eric thank you so much for that great introduction i'm really happy to be here glad to see so many faces um so we had people stationed near the doors with supplies for a little taste test that we're gonna do later if you didn't get one please see one of these nice gentlemen with the baskets and if you can't see very well i encourage you to move closer there's plenty of room down low and i won't be upset if you get up at this point so um before we get started with the actual talk i have a little
experiment that's part of our talk today and i'm gonna get it started because it takes a while for everything to develop so right now these four beakers are just full of water i'm going to add sugar to this one and i'm going to add cornstarch to these two and then we're going to add a secret ingredient to the one on the left oh but before we do that we're going to add iodine to all of them and see what happens who knows what iodine is anybody so we used to use it a long time ago to clean wounds
or to get rid of bacteria and it's also a fun molecule because of a color reaction it has with starch so what do you guys notice is different between the water and the sugar and the starch ones yeah go ahead i see that yeah so these ones have turned kind of a lighter color of the iodine itself so they've turned yellow and these ones have turned kind of a black purple and so our secret ingredient that we're going to add to the last one is saliva and for that i need everyone's help because my mout
h is kind of dry today so my assistant ambria one of the brilliant nutrition students in our department is going to walk around with this and if you are willing please do offer up a sample all right okay so i am so glad to be here to talk to you guys today um i think nutrition is one of the most fun sciences to study because we get to study all kinds of really cool hard science like uh physiology and biochemistry we also get to look at how people interact with their environment or like kind of s
ocial science topics and um we also get to do gross stuff like this so um i for those of you coming in uh if you didn't get a candy from one of the gentlemen's in the basket please get those but don't eat them until i tell you to maybe raise your hands if you didn't get one all right okay so we are talking about the digestive system today and so the digestive system is a system of interconnected organs and so we're going to start today by talking about the mouth and then the food travels down th
e esophagus to the stomach oh right thank you audience participation at its best all right so um after the mouth we travel down the esophagus to our stomachs um where uh it's really acidic and the stomachs then dump the food into our small intestine and we've got some inputs there from the liver and the pancreas and then the small intestine finally ends up in the large intestine and so we're going to kind of take a walk through those different areas of the small and of the digestive system now t
he digestive system has two important functions in the body first it has to take foods like this delicious piece of cheese and make it into nutrients so does anybody have any idea what nutrients we'd find in a piece of cheese go ahead just shout out the answer when i ask a question yeah so cheese is made out of milk so it's high in calcium is it um does it have protein in it and what about fat does it have fat in it all right it also has a small amount of carbohydrates it's a good source of vita
min a as well as a few other vitamins and it's also a great source of phosphorus which is another nutrient that we need to keep our bodies strong so these are all nutrients that our digestive system needs to somehow break apart the cheese and pull it out of there and then once we've broken it down into nutrients we need to move those nutrients from outside the body to inside the body so did you guys know that the inside of the mouth the inside of your stomach even the inside of your intestines i
s actually considered still outside your body it's true the food is only into our body once it crosses into the cells of the small intestine and then from those cells into the bloodstream that takes the nutrients around the body so that we can use them to build our healthy bodies so before we get started um just because we have so many different ages here i wanted to start with some key concepts just so everybody's on the same page and so the first one i wanted to start it out by talking about i
s what molecules are and so molecules are groups of atoms that are bound together into the different physical substances that we know in our world so don't worry there won't be a quiz on this on this diagram but this is a simplified picture of what sucrose looks like and so sucrose or table sugar has carbon atoms oxygen atoms and hydrogen atoms in it and so drawing it like this makes it really easy for scientists to tell what it looks like and what molecules are in it but in real life it actuall
y looks a little bit more like this but it's hard to tell blobs apart so we keep drawing them in the simple form and then the other a special kind of molecule that i want to talk to you about is proteins and so this is the same as when you've heard about protein in your food protein in your food is made up of these protein molecules and protein are long chains of amino acids which is the smaller molecule and they're generally much bigger than something like sucrose this example here is human hem
