Understanding The Microbiome, Erica Sonnenburg, PhD

[Music] [Applause] [Music] [Applause] this is solfege line I think many of you have been here before we do these events once a month this is Erica Sonnenberg she and her husband have a lab at Sanford today she's goes talking all about the microbiota and microbiome when I was in medical school all I learned was that the gut bacteria was dangerous and as Erica will teach us today there is a whole facet of beneficial bacteria in her book the good gut is fabulous if you don't have it we're selling it today when Joey Eric I just want to thank all of you for coming thank Jeanie for inviting me this is a very exciting opportunity for me to get to speech all of you so I'm happy to tell you about what we're learning in our lab about the gut microbiota or microbiome I use both words interchangeably that just means the bacteria that live in our gut I'm a senior research scientist in the Department of Microbiology and immunology my husband and I came to Stanford about nine years ago started this lab together we have about 15 people now working in the lab and we're interested in understanding what these bacteria are doing in their gut in our gut and how we can maximize what they're doing for our best health so this is an image that our lab took in my opinion it's the most beautiful image of the microbiota that's ever been taken it actually came in second place in an icon smallworlds photo contest we were beaten out by a picture of a bee I think collecting pollen so anyway I it's my opinion that it's the best image and and apparently Nikon thinks it was pretty cool too so what this image shows this is all the bacteria in the gut this is a cross-section of the colon so all these little jellybeans looking things are all bacteria and these are all the cells so these each one of these blue circles is the nuclei of a cell and then this is a green mucus layer that separates them from us and what you can see the the striking thing you know have been studying this community of bacteria for 15 years and we knew that there's lots of them but until you see the picture you have in your mind just how plentiful they are how much they outnumber our own intestinal cells so they are a huge part of who we are as humans we have trillions of these microbes 100 trillion in each of our guts if you count up all the genes that there are collective genome encodes it's a hundred times more genes than our human genome encodes so the so as humans we are an ecosystem made up of microbial parts and human parts and from a gene standpoint we're actually more microbial than we are humans we like to in the lab we like to think of our humans as an elaborate culturing vessel we're just a tube to house these bacteria and what we're finding and has been discovered over the past decade is that these microbes are wired into all aspects of our biology they're not just helping with digestion and they're wired into our central nervous system and our immune system and this wiring is profound and we think that it's important for the future of health so my husband and I started studying this community of bacteria about 15 years ago and 15 years ago the microbiota really was just a scientific curiosity there what we knew there were a lot of bacteria living in the gut we had a sense they were helping with digestion but beyond that we didn't really understand what they were doing in the lab we were studying these germ-free mice so this is an isolator we have mice that live in there and this is a way of keeping the environment completely sterile and we have mice in there that we call germ-free mice they don't have any associated bacteria in them at all they're completely clean and what we found from studying these might these germ-free mice is that they were different from normal mice that have bacteria in their gut how are they different the one thing they the people that were working these mice started realizing is that these mice could eat a lot more food than normal mice but they weren't gaining anyway they were leaner and so we thought well that kind of makes sense I guess this bacteria they're helping us digest our food and so if they're not there were maybe not extracting as many calories but then the lab started doing some interesting experiments to see if if there was maybe more to it than that so we had these mice that didn't have any bacteria in their gut at all and we had a collection of obese mice and then a collection of just normal lean mice and we took the bacteria from the obese mice and we put it in these germ-free mice so now they have an obese microbiota and then we also put lean micro mice microbes from lean mice into these germ-free mice and what people in the lab were finding was that if you transplanted the obese microbiota into these mice they gained a lot more weight than if you transferred in the microbiota of a lean Mouse and these mice were eating the exact same food same amount of calories same food and so this idea that you know we have this idea of calories that go in versus what you spend that's how much weight you gain but this kind of threw a wrench into that it's more than that it's not just calories in there's this ecosystem inside of us and it's deciding how those calories are being used or if they're being stored so when this came out this was in 2006 10 years ago we were we were in the lab at the time and the microbiota changed from being a scientific curiosity to what it's become today which is in my opinion this the center of the biomedical endeavor these microbes there was a realization that these microbes were fundamental to who we are as humans since then they've done other transplants they've taken microbiota from obese humans and they put them into mice those mice gain more weight than if you take a microbiota from a lean human and obese humans and least lean humans have a distinct microbiota composition and now there's a bunch of ongoing trials to determine if a microbiota transplant could be beneficial not only for weight loss but for a number of other diseases I think right now there's something like 127 open trials looking at whether or not Maude relating the microbiota can cure or help a number of diseases what we found over the past decade is that the intestinal microbiota controls metabolism and obesity it's been linked to type 2 diabetes cardiovascular disease in metabolic syndrome it is profoundly wired into our immune system what happens in your gut and the immune system that that your gut contains is listening to the microbes responding to the microbes that are there and then it is traveling throughout your entire body it's influencing how your body responds to not only intestinal infections but also respiratory infections and and any other infections that you would have it's been associated with autoimmune diseases cancer allergies and asthma and more recently there's been a connection observed between the intestinal microbiota brain behavior and personality this is very new this is something that's just happened over the past couple years and there's been links to the microbiota and depression autism spectrum disorders and multiple sclerosis the details of all these connections are what our lab is interested in trying to figure out so the problem we have a situation in the Western world where we have chronic diseases that are arising at alarming rates if you look at over the past 50 years the incidence of immune disorders is rising rapidly and the incidence of adult obesity there's some estimations by that by 2030 50 percent of the u.s. population will be obese this is a huge problem for Western medicine unfortunately as our lifestyle spreads across the globe it's becoming a big problem globally now over 50 over half of deaths around the world are from non communicable communicable chronic diseases cardiovascular diseases cancer and diabetes are major killers now and it's not just a health issue it's a an economic issue chronic diseases are estimated to cost the global economy on the order of 47 trillion dollars so this is a problem that we need to solve and we need to get in front of before it becomes a big a bigger global issue than it already has become so Western medicine is very good at treating acute illnesses and has struggled with chronic diseases and a lot of the what mess Western medicine can do is sort of trim the branches of these chronic diseases treating symptoms but not necessarily getting to the root of the problem I love this cartoon it says here great news captain you can inform the passengers we have slowed the rate of sinking and this is what this is what I feel like is happening with Western disease where we're trying to get at the the manifestations of the disease and not necessarily the cause so our lab is very interested in understanding the root causes we want to know what is causing these alarming trends that we're seeing and we're interested are there many different causes that are contributing equally or might there be a few causes that explain most of the increase the interesting thing as you see as these diseases go up as obesity goes up it's all going up in synchrony is it possible that there is potentially a unifying theory that would explain all of these this increase in disease that we're seeing lots of things have changed our diet is different sedentary lifestyle hygiene antibiotic strain chemicals all these things could be contributing but we think that a lot of these new things that we're experiencing could be functioning through our microbiota and that problems with the microbiota could be a unifying cause or contributor of chronic disease you think of yourself as you know this entity that has a lot of control but in reality your microbes are in many ways controlling your health and your physiology which is good news because unlike our human genome our microbiome is malleable so if you are born with a genetic defect as of now you are stuck with that genetic defect for the rest of your life your microbiota however you're not stuck