Instant Genius - How to beat the alarming increase in childhood allergies

Episode Date: December 12, 2025

Currently, around 40 per cent of children in the UK have been diagnosed with an allergy of some form or another – the most common being food allergies, eczema, asthma, and hay fever. Why is this number so alarmingly high, what can we do to treat them, and what measures can we take to ensure that our children don’t develop allergies in the first place? In this episode, we’re joined by Willem M. de Vos, a professor of microbiology based at Wageningen University in the Netherlands. He tells us how the recent rise in births by caesarean section may be contributing to the increase in childhood allergies, how exposure to microbes in early life can have a profound effect on our immune systems, and how cutting-edge microbial treatments such as faecal transplants are showing promise in our fight against this growing health epidemic. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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another, the most common being food allergies, eczema, asthma and hay fever. Why is this number so alarmingly high? What can we do to treat them? And what measures can we take to ensure that our children don't develop allergies in the first place? In this episode, we're joined by Villum M. DeVos, a professor of microbiology based at Vakuningen University in the Netherlands. He tells us how the recent rise in births by Caesarean section may be contributing to the increase in childhood allergies, how exposure to microbes in early life can have a profound effect on our immune systems, and how cutting-edge microbial treatments such as faecal transplants are showing promise in a fight against this growing health epidemic. So welcome to the podcast. Thanks so much for joining us.

Thank you. It's a pleasure. So today we're talking about allergies in children. So anyone that's read the news over the last several years will likely have heard the news that allergies in children is increasing. So first off, you know, what are the numbers saying there? Yeah, you're right. In a way, it seems that the British children are among the most allergic in the world. About 40% apparently are diagnosed with allergies which tripled the rate from 30 years ago. But there's also a number, to put it in perspective, that there has been a five-fold increase in peanut allergies in the UK, between the 90s and 2016 it is the number.

So there's really, I would say, good evidence and that the numbers are going up. Yeah, so can we say that this is an actual effect, or is it due to better gathering of data? Yeah, I think it's not. I think it's a real effect. Another way of looking at it is, for instance, that we have seen that there is a correlation between the mode of delivery and allergic diseases.

And for instance, cesare intersection delivery is correlating quite significantly with increased risk of allergic conditions. And we have seen also an increase in the delivery by C-section in the world. actually there is an enormous increase in the last 20 years now about almost 30% of the children are being delivered by C-section as predicted by the World Health Organization in the coming decade so in a way we see that also correlations with mode of delivery are increasing and

that in a way tells me that those data are really true okay so we can get into that in a moment. But first off, let's get the big question out of the way. What is an allergy? What happens in our bodies when we have an allergic reaction? Yeah, it's an immune reaction. Our immune system takes care of, you know, taking care of what's cell, what we have in our body and what's not cell, what is strange. And in the case of allergic diseases, the immune system incorrectly identifies a sort of harmless substance as an allergen as a threat, as an unknown compound, and then has the cascade of reactions to eliminate that. And that's not what we want, of course, because the substances are harmless. So that is a sort of overreaction on compounds

that we normally engage with. Yeah, so how dangerous can this be? Because personally, I don't have any food allergies or anything, but I do suffer from hay fever quite severely. And it's not pleasant, but I, you know, I can put up with it. I can cope with it. But, you know, for some people, their allergies are very severe, aren't they? Yeah, definitely. I sympathize. I also have hay fever. I'm also allergic to cats, which is also an interesting one. But other people have this, for instance, this peanut allergy. And the peanut allergy, like I said, is increasing. And that can be really giving an anaphylactic shock that people have such an overreaction

that they have to be going to hospital and being treated immediately, otherwise they die. So there is really a reason to think about it because the effects can be very serious, but still also the hay fever and the asthma, which is another,

I'm also asthmatic, so I know what it is, it's not a nice feeling to have no breath, and there's different gradations of that, but then it's not nice at but also it's quite life-sreatening too at some moment, especially when you get older and so on. So in the case of the infants is a different story, they may survive and there's not immediately a life-sreatening condition, but it is something to be avoiding.

And we all know that asthma has a pervasive effect or so on output, and kids can do sports and so on. So I think there's reasons to really address this very seriously. So we've mentioned there, hay fever, asthma, peanut, And you mentioned your sort of pet fur allergy. But what other common ones are there? Well, there's another one of rhinitis, a running nose. You have asthma as an impotin of on dermatitis or skin problems. You also can have this what is called eutricaria,

which is rashes in your skin and hives and so on. Itchy skin. That's something which is also very annoying. Also, it can go to your eyes and give conugiditis. So there are a number of, I would say, manifestations. of allergies, which are really quite devastating, especially in early life. When the mothers look at a child and they are red and they have all kinds of rashes, well, that's not what you want to give to your child in early life. So how do we test if someone does have an allergy,

