Why stomach bugs are essential for optimum health

This conversation with Martin Blaser, MD and Dr. Gloria Dominguez-Bello was recorded on June 7, 2023 and transcribed using Sonix AI. Please check against audio recording for absolute accuracy.

Peter Bowes: The warning is that if we ignore the health of our microbiomes, we could all be in serious trouble. The microbes, you might think of them as germs, inside our bodies are way more important than most people think. And that’s the message that comes through loud and clear from the documentary The Invisible Extinction, which was released last year. It features the work of Martin and Gloria. And I’m delighted to say they’re both with us for this episode of the LLAMA podcast. Welcome to you both.

Gloria Dominguez-Bello: Thank you.

Martin Blaser: Thank you for having us.

Peter Bowes: It’s really good to talk to you. I think before we go any further and I really want to delve into the issues behind this documentary, let’s talk about microbes. What are they and why are they important to us? To all of us. Gloria, let’s start with you.

Gloria Dominguez-Bello: Microbes are microscopic forms of life. And of those bacteria were the first inhabitants in this planet. So all the forms of life, including animals and plants that evolved later had to deal with bacteria. And typically they fuze with bacteria. Some of them. They evolve in association with bacteria and the microbiome of each different animal and plant differs. And this is a community that is necessary for the health of the host organism. That’s why microbes are so important for the life of everybody else on earth.

Peter Bowes: And I say some people might just think of them as germs. And there’s obviously. Martin Isn’t there a negative connotation with that? And I guess certainly having watched your film, part of the the message is that we shouldn’t think of microbes in a negative sense. Far from it, because they’re there. So ultimately positive for us.

Martin Blaser: Yeah, the history of microbiology is the history of the discovery of bad germs. There were important diseases and the microbiologists, starting in the 19th century, started linking them to to microbes, finding that tuberculosis was caused by a bacteria, that cholera was caused by a bacteria, that typhoid fever was caused by a bacteria. So that has really influenced our thinking for the last 150 years that in in the public and in the health professions, microbes are associated as germs as being bad. But as Gloria said, all of us, every animal, every plant has their own microbiome. That’s the collection of all the microbes that live in and on us and that are very beneficial for us.

Peter Bowes: And in fact, is this accurate to say that really we’re made up of lots of different microbiomes that are equally important in our gut as they are in our mouth, as they are in other aspects of our system, our digestion system, our colon, our small intestine.

Martin Blaser: All of our exposed membrane surfaces have have resident microbes, our skin, our eyes, our nose, certainly our whole GI tract from top to bottom, vagina and women. Have I left anything out, Gloria?

Gloria Dominguez-Bello: No. I mean, it’s true that the biggest of these ecosystems with more bacteria and very high diversity is the gut. And because the gut, I mean, everybody every organ has a function. But the gut function is so fundamental because it’s where we nourish and where we absorb nutrients from the outside so that it’s a we understand now that there is a connection between the gut and everything else, all other systems, including the immune system metabolism. And the brain.

Peter Bowes: That’s what we’re going to talk about, the connections and how the microbiome, how the microbes relate to our everyday health, and perhaps even more crucially, to our future health. Just before we do that, maybe I think it’s worthwhile just getting to know each of you individually a little better to talk about your careers to date and talk about how you met. You met by working together. But Martin, give me you’ve been a doctor in New York for a very long time. Just give me a little potted history of what you’ve been doing so far.

Martin Blaser: Well, as you said, I was born in New York. I trained in economics, and then I trained in medicine. And I went to Colorado to explore the West and to do further training in medicine and infectious diseases. I worked at the Centers for Disease Control in Atlanta studying outbreaks of disease. And then for the last 40 something years, I’ve been a university faculty member at the University of Colorado, Vanderbilt University, New York University, and now Rutgers University. So I’ve been somewhat of an itinerant academic, and I’ve been. But by chance I began to study bacteria and how they affect human health first, starting with the pathogens, the bacteria that make us sick, and then eventually moving toward the beneficial ones, the ones that keep us healthy but occasionally cause problems.