with this is something that we assemble upon birth and if you change what you eat today your microbiota will be different tomorrow we can measure it and see it antibiotic use all these things change the microbiota so it's good news in that it puts a lot of power back into our hands that we can change 99% of our associated genetic material we have some control over but it can also change in a negative way and so we just have to be mindful that that can happen there are challenges with using the microbiota as a therapeutic target each person's microbiota is unique each one of us has a different collection of microbes that inhabit our gut there's a lot of similarities but it's as unique as our fingerprint and so therapies that we developed to help one person with type 2 diabetes may not help somebody else with that same disease and most certainly will not help people with a different disease so from a therapeutic standpoint it's it's a complicated problem then there would be a lot of challenges associated with that the microbiota is incredibly complex trillions of microbes like I said hundreds of species it's a complexity that I think rivals the brain trying to figure out what all these different microbes are doing how they're interacting with each other how they're interacting with our biology is a complex problem and then there's issues with regulation the FDA is really set up to regulate drugs that are small molecules or chemicals and we're talking about developing drugs that might be living organisms how do you regulate that what if I take that organism and it becomes ninety percent of my microbiota how would I get rid of that how would I keep that from happening what if I take that microbe and it becomes 90 90 percent of my microbiota but in somebody else it just passes through so it dosages an issue and individual responses are an issue so there are many challenges they think there's a lot of promise in the field but we have to be mindful that a lot of this promise is going to take decades to realize so now I just want to talk a little bit about the links between microbiota and our health and disease so a little bit about how we acquire our microbes we when we are born we're largely like those germ-free mice and the bubbles that I showed you almost completely devoid of bacteria when we're born though we enter this world that is a microbial world there are microbes everywhere as much as we try to sanitize everything and we do a pretty good job at that there are still bacteria everywhere there's a professor that we work with Stan Falco that has this famous expression that I love which is the world is covered in a patina of he is right there there are bacteria everywhere so when you were born do you come in contact with these microbes through your parents through interactions that you have with other people pets outside and that's how you get colonized each of our microbiota is unique but it has a family resemblance so it does look more like your mother than it would like somebody else's mother it does look more like your family members than strangers and these microbes have been traveling with our species for millions of years there's evidence that the microbes that we have in our gut we have gotten from our ancestors dating back to before we were humans so these bacteria are fundamental to who we are as a species so what is the microbiota do the microbiota is often referred to as the Forgotten organ and it truly is like an organ it has a function similar to how we think of like what the heart does or the liver does but its function is to digest dietary fiber so when you eat food that has dietary fiber it goes through the digestive system through the small intestine into the colon where most of our bacteria live that picture that I showed you is the colon it's a dense community of microbes the complex carbohydrates that are found in dietary fiber the bacteria fermentis they break these bonds down and then they have waste products some of those waste products get absorbed into our bloodstream and circulate throughout our body our human genome has about 17 different genes to degrade dietary fiber our microbiome has on the order of sixty to a hundred thousand genes to digest dietary fiber so it is clear that as a species we have outsourced to the function of dietary fiber digestion to our microbes they are in charge of this job for us and that's what makes them an organ those waste products that I told you that the microbes secrete and enter into our circulation here's a small collection of some of the ones that have been identified this is in collaboration with a lab up at UCSF what's striking is many of these compounds look like drugs our collaborator at UCSF likes to call our microbiota the unsupervised drug Factory it is making compounds in our gut these compounds are going into our blood they're circulating throughout our system most of them we have no idea what they're doing and so we're very interested in figuring out what these compounds are doing and if some of them could be therapeutic so our lab is concerned about the lack of dietary fiber in the Western diet if the microbiota is an organ for degrading dietary fiber and you look at the Western diet we eat a pretty sad amount of dietary fiber there's a journalist that we've spent a lot of time talking to Moises Velasquez Manoff he wrote an article about our lab in this magazine Nautilus it's available online so I'm gonna put things like this up so if you guys are interested in reading more about it you can find them this is titled how the Western diet has derailed our evolution burgers and fries have nearly killed our ancestral microbiome our lab is very interested in the effects of our diet on this community of bacteria that's so fundamental to our health humans have been on the planet for about two hundred thousand years a hundred and ninety thousand of those years all of our food came from hunting and gathering so most of our time on this planet we've been foragers ten thousand years ago we invented agriculture that result in a huge shift in how we obtained calories and over the past fifty to a hundred years our diet has shifted to one that's mostly processed and sanitized food now with each advent in food technology we've reduced the amount of dietary fiber we consume if you look at hunter-gatherer populations that are still around today they eat on the order of 100 to 150 grams of dietary fiber per day populations that eat and live a lifestyle similar to our early agrarian ancestors they eat 35 grams of dietary fiber per day the average American eats 15 what does this mean for an organ whose job is to degrade to degrade dietary fiber if you're not feeding it these are the Hogs of Tanzania they are a hunter-gatherer population that we study this population is incredibly interesting because not only do they live a lifestyle like our ancestors did for most of our time on this planet but they're living that lifestyle in the cradle of human evolution they're living where humans evolved in East Africa and these people are incredibly interesting their societies incredibly interesting it's very egalitarian nobody's in charge everybody makes decisions all together and they don't store food at all they wake up every morning completely confident that they will be able to forage and gather the food that they need for that day so they wake up in the morning the men will go out with bows and arrows they're still using bows and arrows they have a special poison that they extract from a flower that they tip they put on the tip of their arrows to kill game and then the women go out and do the foraging they forage for tubers that's what is cooking here this is these wild tubers are like the ancestors of our potatoes but unlike our potatoes they're incredibly fibrous as you can see here they chew these things forever and then eventually end up spitting a lot of the fibers out because they're just so fibrous they also forage for berries the men will go out and get honey as well if you look at what their diet is like the tubers are their staple they rely on that they get that every day they can count on that food many days that is the majority of what they eat they'll also get berries if they're in season the men will go out and hunt but often the hunting is unsuccessful every once in a while they'll get a big game maybe a zebra delete that entire zebra in one day 15,000 calories they can eat in a day but that's because there are many days that they don't get meat at all so so in that way you know the their diet is highly variable but their their high fiber tubers are their staple so we have in our lab right now a collection of over 500 stool samples from these individuals we've looked at their microbiota over various seasons of men women children and what we're wondering is what their microbiota looks like because since we don't have a time machine we have no way to look back in time and see what our microbiota was like for most of our evolution so we use these people as a proxy for that other labs also study traditional populations and so there have been other studies looking at the composition of their microbiota what we find is that our population in Tanzania and another and other populations that are either hunter-gatherers or live in early agrarian lifestyle have a composition that's highly similar to one another they have types of microbes in their gut that we never see in Western guts at all they have many more bacteria in their gut than we do diversity of species is much higher if you look at Western populations we're all over here so there appears to be two different popular or two different compositions that we see the Western microbiota this traditional population the interesting thing about the traditional population is this includes individuals both from Africa and South America these are people that have not shared a common ancestor in over 10,000 years and yet their microbiota looks more like each other than it looks like ours and that we feel like that is