oglobin and again it's it's very hard to kind of tell what's going on in the blob form but i think it's really cool to see what these things actually look like if we could see them with our own two eyes and then i also wanted to make sure everybody knows what a cell is so a cell is the smallest piece of a living thing that's alive and so you've probably heard of bacteria before and so bacteria have one cell and so the whole thing is what we think of as a cell and then humans and larger animals a
nd plants will have billions to trillions of cells in them and so think of that one bacteria cell but all smooshed together and so this is a picture of the lining of the stomach if you put it under a microscope and then if we were able to zoom in right on the edge these these are the cells that we would see all screws together so one each one of these blobs the peach colored blobs with the purple nucleus in the center each one of those is a cell and then the final thing that i wanted to talk to
you guys about was the cell membrane so this is super important because remember we need to bring the food into our bodies so it needs to cross the cell membrane get into the cells and then cross the cell membrane on the other side to get into our bloodstream so you see the line all the way around the outside of the cells that's the cell membrane and it's made up of a special kind of fat called phospholipids and there's kind of this bilayer so we've got the heads and then the tails point to the
middle and what makes it really cool is it does a great job of keeping the things that we want outside of the cell outside and the things that we want inside inside generally while allowing some things to pass through so we call it semi-permeable it lets some things in but mostly does a great job of keeping things out so the last concept i want to talk to you guys about is diffusion so if you were way up in that corner and i took off my shoes and my socks were super smelly and i put them down in
that corner would that person be able to smell them eventually and how would that happen any ideas yeah exactly the smell molecules travel through the air so they when molecules are in an area of high concentration they naturally want to move to areas of low concentration so the high concentration is here by the socks at first people down in this corner can smell them but over time they're going to naturally travel until they hit your nose way up in the back corner there all right so that's eno
ugh terminology let's get to the good stuff so that we start with food entering our mouths which is my favorite organ in the digestive system so what happens in the mouth yeah so we chew food what else happens yeah so we're breaking it down into smaller pieces yeah we taste it exactly that's why it's my favorite all right so um yeah so there's a lot of different things that happen um our tongues and our mouth and our teeth all help bring the food into our into our mouth and then propulsion so li
ke moving the food back towards your esophagus also happens with your tongue um and so uh somebody mentioned saliva what is the purpose of saliva why do we have saliva in our mouths so it helps start breaking down the food other reasons yeah so it helps it slide in your throat this is super important it helps our food clump together so that our tongues can effectively move it to the back of our mouth and then it helps it go down our throat to our stomach where it needs to go next another thing t
hat saliva has are molecules called lysozymes which actually work to help break down or kill certain bacteria species and so this is why when we wake up in the morning we have morning breath or dragon breath it's because the uh um the saliva hasn't been swishing around your mouth as much and so your uh the bacteria have a chance to grow and it's their excrement that you're smelling so that's why it's super important to brush our teeth not only at night but also in the morning all right so we alr
eady kind of talked about saliva what does it do so the next thing i wanted to talk about is why is it possible for us to taste it's such an enjoyable experience but why is it why does it happen and so i wanted to tell you guys about a study that was done it's a pretty cool study these are newborns who before they tasted anything else so they hadn't learned to like certain flavors except for now we know that they do learn to like certain flavors in the womb but generally they they haven't been e
xposed to a lot of flavors in their mouth and the scientists put drops of a bitter substance on their tongue here and babies have stereotypical responses so they do what we call gape on the far side there so that's kind of like uh look i'm trying to get the food to fall out of my mouth or are they grimaced like here um and the opposite kind of thing happens when we put sweet in their mouth so we'll get a little smile like this or they'll actually do kind of a seeking behavior where they stick ou
t their tongue like they're looking for more uh food and so what this tells us is that liking bit liking sweet and disliking bitter are innate we are born with those qualities and so why do you think that it's so it's not a learned behavior it's something that we've evolved and so why do you think we've evolved that behavior go ahead yeah so he said that bad things are usually bitter so it helps us avoid eating bad things and what about sweet why do you guys think we can taste sweet back in the
back yeah so we need carbohydrates for energy to help us move our bodies and throughout most of evolution calories were hard to come by and so having enough to keep the body moving was really important okay so how does taste work now this is the time to take out your little baggie with your piece of candy in it now before you eat it plug your nose i'm going to have you put it in your mouth and chew it up for a few seconds and then pay attention to what you're tasting and then after like 10-15 se
