, but I feel like after they've found a brand of soap that functions as advertised/expected, maybe they could re-visit this experiment to see if different styles of soap are more or less effective.
I'm glad I didn't have to go that far to see this. I didn't think Dove was actually soap. It's clearly marketed as a cleanser and moisturizing bar. If it was really soap, wouldn't it be marketed as "soap"?
We definitely need more experiments on soap. This is very enthralling, and I love learning about how to clean better.
I desperately need more VOs from Steph, I love hearing from her!
Hearing Stephanie is a nice change, maybe she should do this more often?
This and dan. It is fun
I would have zero problem with Steph being the primary voice of this channel. She killed it today.
卐
@@ryanmcmenamim9871I think they should switch off
Agreed
i love having Steph be the voice over, i hope she does more voice overs 💖
YESSSSSS
Matpat yet again questioning my entire hygiene yet again. Classic Matpat.
Fr
Matt pat I Sort that you lost your voice
Then it goes onto you questioning your sanity, then your existence... then it goes worse from there.
Yet again
First he came for your childhood. Then he came for your diet. Now he comes for your ever precious hygiene.
Ahh I love Steph!! She literally moved so we could see everyone ❤❤❤
There is something to be said also about not overly pushing soaps that would completely clean us. Doing so beyond medical need would lead to further development of resistant bacteria as a natural consequence. We make too many of them resistant and we lose treatments to things that used to be fatal and are now commonplace, like strep throat and other bacterial infections.
This is also a factor! I know that before the pandemic, the general rule was not to over-use antibacterial products which tends to evolve resistant strains, but that kind of all went out the window in the past years.
I would love to see you do a test that compares natural/small batch soaps against mass produced soap bars. For fun you could even try making some homemade soap yourself to toss into the comparison.
I love y'all's content, and I am very attached to Mat's voiceovers but... Steph's voiceover was a breath of fresh air!! So glad to see Steph involved on camera more and y'all having so much fun!!!
I wonder if the soap upset the balance of microorganisms in the mud, killing one side and thus allowing the others to propagate, like killing the predators in an environment doesn't lead to an over all reduction of the animal population but to an explosion in the number of prey animals, it's the only thing I could think of that would explain more bacteria AFTER the soap. Great work as always from the whole team.
It might not be that MatPat's jeans are particularly dirty. It might be that everyone else's legs were exposed to sunlight, and the UV was killing the bacteria.
The swabs might also have been dry in the control unlike Matt's sweaty legs, which prevented them from picking anything up.
One potential descreptency I noticed when considering the swabs is that the control swab was seemingly done on dry skin. The other leg swabs all had some added moisture element which would simingly encourage more growth. I'd be interested in seeing this test done again testing different brands and other variables but adding another petri dish sample pre mud with just a simple quick rinse before taking the swab. Just to see how large of a role the added moisture caused. Not that it changes the end result much but it would make the drastic difrences between the first two samples more clear on what elements (moisture vs mud) caused varrying growth.
Yesss I think drying removes a lot of dead skin and bacteria too, so it makes a difference in that aspect as well
My theory(more accurately hypothesis) would be that moisure is the reason for the diffence. Bacteria grows better in moist areas. Tight clothes like jeans will make the skin build up moisture. This can explain matpat's control. Meanwhile during the showers I presume moisture built up in the room. This would allow more bacteria to grow on surfaces in the room. It is also possible that more moisture ended up in the petri dish. Because the soap was tested last the moisture would have been highest during their swabbs.
Exposed legs also would be exposed to UV radiation (sunlight) which kills bacteria. So if they were in direct sunlight, even for a few minutes, it could have a disinfecting effect o those with exposed legs.
I think the additional heat from the air being trapped would help the bacteria grow as well.
You are 100% true, because bacterias can not survive without water, that is why salt is deadly for bacterias, because it removes water from their body.
19:45 where are the videos Amy?? WHERE ARE THEY? WHERREE ARRE THEYYY?
The crew subbing in for Matt that know him well enough to mimic his intonations and vocal rhythm is everything! Love it. Dan and Steph are doing a great job!
As a Dove consumer, I’m SHOOK.😳HAAAAALP
Steph even did all the research 🎉
Mimic? (I'll see myself out...)
you shouldnt be eating soap.