is concerning here's an example of the type of data that we look at in our lab each black line here represents a different type of bacteria that we see in their gut sample and then the coloring just tells us how abundant it is Green is less abundant yellow as medium abundant red means it's highly abundant in the gut and so our population in Tanzania has many different kinds of microbes that's all the little black lines this is a two populations one from allowing Venezuela these aren't hunter-gatherers but their early agrarian they live an early agrarian lifestyle and they also have lots of different types of bacteria in their gut and then here are the Americans there are all these bacteria here that these two populations have that we just don't see in our guts anymore and our lab is interested in understanding those bacteria what they're doing might they be protective against Western diseases these traditional populations don't suffer from obesity they don't have type 2 diabetes and many of the autoimmune diseases that we have in the West are don't exist over there I like to think when I when I look at a microbiota of a traditional of a person living a traditional lifestyle it kind of reminds me of this lush landscape lots of different species very robust healthy-looking environment when I look at the microbiota composition of the average Westerner it reminds me of this species missing it looks a little bit desolate and so what's happened what has happened between these traditional populations and us now many things could have happened there's a lot of differences between the way we live our life and the way they live there's antibiotics antibiotics are highly common vaccinations sanitation I mean ah this population we study in Tanzania when they need water they go out to this river where animals are using as a bathroom or people are washing in and they drink that water they're okay with that it would make all of us very sick they don't have baby formula c-section and then their diet is very different all these things undoubtedly are contributing to why our microbiota looks different from theirs but what our lab was interested in is is diet alone might diet alone be enough to see to account for some of these differences that we see so back in the lab we took our mice that live in the bubbles these mice have no microbes in their gut at all and we give them a human microbiota we call these humanized mice so they are the closest approximation that we have to a human as far as the microbiota is concerned and what we do is what we did was we we put these mice on a low fiber diet and we specifically wanted to know what would happen to that Mouse's microbiota over several generations we know that if you change the diet of a mouse the microbiota will change but what happens if that change occurs over many generations much like what would have happened in human history we also had a control group of mice that we maintained on a high-fiber diet for four generations what did we see so here's the experiment each line across is a an individual Mouse and each box is a species of bacteria that we detected in their gut how that box is shaded tells us how abundant that particular type of bacteria is in that Mouse is good so here's the initial community over four generations there's a little bit of loss of bacteria but for the most part the community remains stable these are the mice on the high-fiber diet here are the mice on the low fiber diet here's the initial community generation one they've lost microbes generation two even more generation three and four massive loss of microbes this last group here we put back on a high-fiber diet to see if we could recover the bacteria they they don't come back they're gone permanently from the system we published this last year in nature we titled it diet induced extinctions in the gut microbiota compound over generations we think this is a model of potentially what has happened what we're seeing in these traditional populations versus Westerner they have microbes in their gut we don't have maybe our change in diet has made these microbes extinct over generations even if we switch back to a high-fiber diet all these microbes are probably not going to come back we have this model for how the Western diet starves our microbiota the Western diet is high in simple carbohydrates this was the top part that I showed high fiber diet microbes are happy fermenting these these complex carbohydrates they release this one of the molecules they release is called short chain fatty acids that gets absorbed into our circulation we know that short chain fatty acids help depress the immune calm the immune system down in the Western world we're eating a simple carb diet those simple carbohydrates are easily absorbed early in the digestive system the human gut is very good at extracting things like sugar so if you're not eating high-fiber then the microbes that have no food because all these simple carbs are absorbed early so what happens do they just sit there waiting what do they do we wanted to know so we have mice again with a human microbiota this is similar to the picture that I showed you these are all the bacteria on this side these little red and green dots here this is this yellow thing is actually a piece of dietary this is a cell wall this is dietary fiber so you can see the bacteria all around they're eating it here's the mucus layer here's the intestinal cells that mucus layer is what keeps them from us we developed software in our lab to quantify how thick that mucus layer is so this is a line drawn by a program it does measurements all along the colon and can tell us the thickness of that mucus layer what happens when we put my son a low fiber diet you can tell they're on a low fiber diet because you don't see that plant material that's all gone what was striking is this mucus layer was noticeably thinner about half the thickness of the high-fiber diet when we saw this we thought the the thing that came to mind was this good fences make good neighbors and here's an example of not a good fence the microbes you can tell are getting closer to the intestinal cells and what why is that a problem our intestinal cells are constantly monitoring the microbes that are there these microbes are healthy but if they get into our bloodstream that's problematic they can cause sepsis so our immune system is constantly just making sure let's make this mucus layer let's make sure they stay where they're supposed to be and that we're safe over here when microbes start encroaching then the intestinal cells know they say wait a minute these bacteria they're getting close this is getting dangerous we're concerned that they're going to infiltrate our barrier that we've we've erected here and so we are going to start an inflammatory response we got it push these microbes further away and keep ourselves safe and that does keep ourselves safe from an acute infection what it doesn't do is when you have years months years decades of chronic inflammation from this tiny mucus layer this is the seed of Western disease all these diseases that are going up in the Western world at their core their diseases that are from chronic inflammation obesity diabetes metabolic syndrome all these autoimmune diseases could all be a result of these microbes getting too close and inciting inflammation in the gut we have we wrote this perspective a couple years ago and cell metabolism starving our microbial self the deleterious consequence of a diet deficient in microbiota accessible carbohydrates when we started doing this research my husband and I started getting very concerned because you know we we are Westerners we have these microbes in our guts too and we were thinking you know the implications of what we were seeing for the health of so many people was so profound that we felt like we really needed to just spread the word about what we were seeing we have this model for what we think has happened to the microbiota over time when we were hunter-gatherers for 190,000 years we had this diverse rich ecosystem living in our gut with each advent in food technology that ecosystem has been destroyed and we're at a point now where it's a fraction of what it used to be and we're concerned that this is causing a lot of Western disease how do we get it back to where it was can we do dietary change can we reintroduce species these are all things that we're studying in our lab and interested in finding solutions for we have this human genome that evolves relatively slowly but we have this microbiome that can change on a daily basis depending on what you've eaten if for 190,000 years we ate a certain way our genome would get used to the microbiota that's there and they would start interacting and kind of like this this lock and key idea in a way that's beneficial if we change the diet rapidly which is what we've done then that microbiota composition has changed and our human genome can't adapt as rapidly so we're concerned that there's been there's now an incompatibility between our human genome which is more ancient and our microbiome which is new we know that dietary fiber is associated with health this is nothing new here is an analysis a meta-analysis that was done they took 17 different prospective studies that had a total of 76 thousand deaths almost a million people were included in the study and what they found was a 10% reduction in all cause mortality risk for every 10 grams per day of increase in fiber if we there's been other studies showing that people that have they did 300 microbiota roughly of Europeans people fell into two categories either low microbiota composition low diversity or high diversity they found that people that had low diversity had increased adiposity increased cholesterol inflammation higher insulin resistance all bad news for the low microbiota composition are low diversity people they put these people on a high-fiber diet that also included reduction in calorie the people in the low diversity group actually increased