conds go ahead and unplug your nose and again pay attention to what you're tasting as you continue to chew so what do you guys think what did you notice about what was different when your nose was plugged versus when your mouth it was open yeah go ahead and what about that when you open your nose all right so the taste changed yeah okay so this young woman had the grapefruit flavor and she said that she couldn't taste anything when her nose was plugged but then when she unplugged her nose sudden
ly she knew it was grapefruit flavor did other people have similar experiences yeah and so why do you think that is do we only taste with our tongues no everybody no all right and that's exactly right some molecules we do taste on our tongues and so things like the sugar molecules or the protons that make things acidic those things are noticed by our tongue but a lot of flavor molecules are actually smell molecules and so you smell them in the back of your nose here where it attaches to your whe
re it attaches to your to your mouth in the back of your throat now this is another reason why saliva is super important if you did not have any saliva and you ate a saltine you probably would not taste very much at all because for us to smell those molecules we need to get them wet so they swish around our tongue and so they get aerosolized and move up into our nose so that we can smell them so yet another reason why saliva is super important so um if you guys remember we talked about the very
edge of cells in the body have these cell membranes on them so on our tongue you can see these little bumps which are called papillae and in the little bumps are taste cells and this is a zoomed in close-up picture of the edge of one of the taste cells and so in the fatty membrane that's the edge of the cell here we have outside the cell in the mouth swimming around in our saliva we have a sugar molecule and so this is just a really simple picture of a glucose molecule and then embedded in our c
ell membrane are these special proteins called receptor proteins and you can probably see from the picture that the glucose has a little spot where it can fit in the receptor protein and so i like to think about the receptor proteins and the molecules working together kind of like a lock and key so the sugar molecule is kind of like a key and when you insert it in the receptor molecules then something happens we don't unlock a door but we actually send a signal to the brain and so the signal tra
vels along our nerves up into the brain and tells us that we're tasting something sweet and so that's how the majority of our tastes work so that's how sweet and salty and sour and umami work but when we taste things it's not just those things that we're sensing we're usually also sensing like the the texture and the temperature of the meal and so that contributes to our flavor experience and um you may be surprised to find out that the science of taste is still still ongoing there is room for e
ach and every one of you to make your mark on sensory science if you would like to so for example scientists are learning a lot these days about the fact that we can actually taste a sensation called fat so it's not just the texture of fat but there's actually a taste receptor like this sugar receptor okay so after we've tasted the food we've chewed it up and swallowed it heads down our esophagus and it doesn't just fall down by gravity there are muscles that push it down that you can see when p
eople swallow and then we end up in the stomach so who knows what happens in the stomach go ahead and shout it out yes so you can see in this picture that the stomach is surrounded by all these different layers of strong muscles and those are squeezing the food and breaking it down to even smaller pieces than what your mouth was able to do what else happens in the stomach yeah go ahead yeah so our stomachs produce acid it's actually hydrochloric acid and that's really important to start breaking
down proteins to get them to unwind from that big blob that we saw earlier on when we were talking about proteins so that um so that our enzymes can get after them so if our stomach is so acidic how come the stomach doesn't just dissolve what keeps the acid in the stomach and from going out the rest of the body any guesses we've got one here yes so the stomach lining has special cells that actually produce mucus just like in your nose and the mucus coats the inside of your stomach and keeps the
acid from attacking the cells how cool is that so um what about people who get stomach ulcers has anybody ever had a stomach ulcer here in the audience i see one hand in the back do you remember if you don't mind sharing do you remember how they treated your stomach ulcer okay so they were trying to decrease the amount of acid that your stomach was producing and for years even when when i was an undergraduate which wasn't that long ago we were taught that the way to deal with stomach ulcers was
to decrease the amount of acid in our stomachs and so you've probably seen in older films the stereotype of you know the workaholic who's like chugging tums or anti-acids and that's kind of where that comes from but the reality is is that most stomach ulcers are actually caused by a bacteria called helobacter pylori so why for years did everybody think stomach acid was causing it well it turns out way back in the 1950s a lot of people were arguing about whether stomach acid or bacteria caused s
