Preventing Childhood Allergies with
Gastroenterologist Vincent Ho

(Note: The following transcript is auto-generated and may contain errors.)

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Think of it as an industrial process. You’ve got your VAT, you’ve got your process, your engines, and you. You’re basically whirling and shutting things in smaller part. Hey, guys, welcome to another episode of the Science Centric Podcast. I’m your host, Eric Olson.

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And we’ll add your name to the end of four podcast episodes. So check out the show notes or head over to science centric dot com slash support. So our guest for this episode is Dr. Vincent Ho. He is an academic gastroenterologist who works as a researcher and senior lecturer at Western Sydney University in Sydney, Australia.

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He is also a practicing doctor who sees patients with all kinds of gut problems. In his spare time, he’s created a website and a YouTube channel called The Gut Doctor and is the author of the upcoming book The Healthy Baby Gut Guide, due out in June of 2022.

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So hopefully I got all of that right. And welcome to the show. Thank you very much, Eric, for inviting me. Cool. So I have a I’ve I’ve read your book. I have a ton of questions for you. So it’s a little bit tricky where to start.

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We can definitely talk about, you know, the book. But I think what might be interesting to for people to understand, first of all, is just what is your gut? I mean, we all know that phrase from like, oh, I have a gut feeling or whatever.

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But what constitutes the gut? What makes you that gut doctor? That’s such a great question, Eric. And really, the gut is an organ that I am so interested in. The best way to describe the got really is it is an organ, but it’s more than just an organ because it’s an organ that connects to every single other

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organ in the body. So while it’s internal and it’s hidden and that’s why it’s kind of mysterious because you can’t really see it, it’s it starts really from the mouth itself and it ends all the way at the very end out with the anus.

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And so anything along that tract which is involved in handling food, digestion, absorption, breaking down, importantly food into its smaller parts, all of that is part of the gut. So the guide is really what I would term to be an organ quite complex.

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There’s a lot of action that’s going on and we’re learning more about it all the time. Eric It’s actually so amazing and is a way to think of it as like kind of a big fermentation chamber. Is that is that a good way of thinking about the gut?

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That’s absolutely right. So in the past, we used to realize that it was just the tube. There’s a lot of processing, mixing. But as you say, this is it’s teeming and teeming with bacteria. So fermentation takes the show.

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Lots of stuff is being processed and actually is producing a lot of ingredients to this gas and a lot of other good stuff too, that it’s actually that’s crazy. It’s creating. So as we’re as we eat something where it’s going down through all these chambers and tubes and being digested and fermented and and then we’re extracting out

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all those nutrients and things like that. That’s right. That’s that’s kind of the main function. That’s exactly right. I mean, think of it as an industrial process. You’ve got your vats, you’ve got your process, your engines, and you you’re basically whirling and shoving things into smaller parts.

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And as you say, you know, this store, it just this vats, the storage, these are enzymes which have been additive. So chemicals which we add in to break down foods, all that is occurring. And at the end of it all yeah.

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Get gets waste which is eliminated from the process as such. Right. So I think, I think what you were, what you were talking about before is this this idea. And we’ve had other guests on the show talking about, you know, the microbiome and things like that.

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But there was this idea that it was just sort of this all these chemical processes going on. But there’s also all these biological processes going on. Right. Like with with. Yeast and bacteria and all these other microbes and things that that that’s kind of a would you say that’s a new idea or it’s just one that’s become

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popular? It’s look, it’s been around for a while. We’ve realized that there’s been gut bacteria present for quite some time, at least over 100 years. But I think what we realized now is that it’s an amazingly complex ecosystem.

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So you’ve got your microbiota such as just is you bacteria, I think is a dominant living species. But you’ve got other things too, as you’ve pointed out, fungi present. You’ve got a group of similar to back to call archaea which are present, and you’ve got other things which can exist sometimes like parasites that play a role.

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Viruses themselves. So the guy has got virus which, which is part of the microbiota. So it’s actually a very rich ecosystem. And I think what’s exciting about this is that and this is something that we’re realizing over the last couple of decades that the microbiome is very much tied in to our health, also stomach health and the

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development of different diseases. Yeah, and we’ve only kind of realized that diversity in that in our terms of the microbiota. So what’s, I guess the question for you is like what’s the difference between the microbiome and the microbiota?

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Yeah. So I would like to say that the microbiota is really the collection of all your organisms, whereas the microbiome is very similar, but it’s also referring to genetic material or genetic information because the old days we used to be able to detect the presence of bacteria predominantly through culturing based techniques.

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So that’s why the term microbiota was was used a lot. But now that we’re using more techniques to look for genetic information, we’re using the term microbiome. So the very similar microbiome and microbiota, I would view the microbiome as really all of the the microbes, but also the genetic information as well.

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So you need the genes that that information is is critical and it’s a critical part of the definition of microbiome. And it’s I think this is true in a lot of different fields, whether you’re talking about oceanography or you’re talking about human health or whatever.

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Like we have so much more information about the diversity of microbes because we have genetic sequencing and things like that. Before we just maybe had less precise tests, right, in terms of what we could identify. So so that’s a good maybe segway into into talking about, you know, human health and in particular health for infants, although obviously

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we all started off as infants. So it’s all it’s completely relevant to to adult health as well. But how does all that how do how do all those microbes get in there? What you know, how do we because what I gathered from the book is that we’re not really born with any of that stuff in our in

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our gut, those important microbes. Yeah. So this again, is such an interesting point because for a long time, Eric, there was a debate about whether the infant gut itself suddenly growing in the womb was sterile or not, whether it was it was full of microbes or was it actually sterile?