their microbiota diversity and when their microbiota diversity increased they had all kinds of clinical improvements decreased adiposity improved insulin sensitivity decreased triglycerides and decreased inflammation so this is evidence that in humans if you change your diet if you increase the diversity of the microbes in your gut you can improve your health we know that dietary fiber protects against Western disease what we're figuring out is how that's working and we think that that's working through increased diversity and metabolic output of your microbiota this idea of fiber being healthy is something that we've heard about for decades the difference now is we're starting to understand why why it's so helpful my husband and I started the Center at Stanford the Center for human microbiome studies we're trying to translate the work that we've done into humans we've started human trials where we give people high fiber diets high fermented food diets we're following their microbiota over these dietary interventions and we're also following a huge number of immune system parameters we're measuring everything that you can in the human immune system and we're trying to figure out do these changes in diet affect the microbiota and is that changing the immune status of the host in this case humans okay now I'm gonna talk about probiotics because it's something that everybody always asks me about and has lots of questions of one thing I want to say about probiotics is that there's this misconception out there that if you take a probiotic that the microbes in that probiotic live in your gut they don't most of these organisms are transient members there are most probiotics that you buy off the shelf came from yoghurt or other fermented foods they're adapted to those foods they like to live in yogurt they don't like to live in the human gut now that doesn't mean they're not doing anything they just don't populate your gut the the bacteria that are living there long-term are the ones that you got as children so just clear up that misconception there's two major ways of getting probiotics either through fermented foods or supplements the fermented food and supplement aisle for probiotics is completely overwhelming it's like exploded I mean the yogurt section alone is just like unbelievable and then forget the probiotic section it's impossible to navigate that and so my hope is that I can give you some tips or ideas or ways of thinking about these different things what is a probiotic how is it defined defined as live microorganisms which when administered in adequate amounts confer a health benefit to the hosts that definition has evolved over time to one that is more that when we conclude that when evidence is sufficient to support the concept of potentially beneficial like live microbes which some plausible benefits are reasonable to expect including strains of microbes that have not been specifically tested for health benefits but are members of a well-studied group so to be considered a probiotic you don't have to show that it has a benefit but just that it is reasonable to expect that it would have a benefit so what are the there are pros and cons to both of these things fermented foods one of their major pros is that they provide external digestion of your food so you think of something like milk has a lot of lactose that's type of sugar if you add microbes to it the bacteria ferment the lactose and turn it into lactic acid so in that fermentation product they have lowered the glycemic index of Mel so now instead of getting the lactose which if you're not lactose intolerant your body can use instead you're getting lactic acid not as much sugar doesn't raise your glut that isn't as high of a glycemic index but it can't be cooked or canned these are living organisms if you cooker can them you kill them often the composition and density of the microbial community is unknown they write stuff on the label we've checked it in the lab it's not always what they say and then you have to watch out for salt and sugar that yogurt aisle is like a minefield of sugar if you read some of the labels on there I mean some of the sugar and the yogurt rivals that of soda so you just have to be careful that and unfortunately they couch it as a health food because living organism probiotic but but they can have some other unhealthy things I always look for this live in active cultures label that means that at least at the time of manufacture they were living organisms in the in the fermented food ok probiotic supplements there's a convenience as far as the dosage many of them will write how many organisms are there it's not a guarantee that all those organisms are alive but at least it's something and then they don't have any added calories so there it's an easy thing to take the probiotic supplements like all supplements in the United States are unregulated there is no body to police whether or not what is written on the label is accurate that any of those microbes are alive or that they are doing anything the claims that they're that they write on there are overseen by the FDA they are not allowed to write things on there that claim to treat or cure disease they can only put what they call strong structure-function claims promotes a healthy digestion or promotes a healthy immune system and so and then many are mislabeled contaminated not viable there is this USP symbol that means that the probiotic company has used a third party to verify that what they write on the label is accurate that is usually a sign that it's quality probiotic but again you know it's not a guarantee so what is somebody to do that wants to use probiotics to find a product that's right for you if say you just want to maintain health prevent infectious disease or aid in digestion or motility then we feel like the best thing to do is to find a food or a product that agrees with your system everybody's microbiota is different so depending on your system a probiotic that might be right for you might be a disaster and so you just have to kind of be your own experimentalist and see what can you look for if you're already healthy it's not easy to know what to look for the most obvious thing is bowel movements if you see an improvement of your regularity or ease of passing stool that's an indication that the probiotic is providing some benefit what if you want to treat a health issue like IBS then probably the best thing to do is to go into the scientific literature and see if there have been human studies done for your condition with a probiotic and then look for that Pro buy it because most of those studies are funded by the probiotic industry they want to make them available to people you can try those first because there's at least some validation but again it has to be you sort of have to be your own experimentalist and see what seems to work for ameliorating your symptoms and agrees with your system you have to be mindful if you have a serious medical issue there probiotics in general are extremely safe but if your immune compromised they could they could be a problem so you just want to consult with your physician if you're going to try probiotics the probiotics of the future will extend well beyond what's available now most of the strains that you can purchase are from fermented foods like I said they're transient they don't colonize the gut there are a couple strains that sort of got grandfathered in that were derived from the human gut these Bifidobacterium strains and lactobacillus jiejie those two on your system may take up residence they will never be large components of your microbiota but they could stay there more long-term but our lab is interested in other probiotics that would be provide a better benefit and maybe be more reliable there are also unique products this is a company that sells probiotics that the microbes were derived from soil they've done a handful of little studies show some benefit something to think if you if you've if it's something that you want to try there's a microbe that actually they found that people that had this microbe were less likely to get kidney stones turns out this microbe digests oxalate which can form kidney stone so if you have this microbe it's a way of getting rid of oxalates people are looking into using that as a probiotic for people to have and then fecal microbiota transplant pills I'm sure most of you have heard of what fecal microbiota transplant if you haven't it's exactly what it sounds like and the way that fecal microbiota transplants are done right now are usually either via enema or a nasal gastric tube companies are trying to develop little capsules that you could take that would repopulate your gut it sounds disgusting but if you have suffered from ulcerative colitis as a result of a c-diff infection this is a godsend for these people this is an example of a microbiota reboot that has completely changed the way that recurrence c difficile is treated and it's highly effective so what can we do now I didn't talk a bunch about kids but the microbiota of children is incredibly important whenever I get a chance I try to write articles that appeal to a large group of people to get this information out there this is an article that I wrote for Parents magazine five ways to boost your kids gut health what do we know it's all the same things I told you feed your microbes dietary fiber kids need to be eating dietary fiber their microbiota is developing still this is the community they're gonna have for their entire lives eat bacteria fermented foods or probiotics don't over sanitize this is something that is it's difficult to because sanitation there is no doubt has saved number on you know innumerable lives we don't want to go back to having to deal with the diseases associated with not having sanitized water or an environment but I think all these things are a result of us viewing microbes as bad things and I think what we're realizing is there are bad microbes but there are good microbes and we just have to be