tomach ulcers and so this famous physician examined a whole bunch of stomachs hundreds of stomachs and he didn't find any bacteria and people trusted him and so they decided okay it must be acid and that's where the science generally trended however in the 80s two scientists from are not scientists well doctors are scientists but two physicians from australia found this bacteria helibacter pylori in the stomach of some of their patients with ulcers and decided to treat with antibiotics and guess
what their patients were cured however they couldn't get any other doctors to listen to them they couldn't get any journals to publish their findings because everybody was convinced that stomach ulcers were caused by acid so you know turning over opinion in science can sometimes take a long time and the original doctor who didn't find any bacteria he wasn't trying to like hoodwink us or put one over on us he was just using the best methods he knew how and they didn't pick up this specific type
of bacteria so finally one of the researchers in australia decided to drink a beaker of helibacter pylori he documented that he didn't have stomach ulcers before he drank it he documented that he did have stomach ulcers afterwards and that he was able to cure stomach ulcers with antibiotics so a little bit of a media stunt to try to get the rest of the doctors to listen to him in a faster way uh than he would have been able to otherwise and uh he and his colleague went on to win the nobel prize
for medicine in 2005. all right don't try that at home so after the stomach um there is um a special valve at the bottom of the stomach that slowly lets food out into our intestines and so that's the other thing that the stomach is important for is it stores the food so that our intestines can get it when they're ready for it and so the small intestines are small only in diameter they're about three inches in diameter but they can actually be quite long so we've got zero feet marked up here and
depending on how big the person is and the technique they used to measure their small intestine small intestines can vary from 9 feet long all the way to 34 feet long can you imagine fitting all of that in your stomach all tied up well luckily most of us don't have to that's an incredibly tall person um on average our intestines are 11 feet long and so the intestines have um two two rolls so they continue breaking the food down like we started to in the in the stomach um and we use special prote
in molecules called enzymes um and there are some enzymes that happen in the stomach and earlier in the digestive tract but the main place where they happen is in the small intestine and some of these are made by the small intestine and some of these are made by the pancreas and then there are other molecules that are made by the liver that also help us break up our food but these special protein molecules um kind of like the receptor molecules have a special space where they can fit a nutrient
that we need to make smaller so that we can bring it into our body and so in this case um this is a sucrose molecule so table sugar so it's got two different sugars bound together and we need to break them apart before we can absorb them and so when they fit into the lock of the enzyme molecule they end up getting broken apart and so enzymes are really cool molecules they speed up chemical reactions so eventually those two sugar molecules would probably drift apart on their own but it's going to
take a really really really long time longer than our bodies can wait for energy and so the enzymes help speed up the reaction and um they can either break down molecules like this or they can build molecules in our bodies so there are enzymes in our body that are making hemoglobin for our blood and insulin to help regulate our blood sugar all of those are molecules that are being made by enzymes all right so we saw how long the small intestine is so if you take those three centimeter diameter
by 11 feet on or three inch diameter by 11 feet long you get a surface area that's about three three square feet a little bit less and but the surface of the small intestine is not smooth so it is actually covered by tiny fingers that we call veli and then if you and so on the right you can see well on this side depends on who's right but on this side you can see these are actually scanning electron microscope images of these little fingers that line your small intestine and it's just more zoome
d in on the bottom and then in this cartoon over here you can see here's the small intestine we've chopped it in half so you can see the fingers sticking out and then on the edge of each of the fingers is a tiny cell and the tiny cells have even tinier fingers on them called uh microvilli so if we think of a car that has to go to a certain distance if it's on the flat it has to go a much shorter distance than if it has to go up and down over hills right so if we were able to flatten out all of t
he vela and microvilli in the intestine how much bigger do you think it would be than if it was flat than the squeeze three square feet do we think it would be 10 times bigger anybody what about 50 times bigger 100 times bigger 200 times bigger all right let's see shall we all right so everybody who's sitting on either side of the aisle here you've been voluntold please stand up and uh if you could come over here to the bottom all right so if if people aren't right on the aisle if they can move
over so take this corner no no wait there we go just a moment take this corner and hand it to the person behind you and keep handing it to the person behind you and holding on to the part that's in front of you so keep keep passing it back and we'll unroll it and we'll be able to see the total surface area of the small intestine so it is actually 160 to 200 times larger than it would be without the v light and the microvilli it's about keep rolling we're almost there keep passing it up it's abou