Peter Bowes: And Gloria, you’re from Venezuela. In fact, Venezuela features quite heavily in this film?

Gloria Dominguez-Bello: Right. Yes. I was born in Venezuela, in Caracas. And I was I grew up in the in a rural little town. Not not that little anymore. Marty and I went two weeks ago called Bejuma. And and then we had to move to the next nearby city Valencia because there was no high school in Bejuma. So I grew up my teenage years were in Valencia. And then I went to university in Caracas where I did biology, ecology. And then I got a British Council scholarship. I owe the British all my graduate education, a master’s degree in nutrition, and then a PhD in in microbiology, which I did in Scotland at the University of Aberdeen. Then I returned to Venezuela for about a decade, and I started studying, studying symbiosis between animals and their gut microbes. And also I started my human studies there, especially with traditional peoples from the Amazon. Then I moved to Puerto Rico when the revolution started in Venezuela, reflecting my very pessimistic view of the future there. And then after about another decade, I moved to New York. And now Marty and I have been together for quite a few years.

Peter Bowes: And it’s in New York that you were working together and that’s actually how you met?

Gloria Dominguez-Bello: Well, we’ve met professionally before we became friends and more than friends. But our fields were and are still our the problems of our labs differ, although we collaborate. We have I’m very focused on early life assembly of the microbiota and perturbation of C.S. and also differences in the microbiome with urbanization as people integrate modern high tech lifestyle, Marty’s focuses are more somehow related to medical questions and broader, his lab is bigger too.

Martin Blaser: Gloria has the background as a biologist and I have the background of a medical doctor and particularly a specialist in infectious diseases. And a large part of the specialty of infectious diseases is about antibiotics, about how to use them and when to use them. And antibiotics are major tools. And so I have really been focused on or what antibiotics are costing us, how how we have overused antibiotics and how there’s there are paradoxical effects, not just benefit, but but real cost.

Peter Bowes: Well, we’re going to get into all of that. Let’s start by talking about this film, which really is it’s a great watch. And I watched it twice now. I think you need to watch this kind of film several times to to really fully understand its message.

FILM CLIP: Bacteria have been the dominant form of life on Earth. Everything about human life depends on bacteria. They are involved in almost everything our bodies do. But just as we are learning how important they are, our microbes are disappearing.

Peter Bowes: It was actually inspired by your book Missing Microbes. Wasn’t it initially Martin?

Martin Blaser: Yeah. So so I wrote Missing Microbes in the early 2010s, and it was finally published in 2014. And it was it was to sound an alarm. It was about the work that both Gloria and I have done about how our human microbiome is changing and how there are costs to those change disease costs. And a very important part is, is the role of antibiotics in what we said is fueling our modern plagues. These are the plagues of obesity and asthma and allergy and autism. And that book got a lot of attention. It’s now been translated into 20 languages. And shortly after the book was published, some filmmakers approached us and said, We think there’s a movie there. And we were interested because even though books influence people. Films influence people even more, this is a chance to reach a broader audience. And that’s that’s what we really want to do. We speak to professionals all the time, to scientists and doctors, but we really need to speak to the general public so they can understand what’s at stake because it’s their future and their kids and their grandkids.

Peter Bowes: And I think what is interesting, one of the interesting thing you just said is that you both come from different disciplines from that of a practicing doctor and a researcher. And I talked to a lot of people for this podcast, sometimes individuals who have started as a doctor and moved into research, but they always stress how beneficial it is to have the experience of essentially both disciplines or both careers. In other words, as a doctor dealing every day with patients, with people, but also having that laboratory experience and that laboratory perspective on a subject, on a scientific issue, that you’re bringing these two disciplines together and that kind of helps you in your mission.

Martin Blaser: I’ve mostly become a mouse doctor these days!