aware of that and so when you're in an environment where you feel like you've been in contact maybe with bad microbes say like on a an area where there would be a lot of people around so like in the train or you know in a physician's office then you want to sanitize but in situations where you're just like petting the family dog you don't need to go and rush and wash your hands right away before you eat and that is a way of getting more microbes incorporated into our system avoid unnecessary antibiotics again antibiotics are a wonder drug they've saved tons of lives but antibiotics were developed at a time where we didn't really understand what the microbes in our gut were doing most of these antibiotics that are available today are broad-spectrum they kill the bad microbes they decimate the good microbes until we have very precise Mike antibiotics that only go after the bad ones we have to be careful when we use these and be mindful that when we do need them that our resident healthy gut bacteria have been harmed and we need to increase our dietary fiber consumption maybe increase our probiotic consumption until that community has a chance to rebuild and then expose yourself to nature's microbes get out in nature and there's a reason why I think that gardening usually makes people feel happy you're interacting with dirt and bacteria that it gets incorporated into our system and is probably helpful I have two children as my husband and my two girls this is an article that Stanford medicine wrote about us eating a high-fiber diet is the culture in our home the same way that when we get in the car we put our seatbelts on nobody questions it nobody complains about it because that's just what it is every meal there's lots of vegetables there's lots of grains there's lots of legumes if my girls aren't happy about it they know that the next meal is going to be the same so they just there's no there's no option and and I can say that you know they've they've come to love and expect that food this is the food that they were raised on this is the food that they're used to eating so it's not a battle that you would think we've changed our front yard and turned it into a vegetable garden I feel like when my girls grow the food themselves they're way more likely don't want to eat it and talk about how tasty it is we had a journalist a couple years ago come and spend a weekend at our house he wrote an article about us in New York magazine and then a photographer came and spread manure all over our table and took this picture we don't normally eat with manure on our table but we do eat with the you know this amount of plants in the article I thought was very interesting to hear this person's take on our life he said in the article that we are making a commitment to fiber consumption that today borders on the comical and I found that very interesting because I look at these traditional populations that we study that eat a hundred and 150 grams of dietary fiber per day our family is getting nowhere near we're eating probably on our best day 50 grams of dietary fiber if you look at what the recommended amount is like 38 to 45 grams of dietary fiber per day so the fact that he found that comical really made me think that our diet has gone so far from what it should be that even something that looks somewhat like what we're supposed to be eating looks ridiculous to somebody and I think that's kind of sad so what does increasing dietary fiber and changing your lifestyle look like when we started the lab we needed a sample to humanize our germ-free mice with and so we thought well we'll take my husband's sample he will always be a part of the lab and we know we can come back to him for more samples so we used that for our experiments you know as part of the experiment we had to see what his original composition look like he had about a little over 600 species of bacterias gut we didn't think anything of it back in 2010 we finally in 2005 15 ran out of that sample and we said hey we need we need another sample from you he gave us another sample and we found that he had increased his comp his diversity almost 1/3 again so he was up to 1,100 species of microbes over that time period what did he what did we do over that time period like I said we changed our front yard into a garden we eat so many more plants than we used to this is my kids playing in a turkey compost pile we're just so much more relaxed about things like that now before we would have been like oh you got to wash your hands there now we we try to be more calm in situations where we feel like it's safe this is an example of the pizza that we'll make we make our own kefir so we're fermenting stuff and then we got a dog and pets are a great way to expose yourself to the outside our dog goes outside he comes and sits on our couch and you know so there there are bacteria everywhere and so this is you know N equals 1 we didn't set this up as an experiment it just happened that we had this old sample and new sample and we had changed our lifestyle pretty dramatically but I think it does show that it's at least possible to increase the diversity of your microbiota and and to it to a better spot just through simple things like diet three take-home messages the Western gut microbiota has low diversity which is associated with poor health dietary fiber or max these microbiota accessible carbohydrates can help retain an increase that microbiota diversity we joke at our house that we eat a Big Mac diet lots of microbiota associated carbohydrates and then fermented foods and probiotics have been shown to have health benefits and can help increase diversity and are something to try okay so one last thing when the I'm going to totally shift gears here when that when the new proposal for the NIH budget came out and there was this talk of severe cuts to the NIH I decided to add the slide into my talks because I felt like as a member of the scientific community I could it's on me to explain in situations where I have an opportunity how our research is funded and I think the scientific community in general has done a poor job of explaining how research is funded and how we rely on this money and so I think it's our responsibility to educate people on how we do research in our lab almost all the money that funds our research is from the National Institute of Health and then we have this other National Science Foundation money this is all federal money we get a small slice from nonprofit foundations and then more recently we've been doing private donors and Industry funding as well a few years ago that yellow slice would have been nothing because we would have been completely reliant we feel like now that isn't a good strategy moving forward because we have to we feel like it's important to keep our research going and so we have to look at all sources of funding now federal funding is incredibly important for research like what we do because a lot of what we're finding is that safe components of food like dietary fiber are beneficial no company wants to fund that because food is not patentable you can't make money off of any any dietary supplement that has a particular type of fiber somebody else could come up with something that's a teeny bit different and it would probably be just as effective and then it keeps our research honest we're not when we get private funding from a corporation say that wants us to use their probiotic we thought we make sure that the company understands that we will publish the finding regardless of what it is and that that that will publish a finding regardless of what it is and that we we will not be we won't have this sense of showing them a result that they want to see just to get more funding so what that normally means is that most companies do not want to fund our research because the biggest concern for say a probiotic company is if they give us money we use their probiotic in a human study and there's no effect we will publish that and that's a PR nightmare for them so often we we have had very strained relationships with with industry sometimes we will get companies that are very forward-thinking and they want to improve their product and are happy funding and figuring whatever we figure out we're happy to share with them and share with everyone okay so finally I want to acknowledge the members of our lab we have this incredible group of people at Stanford that range from MDS to computer scientists we feel like we have to really approach this complex problem from many different facets and that's why we've assembled this group of people we felt so strongly about the research that we were doing in its importance in human health and realized that when we would talk to our other science friends that weren't even us that weren't working on the microbiota and our friends our educated friends that didn't know about our research we saw that we were raising our kids and making choices that were different than what they were doing we had this privileged access to this knowledge that other people didn't have and then we would go to conferences where it's all microbiota scientists and we saw that what we were doing they were all doing - we had all come to the same conclusion that high fiber diets were good fermented foods were good this overuse of antibiotics and and sanitation was had gone too far and so we felt very strongly that we had to convey this information in a way that would be accessible to everybody and that's the impetus for writing this book we wrote that book with the idea of spreading the information of our lab and other researchers in this field in a way that was scientifically sound evidence-based but also easy for for anybody to read and so I would like to offer up if you guys have questions I'm happy to answer any questions okay a lot of questions already they say when they turn 50 their metabolism changes their things slow down they gain a lot of weight and often they don't change their diet and on the contrary they but try become a little bit more