t 320 square feet of surface area so why is surface area so important like obviously if we have this much surface area it must be important for something right any guesses all right hold on to the ends down here don't pass it any further any ideas why surface area is so important in the small intestine i see one go ahead digestion that's right over here yeah so the folds help the digestions fit helps all of this fit in our bodies um so the really important part of digestion is you know we've bro
ken it down into those small molecules but we need to move them into the body and so the molecules are just kind of randomly moving around in the juices in the small intestine and the first thing for absorption is they need to contact one of the cells that line our small intestine so the more surface area we have the more likely we are to have those uh nutrients contact the cells now don't go anywhere we're going to do another part of the demo can i have uh four or six small children come down h
ere please yeah come on down just come down yeah hey can i have a little slack okay one more everybody else sit down please sorry can't have too many all right can we um yeah we need just a little bit of slack can you velcro this in down here can you help the velcro stick in down there all right okay all right so we have little mock nutrients so i want you and you and you and you just stand over here please don't trip on the cord and then the rest of you come over here please and then who's the
lucky person who wants to hold the flat version of the small intestine okay come on down you get to toss balls if you want all right so you're gonna toss the balls so you just hold this back here nice job okay so you're gonna toss the nutrients at the small intestine at the white fabric and try to get them in the baskets down below okay okay on your mark get set go don't get too close don't make it too easy all right oh don't get too close all right so this is not a perfect analogy because obvio
usly they're getting too close we are not directly throwing nutrients at our small intestine they are moving around randomly but i hope that this has brought the idea home to you that the surface area is really important because it makes it easier for the nutrients to interact with the cells on the edge all right thank you all so much for your time we will go ahead and return the volunteers to their seats thank you guys so much very nice job both teams winners all right thank you so much so afte
r after the molecules interact with the cell membranes they actually need to move through the membrane into the cell and then from the cell into the blood um before we can use them thank you so much don't yeah we can clean up at the end too thank you very much very helpful um and so how do those nutrients get across the cell membrane well it depends on what kind of nutrient it is so we have some small nutrients shown here in purple and fat soluble nutrients so if you think about a vinaigrette th
ere's the fat layer and then the vinegar layer or water layer and you can shake them up and they mix but they're always going to separate back out and that's because certain things are soluble in fat certain things are soluble in water and the two don't mix and it's really a good thing that they don't mix because otherwise we wouldn't be able to have cells right so we've got this fatty layer with water on one side and the other side and that's what keeps things in our cells so some things can ju
st diffuse across so remember we talked about the sock smells and how it moves from high concentration to low concentration the same thing can happen when we've got high concentration outside the cell it can diffuse into the cell and then what about things that aren't fat soluble that are hanging out in the vinegar with the water these are uh molecules like that and we have special proteins called transport proteins that help them move through the barrier uh in some cases they're just open chann
els like this and in other cases they're molecules that actually move so they'll attract a certain type of molecule and then the protein will actually move and shove it into the cell so this will happen for nutrients that that are are really important so for example we've got facilitated transport for our amino acids which are part of proteins or for our sugars and then we even have active transport where the body spends energy to move the molecules and that will happen if our concentration grad
ient isn't right so you can think of it as a little molecule that helps those smell molecules move from up here all the way back down to where the socks are which doesn't usually happen naturally okay so once we have it in the cells we are almost done we are almost to the point where those molecules can be used to build all the parts of our body and the last thing that needs to happen is the nutrients need to move from inside the cell to our blood so there are tiny tiny little capillaries that g
o up inside of each of those little vli fingers that i was talking about so capillaries are very small blood vessels and so they come in and they pick up nutrients and then they leave and they go to the liver and the liver is the sorting house it makes sure that all the nutrients go where they need to go it stores some nutrients it breaks them down it builds some back up it's really the soul of metabolism in our body so once most of the nutrients have been absorbed the small intestine passes the