Gloria Dominguez-Bello: But but it’s true that you need you need to be able to measure things. Also, you know, being a doctor also helps in doing clinical trials, for example, and and doing work with on human beings as well. But to understand mechanisms, we need to have animal models that we can control the conditions of or subject to treatments that would be unethical in humans.

Martin Blaser: One of the ways that being a doctor was really helpful to me is that early in my career I was at the Center for Disease Control in the Enteric disease branch that deals with infections of the gut. And and what I learned then 40 years ago is that most of the antibiotics used in the United States and in other countries is used on the farm. And the reason they’re used on the farm is they’re used as growth promoters. They make farm animals grow faster, grow bigger, faster. And the reason they’re used so much is because it works. And one day about 20 years ago, I was advising a young doctor about career choices. And I said to him, I said to him, Well, you know that farmers use antibiotics to fatten up their farm animals. And just at that moment, I had kind of a eureka moment. And I thought to myself, wow, I wonder what if that’s what we’re doing to our kids? And that I think that’s where the medical background helped me to kind of make that leap and say, well, if if farmers can make can change the metabolism of their farm animals, maybe antibiotics are changing human metabolism also.

FILM CLIP: It’s now been 70 years since farmers discovered that if they gave antibiotics to their farm animals, they would fatten them up. And the earlier in life they started it, the more profound the effect.Some antibiotics added to the feed of young animals promote more rapid growth. The larger pig was raised on feed containing an antibiotic, the other from the same litter was not.

Martin Blaser: The story begins with the partnership between humans and our microbes. This is a partnership that is very deep in our evolution for a very long time, and it’s become clear that our microbes are our partners in guiding the early steps of how we develop our metabolism and our immunity, how we how we handle energy, how we distinguish friend and foe. They’re they’re our partners. And when we’re born as babies, we’re very small. We have, let’s say, relatively simple systems. And then gradually we follow a trajectory. Let’s say in size. We get taller, we get bigger. And and there are trajectories. And and what the farmers found is that if they gave the antibiotics early in life, they changed their trajectory. And that’s just what we think is happening in humans. And we can show this experimentally in mice that if we give antibiotics, the mice grow bigger, faster, just like the farm animals, which we we think is what’s going on in kids. And it can it doesn’t have to happen the next day. Sometimes in mice it happens months later, which is the equivalent of years or decades later in humans.

Gloria Dominguez-Bello: And that’s in part the reason why people don’t do the connection. It’s not obvious immediately. So this is something that you will be able to see in years. So the increased risk of of obesity, but epidemiological studies show it babies that have been exposed to antibiotics that have been born by C-section, which entitles also the use of antibiotics. And I think any preservation in early life will alter the trajectory of both the maturation of the microbiome and also the development of all the systems in the baby host. And in general, they have one thing in common and that is underlying inflammation and increase growth. So why do the babies increase growth when you preserve their microbiome? It’s a we don’t know, but it might be that that’s a way of saving their red red flags and alarms and the babies depositing fat and growing fast so that as a mechanism of saving that baby.

Peter Bowes: What you’re saying is, is contrary to what most of us are brought up thinking, and that is the use of antibiotics throughout our lives is good for us, that it saves us, it protects us. It helps us get over some medical conditions. So are you suggesting that all antibiotics and maybe especially when we are younger, are not good for us and that we shouldn’t be using? Or is there a fine line? Is there a line beyond which perhaps you wouldn’t like to see us to go, but the use of some antibiotics is clearly beneficial to us?

Martin Blaser: Yeah, I would never say antibiotics are bad. They have benefit and they have cost. And the the proper practice of medicine and health care is to optimize is to optimize benefit and cost. And so I could go on on this for hours and I’ll be I’ll try to be brief, you know, you know, for example, a very common problem with kids is that they have ear infections and we can think of ear infections as a gradient. There are some ear infections that are really terrible that need antibiotics, that every child should have antibiotics. We can call those black. And at the other end, there are ear infections that are very mild that a child should never get antibiotics. And then there’s a lot of gray in the middle and different doctors cut that gray at different points. So in Sweden, for example, they use 40% of the antibiotics that we use in the United States, Swedish and Swedes seem to be just as healthy as we are. So they’re they’re able to to use much less antibiotics and get the same results. So it’s been pretty clear for a long time that we’re overusing antibiotics.