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And what we’ve come to realize is that it actually is sterile. And the reason for that is that it’s it’s unusual to get microbes in utero in the infant got it generally only happens if the the infant is very sick and often if there is if there is sepsis going on in and what we call enterocolitis, those

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sorts of conditions, you can get these microbes which which are present. But as a general rule, microbes are not found in utero, in the infant die. So they are acquired in life. And we know that when it comes to that mode of delivery, that’s actually really important, Eric, because we know that if babies are born via a

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vaginal delivery that the they tend to quiet microbes from the vaginal, whereas from a caesarean section they tend to pick up, not surprisingly, skin microbes. And so it’s those microbes that tend to populate the infant gut and the the because it’s sterile, it, it colonizes really rapidly.

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And we see the development of quite unique microbiota profiles in, in those babies. And you highlighted something really important about caesarean section is that they often give the the mother like a prophylactic. Tick. Antibiotic meaning something that would prevent infection before even before there’s the delivery happens.

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And how does that what effect does that have on this transfer of microbes? Yeah. So it does play an important role because when you have that prophylactic antibiotic, you are disrupting the natural gut microbiome. So we’re looking at that using the term microbiome itself.

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It is being disrupted by the use of antibiotics. We know that that itself and I write about this in the book that exposure to those antibiotics, early life, by causing that alteration in the microbiota balance, it can lead to an imbalance of the gut microbes, what we call a dysbiosis.

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And that actually has health implications. For example, it increases the likelihood of a child developing an allergy in life. Mm hmm. Mm hmm. So that’s. That’s what’s I think most interesting about your book is that, you know, you’re a gastroenterology entomologist, but you spend a lot of the book talking about allergies, which is immunology, right?

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Yeah. So what what is the connection there between immunology and and the gut? And why would why would disrupting why would that disruption of the microbiota mess up the immune system and cause allergies? I mean, that’s that’s yeah, that is not intuitive and it’s really, really good question because I think what it comes down to is the

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recognition that the gut itself is a very important immune organ. For example, two thirds of all the immune cells in the body out of the gut. So we don’t realize this. I mean, we’re realizing a lot about the gut itself.

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We know it’s important for the process of medicine, for digestion, absorption full of microbes, but actually it does play an important role in the immune system. So as an example of this, we know that from experiments that some animals can be born germ free, so that born in a germ free environment, that actually born in these incubators

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which have an independent, sterile circuit and they’re born by cesarean section. And what we realized about these mice in particular, and as I said, a lot of the work’s been done in mice, but we realized that they are different from normal mice in that their immune systems is quite compromised, so they are much more susceptible to it

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into infections. And as the example that is that with these germ free mice, they can get sick from just ten salmonella cells in the gut, whereas conventional mice can withstand about a million salmonella cells before becoming unwell. So oh wow.

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So that’s very important for the immune system. And the reason why it’s important when it comes to humans and infants here is the same principle applies that if you’ve got disruption of your normal gut microbiota. So if you think about it, the antibiotics being exposed early in life is actually wiping out some of the some of the

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some of the microbes that then that itself means that you’re going to get less of the normal or commensal bacteria in the gut. And because those two are so important for your immune system, it actually leads to two problems and it leads to those that susceptibility to certain kinds of immune problems like allergies.

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00;14;23;10 – 00;14;42;16

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So, yeah, one thing I always find what should I say interesting or challenging about when you’re talking about immunology, is there’s this thing where, you know, if if something is if the immune system’s not working well enough, you get sick and, you know, like extreme case would be something like HIV, where your immune system’s just not working

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at all. And you’re you’re getting sick from these common things. That would not make people with a healthy immune system sick. But then on the on the other side of it, you have autoimmune diseases where the immune system is like overactive and and doing things that are not, you know, attacking the body itself, things that aren’t foreign

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objects. So how does how does this, as you said, commensal bacteria, that’s that’s the sort of symbiotic bacteria living in our gut. How does how does it affect the immune system in terms of making it responsive enough but not too responsive?

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That’s that’s something I, I it does my question makes sense. Yeah. First of all, you know, I mean, to answer the question, I guess I’ve got to do a bit of a deep dove into immunology and talk about some concepts which I think your audience may have heard about already, but I think it’s important to go through

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them. So I think the yeah, I think I think that would be helpful. Yeah. Yeah. So look, I suppose if you want to go back to the very beginning, well it all links back to the hygiene hypothesis. So this is the idea Eric, and it’s a very popular one as well that, that, that if you are exposed

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and this is the conventional thinking behind this is that exposed to dirty things out there, then it actually somehow primes your immune system, it makes you more resistant against infections. But actually it’s a bit more complex and more nuanced than that.

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So really, it came back this came back to a large study was done in the United Kingdom where they looked at the incidence of hay fever in children in the United Kingdom after the war. And what they found was that in these children that the more older siblings a child would have, the less likely that he or

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she was developed eczema by the age of one year and hay fever by the age of 23. And what is eczema? Sorry, what is eczema? Just for our customers. Dermatitis. So allergic dermatitis. Contact dermatitis. Yeah, that’s okay. So that’s like wearing an out an allergen is like irritating your skin or something.

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Yeah, exactly. Right. So like, yeah, so. Okay, so go ahead. Sorry. I just wanted to clarify because I’m not sure everyone knew what that meant. So that that’s. Yeah, thanks. Thanks for clarifying that. And so the the professor who who reported this, Professor Strawn, he recognized that was some protective effect that the older siblings were passing on

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to the younger children. Now, I think that most of us who have more than one child, we know that these children, when they play together, this can be a bit rough. So, you know, sometimes, you know, they can even bite, scratch and and there’s something that’s been passed on from one child to another that’s considered to be

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protective against allergy. And so, Professor Strawn, he felt that that special protective effect was actually microbes and that early childhood exposure to particular microbes could protect against the development of allergies by affecting development the immune system. And so that was what the hygiene hypothesis about.