healthy so I'm just wondering if in fact you've looked into something like that and how that may what research you may have found yeah the field is very for the last 10 years was very much in like a stamp collecting phase I mean we really didn't know what types of bacteria were typical in a human gut and so we've spent the last 10 years cataloguing that everywhere and one of the things we found and by we I mean the community of researchers not necessarily our lab specifically is that as we age the microbiota does change and composition and if you look at people like you know over 7080 their microbiota composition looks completely different than somebody that's in their 30s or 40s we don't know what that means some of these microbes that we see that become more abundant later in life appear to be microbes that are not beneficial that result in more inflammation but we don't we don't know what what's caused is that just aging is there something else happening that's causing that and whether or not that's something that we could slow down again we don't know it's possible that this shifting community is what's making you know weight gain and those kinds of things easier as you get older it's clear that the microbes that we inhabit are largely determining things like how our metabolism works but we'd beyond just knowing that there's a difference there we don't know much I'm curious about the effects of caffeine perhaps on the gut in the digestive process went through coffee or tea yes I mean caffeine results in motility changes in a lot of people and we know that you're a large part of the community that you have in your gut is a product of your system so depending on how often you have bowel movements will influence which type of microbes and habit your gut and so in sort of an indirect way it could have a effect on your community whether or not caffeine like that molecule specifically I don't know of any studies that have looked at that but you know the field is rapidly growing and people are looking at things like artificial sweeteners chlorinated water like all these things that we're ingesting what influence that has on the microbiota in many cases you see a difference if that difference is meaningful we don't know did that tribe have caffeine in their diet let me think they will so they live near by a group of pastoralists that have access to tea and so they will drink tea periodically but for the most part they don't yeah okay so for me I would just like clarification so I don't leave confused your slides in the beginning led me my perception was that I couldn't change so so this is why I'm so confused at the moment honestly because the first slide were you said unless we were to get a transplant I couldn't change it or didn't studies haven't shown yet and then the slide were after generation four you gave them back the fiber nothing changed yes but then you showed your husband at the end so I'm a wait maybe I can okay can you clear yes yes so okay so the the mouse experiment remember they're done in those bubbles so bacteria can really only leave we've enclosed them in a system where there's no opportunity for new bacteria to come in so what we were testing when we added the fiber back was maybe there were reserves of microbes in their gut that we weren't detecting that if we fed them they would come back which didn't happen so those that's why we said extinction they were gone husband's example he lives in the microbial world so if he when he increased his fiber consumption increased exposure with bacteria we can you know the patina get microbes from other individuals and if we have a lifestyle that is amenable to those microbes living in our gut they can take residence and that's what we think happened with my husband now for the there are kind of two things happening the Western microbiota is less diverse than these traditional populations those microbes that they have that we never see here we so far have no way of getting them unless we would go to Tanzania and hang out with those people so part of what our lab is studying is these microbes can we reintroduce them into people in a safe way that's a big question we don't know we have to be very careful some of these microbes might cause disease in Westerners and so that's kind of one thing of regaining this like ancestral microbes but because we can't do that in a safe way now what can we do now we can increase the microbes that are in our environment so from interacting with different people interacting with the environment increasing the dietary fiber you can increase the diversity of your microbiota you will not get some of these microbes that these traditional populations have but maybe you don't need those maybe increasing the diversity of just the the microbial pool that we have access to is that what happens when we eat meat or animal products that have been treated with antibiotics yeah that's but I mean this is a big issue and where our lab doesn't study that directly some other labs are looking into that whether or not some of the I mean the amount of antibiotic in the meat appears to be small but that doesn't necessarily mean that it's not doing anything I think a lot of the field right now is most concern with the antibiotic resistance that those antibiotics are causing in these animals and so if you come in contact with a microbe from that meat that has an antibiotic resistance gene you eat that microbe those Anam microbes are amazing at sharing genes they will swap them back and forth your bacteria now can pick up that antibiotic resistant gene and all of a sudden know you have a resistance to an antibiotic that you never took that the animal took and so a lot of the field now is trying to figure out safe ways to make you know animals healthy for meat consumption but not transmit these antibiotic resistance genes to our own community if they're gonna mention drains but that's not really hunter-gatherer and also it's fermented foods he said that they were lot it to be live it can't be cut there's this hole so part of why we started that Center for human studies is we want to ask these questions of does any dietary fiber help is it Lots amount lots of any one type or does it have to be a diversity of different types of dietary fiber we don't know the answer to those questions what we think is if we look at these traditional populations their diet is pretty simple they're only eating like five or six different kinds of foods but if you look at the composition of the foods they are eating the carbohydrates in there are incredibly complex so we think that a diverse amount of dietary fiber is good so that would be from plants fruits vegetables whole grains legumes whatever so these populations don't eat things like legumes and whole grains because those are a product of agriculture but I think part of the the problem with this like it's sort of this Paleolithic diet that people are interested in is that we don't have access to the food that our Paleolithic answers ancestors ate because we've domesticated all the plants to make them less fibrous and higher in sugar and so like that tuber that I showed you there's no whole foods that you can go and find something like that that food doesn't exist and so how do you get a high fiber diet with the foods that we have and legumes and grains are great because they have a lot of fiber so it's an easy way to eat a lot of fiber in a small amount of food we're running a study right now where we're telling people to increase dietary fiber as much as they possibly can we don't give them an upper limit we want to see what's possible in kind of a Western culture these people at best can get 280 grams of fiber per day they said it's incredibly difficult because there's no like convenience foods really I mean you can eat like raw fruits and vegetables but you know they're eating a lot of beans and stuff the other thing they said is it's incredibly hard to eat a lot of dietary fiber because they're so full if you get to like 50 grams of dietary fiber that's a lot of plants you're just you become so full you can't eat anymore and so you know my husband and I joked that oh if we write another book it should be the one rule diet because we tell these people just get as much dietary fiber as you can and what we find is that their amount of saturated fat goes down their amount of sugar that they eat go down their total calories go down we haven't told them to do any of that it's just to eat that amount of fiber you have no room for for other types of food the fermented food that the thing that's important to remember is if it's if it's in like a refrigerated section chances are it's not been processed in a way that would kill microbes so sauerkraut is just cabbage they cut up you know ferment and then if you find it in the fridge section and often you can tell because you open it in it like fizzes that's the microbes generating gas from that and that's a way to tell that it's alive the brain and I saw yours live you talked about connection between yeah our lab doesn't study the gut brain access specifically there there's a there's a guy at UC a UCLA and Marin mayor and I think he has a new book out trying to mind gut connection something like that he studies that and I haven't had a chance to read his book but he's you know a reputable scientist so I would assume that his book is pretty pretty good mayor Ameren mayor at UCLA the there's a ton of serotonin in the gut but we know that serotonin is responsible for regulating gut motility so what we don't know is all that serotonin just for that is any of that serotonin made in the gut getting to our brain we don't know if that's true it's it's exciting to think that that's what's happening and we know from some other studies that they they did this one study at they did F MRIs F MRIs of women that had either had a probiotic supplement I think yogurt versus not and they when they just scan their brains the women that had had this yogurt had a different scan than the people