Peter Bowes: Are they just as healthy or indeed, are they healthier?

Martin Blaser: These are hard these are hard comparisons to make. You could look at some ways they’re healthier. In some ways they’re not. I just make the point that we have reasonably healthy people and they’re using much less their doctors are using much less antibiotics. So for certain infections. Antibiotics are required. They’re absolutely required. But for most infections, they’re not. Most of the use of antibiotics is not for life saving. It’s for mild, mild illnesses, many of which are viral. Antibiotics don’t even work. So some of this is is the practice is the fault of the practice of medicine, where overtreating.

Gloria Dominguez-Bello: When doctors are thinking that this could be an infection, a bacterial infection, they should take into account the costs of antibiotics that were unknown until very recently. You know, a few years ago, people would say antibiotics are okay because they only kill bacteria, not they do nothing to human beings. But now that we know that human beings are form an ecosystem with bacteria that are important for health, then we care. And doctors should consider that. Is it worth the consequences of antibiotics? And you know, I think because we will always need medicine, we will always need antibiotics, although we can there is a lot of room for improvement, but we will need practices when to save lives for sure. The question is how? How do we restore? We have to learn how to restore the microbiome to the pre stressor, you know, state and return people what they lost because of the treatment.

Peter Bowes: And you made the comparison, Martin Between Sweden and the United States in terms of the use of antibiotics. You also in the film cover China and the use of antibiotics there. And this is somewhere that you’ve traveled to. What did you learn?

Martin Blaser: Well, actually, even before we were there, I learned that they’re using tremendous amounts of antibiotics in China. And this actually gets to an issue I wanted to raise, which is that there’s there’s a lack of transparency. We we overvalue the benefits of antibiotics. We have fallen in love with antibiotics. Everybody knows antibiotics are miraculous. So we overvalue them and we we underestimate the cost of antibiotics, this lack of this lack of transparency. That’s why we’re on a crusade so that we can teach people, we can show them the evidence that antibiotics actually have costs. And for some individuals who don’t really need antibiotics, if they take it, all they’re getting is costs. They’re not even getting any benefit. And so in China, they’re using several times as many courses of antibiotics per capita as we are in the United States. They are awash in antibiotics.

Peter Bowes: And have you seen the negative repercussions of that?

Martin Blaser: Well, China is has an epidemic of obesity in obesity in Chinese teenagers, has reached in boys, has reached the level of teenagers in the US and what took us maybe 60 years to do, they only did it in 20 years. So I think there and of course, there’s asthma, there are allergies, there’s autism. As we point out in the film, China, unfortunately, they they have been developing socioeconomically very fast. And unfortunately, they’re developing the health hazards associated with that development as well.

Peter Bowes: This is the Live Long and Master Aging podcast. We’re talking about the feature documentary The Invisible Extinction, with microbiologist Gloria Dominguez-Bello and Martin Blaser. Coming back to the issue of obesity and people who are overweight and perhaps are perplexed by and don’t understand why they’re overweight. And you hear so many stories about people spending their lifetime really on on different diets and nothing ever seems to change just based on what you’ve been saying. To what extent, then, do you think it is their microbiome that is dictating whether they are overweight, whether they are fat or thin?

Martin Blaser: Well, that’s why we do experiments in mice, because we can control these very carefully. And we did what for me was a very important experiment. We gave mice antibiotics, young mice antibiotics, and they became fat. We gave mice a high fat diet, high calorie, high fat. They became fat. And when we gave them both together, they became very fat. So it’s not like it’s one or the other, but in fact, they’re synergistic. The effect of antibiotics shaping the early life microbiome and the high availability of calories together two plus two equals 20.