I remember being told that Dove was a “beauty bar” and isn’t actually soap, did no research for this comment, but i was told that it has a small amount of lye and then a bunch of moisturizers.
Yeah, that’s why it doesn’t dry skin out. The only way to get off bacteria is to strip the oil off the skin, which dries it out. That’s why you shouldn’t shower every day and you should put on lotion afterwards to protect it until it can oil up again
@@alliew31 also, bacteria ≠ bad, so I wouldn't worry too much about the results in the video
All soap is made with lye. Soap is generally created through a process called soaponification in which lye chemically bonds with fat. During that process the lye changes at a chemical level and becomes soap. After that process it is no longer lye, nor does it have the same properties as lye. It's kind of like how table salt is made up of the chemical chlorine but it acts nothing like chlorine because it's sodium chloride and not just clorine.
thank you
Their slogan literally used to be “Dove is not a soap” 🤣
My thought for why Matt's leg was dirtiest to start with was not necessarily the jeans themselves leaving things on his skin, but it being summer, It's possible that Matt's legs had a bit more accumulated sweat that could cause a more active culture.
Sunlight might have to do with it. Many bacteria die this way
Or that he had a shower closest to the experiment
Maybe he was a bit sick and the culture is a proof of it
I would say that each of the named factors plays a role but I would say the sun light with UV light seams too play a big factor in reducing bacteria on bare skin compared to covered skin
@@Marynicole830 I'm surprised matpat didn't put 2 and 2 together after saying he had a shower a couple hours before the experiment 😭
Worked with a nurse 20yrs ago that always stressed that scrubbing, with just hot/warm water only, was doing at least 90%
I just got to them showing the petri dishes, and I'm wishing they had thought to do another culture maybe 6 hours after shower. Considering how clean Amy and Josiah's control samples were. I wonder if they would have seen a significant difference from just waiting a few hours.
Honestly I think this just shows that our bodies are more resilient than we think. Yes, soap should do what is says, it's scary if you buy a product thinking it will do one thing and does another. But also our skin is a barrier that does a great job at protecting our body. Excited to see what other videos come off of this
Also most microorganisms aren't trying to kill us. Some are opportunistic, but in most cases we don't need to be sterilizing our skin.
I mean, our skin has weathered the outdoors for 200K years, it has to be doing something right.
Also most of them aren't pathogenic and actually help us
Big props to Stephanie for HER EPISODE since she did everything. Unsung hero of many an episode, hopefully getting the attention she so rightfully deserves!!
Sho read the script for Matt…. That’s it….?
I see the main point however the way you wrote this is VERY aggressive you might want to try to reword this
6:34
Everything, you say?
Her voice is so calming I NEED HER TO DO MORE
@@diegeticfridge9167 She basically supported matt throughout all of his youtube career, but I agree that the commenter was strangely aggressive
22:42 i guess imma start showering with dawn
It feel like forever since we’ve seen Steph 😭 so glad she’s back.
Next we need a return to kindergarten so we hear more of nugget
Well she’s not back for gtlive, she’s been around on the other theory channels just doesn’t do gtlive anymore
Steph is so great yeeeessss~! Her VO sounds like she lost a bit of her voice at VidCon too but girl has done so much for this channel behind the scenes so I love it when she gets to be on camera! She always has such great chemistry with Mat and they're such a great couple. I've missed her on GTLive to bounce off of, so her being in the live action segments of episodes is just so amazing.
I was surprised when Steph said "soap actually kills viruses" because I thought viruses weren't living things (or at least I remember that being a very debated topic when i last heard of it), but when she explained it firther, yeah, even if they aren't alive in the first place, they're neutralized
12:25 the part of matpat's face that has dried mud looks like its unrendered compared the the fresh mud on his face
It’s kind of fun and interesting to have some other crew do VO’s. Definitely still gotta have MattPatt for 99% of them 😂 but it’s nice to shake things up.
Eh, 80% Matpat, 10% Alex, 10% Stephanie
Steph could vo style theory
Mat makes the show for sure
did you guys forget about head editor dan?