food on to the colon and so the colon is much smaller than the small intestine but it's wider in diameter and what happens in the small intestine so it's a little hard to hear uh in the small intestine we absorb the rest of the water that we didn't absorb in this or in the large intestine or the colon we absorb the rest of the water that we didn't absorb there it's also the home of the microbiome so these are bacteria that live inside our bodies and for years we thought that they were just ther
e and that they could make us sick if we got them in our food on accident that's why it's always super important to wash your hands after you go to the bathroom or before you make any food but we're learning more and more that these bacteria in our colon can actually have really surprising effects on our health and that depending on which species of bacteria are in our gut we may be more or less at risk for certain disorders and so that's a really another very exciting field of science that is g
rowing and we're learning more about it every day it's one of those places where we still have more questions than answers which i think makes it a lot of fun okay so i'm not sure you guys spat enough in the saliva jar because we don't have a change in color here happening yet if you want to check back later after you visit the booth we may actually be able to see the color but if we had properly calibrated the amount of starch to the amount of saliva this would actually be starting to turn more
of a reddish color like the sugar or the water and any guesses about why that is yeah so there's an enzyme in our saliva that actually breaks down starch so starch is just a long chain of sugar molecules and so this enzyme here's a picture of what it really looks like and here's the cartoon this enzyme will slowly break off sugar molecules and the sugar doesn't react with the iodine to turn black so that's why this will eventually turn a lighter color and i think that that molecule is so intere
sting for a lot of reasons but historically in cultures where they didn't have access to a sweetener for their foods there are actually historical dishes where you put the carbohydrate in your mouth and you chew until it tastes sweet and then you spit it into the batter to actually make sugar so that you can make a sweet bread so be glad that you can buy sugar at the supermarket and your grandma isn't pre-chewing your food for you all right so we have gone on this long journey from the mouth dow
n to the stomach through the very long and large surface area small intestine and then through the colon with the microbiome and i just want to leave you guys with the thought so we've been talking a lot about the food and the nutrients that it breaks down into and the reason why those nutrients are so important is because they are what our body is built out of not only are they fuel for our body but they are actually what we are made up of so the protein in our skin in our hair and our muscles
and our bones is protein that we've eaten the uh fat that is the lining of each cell that makes up most of our brain that's fat that we've eaten and so when we're thinking about digestion and nutrition and what we eat the ultimate effect is the health of our bodies and our ability to do all the things we love so thank you all very much for your time and attention and i think that there's a brief intermission where people can leave but i'm here all night so if you have questions stay and i'd love
to answer them [Applause] okay great first question is the colon the same as the large intestine and that is exactly true they are two different names for the same thing other questions yeah go ahead sure so the question is if somebody has a nutrient deficiency that is there not that enzyme to break it down and that can definitely be one of the reasons so there are some rare genetic disorders where people have trouble breaking down certain molecules because they're missing enzymes one of my fav
orite molecules is vitamin b12 and if you're not able to absorb enough b12 you get pernicious anemia and that can happen for a lot of reasons but one of the reasons why it can happen is if you don't make a protein called intrinsic factor which is kind of like the opposite of an enzyme it actually holds on to the b12 and make sure your body doesn't digest it and takes it to the place where it can be absorbed so yeah so there's a lot of different reasons why people can end up with nutrient deficie
ncies and it's not always about what we're eating sometimes it's about our body's ability to process it other questions so if what our digestive system is trying to achieve is to extract the nutrients could we conceivably come up at some point with a pill that has all the nutrients we need and then we don't have to eat so the question is could we come up with a pill that has all the nutrients that we need and we don't have to eat and so this has already kind of been uh created it's not a pill bu
t it's a drink called soylent green supposedly it tastes disgusting and i don't know who came up with that name but it has all of the basic nutrients in it the problem with trying to recreate foods is that we don't know all about what makes foods healthy for us so i think a great example of this are special molecules that we call phytochemicals so you may have heard perhaps of anthocyanins in your grape juice your red wine you may have heard of lycopene and tomatoes and so these are molecules th