Gloria Dominguez-Bello: And I want to add a stress that the early life is key. If you you know, these developmental issues don’t exist if you have past development. So a baby that is growing, so antibiotics and C-sections make babies grow fast and that is already a risk for being in humans, for being overweight or obese when they are children. So there are plenty of data showing how much faster babies that are given antibiotics in early life or C-sections may make them grow. So independently of what happens after that developmental window. If you mess up the microbes, then then you are already programed and your immune system and your metabolism and the risk is there. Marty has shown beautiful experiments where he stops antibiotics after four weeks after strict lactation, and then the phenotype is there. You can’t help it anymore.

Peter Bowes: Let’s just go into that a little more detail because you do in the film, and that is the difference between babies that are born through the vagina as opposed to babies that are born by C-section. Can you maybe just go back to basics in terms of the sheer mechanics involved and how they, you think, affect that baby and its babies health in the coming months and years?

Gloria Dominguez-Bello: Sure. So all mammals develop in utero without live microbes. The mother has microbes, and those microbes don’t reach the baby in utero. And the first encounter with live bacteria is at birth during birth before the baby is out. For humans, labor is longer than for many other species, but that is the time when the mother breaks waters. The baby is getting out of that sac and is being acquiring, swallowing, rubbing against the walls of a canal that is loaded with lactobacillus bifidobacteria. Everybody knows these microbes because they know it in probiotics, etcetera. So these bacteria are very good and these bacteria respond to breast milk. And so nature wants those bacteria to arrive first, establish there and be boosted by breastmilk. And that baby will not eat any other diet, just a secretion of their mother. That’s nature design. And this happens during a period that in humans is between five and a half and six months when the baby has developed enough to sit, enough to grab things to the mouth, enough to ask for food, you know, enough to communicate. That’s a huge brain motor sensorial development. When babies are born by C-section, which sometimes is necessary, according to the W.H.O., about two out of ten babies. Not yet. 17% of the babies are need a C-section. Those babies are taken out sterile. And the first microbes that arrive are not the vaginal microbes are typically skin microbes from the air of the operating room. Skin microbes shared by previous patients. The cleaning team. The nurses. The doctors. And although there is a convergence during the first month between the two groups of babies born vaginally or by C-section, there are still differences and the trajectories are different up to the first year. So those babies are and by the way, C-section entitles antibiotic use also. So it’s missing the birth canal exposure, plus the effect of antibiotics. Those babies have a different trajectory and epidemiologically we know that those babies are at higher risk of exactly the same diseases that antibiotics are associated with.

FILM CLIP: There is a difference between babies born vaginally and babies born by C-section. C-section. Babies have higher rates of asthma, allergies, diabetes, obesity and many other illnesses. The question is why? The womb is mostly free of microbes. So when the babies are born vaginally, they first get covered with the mother’s microbes as they move down the birth canal. These bogs become the starter of their own microbiome. But babies born by C-section only get their first microbes from the operating room. My hypothesis is that this puts them at a disadvantage from day one.

Peter Bowes: And you show in the film studies where those babies born through C-sections have essentially been given those microbes that they would have received through, as you described it, the process of essentially a normal birth through the the vagina. What was the result of those studies? How did it change the trajectory in terms of of the the health of those babies born by C-section?

Gloria Dominguez-Bello: Right. So we so far the studies are ongoing. We have shown that there is microbial restoration. You can normalize partially. Remember that mother had antibiotics for the C-section. So there is some impact there. But we greatly are able to normalize the microbes microbial trajectory in the gut of those babies. If we give them back vaginal microbes right at birth. What we are now doing is a much bigger and challenging study because it needs five years at least of follow up to answer the question. So what are we helping those babies to be protected against the increased risk for rapid growth in during infancy, which is a marker at risk for later obesity? Are they going to be bigger when they are five years old? Do they have can we detect markers of asthma and allergies? So those studies take a lot more babies and a lot longer time.