@@Bruh_Moment.. almost like I said “other crew members”
I don't care what anyone else says. This theory channel is my hands down favorite now. This episode just helped me have a breakthrough with my OCD. It helped me realize that it wasn't germs and bacteria triggering the response, because NONE of this upsets me, none of it triggers compulsive behaviors in me, or even much more of a response than: ew, gross. I literally have to sit washing dishes over and over at the sink, but now I know WHY I'm doing it. Which means I might be able to fix it, or at least moderate it! Thank you SO SO much for making this video. This one was more than just fun to watch.
It would've been interesting to have included a traditional soap bar in the tests vs the Dove bar, which is more of a detergent based bar.
Yeah I feel it’s obvious body soap doesn’t contain lye or something similar to denature viruses and bacteria
Agree! Also since it's like the only bar soap I use on my body. So I want answers. 😅
@@marillmusik I think it's proven they're the worst, cos they're just left exposed in the open, in a moisturized environment.
I would love to hear Steph's opinion in Dr. Squatch soaps if possible. They say they have real ingredients that don't need a science degree to understand. I feel it would be interesting since it's different from all other soaps.
Steph should be the VO for all Style theory videos from now on, she did awesome here!
Agree with others in saying that Dove, to me, never classified as a soap. That may just be bc I always look for exfoliaters and other “cleansing” soaps, but I always was of the opinion that Dove left a weird layer of oily thickness on my skin. That may just be my personal anecdote though.
Definitely would love another episode where you test out different brands of soap though!
The bar they used isn’t even really soap, but a “beauty bar”, and the oily residue you feel is probably the 1/4 moisturiser which was their popular selling point.
i actually like the the layer of "something" after you wash with dove. other soaps makes me feel weird because I'm not used to how stripping it is
One absolutely massive point of contamination that i'm honestly shocked no one on this project considered after seeing just how much difference Mat's jeans did is that Y'ALL WERE SHOWERING WITH CLOTHES ON. Clothes that not only hadn't been properly sterilized beforehand but were also part of the mud bath. Your water rinse was just that, a quick rinse with water really only touching your exposed leg and barely anything else where as while using the soap y'all got fully in there and let the bacteria stuck in your clothes run all over your body.
I like the take but I personally don't think it makes much of a difference. When they rinse their shirt and shorts with water, all that bacteria is running down to their legs. But because they're washing their legs really thoroughly, they should already be getting bacteria down there.
@@arsongamer1510since they made no attempt to remove the microbes in their clothes it would’ve still contaminated their legs
I’m so glad I wasn’t the only one thinking that. They should do a hand washing experiment instead
My thoughts exactly
@@arsongamer1510 it makes a huge difference bacteria in cloths is way harder to get out and when they did the bacteria could've been dripping down their legs not getting washed away because they would've been "finished" by then
So a quick correction on agar from my microbiology professor: it is not food for bacteria or any other microorganism. If it were you wouldn't see things growing on it, but it would have holes or it would be visibly smaller in size. It is more of a media from which microbes could get nutrients and their actual food if you put it in with the agar, kind off like dirt with plants.
Love Steph’s VO. More Steph VO please. Her recapping the results was awesome
I never knew I needed Steph popping up from behind the couch like that, but can it happen more please? 😂
I feel that the reason everyone else's legs were cleaner than Mat's is because of the exposure to both sun and air they all had, while Mat's jeans made it a better environment for bacteria to grow in.
Also, here are some suggestions for future episodes:
- Does the "rinse lather and repeat" actually work better than just a single scrubbing of shampoo?
- Would using a scrub help get rid of bacteria when showering and are they really "clean" before each use?
- Is showering before bed better for you (health or otherwise) than showering after waking up?
- Would you be "dirtier" if you don't shower for quite a while as opposed to having daily showers?
Kinda going off of your 2nd suggestion. Which scrub is the best if so? Cause I can see using your hands as a control if that's the case.
Do shampoo bottles really say rinse lather and repeat in the US? Cause after that last episode about washing your legs I checked if it really says repeat and at least in my country it doesn't.
That was my exact response as well.
I also believe direct sun light exposure is the cause bacteria on the Body is less prevalent,
then the question is how long do you have to remain in the sunlight to take advantage of this effect though I wouldn't want these guys to get sun burns from testing like that
@@paikio I live in Mexico, but my shampoo bottle does say to repeat.
A colleague of mine did her thesis on the effect of detergents on the anaerobic digestion of food waste, and the detergents actually increased the growth rate and production of methane.