at we are finding in foods that it turns out are really good for our health they're not necessary they're not essential in the same way that vitamins and minerals and calories and protein are but without them we're at higher risk for certain diseases and so that's why i always worry about a pill or a drink to solve all of our nutrition problems is because i just don't think we have all the answers about what is in food that makes it healthy for us and then the other reason why i think that's a h
orrible idea is because i love to eat and i think most people do and so why miss out on that experience other questions anybody in the back all right well oh yes yey and i've heard that some some biomes insane yeah so the science in so the question is about the microbiome and the collection of of uh bacteria that we have at bacteria and other unicellular organisms that we have in our gut and how they affect our health basically did i get that right it's a little hard to hear down here oh sure so
he's bringing up mental health as well as physical ailments yeah definitely so i think especially some of our common mental health issues like depression and anxiety we are sometimes referred to as like diabetes type 3 because they are also have a very strong association with inflammation throughout the body and we think that the microbiome plays a really role a really important role in kind of controlling the inflammation in the body and so you know different disorders are definitely linked to
different microbiomes but we're still learning about exactly which bacteria are healthy and in which amounts and but there's a lot of really fantastic science going on where you know you take a sample from somebody who has obesity or diabetes and you transplant it into a sterile mouse and the sterile mouse becomes obese or develops diabetes so there's obviously a link there and then there's also really interesting science going on about microbiome transplants so typically this is being used rig
ht now for very hard to treat bacterial infections in the in the colon so things that cause horrible diarrhea like clostridium difficile and so getting a transplanted microbiome from a healthy individual can actually help get rid of that negative bacteria that's causing the the really extreme diarrhea so there's kind of a lot of interest in ways that we can alter our microbiomes and it really seems like the best way to alter your microbiome is to change what you are eating so the bacteria in our
guts live on what's left over after we take out most of the nutrients and it really seems like the best way to get a healthy microbiome is to eat more fiber and so that's your whole grains that's your fruit that's your vegetables and so you know what nutrition science has been telling you for years we have yet more evidence that it is the truth yeah so the question is whether i recommend that people eat a probiotic whether it's through yogurt or a pill and so the thing that i have a hard time w
ith especially with the pills is that we just don't know exactly which species are super healthy and there's not a lot of great evidence that the the species in the microbiome actually take over and colonize your gut they are present as long as you keep taking the pill so i think if people have gi distress that is bothering them i think it's something definitely worth trying it might work it might not i think foods like yogurt or kefir or kimchi have a lot of beneficial effects and so if you enj
oy those foods eat them and if they help your stomach stay more regular all the better but we don't have definite answers and i'm not definitely not going around to everybody and being like you need to start drinking kombucha just just because yeah yeah the immune system that's part of the gut um so typically uh the immune system that's part of the gut we think of it the most in the small intestine as well as large intestine but it's it's really throughout um you know there are immune cells maki
ng sure that you know the the food that we eat is is covered in bacteria and viruses and stuff like that and so making sure that those things don't get in if if we don't want to get them in uh there's kind of cells all throughout uh doing that for sure but when we think of like kind of interactions between like the microbiome and the immune system then we're definitely talking about the large intestine or the colon so how do we keep the immune system healthy uh yeah so um definitely our immune s
ystems function better if they have the appropriate nutrients that they need to make the cells um i think a lot of our uh immune system functioning also happens when we're younger and to be honest i this isn't an area of my specialty and i don't want to i don't want to explain to you when i when i don't know but i think that's a really great question and i i'd love to know more about it how long does the whole journey take typically from the mouth too oh so it's so different for different people
a really fun experiment that you can do which we can't do within the confines of our time here is to not eat corn for several weeks and then eat a can of corn and then closely examine your bowel movements for corn and when you see it come out then you'll know how long it took to go through your specific digestive system but yeah it can really differ quite a bit depending on uh exactly what you've eaten that day for example insoluble fiber makes things move through a lot faster soluble fiber lik
e what's an oatmeal kind of slows things down a little bit and then just what's going on with you physiologically so pregnant ladies for example everything slows way down it takes forever for things to move through and yeah i recommend that experiment if you've never done it it's it's fun any last okay um so the question is if you're taking a protein supplement should you also take fiber with it to help absorb the protein and i do not think that that is true generally fiber does a lot of great t