you know, what's the procedure there? Well, that's complex. There's all kind of skin tests you can do and you can look at immunoglobulins in the blood, so I have a blood sample for that. And that helps you to understand when you have allergy. But also doctors, and I have to give a disclaimer, I'm not a medical doctor, they can also diagnose it based on the symptoms. So let's have a look at what might be causing this increase then. So I've heard about something called the hygiene hypothesis. So could you explain how that affects this issue, please? Yeah, the hygiene hypothesis is there. They also call sometimes the diversity hypothesis, also the old friends hypothesis that certain microbes actually are relevant for us. There are some tools in there that,

yes, we know that exposure to microbes, especially in early life, in a way, primes our immune system. And if that is primed in the wrong way, it can also predispose for a virilegy. So that brings me to the microbiota, the microbes inside our body, notably in the gut. And those have a very important impact on early life on the metabolic and immune. imprinting. And when we look at that and we see deviations of that process, we can see that it has long-term effects. And you can see that changes and I would say incorrect development in early life may predispose for asthma or other allergies and even for overweight if you talk about metabolic programming defects. So we have this hypothesis which is not proven because

it's a hypothesis, it's difficult to prove that, that microbes may play a role in life and therefore you can also do something about it. Yeah, so you mentioned this idea there, but do you think these days like parents are perhaps a little bit afraid to give their young children things like milk, eggs, peanuts in fear that they'll have allergies? And perversely, this is contributing to the increase in allergies? Yeah, that's an interesting one. I think there's data to support the fact that if you don't give this too late into the of milk or eggs or peanuts actually increases the risk on food allergies. And that has been shown actually also to be involving the good microbiota development.

So I think it's important to keep track of your microbiome and understand what the impact of the microbiome development is on life of a baby. Because for instance, we have seen our own work that the use of antibiotics, especially the recurrent use of antibiotics, which disturbs the microbiota development, has an impact on later life and asthma and allergies. So we do have that correlations. And once again, in this case, we talk about correlations, but we're moving towards causation too. And I've been involved in the trials in Finland, where I had a chair for a long time, that correcting the microbiota with specific supplements also reduces the risk on atopi and,

female in high-risk babies. So you can do something about it. And I can tell you more about other trials that we have ongoing, where we look at causality rather than correlations. Oh yeah, please do. Can you tell us about those, please? Well, I told you in the beginning that Cesarine section delivery actually is a bit different from vaginal delivery. And why is that? Because there's not immediately a contact with the mycops of the mother, because you or me, we are borne sterile, but we are colonized quite quickly with the microbes of the mother, and there's a maternal transfer. Usually using the fecal microbes of the mother, they colonize the early, early life baby. In the C-section baby that's compromised, also because of less contact, also about

use of antibiotics, which are normal for the mother to be exposed to because she is cut open. So, there are compromised development. And we can see that the C-section delivery is then also correlating to higher risk of allergies later on. Now the question is can we normalize that system, this marcobiota development because the kids don't get the mycops from the mother, can we normalize that? Because we see a different development pattern in the C-section babies. Now we have done a simple proof of concept experiments where we give the C-section babies a maternal fecal transplant. So we give them a little bit of poo from the mother, very diluted in other conditions and we could see that could normalize the development of the marcobiota like a vaginally

delivered baby. Now that's an important discovery we published a couple of years ago and now we have a trial where we do this in a double-blind placebo-controlled way, where we also follow children in time to see whether their immune system is affected because that would be a causal effect that the placebo children born by C-section would have a different immune development as compared to the normal normalized children. And yes, we do see an effect there. It's too early to say exactly what we see, for instance, effects on the vaccine response and more is to be discovered, but we do see effects on the immune system. And I think that will be one of the first examples that we can see a causality between C-section delivery and abnormal colonization versus vagina-delivered babies

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Visit focal powered by name.com for more information. So are there any other factors in infants that can influence their sort of susceptibility to allergies? Yeah, there's also back in Finland. There has been quite some work on preventing allergies by exposing children to, soil in kindergartens, you know, when they go to the play schools and so on, then they get this exposure to soil and they have all kinds of ways of doing that. And there you can see also effects on the microbial world in the children by doing that. And there is a correlation with less risk on allergies. So that's an interesting, I would say, outcome too, that there is ways

of overcoming, that sterile way of exposure. children and remember Finland is pretty cold in the winter and children are at home all the time. So it's a very unusual situation actually compared to the rest of the world maybe because it's pretty cold and people are inside. Here their children are exposed outside to the outside world in a way that allows them to trigger their immune system maybe in a better way. So you mentioned asthma earlier. Over here in the UK now, there's a lot of reports that air pollution levels are getting so high that they're damaging our health. Is this having an effect on the sort of allergy problem in children?