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It wasn’t about not washing your hands or just getting dirty that that wasn’t what that was about. It was about exposure to particular microbes, early life. And so I see the scientific community got really excited by this and they came up with this, what we call H1, H2 imbalance.

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So what once we had a case refer to, they are really what we call pro-inflammatory cytokines. So that specific designed to actually kill off bacteria that could set ourselves and viruses out. But when you’ve got a really excessive pro-inflammatory response which can cause a lot of tissue damage, there’s got to be a way to counteract that.

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And so are the two cytokines and the teach two side of the counteract one cytokines. And they’re really good at fighting off parasites such as worms that are located outside of our cells. And so some of these teach these to cytokines are anti-inflammatory.

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The problem, however, is that if you’ve got a very vigorous two cytokine response that can actually promote allergy. So that’s the that’s there, I suppose the trade off there. And what we realize is that there are some factors that promote ath1 response.

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So presence of older siblings, early exposure, for example, daycare, household pets, exposure to a room environment, those are very much stage one promoting. On the other hand, teach to cytokine response that’s favored by use of antibiotics, as you talked about, and generally a more industrialized lifestyle.

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So now that we know that there. See this kind of it’s a simplistic concept because this is a bit more to immunology than just teach one, teach two. But what we realize is that we certainly would teach one.

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You do need to have this comes back to the whole idea of microbes, that exposure to these microbes early in life. And we realize now that these microbes have been around. The microbes that really promote the take one response.

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They are microbes that have been around for a long time. And so, you know what we call old friends. In fact, there’s a whole hypothesis on this, Eric, what we call the old friends hypothesis and that, you know, we need these old friends, these microbes, these commensal.

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We need them to face each one response. And when we don’t have those or when those old friends are around because of things like antibiotics or more industrialized lifestyle, you know, herbicides, pesticides, etc., then we see now more of a T-H to response and hence the biology.

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I see. Okay, so, so those so those all those old friend microbes are maybe over time, our through evolution, our bodies sort of started to recognize those as not being a threat. Is that a way to think of it?

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Yeah. And that these newer exposures to, you know, as you said, you know, chemicals and industrial kind of things in our environment is a new kind of thing. And so that that’s going to set off an alarm for that teach to responses, that is.

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I think it absolutely does. So, for example, we know that many of the pesticides, herbicides, organic solvents, they actually favor THC response. And so these are things that have been around recently, recently, you know, because of industrialization. So we’re seeing more of that out there.

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We’re seeing more of that. Yeah. You know, these these these artificial chemicals out there. And so it’s it’s it’s really pushing this more towards that THC response. And when you get that early in life, then you suddenly get promotion of a more of a more of an allergic response in young children.

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Mm mm hmm. And it’s it’s almost it’s not. It’s like having an overactive immune system in a way, right? I mean, it’s it’s it’s overreacting to these things that aren’t aren’t necessarily threats, right? Yes. Well, that’s that’s correct.

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So what we know about that is, you know, your allergy certainly has been linked to an elevated th2 response to elevated th2 reactivity. And in fact, after birth, we know that th2 reactivity in most infants, it actually goes it goes down.

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So most infants tend to be what we call non atopic or don’t have a genetic susceptibility to allergy. They don’t have the teach to reactivity goes down. We know that that that activity can persist for a few years in a lot proportion of infants but again eventually dampens down.

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So that’s why some children might have some allergies early in life. For example, they might have this childhood asthma or allergic rhinitis in life, but it disappears and that tends to close down. But there is a small portion of children that have a persistently elevated THC response.

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We know those children that they tend to have allergies that develop and persist later in life into adulthood. Mm hmm. So so the timing also is very important for for this these exposures to these different things. Right. And I think you said in the book it was, you know, maybe the first six months of life, too.

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You need exposure to these old friends. And to avoid these, I don’t think we want to call them new friends and they’re not friends at all. You need we need a clever name for that, too, I think for, you know, new new kinds of exposure.

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So is that right? Is that the timeframe or how about in particular for infants? Absolutely right. So, look, I think that, you know, early exposure to these old friends is very important because it helps to prime the immune system.

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So in other words, when you have these bacteria which can right environment for a long time the and when the when the infant recognizes these these old friends, the the gut itself is recognizing it, too. And and it’s it’s necessary for the for the gut, for the commensal, for that for the natural resident bacteria to recognize these

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. These bacteria and then helps the trigger and promotes that positive one response. It’s quick to balance, essentially. So that’s all really important. And the other important thing as well, and it’s important that I raise this in the book, it’s the concept of tolerance.

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So we know that when it comes to allergies, that it’s a balance really between recognizing you just recognize an invader. So recognizes what we call a pathogen or an allergy, recognize a beta and a primes. It has a mean response and that’s normal.

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That’s a natural. Like Eric, you and I, our immune systems are designed to respond to pathogens, invaders, and they quickly mount a response and gets rid of it. But we also need to recognize that there are some what we call old friends and in fact, other of the other resident bacteria.

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We need we need our what it means to recognize that the resident bacteria in the gut itself is actually commensal, that it’s actually part of us, and it needs to not have a hostile immune response. And that’s why the idea of tolerance comes about.

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So tolerance comes about early in life. You recognize it recognizes these you know, this is normal. This is part of us early in life. And so that bacteria, those bacteria that I mentioned before, the old friends, it’s recognizing them.