Peter Bowes: Very keen to see how all of that pans out. I want to talk to you, Gloria. I mentioned at the beginning of this that Venezuela features quite heavily in this film, and I know one of your passions is preserving microbes. And you’ve done a lot of studies with Native people, native villagers to and to some people. And this might be a little crude, but essentially you’ve been collecting poop and examining it and studying it. How important is that? And essentially, what are you trying to achieve?

Gloria Dominguez-Bello: So when we saw that there, the microbial, the bacterial diversity in the gut of indigenous peoples that are survivors because they have lived without medicine and are extremely healthy, these survivors are very healthy. When they when we saw that their diversity is almost twice the diversity of the gut of Americans, North Americans. And and then we studied gradients of urbanization, and we see that as urbanization is deeper and industrialization is more widely the form of life, there is a correlative decrease in diversity. So what we want to answer is how does that happen? What are the factors that affect the diversity and kill the diversity? And why is that important? What are the functions that might be lost as we lose diversity and do we need them in if we have a modern lifestyle? So these are all questions that are relevant to trying to understand what is the genesis of the current plagues as we call obesity, asthma, allergies, type one diabetes, autoimmune diseases. We need to understand, well, what does what has urbanization entitled? What has been the effect on the microbiome and on the human host?

FILM CLIP: We explain to the villagers that they have more microbial diversity than us and there is much we can learn from them. …..When we asked them for stool samples…sometimes they laugh and they say, Did you come all this way just to see my poop? And we say, Yes.

Gloria Dominguez-Bello: qsWe have been working with these communities for many years. I started actually when I was an undergrad and we started with nutrition and parasites. And then when the microbiome was discovered at the turn of the century, we started telling them, you know, we all have good microbes and we want to compare yours with ours. And as they integrate because they are integrating is a progress. They want medicine, they want technology. And even if they stay there, medicine is getting closer every year to them as they want. So they they understand our questions. These are very intelligent people. We don’t patronize them. We sit with them. We show them what our problems have been and what they will have to face. You know, and obesity is something they have already experienced because they have sent kids to become nurses or doctors and they return obese when they come back to the community. So they they feel very directly. They see the problem that urbanization increases the risk of obesity and diabetes. And, of course, they want they want to help us understand, you know, can can they be protected and not suffer the same consequences and pay the same price as we have?

Peter Bowes: Martin the point is made towards the end of this film in terms of microbes and the the umbrella research that you’re doing, that we are in the early days of a revolution as it applies to this science. What do you mean by that, exactly?

Martin Blaser: Well, I guess there really are two parts to the revolution. One is the understanding that something is going on. It’s very similar to climate change. Actually, I learned about climate change when I was in high school 60 years ago. I learned about climate change, but it wasn’t in the public vernacular. Nobody understood it. And it wasn’t it wasn’t actionable at that point. And so the first part of the revolution is understanding that we are in an extinction crisis, that it’s slow moving, but it is moving absolutely in the wrong direction. And the second part of the revolution is to identify the solutions to the problem. And there are two fundamental solutions. One is to decrease the damage that is lower our use of antibiotics, of C-sections, of antibacterials, etcetera. And if we if we succeed in doing that, then the problem, let’s say, won’t get any worse. But if we want to make it better, then as Gloria says, we have to restore we have to find ways to return our microbiome to a state that is more ancestral, closer to the peoples out in the Amazon than than ours today. And that’s not necessarily so simple because it’s not if you lost something, it’s not that you can easily replace it because sometimes somebody else, another organism came in to occupy that niche. So we have to figure out strategies to displace some of those bad guys and bring in good guys in it.