that hadn't so there's there's something there but again like that community of microbes so complicated our brain is so complicated trying to figure out how these two things or it's gonna take a long time to figure that out but there's there's something there they're connected there's no doubt from our garden no no and I that like my kids will pull a carrot out they'll just brush it off and eat it but that's only because I know I don't spray my garden I don't you grocery store vegetables I wash I mean the stakes are high right you hear these stories of E coli Salmonella getting in the food we don't want to go to a spot where we're so lacks on our hygiene that that becomes more prevalent but we just have to think about like when are situations where it's to to be a little less careful with sanitation yes so I'll start with the second part soluble versus insoluble is is completely a chemical definition and in fact I think the new Nutrition Facts label isn't even going to include that because it's meaningless as far as the biological activity some insoluble fiber is not fermented by the microbiota so cellulose is an example our gut microbes can't digest cellulose we can't digest cellulose that's the like roughage that just goes through but some soluble fiber is fermented isn't some insoluble fermented isn't that's why we came up with this term microbiota accessible carbohydrates because that means those are carbohydrates of our gut bacteria can ferment now the complicated thing about that is what your gut microbes can ferment and what yours may not be the same there was a study done in Japan many people in Japan Harbor a microbe in their gut that's able to degrade a type of carbohydrate that's found in seaweed when we looked at American guts they don't have that microbe so for those people they're they're getting something out of that seaweed that we're not getting and so it's gonna be a complicated thing to try to figure out what is fermented by your gut but our goal in the future is that you would go to the physician you would do is like a microbiota typing and then they would tell you these are the foods that are going to be best suited to the community of bacteria that you have these are the probiotics that are best suited for the community that you have though we're just not there now what my family and I eat we focus on the fiber thing we try to eat something fermented every day usually it's yogurt we make our own kefir we also ferment like vegetable make sauerkraut kimchi those kinds of things a regular yogurt which I get unsweetened and so my kids are used to unsweetened yogurt which I know not all kids find appealing so what I did I actually had a little trick for how I did this because they used to eat sweetened yogurt so I would buy the unsweetened yogurt and I would put like a little bit of maple syrup and then I would like slowly every time less less less though and they didn't they never said anything and then all of a sudden they were eating regular yogurt and then there was a time we went to a hotel and they only had sweet yogurt and they ate it and they were like this is so weird and I mean they just were used to that kind of sour taste you know a lot of my husband and you know I hate to talk about this because then it seems unattainable my husband likes to make sourdough bread from flour that we mill ourselves from wheat berries but that's just because that's what we like doing that yeah so you know so we will eat that bread that we put like nut butter on nuts are a great source of fiber a lot of oatmeal those fruits and green smoothies in the morning we're big fans of smoothies not the juice you know when you juice stuff there's all that pulp that's that you throw away that's all the stuff the microbes want to eat so if you have it in a smoothie then you're eating that - we just hummus beans we don't we're not vegetarian we're not anything we'll eat meat we'll eat fish but we we just focus on getting a lot of fiber and so many days we end up not eating meat and so we so one thing I didn't talk about and we have a study coming out hopefully in the next couple of months on this that that hides a population they eat extremely seasonal if they don't have a grocery store so they just get what's and what we find is their microbiota over the year changes in a seasonal pattern so in the wet season they're eating this one type of food their microbiota looks this and the dry season it changes when they go back to the wet season it goes back so there's the cycling thing we don't see that in Westerners we don't know if that's important so our family tries to kind of eat in a seasonal both to try to mimic that a little bit in case it's important and also it's a way of getting a diverse diet many types of dietary fiber when I talk about diverse diets people are like how can I eat all those different foods like all in one day but I think you have to think of it like in the span of the year so when it's like strawberry season as far as you lots of that and then in the time of year where something else in season you eat lots of that that's a great question we don't know so we think what's happening if you look at the way the intestine is set up there's these these little villa these little crypts there's a little like dips in there and what we've started to see is that microbes will hide in there and so we think what's happening is you know when times get let's say you're a bacteria that loves the type of fiber that's in strawberries so when it's strawberry time you are going nuts lots of you around because your food preferential food sources available when strawberries aren't there what we think happens is they hide in these little crypts it's like a way of you know hunkering down and then they wait there and then when the food comes back they come back out and blooms we think that's what's happening we don't know it's possible that maybe there all the bacteria is all gone and then when that food is reintroduced in the next season they're actually eating that bacteria along with the food like it's part of the soil or the environment we don't know we have soil samples and environmental samples we can look and see if it's there but it's still hard to know if that's if it's supposed to be there or if it's just there because it's contaminated from the I know we know what effect cheating on your fiber with methyl cellulose or sodium in a Metamucil yeah yeah so it's interesting because I've so I've talked to physicians about then what they've told me is that you know though for people that they want to increase motility they'll give them something they'll recommend something like Metamucil and for some people it works great and they said for some people it severely constipated them yeah and so what we think is that those people maybe has a community that can't ferment it or it's like resulting in something that is negative for them and so you know we we view those types of supplements as the bulking kind of like cellulose like it's not being fermented by the gut but we don't really know and it could be that it's different for each person - exactly yeah well I think the fact that it's not the same in each person makes me think that it's maybe not just bulking and everybody maybe for some people it is fermentable we don't know again one of these things in the future will we'll be able to tell you these are all the different enzymes that your gut has you can degrade cellulose you psyllium husk so you can't and yeah can you I know in your book you talk about it meat and the TMAO yeah so this was a study that was I think at the Cleveland Clinic they looked at individuals so there's this TMAO is this molecule that circulates can circulate in our blood and it's associated with adverse cardiovascular events if you have high TMAO you're an increased risk for a heart attack or stroke they were trying to figure out where this molecule came from turns out it's a product of one of the waste products that microbes make in fermentation they make this molecule TMA and that gets absorbed in the blood and it's because the blood is oxygenated it adds an oxygen and it makes TMAO and so what they found was that individuals that ate a lot of meat they're microbes were producing a lot of this TMA and that was kind of the length then they were psyched this is the link between high red meat diet and increased risk for cardiovascular events so the the kind of cool part of the studies they found a I can remember they were a vegetarian or a vegan and they convinced that person to eat me this person had like never meet before and what they found was that person made tma but much less so than a normal meat-eater and we know that vegetarians and vegans have a different microbiota than than people that eat meat and so the idea was that there were microbes and the meat eaters got that was producing this compound that was leading to increased risk for cardiovascular events and so the implication for that is that if we can steer the community in a way that you decrease production of that TMA all of a sudden now you have a good therapeutic for decreasing the risk of of heart disease I am familiar with some of them and I think for the most part it's just bull I most of it I think the so American gut is one we talk about in our book that was started by a guy he's a professor at UCSD and he doesn't make any claims about diagnosing or telling you anything he started that as a citizen science project he wanted to just get a sense of like what does everybody's microbiota look like and I like that project because he doesn't say that he's you know gonna cure any diseases he charges what the cost is to run the sample and he makes that data available to researchers so we've used that data when we compare like our Tanzania group we use American gut people as our American cohort some of these other companies not only I don't know what their business model I don't know if they're making money off of the the test alone some of the tests I've seen other people that have