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Yeah. Part of us early life and not mounting an immune response and that’s actually a really important point. Yeah. Okay. Yeah, that I mean it. I think that makes sense. But it’s a little bit different than, as you said, than the idea that.

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Well, let’s let’s talk about this for a second. So there’s this I don’t know, I’m not sure the official name, but but you have this a couple of times is that both pregnant women and young kids, it’d be really beneficial for them to hang out at a farm for a while, for a bit, or at least have

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a visit there. Now, that sounds like a crazy idea to me in a way, because, you know, a farm is you know, the perception is it’s very dirty. There’s a lot of animal waste. There’s, you know, probably all kinds of pollen everywhere.

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And, you know, who knows what else? So could you. So in a way that seems like kind of a an extreme way to like expose kids to to a ton of microbes. But there’s some evidence that like this is actually really beneficial, right?

00;27;52;01 – 00;28;12;09

Yeah. So, Eric, we know that there’s been some really good evidence based upon very large studies looking at this. For example, there was a possible study, the powerful study that was published about a decade ago, actually now at full, about a thousand children born to farm and what they term non-farm mothers.

00;28;12;09 – 00;28;26;17

So really children that were not are that were not born in a very rural environment, in a more urban environment. So this is actually a large study. It was done across a few countries, so in about five European countries.

00;28;27;09 – 00;28;49;18

And what they wanted to look at was the I guess, the linkage between childhood allergy fatigue, childhood asthma and also what was going on with their environmental circumstances. And they looked at course at the farm environment because they realized that there was a difference between the groups, between the children that were born to the farm, the farm

00;28;49;18 – 00;29;12;06

mothers and non-farm mothers. They realized that there was a reduction in childhood allergies and they realized what was that protective effect. And so that carried out over 8000 questionnaires. And what they found was that when they looked at the specific factors, the interestingly enough, that the children that had, I guess, the best immune systems, the ones who

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had the less least allergies, the mothers were actually involved in stable work during pregnancy. So exposed to stables. So which was like thinking about doing stable work when you’re pregnant. If it goes against something that is almost know, it’s like it’s like these days.

00;29;36;11 – 00;29;56;24

Would we even consider the idea of having a pregnant woman on a farm working in stables? No. I mean, that’s it sounds it sounds absolutely crazy, as you said. But what they realized is that it was a protective effect and it was probably something in the farm environment that was protective.

00;29;56;24 – 00;30;11;03

And in fact, you know, what was actually protective was was it was thought that if these these no toxins, it sounds like, again, a pretty crazy concept. Okay. But the end of toxins is actually something in the environment.

00;30;11;10 – 00;30;27;24

It’s actually very good for the. For the immune system and particularly promoting it to switch from two to more towards more of a take one response. So you get a lot of anatomic and hence I’m sorry. So what is an endotoxin exactly?

00;30;28;03 – 00;30;52;22

What what they basically are is that they’re basically chemicals, essentially, that are produced by microbes. So it’s probably the best thing to to say that they’re they could be the the wall components of microbes. For example, they there’s something called Lipopolysaccharide, which is part of the bacterial wall generally that the components of microbes and they are particularly

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high in fast tables, very, very high. And, you know, particularly in horse, you know, another poultry. So it’s thought then speculate now that perhaps exposure to these end of toxins is actually what is protected here. And yeah, that is that’s probably underpins why the possible study showed such an important and I suppose surprising results that protective effect

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of of the mothers being exposed to stables and it really I guess if you think about it Eric it actually turns out thinking around here and maybe, maybe just maybe instead of having a baby mood in a normal kind of a, you know, a typical, you know, beach kind of environment, perhaps a baby milk would be spent

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00;32;29;06 – 00;32;48;01

I mean, you could you could apply this to other kinds of exposures. But, you know, in reality, there actually are some kind of nasty bacteria that are around, too, that, you know, you could get sick from or, you know, some kind of avian virus or something like that.

00;32;48;01 – 00;33;09;04

When you’re in that kind of environment, is there I mean, is there any risk associated with doing that sort of thing as well that that you could, you know, get sick from that? It it almost seems as if, you know, you want a bit of an exposure, but not but once you expose yourself, you’re exposing yourself to

00;33;09;04 – 00;33;26;10

other things I guess is what I’m getting at. Yeah. So again, I think that is a good a good question because, you know, suitably we would think that going to a far more evolved idea. So it just it just feels like wrong, right?

00;33;26;10 – 00;33;40;24

I mean, they go it’s we realize when you look at the data and you look at the hygiene of Polyposis, I think that I think it’s important to recognize that, you know, this kind of exposure has been around for a long time.

00;33;40;26 – 00;33;57;20

In fact, it’s been around for thousands, thousands of years. All right. I mean, this is what happened thousands of years. It’s it’s actually changed with us. It’s a it’s a kind of a radical paradigm shift, but assault of a more industrialized society, we no longer do this.

00;33;57;26 – 00;34;14;22

We no longer have these exposures to a predominantly, you know, rural or agrarian type of environment, which is around for thousands and thousands of years. So that that was the conventional thinking for thousands of years. And it was almost expected, you know, in recent times.

00;34;14;22 – 00;34;30;09

The last now certainly in the last 100 years, it’s been a big switch. But you know something what’s really interesting, Eric, is that what we’ve realized in the last hundred years is there’s been a spike in allergies and all the other conditions that we’ve talked about as well, including autoimmune diseases.

00;34;30;09 – 00;34;49;00

So right there is something to all this, I’m sure. Of course, there’s potentially pathogens that may be potentially, you know, potentially dangerous. Certainly that that that’s a possibility. But in reality, I think the risk is actually quite low.