Gloria Dominguez-Bello: And in the meantime, we need to preserve that diversity because it’s disappearing. And that’s where the microbiota vault came. The idea of offering because this high diversity is in developing countries, we’ve lost it already in Europe, US, China is losing it. So how do we educate people in developing countries and also standardize the methods and give them access and help them build their local collections of microbes from the human microbiome before it disappears? So we and offer them also a backup, a safe backup for that collection, where to which they are the only ones that have access. Each is like a bank. Each deposit will only have will be the only one having the power to move that collection, but also integrating the people who have high hotspots in biodiversity connected with the hotspots, in technology and resources to do research.

Peter Bowes: We get a glimpse in the film, don’t we, of the preservation efforts that you’re involved in, you travel to Switzerland? I think it is to try to find somewhere…

Gloria Dominguez-Bello: The pilot is happening in Switzerland now. We, you know, now with the war in Europe, we are thinking we should may have a may need a redundant site because again, we we want a safe place that is not affected by wars that is called in a relatively rich country. And it probably is not a bad idea to have two sites and have duplicate the backups.

Peter Bowes: Let me ask you both a much more general question, post-COVID, and let’s hope it is post-COVID that we’re living in a very sanitized world. Amongst the many things that it drew our attention to was that was seemingly the need just to be cleaner, to use solutions to clean our hands, to wash our hands, essentially to protect ourselves from spreading the virus. Is there a danger through your eyes of being too sanitized? No, that’s a very general statement. But I remember being a kid and you maybe wouldn’t worry about dropping something on the floor and picking it up and putting it in your mouth. And it can be as simple as as that. Is there a concern there?

Martin Blaser: Yeah. You know, it’s Covid was is and was strange in many ways. One is this this germophobia that Covid has has enhanced. And as you as you indicate, I think that’s pernicious. We’re again, we’re just we’re overtreating we’re over preventing. And that has cost because, you know, when you wash your hands with hand sanitizer, you’re eliminating potential bad germs, but you’re also eliminating good germs. And the good germs help keep out the bad. So in net, are we doing more good or more harm? I don’t know. One of the paradoxes about Covid is that in the first year there were many fewer visits to doctors and as a result, antibiotic consumption went down. And I consider that a plus. So…

Gloria Dominguez-Bello: I’ve had another plus, Marty, and that is that moms were with their babies at home. And I think that binomial of mothers and babies has to be respected during strict lactation, and societies need to adapt to that. If we want to have not only moms that have a better life without the anxiety of separation, working moms with their babies, but also for the health of their babies. So like never before, babies were directly breastfeeding, getting microbes from the mother at home. So those are two plus of the Covid epidemic.

Peter Bowes: And like so many things, it’s a matter of balance, isn’t it? It’s a matter of of moderation. The dilemma for a lot of people is, is how far to go to try to be very clean. Is it protecting them ultimately or it could it be actually causing them some problems?

Martin Blaser: You know, maybe it’s my background as an economist. I think we don’t shouldn’t look at it as yes, no, but really about cost and benefit. What is it? What’s the benefit of the treatment? What’s the cost? And that’s why we need to do more science so that we can have more transparency about what are the costs of all the different things we’re doing, whether it’s handwashing or antibiotics or C-section and good doctors and people who are health conscious, they can individualize because it’s not going to be one size fits all. The public health model is kind of a one size fits all model, but that’s I don’t think that’s sufficient.

Gloria Dominguez-Bello: And I think it’s useful if people understand that covering their skin. There are good bacteria that they have to protect. Soap is okay, but there were I’ve seen antibacterial creams to put, you know, when you shave your legs or that’s crazy. You know, using antibacterial on your microbiome places is a very bad idea. So if people know, then, you know, people will understand that you can be clean without being excessively antimicrobial.

Peter Bowes: Let me just ask you a final question in closing. This is a podcast about human longevity. We look to the future, talk about the the interventions that we could make in our lives to help us live. I use the phrase a longer healthspan to live with optimum health, not necessarily lifespan, but optimum health for as long as we can. And of course this this very subject comes right to the heart of what we’re interested in. As you look to your own futures, to what extent do you think about longevity and the years and the decades ahead? And how do you apply the knowledge that you have that you’ve gained over the years to your way of life, every day, to your routines, every day with that longevity in mind? Martin first.