Yeah, there is a correlation between the pollution and asthma exacerbation. So in a way, it's not nice. I mean, I know for myself being asthmatic that if you insert in environments when there's, you know, high air pollution, that you have more problems in breathing, is it causal? That's difficult to measure, but then it could be. We also know there's a correlation with the pollen, which is in the air, and that may also trigger an immune response, and if there is, you know, aberration there, it may also affect the immune system. So it's a bit more complex because causal studies are difficult to perform here.

You know, it's easy with the C-section where we can give a little bit of, you know, a normalization by the maternal fecal microbiota transplant as compared to getting a child in a different atmosphere. How about things like celiac or gluten allergy? Because I'm 46 now. And when I was younger, I met one person who had this. And now it seems that's shut up to something like, I don't know, 10%. Is that a problem? Yeah, it's a problem too. It's also an allergic response in a way on a gluten peptide,

which is present in wheat. But there's this so-called gluten. allergy is called celic disease, but there's also non-glutin allergy, so it's more complex. So I'm not so familiar with all this and can't answer it completely because it's a moving area. But basically there's also a correlation between antigen exposure and response of the body. But then the gluten allergy, yeah, the simple avoiding strategy, so you know, avoid the foods with gluten, helps at least to avoid the symptoms.

Yeah, so moving on from that, let's have a look at some treatments. Like you mentioned asthma there, we have the inhalers and the steroid things, etc. So what things are currently available to treat people with allergies? There's, of course, affecting the immune system. There's drugs, corticosteroids are being used there and so on. I'm not going there. I think more about, you know, what you can do to also improve your microbiome, to have it the right development.

That can be supplements. We have seen effects on specific lactobacillide that helps also to reduce the incidence of allergy in C-section babies. We also think there is an increase in babies which are born without so-called Bifida bacteria. Bifidabacteria are a group of organisms which are very prevalent in early life. But in the study we have done here in Sweden

with Alba Health, we have seen that 30% of the babies in a nationwide analysis don't have beef with the bacteria in the first half year of life. And that's contrary to the conventional belief. And there are trials ongoing where those people get beef with the bacteria in order to normalize the microbiome. We did that also in a case study because if you don't have beef with the bacteria and they can make up about 30 to 50% of the marcobiota in breastfed children, if you don't have a case study, have them, other bacteria are there. And those other bacteria often ones we don't want to see. They have names which also suggest there can be pathogens, the most of a petobions, and we don't

want to see them. They have high numbers. And we saw that if we have this one case that we give that infant a supplement containing Bifida bacteria, you could see that Bifidabacteria were actually out-competing those organisms you don't want to see. And that is now being done also in different trials around the world, and there is reasons to believe that you can normalize potentially part of the defects, of the absence of a bifle bacteria by a simple supplement. But you have to know it. You know, you don't know it when you don't look at the microbiome. So the babies apparently look normal, but there's something not really normal in the microbiome. Davis is good to look at that. You asked me about other examples. I talked about the FMT, but that's not to be

done at home. Another one is, that's an interesting one about this peanut allergy that you can also have a combination of a supplement with a lactobacillus and a specific immune therapy with a bit of peanut,

you know, compounds based on peanut. And actually that helps to prevent peanut allergy on later life in children which are susceptible to that. So there's, trials which looks successful but it's not you know there's not a golden bullet yet for everything it should be case by case and personalized and I think here is where the research in the coming years will be focused on yeah so let's look forward then to the next 10 5 10 years say you know what are some

sort of key areas that you think we really should be targeting the areas we should be targeting actually is in my opinion, and I preach for my own profession, my microbiologist by training, it is the microbiome. I think a good microbiome is under pressure. We have seen, like I said, the absence of beef with the bacteria, which should be there and not there, maybe due to antibiotics, maybe due to specific other circumstances that we're not aware of.

But in a way, it's alarming. We also know that if you have an, what's a barren, microbeome development in early life, then you can also have effects on the child health, but also of its behavior. More crying, more fuzzing, not easy sleeping, and that kind of aspects we are measuring. And I'm quite convinced of the fact that we could make a contribution there by specific supplements or by combination of supplements and even by in later life using right fibers in order to develop the mycobion in the right way. So be careful with the fact that early life, of course, children have to be breastfed.

WHO says six months and up to 24 months. But at some moments when they stop having breastfeeding, they have solid food. And that solid food should not be the processed food that we maybe want to give because it's easy, no, it's good also to give fibers. and fibers are in plant cells so giving plant cells is the best so I always come not to the hygiene hypothesis but

the old France hypothesis I come to the old root hypothesis that you have to give root fibers which are often plant cells with fibers in there and that is a way to have a sustained release of fibers in the gut of older children

and I think it's important to focus attention there in the next five to ten years Thank you for listening to this episode of Instant Genius, brought to you from the team behind BBC Science Focus. That was Professor Willem M. DeVos. If you liked what you just heard, then please do consider subscribing to Instant Genius on your preferred podcast platform.

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