hings in our body but generally it doesn't help us absorb nutrients typically it's the opposite so like there are nutrients in certain vegetables that can bind vitamins that we need or minerals that we need and make it so that our body can't access them because we don't really break down fiber but i don't want to dissuade anybody in this room from eating more fiber because americans need to eat more fiber we generally only eat like 10 to 13 grams of fiber and the recommendation is 25 to 28 grams
of fiber so we're way off that recommendation and so what does fiber do for us it fills us up it helps us keep us full for longer it provides bulk in our meals it uh slows down digestion so we don't have like a huge blood sugar spike and then a fall off and it also keeps our colon clean you can think of it as like a little scrub brush going through your colon and it picks up the carcinogenic molecules that we don't want in there causing colon cancer and it helps us eliminate them so yeah more f
iber it also helps keep you regular so other questions yeah so a few things can make you feel sick after eating a big meal there's just distension that happens and and that comes with discomfort the stomach has those little ripples in the inside of it you probably saw on the diagram called rugae and those allow the stomach to stretch quite a bit but if it's a lot further than it usually stretches then there are kind of pain receptors in there that will that will tell you that things are uncomfor
table um feeling sluggish uh can happen for a lot of different reasons i think one of um the reasons that we like to think about is the fact that you know blood is being diverted to our digestive system to deal with that meal um of course if somebody if an axe murderer breaks into your house after thanksgiving your blood doesn't stay in your digestive system and you don't stay sluggish it moves to where you need it in your body but definitely if you're in a situation where you can just kind of l
ike hang out and digest your food the blood is going to move to your digestive system to concentrate on that task great question thanks sure so um people have a hard time digesting certain foods like beans and gluten so i'm going to address that in two parts so um foods like beans and cruciferous vegetables like broccoli or cabbage tend to have fibers in them that we can absorb as humans and so they end up in our colon and they feed our bacteria and so that's where that discomfort comes from the
bacteria are like yum and they eat it and they pass a lot of gas which makes you bloated and uncomfortable uh which causes the discomfort that comes with those foods and so the way to deal with that bino is a very effective it's an enzyme that will break it down in your small intestine so that you absorb those nutrients and they don't go to your bacteria or you know you can kind of start small and slowly build up and so the idea is that your gut microbiome will slowly change over time to allow
you to eat more of those foods because you know beans are are really one of nature's super foods and we don't want to avoid them just because they make us a little gassy now gluten there is a specific disease called celiac disease and it is where the body's immune system is triggered by gluten and it actually attacks the inside of the small intestine so those fingers we were talking about they actually end up getting flattened which makes it so that we can't absorb the nutrients that we need and
people get really sick and so that's why some people can't digest gluten and need to avoid it recently there's been a lot of interest in people who although they don't have celiac disease like when we take a picture of their small intestines we don't see that flattening they still feel like they have a reaction to glucose or gluten so it might cause them to have headaches or a lot of various kind of non-specific symptoms and it seems pretty clear that this gluten sensitivity is is a thing so wh
en we have people do elimination and trial diets and they bring gluten back into their life it does seem to cause the symptoms the thing that i would really encourage people if they think that they are sensitive to gluten is to do a well-controlled elimination and trial diet where you try to take out all the foods that you might be reacting to and then you slowly add them in back in one by one because there's been some really good research done where they have tested people who felt that they we
re sensitive to food and although the majority of the participants were actually sensitive to a food a very small percentage of them like 10 percent actually had it right which food they were sensitive to right so they thought they were sensitive to gluten but they were actually sensitive to dairy or they thought they were sensitive dairy but they were actually sensitive to eggs so because we eat food in these combined forms it can often be really difficult to tell exactly what's causing exactly
what's causing our symptoms and then you know the vast majority of people don't need to avoid gluten which is great because gluten makes bread delicious it really provides a texture that's not there and a lot of the gluten-free foods are actually not as healthy for us as the gluten-filled foods so wheat especially whole wheat provides a lot of really important nutrients to our bodies so if we can eat it it's better to eat it other questions okay that'll be it thank you guys so much for your gre
at questions
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