Martin Blaser: Well, it’s funny. I wanted to give you a kind of summation, and this this is the the introduction. You know, in my career over these last 20 years studying the microbiome, I think that I have four insights. The first insight is the one I told you about, about farm animals. And and maybe that’s what’s making our kids fatter. And then the second insight is that I realized that it wasn’t just obesity that was going up. It was so many different parallel problems. It was at the same time asthma was going up and autism and allergies. And I thought, wow, it’s something that affects everything. It’s really global. And then I thought, well, what could be big enough to be global? It’s not it can’t just be air pollution. It can’t just be calories. That’s where I got to the microbiome and got to antibiotics. And then we showed experimentally, as Gloria mentioned, in models in mice, we can give antibiotics to mice and they’ll get asthma, they’ll get allergy, they’ll become obese. It changes the development of their brain. The third observation, and that’s in conjunction with Gloria, is how important early life is. That’s that’s the time when everything is forming. And again, we have experimental models that are completely consistent with the epidemiologic data in people. And then the fourth breakthrough is that it’s now becoming clear that even though early life is the most important time, things are happening in later life also. So there have been studies now looking at people with diabetes and asking what was their antibiotic usage and finding that people who develop diabetes had much more antibiotic usage than people who didn’t usage when they were adults. And the same thing for kidney stones and the same things for certain pre-malignant lesions of cancer. So again, the microbiome, this is suggesting that the microbiome continues to be important through life and we need to care for it at really at every stage.

Peter Bowes: Gloria, the tone of the film is optimistic. And I think Martin, You’ve just reflected that. We have all of this knowledge which we can apply to ourselves moving forward. But, Gloria, how do you see the future?

Gloria Dominguez-Bello: You know, I’m really concerned that, you know, all nobody will live to 100 or 90 if they suffer these diseases. Right. We are witnessing a generation that and generations of kids that are becoming obese. Diabetic, allergy, allergic, asthmatic. How long can they live a life? Probably less. That’s my big concern. Less than their grandparents. So have humans really reached the longevity? Possible. And now, because thanks to having control infectious diseases, but now they have created new risks for chronic diseases that will shorten our life. There are cancers that are rocketing also. So we are if we are modifying human development, which is something very delicate that took nature millions of years to create, we have to respect nature and go back and we can be the most highly technological, but we need to respect our human biology, otherwise we won’t have health. So I wonder if our future, our kids and grandkids will be able to live as long as their great grandfathers and grand grandparents.

Peter Bowes: So maybe not quite as optimistic as I’d been thinking.

Martin Blaser: Well, I would like to add something that I would both recommend, and it’s something that Gloria and I do, and that is that we eat a very diverse, plant based diet. The more different plant foods we eat, different fruits and vegetables and nuts, that’s that’s food for the microbiome that that diversity permits diversity of the microbiome. A diet based on bread and pastries and meat is very restricted. We’re trying to we’re trying to diversify our diet, eat a lot of fiber. That’s that’s the food that the microbiome likes the most.

Peter Bowes: And that’s probably. Martin An entirely new conversation, which I’d love to have with you one day. Look, both of you, this has been really fascinating. The film The Invisible Extinction is gripping. Really interesting. Thank you both very much for your time.

Gloria Dominguez-Bello: Thank you, Peter, for inviting us.

Martin Blaser: Yeah, thank you for having us. Great to talk with you.

Peter Bowes: The clips we heard in this episode were all from the Invisible Extinction documentary courtesy of Microbe Media, LLC. I’d also like to thank Stephen Lawrence, the film’s co-director and producer, and Paul Clark from Newsworthy Press, for their help in the production of this podcast. Live Long and Master Aging is a Healthspan Media Production. There’s a full transcript of this conversation, along with show notes at our website.LLAMApodcast.com. LLAMApodcast.com. I’m Peter Bowes. Thank you so much for listening.