00;34;49;00 – 00;35;08;28

And I think that what needs what we need to think about here is that, you know, if there is and I guess this is where the radical mind shift here is here as well, if there is a real imperative to look at addressing some of the root causes of childhood allergies, and we could do something about that

00;35;09;01 – 00;35;32;10

and intervene early, you know, that it just might be worth thinking about something like this. It’s a radical change. Yeah, but perhaps we should be open minded. Yeah, well, it really does seem to argue for, you know, adopting, or at least, you know, adopting temporarily a sort of agrarian lifestyle where you have, you know, a lot of

00;35;32;10 – 00;35;53;16

animals around. You have a lot of other kids around your kids, and they’re just getting exposed to a lot of different things. Right? I guess maybe I’m thinking like also when we’re talking about farms, maybe it makes a difference to whether you’re talking about like a family farm or you’re talking obviously, you know, industrial agriculture has other

00;35;53;16 – 00;36;06;14

problems with, you know, diseases and things like that because it’s a bit of a monoculture. Yeah. So maybe so when we’re talking about farms, maybe we’re talking is that am I right there or I mean, I see you’re quite correct.

00;36;06;14 – 00;36;30;05

So yeah, we we’re looking at the ideal baby move. Well, we call it maybe we call a baby farm as such. But if we were looking at the ideal state dependency, it would it would be, as you mentioned, not a conventional industrialized farm where you see lots of herbicides and pesticides because it kind of becomes a sort

00;36;30;05 – 00;36;45;08

of counter to what we’re we’re talking about here. But a traditional farm, you know, a very small farm environment. And I feel even exposure and, you know, the data supports this is just talked about even if this exposure to to a number of pets.

00;36;45;25 – 00;37;03;03

No, I think that in itself would be very, very beneficial because having a number of pets creates almost a mini farm environment. And so that there there is there is benefits there from having just even a few domesticated animals in sort of close contact.

00;37;03;09 – 00;37;29;11

I’m not just for the pregnant mother, but also for the young infant. And I think that’s important to recognize the young infant, too, which has no benefit from being in that farming environment. Right. Yeah. So I mean, yeah, that definitely runs counter to the idea that if you are prone to allergies and as you mentioned, I think

00;37;29;11 – 00;37;46;29

in the book, there is definitely a genetic component to this, right, in terms of risk of allergies. But you shouldn’t because you have that risk, like let’s say you had let’s take a situation like you had parents that are both have allergies to some kind of animal or cats or whatever.

00;37;47;10 – 00;38;06;03

Then they they would go, okay, well, my kid, my, you know, we’re having a kid. This kid’s going to be, you know, probably going to have a higher risk of having that allergy. So their their their immediate thought would be, well, we need to isolate that kid from that animal, that allergen that we have exposure to.

00;38;06;03 – 00;38;24;21

But actually, it’s it runs counter to that. They should expose that kid early in life. Right. Is that. Exactly. Exactly. That’s exactly right, Eric. And that yeah. One of the key points that I that I talk about in this book and really it’s about getting exposure early.

00;38;24;21 – 00;38;48;02

So the things that we think as typical allergies get exposed to those early because it is importantly it can build up tolerance. So you’re quite right, um, you know, getting exposure to some of those animals early on. But I think, you know, because the animals themselves, whether it’s through their endotoxin or sort of, or the microbes that

00;38;48;03 – 00;39;03;09

, that that are present. But certainly there is a protective effect for pregnant mothers and for and for young children. But it’s not just that, as you know, Eric, it goes beyond that exposure to allergenic foods early in life as well.

00;39;03;09 – 00;39;29;18

Yeah. Can also promote tolerance. So the concept is get exposure. The things that we think intuitively want to avoid getting too early life after we get right get exposed and and you so to kind of bring it back to food and which you know ties directly into gastroenterol and serology which which is what your background is in

00;39;29;29 – 00;39;50;19

what you highlighted, there’s like nine different foods that are something that are responsible for 90% of allergies. Right? So what are those foods? And and and, you know, should you be feeding your infant these things or toddler at least maybe not infants, but toddlers?

00;39;50;19 – 00;40;10;21

Absolutely. So you’re you’re quite right. Okay. There are indeed nine different allergens, food allergens in particular that underpin about 90% of all of the food allergies. And that will be the case for Australia and for North America. So, you know, the big ones would be, you know, peanut, obviously egg, milk, sesame.

00;40;10;24 – 00;40;30;08

We know that our shellfish itself. And wheat are also big ones too. But I guess also egg allergy to dairy. I’m a big ones. So there’s about nine, nine of them that are really important. And in my book, I actually talk about a nine week plan to introduce infants.

00;40;31;07 – 00;40;52;19

We save for about six months of age to these these allergens. And again, it’s about the recognition that if you expose these infants early in a very controlled manner. So you want to do it in a controlled manner where you can observe for response early in life, study for about six months, between six months and 12 months

00;40;52;19 – 00;41;14;25

is the critical time there. That’s the time when you can prime the the the the young infant to develop an immune response that promotes tolerance for these for these foods. Mm hmm. Mm hmm. So is there looking at that list?

00;41;14;26 – 00;41;38;28

My immediate thought was, well, a lot of these foods are high in protein. Or is that is that a component to why there tend to be allergens? Yeah, that that is that is true. So, for example, we know, for example, that with many the proteins themselves, they are not broken down necessarily all that well.

00;41;40;02 – 00;42;04;14

But by the got a good example of that example is gluten. Gluten which is commonly found about found in wheat is, is one that we know isn’t commonly broken down very well. Now, when you’ve got proteins that are broken down very well, what that can what that means is that the proteins themselves can get across into the

00;42;04;23 – 00;42;20;04

bloodstream what we call the systemic circulation and not an immune response. And it does that because of factors like the leaky gut. So the medical term for that, Eric, we call that intestinal permeability. That’s where things can get a can get across the gut.