done it they make pretty incredible claims on there they will tell you like this is the probiotic you need to take and this is your missing this type of microbe or whatever and it's not based on anything that I've seen that's that's legitimate some of these companies even offer to make you like a custom probiotic cocktail based on your thing and that's just complete I mean that's just an I don't know where they're getting that information from so I would I mean unfortunately like it's great that people are excited about the microbiota for our field it's it's amazing but it what if what I'm seeing is a lot of companies and people profiting off this interest and putting information out there that's not real that is you know ways that they can make money so I would say like you know if it's not apparent to you or if the if it looks like the person selling the thing has something to gain financially from it I would be more skeptical of it yeah and I mean there are physicians that are ordering microbiota tests I don't know what they're doing with that information because Ulta I mean I've been studying this for 15 years people will show me their thing I'm like I don't know what to tell you like it looks I can look at certain microbes and say this one looks like not the best but maybe in the context of the other 500 that are there it's totally fine I mean we know people with Caesar you know twenty percent of the population is walking around with C difficile in their gut and don't know about it so it's not that C difficile having it causes disease there's some other perturbation that has to happen and so looking at your microphone and saying oh well this is a bad character we need to get rid of it I think it's just too simplistic for Mayan verses do we really need the ancestral microbiome and the specific microbiota of that did get Eradicator in that we're not sure it can set up residents again and we want them to be residents versus if maybe now since our genome hasn't caught up with the microbiome that the resident microbiome that we're going to cultivate is really just about this dietary fiber yeah and the best we can do is have a broad a diverse neck I think that's a hugely open question and that's something that our lab is actively pursuing we're isolating microbes from these traditional populations we're gonna start putting them in mice seeing what happens and eventually we want to put them into humans and see what happens if they're safe we have no idea if we need those microbes or not and so why I talk about diversity and fibers that you know people want to know what they can do now these studies on these traditional populations and their microbes could be decades off before those things are realized as therapeutics and so we're trying to think of ways that we can because we know the composition appears like it's not great how in the Western world how can we fix that with things that are safe to do now and so we think this increase in diversity through dietary fiber is beneficial I mean there's been lots of studies showing that fiber is beneficial and we think it's through this increase in diversity whether or not adding those ancestral species back provides an even greater benefit is a completely open question can you explain the difference between prebiotics and probiotics and the fact that you need the pre BIA prebiotics before the probiotics can actually do any good in your body and then what really are prebiotics so prebiotics are really they I think they're officially defined as carbohydrates that feed beneficial bacteria so in that definition dietary fiber is a prebiotic those carbohydrates feed the beneficial bacteria in their gut I think like inulin is an example of a prebiotic fiber that's every where there's nothing special about inulin it's just been heavily studied and so people are familiar with that so prebiotic manufacturers use that as a as a prebiotic there are some things that people sell that are called syn biotics so they will add a prebiotics a inulin and then they will add a probiotic and organism that utilizes that inulin and the idea is that having the two of them together is provides a better benefit than having each one individually I don't know if that's really the case I kind of this I just you know I I think in our book we wrote like I view that the produce aisle as the prebiotic aisle that's that's where all the beneficial stuff is you've gotta be really excited about expanding my vegetable garden um when you look for seeds do you care about whether they've been hybrid or if they are if they're heirloom or what do you do when you look for seeds for your garden I I'm I I should be like looking into this but I don't I I if it's possible I choose organic seeds but that's not from any sort of health standpoint it's just more of like I don't want the chemicals used in the environment because again even things like you know roundup is that the chemical found in roundup there's been early studies showing that it affects the microbiota so we don't really know I just pick like what grows well and and actually because my kids I try to pick things that they can just pick and eat right they're little tomatoes these little Mexican cucumbers that are like small so they can just pick and eat carrots those kinds of things I so we've made kombucha before and we like it but yeah it was just we're making kefir we're making bread we're just kind of picking a couple of things that yeah it's easy but I mean a lot of people in our lab make kombucha I really like it yeah oh sorry so I have two questions one is I had spent some time in Nepal and the physician there had said oh my gosh these little kids running around the Himalayas have like 13 species of bacteria that would make you and I sick Giardia I'm salmonella Niko lines you go and they don't have diarrhea so when you talk about the micro bio by a biome of these traditional remote groups are you including in that those pathogens that we would consider pathogens and I always about that that's the my first question and the second is totally unrelated which is have you looked at what chemotherapy does to the microbiome or in particular bone marrow transplant patients pre and post because we really slam them to get rid of and you know their guts go through you know really a tremendous that people to say I'm ugly yeah but that I wonder what happens like at six months or a year I don't know if anyone's looked at that but in those BMT patients I think I I don't I mean I know that people are looking into this and I for cancer patients and and bone marrow transplant and so I don't know if those studies are out yet I'm sure they're seeing differences I mean anytime you forget this is let me see a difference I wear a lot of the exciting stuff is happening with cancer patients is with this new like immunotherapy we know that the microbiota is wired into the immune system and tunes that in a very profound way and so a lot of people are looking into whether or not they can make these immune therapies more effective by priming the the microbiota first get the immune system tuned in a way that when the like you know anti PD one or these other drugs come in that the immune system is really ready to pounce on those cancer cells that's all very early I don't know of anything data why's that that's out on that and then what you're first the pathogens you know about remote cultures they have a lot of pathogens that would make any of us sick so you know people talk about bacteria in the gut but there are tons of viruses in there and there's tons of parasites in there at least for these traditional populations the way that our lab studies it we're only focused on the bacteria because it already seems like kind of an overwhelming problem or you know thing that we've started looking at viruses in the gut it's what's a maze so there are viruses in the gut that that aren't human viruses they're viruses that infect bacteria I mean the gut is so fascinating there's like you know this community of bacteria there's these viruses it's like you know predator or prey there's all these dynamics going on that we're just starting to get a handle on the the bacterial viruses that are in the hodza are very different than what we see in Westerners but we don't really know that much about what those viruses are doing we know that these guys have tons of parasites we don't look for that we're not looking at that either we know Westerners basically don't have parasites and there are people that study this and feel that part of the increase in Western disease is that we don't have those cues from the parasites anymore our genome evolved in a time where parasites were just a part of being human and so it it tuned our immune system it was something our body expected and and the question is now that we've eliminated that completely have we changed our immune system in a way that's not normal anymore and there are people that have you know allergies or inflammatory bowel disease these other autoimmune issues that will say that if they you know get a parasite they feel better and so some people are looking at parasites as maybe being a way of treating inflammatory diseases but that's you know early on ideally you would have you know people talk about you know maybe in childhood we need to give kids parasites get the immune system primed properly cure them of the parasites and then hopefully everything is as good after that but that's just starting [Music] [Music]

Channel: SOUL Food Salon

Views: 361,644

Keywords: microbiome, microbiota, Stanford University researcher, The Good Gut, bacteria, gut, gut health, fiber, fiber rich diet, fermentation, health and wellness, healthy eating, gut bacteria, colon health, depression, metabolism, obesity, probiotic, research, researcher, science

Id: miEngVBrrIc

Length: 91min 18sec (5478 seconds)

Published: Wed Jan 10 2018

Reddit Comments

[u/fddfgs]

Great talk, particularly her talk of human genome/microbiome interactivity as it relates to autoimmune responses.