00;42;20;16 – 00;42;40;21

There’s the gut normally has a barrier. And when you get across that barrier in the bloodstream, you get that. You get about an immune response. And so that actually is the reason why we have a response, a systemic response to to to these allergens.

00;42;40;29 – 00;42;56;10

And, you know, it was said with once we get once we get that immune cascade, we get that that response happening. And then you have and this is what I talk more about anaphylaxis as well and what can really happen.

00;42;56;10 – 00;43;16;01

Yeah. When things don’t go quite diet because you actually have and it’s it’s kind of complicated but you’ve actually got special immediate goblins like IG work here. You’ve got certain cells which release a lot of chemicals and these cells are actually primed with chemicals that release it in response to these allergens.

00;43;16;08 – 00;43;36;10

And the response is really quick and can lead to all sorts of problems, including reduction in blood pressure, difficulty in breathing and all the and all that. All the really concerning symptoms that you might expect in someone who has a hazard has a major response or major systemic response to an allergy.

00;43;36;10 – 00;43;58;29

And so is there. So one question about that anaphylaxis thing, I mean, is there it seems so extreme and the fact that you can actually die from it, right. Because your airways can close off. And is it I mean, is that how is that protective, I guess?

00;43;59;18 – 00;44;14;19

QUESTION It’s so extreme and your body’s going through this terrible experience. I mean, is that is there is there a good reason for anaphylaxis to exist? Or is that just kind of your immune system freaking out and and, you know, overreacting?

00;44;14;28 – 00;44;36;00

Well, look, I think that the important point here is that there is a very rapid release of chemicals in the body that’s resulting, as you say, in this very profound, life threatening response. So the things that you’re getting essentially that week in Rapid Pulse, you know that the low blood pressure constriction, the airways, all that is occurring

00;44;36;00 – 00;44;56;15

because your body is responding to an allergen and responding to it in a very adverse way. Now, there is a natural, I suppose, if you think it from an evolutionary perspective, you know, we have these allergens that we mount a response to.

00;44;56;15 – 00;45;21;23

So it’s when you’ve got pathogens, our body has as a natural immune reaction to a pathogen and we actually have an innate immune response. So it’s like the body mind to respond against these these pathogens and certain. When it comes to an allergic response, our body also is primed to respond against certain allergies because it recognizes that

00;45;21;23 – 00;45;40;23

those allergens shouldn’t really be there now. Yeah, for the most part, the response is actually fairly well controlled, so you don’t typically get an allergic response that is life threatening. Fortunately, most of the time, otherwise we all be in a lot of trouble.

00;45;41;00 – 00;46;03;09

You can imagine people right now rebuilding a lot of trouble. But but what is occurring essentially is that that there is this recognition by the body of of the allergen and a profound response is developing to the allergy based upon immunological memory.

00;46;03;09 – 00;46;25;24

So the body has a memory of this of this allergen being there. And the response at mouse is actually really profound. Now, we think that this that the research is now favoring that. Yes, for many of us predict when we’re infants, we could have been exposed to many of these food allergens if you talk about food allergies

00;46;26;16 – 00;46;53;14

. But yeah, if exposed to these allergies early life, it tends to be more what we call and that the immune system tends to recognize it and develops tolerance. However, if you are exposed to that allergen later on and maybe because of some erroneous assumption that your that the infant should mature, should you should actually have a more

00;46;53;14 – 00;47;16;17

developed immune system. What we know is that when that happens, the response itself tends to be a lot more profound. And then when you’ve got another challenge, it tends to. And yeah, this is a this is what we what we’re noticing here based upon large studies that each have a happens, you get a more profound response.

00;47;16;23 – 00;47;39;23

And that’s why anaphylaxis could occur, for example, to peanuts with only very, very tiny amounts. So, yeah, so it’s not I mean, yes, you know, there there’s memory. We we recognize early life was exposed to certain allergens. But the earlier you’re exposed, the more you develop more like you develop tolerance later on.

00;47;40;12 – 00;48;00;20

Michael Good. Sorry for the interruption. I swear. I swear. This is the last one. I just wanted to tell you about the reading room that we have set up over at Science Intercom. It’s a page dedicated to cool science and nature books, many of them written by authors who have appeared on this show.

00;48;01;06 – 00;48;21;19

Any book you purchase through the links on the page directly supports the podcast and the other amazing projects we have in the works. The nice thing is there’s no additional cost to you. So if you’d like to see a nice collection of science books that you can purchase, head over to science centric dot com and check out

00;48;21;19 – 00;48;40;21

our reading room. My background’s in genetics and I’m really interested in human evolution and things like that, and I always think about it in those in that context. But it does kind of make sense when you think about it, that if if we were, you know, hunter gatherers, we would have been exposed to so many different things

00;48;40;21 – 00;48;58;13

when we were very young. And those things wouldn’t change over time. Right. I mean, there’d be there’d be this kind of consistency of the things in our environment. And now we live in this world where it’s like we may not be exposed to things when we’re very young and then all of a sudden we’re getting introduced all

00;48;58;13 – 00;49;13;09

these different foods and things from like all over the world, basically because we’re in this global economy from all these different continents and and, you know, and it’s like those are not things that maybe we would have evolved with.

00;49;13;10 – 00;49;28;12

So that does it does seem to kind of make sense in a way. Right. It absolutely does. And a good example of this, Erik, is from what we know from Singapore. So prior to 1999, peanut allergy wasn’t even a major food allergy in Singapore.

00;49;28;23 – 00;49;44;29

But then with the adoption of a more Western diet, as and as you say, a more international cuisine. Very quickly. Yeah. I 2006 peanut allergy became the number one food allergy in Singapore. So you’re quite right in that.

00;49;45;08 – 00;50;07;02

Yeah. These as far as globalization, international exposures to different, you know, foods and chemicals and substances, that’s actually changing the immunological response of all of our infants, our children. Yeah. Yeah. And peanut allergies have been on the rise, I think, in the United States as well.

00;50;08;16 – 00;50;23;07

So I guess so. As parents, I guess the the idea. That you need to, you know, be deliberate about exposing your kids to these things and not just kind of wait for them to encounter them later in life.

00;50;25;00 – 00;50;42;08

But again, it’s like comes back to, okay, well, if you already have an allergy to that thing, you know, you’re probably going to be reticent to expose your kids to those things. So it’s like, you know, there has to has to be a has to be very intentional, I think that you’re going to do this.

00;50;42;09 – 00;50;57;28

And that’s absolutely right. And that’s one of the key messages that I want to convey in this in my book, in that I think that we should be and parents especially need to be open, open to that. It’s very important to recognize that.

00;50;58;08 – 00;51;20;09

And certainly during pregnancy, there shouldn’t be any restrictions on allergenic foods, unless, of course, you’ve got to know an allergy. You’ve got to know that allergy to that particular. Yeah, of course it’s different. But you shouldn’t be worried about, for example, your your children developing an allergy to a food and thereby avoiding that during pregnancy.

00;51;20;10 – 00;51;43;10

That’s not that’s not that’s completely not not not what you should be doing. In fact, exposure to these allergenic foods like peanuts early in pregnancy, again, is considered to be very beneficial, promotes tolerance, exposure of your infants to different foods and to different exposures, positive exposures, early life like pets, for example.

00;51;43;10 – 00;52;01;25

That environment, those are beneficial. Yeah. So again, yeah, yeah. It’s, it’s, I think we’ve got to change the mindset from, you know, being, you know, worried and anxious about it to actively promoting that actively. Yeah. Looking at, you know, encouraging exposure.

00;52;03;15 – 00;52;19;14

Now if you, if you are an adult or you have kids that already have allergies that they’ve developed because they haven’t, you know, you haven’t done this or you weren’t as a child exposed to a lot of different things that you probably should have been.

00;52;20;05 – 00;52;34;21

Is there anything that you can do or are you just kind of is your immune system kind of locked in to having this overreaction to that to that allergen? Yeah. So, again, you know, I’m of the belief that that, you know, DNA is not destiny.

00;52;35;02 – 00;52;50;17

I’m of that still thinking. And you might think, why do I think that? And I think I although it’s true that your genetic predisposition to allergy ATP is very important, there are things that you can do to modulate that even later on in life.

00;52;50;17 – 00;53;13;00

So we know from one study that was done in Denmark and published in 2015 that if adults were exposed to environment, it could actually make a difference and it actually does reduce their likelihood of adult allergies. So it’s not too late to have the positive exposures.

00;53;13;19 – 00;53;32;20

The certainly we know that the farm environment or exposure to a mini farm environment with pets is considered to be very, very helpful, very beneficial from all the data that we that we know about it. And it’s been replicated across many studies across the world.

00;53;32;29 – 00;53;57;01

I think the difficulty there is is actually encouraging people who are busy, have people to take time, their busy lives to actually make a trip out and go and go to the farm. And certainly for myself and my family, you know, it wasn’t something that was on our radar until, you know, my first you know, my my

00;53;57;01 – 00;54;15;07

first and my my daughter Olivia, who inspired me to write the book in the first place until she developed ecology. It was after that that we once I started researching it, I realized, you know what, I’ve got to get out of the city, I’ve got to act because I grew up in the city myself and so did

00;54;15;07 – 00;54;29;19

my wife. And it was a big mindset to actually do that. But I think once you once you put your mind to it, you realize, yep, it’s worth doing. And you know, the data says that even at any age it’s beneficial.

00;54;29;29 – 00;54;50;15

So not too late out there on the farm. Well, I can tell you from experience, there’s there’s a great way to do that. And you can also support your support. Local agriculture is to join a farm chair, you know, where you get a box of fruit and vegetables from local farmers, and then they often do farm invites

00;54;50;15 – 00;55;12;25

and you can go visit. So that’s that’s just one thought on that. And you’re getting you’re getting fat as well. So that’s always, you know, makes it makes it a double win also. So so in your book, you talked about some more novel ways to mitigate, you know, living in an industrial.

00;55;12;27 – 00;55;32;00

Society where infants are not exposed to to microbes that they need to or allergens. What are what are some of those cool new out of the box things that are people are trying. Yeah so these are what we call potential future treatment strategies.

00;55;32;09 – 00;55;54;03

Now they’re not actively recommended at the moment because we need more evidence for certainly these are things that are on the horizon. One of them is vaginal seeding. So that’s the idea that we can swap a newborn that’s delivered by C-section with that mother’s vaginal fluids shortly after birth.

00;55;54;09 – 00;56;21;05

And the reason why we might do that is because the data supports that in infants that are born from sex or from C-section, they are at a greater risk of allergies, notably asthma. And so if we can modify their microbiota by actively giving them some of the microbes from the vagina, that may be beneficial.

00;56;21;05 – 00;56;44;05

And so there is one study that’s being done that was actually done in 2016, and this was only a very small study. So they decided to invest in California and they found that of those that’s actually four of the C-section infants that were treated with vaginal us so swabbing or seeding I should call the after birth and

00;56;44;05 – 00;57;02;04

what they found was that a month after the swabbing they found that their gut microbiota and also the skin microbiota was actually very similar to that of vaginally delivered babies. So it had change compared to what you might expect from C-section babies.

00;57;02;04 – 00;57;19;19

So that was actually a very interesting that study wasn’t designed to show health outcomes, but it was just meant to show that if you can transfer microbes from vaginal fluids, that it can actually lead to changes in that infant’s gut microbes.

00;57;19;19 – 00;57;33;28

So that was what was interesting, got a lot of attention. Would we support that actively? I think if we’re going to if what I would say is that that should only be done in the context of a clinical trial.

00;57;34;03 – 00;57;44;29

The reason for that is that you want to make sure that if you work, you’ve given those microbes. There’s microbes actually safe. For example, we don’t want any groups. Yeah, that’s actually very harmful for the for the infant.

00;57;44;29 – 00;58;03;18

And so yeah, could be a way to screen for that. So really I would only recommend it in the context of a clinical trial. So that’s one thing. So, so I just wanted to jump. So I know the one thing that they’re doing with C-section babies is they’re they’re making a big point also to to have the

00;58;03;18 – 00;58;21;28

baby have some initial contact with the mother skin to skin contact. Is that would that also be of benefit to, um, to youngsters, to newborns? Definitely so, yeah. In contact. I think that’s really important to have that skin to skin contact early on.

00;58;21;28 – 00;58;43;11

That does make a big difference with the mother and also with with a partner as well. So I think that close is really important because it does promote a lot of transfer of some healthy microbes. Now, a lot of those might be might be actually skin microbes, but that’s still considered to be very a very healthy transfer

00;58;43;11 – 00;58;57;05

of of good of good microbes. And that’s really quite. Yeah. So yes. And we have a skin we have a skin microbiome as well. So it’s yeah, there’s lots, you know, that, that the infant would be getting as well as the and then also breastfeeding too.

00;58;57;06 – 00;59;13;11

We didn’t talk about that but and maybe not exactly right for this audience, but that’s another way that that babies can get microbes or hundred percent or not. And the best way I would describe breast milk is that it’s really personalized nutrition.

00;59;13;18 – 00;59;29;21

The baby, you know, it’s adaptive, it’s dynamic, it responds to the baby’s needs. And there’s a lot of healthy microbes in a tube. And so, yes, we haven’t covered a breast milk that there’s a lot to be said for breast milk and passing healthy microbes to the baby.

00;59;30;02 – 00;59;50;20

Yes. Yeah. And then I think you mentioned another kind of interesting trial that someone was doing to, you know, in this space with like B venom or something like that. Yeah, well, there’s something called immunotherapy, so immunotherapy is actually really interesting.

00;59;50;20 – 01;00;12;21

So that’s something that actually has been looked at currently as a way to the best way to describe it is it’s allergy vaccination. So, you know, it’s a type of, I guess you’d say even a therapy is a type of allergy whereby the body’s exposed to small amounts of an allergy and you gradually increase that dose eventually

01;00;12;26 – 01;00;29;15

. The body builds up immunity to the allergy. And that means that in the future you should have a reduced response to that allergy. Now it’s being done and it’s been quite successful when it comes to insects, allergies. So people have looked at it.

01;00;29;29 – 01;00;54;15

It’s been quite effective, for example, of bee stings when it comes to peanut allergies because peanut allergies, you know, can be so lethal to 2 to 2 young children. It has been studied. Now, initially, they used injection based in the therapy and they found that was actually very dangerous to infants.

01;00;54;15 – 01;01;18;18

And so they’ve gone to oral immunotherapy where you swallow a small amount of peanut extract and see that actually makes a difference. It’s still controversial because even though it’s been used and certainly I know that in North America it is available, it’s still controversial because there have been some large studies and what we call systematic reviews that

01;01;18;18 – 01;01;45;04

have found that the oral immunotherapy of the peanuts does actually increase the risk of anaphylaxis. So it needs to be used judiciously and with care. And so I would recommend if a parent is thinking about, look, the use of oral therapy for peanuts, you know, careful discussion with an immunologist before embarking upon that.

01;01;46;15 – 01;02;05;16

Yeah. It’s not something you should just experiment with at home, right? Yeah, that’s that’s basically novel. And we’re collecting more evidence about it all the time, so. Yeah, watch this space. Yeah, yeah. That’s interesting. Cool. So that’s probably a good place to wrap up.

01;02;06;22 – 01;02;25;12

So I always ask guests and I think I mentioned this at the top of the interview, but is where can people find you and interact with you online? Are you on all the social media platforms or have you successfully avoided those or I know you have a website, so maybe you could just could just tell people where

01;02;25;12 – 01;02;43;14

to find you. Yeah, sure, sure. So if you want to find more information about the diet and wave, make sure about the interesting topics that we talk about today. You can find me on my website which is WW We’ve got Dr. dot com, so g u t d r tor.com and you can find all my visual media

01;02;43;14 – 01;03;04;29

links on the website and also where you can find other books. Cool. And the book’s coming out in June, I believe. Yeah, at least in the U.S.. That’s right. Cool. Awesome. Great. Well, this has been such an interesting and enlightening conversation and thanks so much for speaking with me.

01;03;04;29 – 01;03;18;27

I really appreciate it. And I hope I hope the audience I know they will take away a lot of great information. So thank you. Absolute pleasure. Thank you for having me on the show. Well, that’s it for this show.

01;03;18;28 – 01;03;36;15

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01;03;37;00 – 01;03;54;18

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01;03;54;25 – 01;04;05;10

Our audio engineer for this episode was Deon Chadwick. Guest booking was handled by Melissa David. Thanks for listening. And until next time. I’m Eric Olson.