Food Allergy Prevention Strategies Explained: A Conversation with Professor Carina Venter

Join Dr. Sakina Bajowala and Venus Kalami, RD as they interview Carina Venter, RD, PhD. Dr. Venter is an internationally recognized clinician-researcher and founder of Grow Happy, whose work is at the cutting edge of nutritional science. Listen to the latest research on how baby’s immune system interacts with parts of the food they eat and what this means for baby’s long-term tolerance of allergens.

---

---

Dr. Bajowala: Hi, everyone. My name is Dr. Sakina Bajowala, and I'm an allergist and immunologist here at Solid Starts. And I'm joined by my colleagues, Venus Kalami, a pediatric registered dietitian, also with Solid Starts. And we're both so excited to be in a conversation today with Dr. Carina Venter. She is a dietitian and PhD researcher, and a globally recognized clinician whose work has been instrumental in shaping our understanding of infant nutrition, food allergy prevention, and the role of the microbiome in early life.

Venus: Oh, I am so excited. Dr. Venter's research has really helped us move the field from a narrow focus on just individual allergens to having a much broader understanding on how dietary patterns, microbial exposures, and how key nutrients may influence immune development, as well as tolerance. So today, we're really excited to have her here. She's a little bit of a hero, so I'm geeking out. And zoom out a bit and explore the bigger picture together, and think through where the science is now, where it may be heading, and what it really means practically for our patients.

Dr. Bajowala: Well said.

Dr. Venter: Well, thank you. And thank you for having me. I'm excited to be here. And I have many people to thank for the research I've been able to do. It really takes a village.

Dr. Bajowala: Absolutely. All right. Well, let's get right into it. I really would love to explore the intersection of nutrition and food allergy prevention today, if we might. And hopefully our audience can feel like they have a front row seat to a conversation amongst colleagues, and we're really going to geek out over the science. So let's start by just talking about the way we've been framing allergy prevention and food allergy prevention. I feel like we've been emphasizing early introduction and sustained introduction and exposure to these food allergens for the purposes of allergy prevention. But nothing is in a silo, and that cannot be the whole story. So Carina, what do you think this framing of food allergy prevention is missing?

Dr. Venter: Yeah, I really think it is about the bigger picture. And I think everybody has heard of Dr. George du Toit and the research he's done on early introduction of peanut and peanut allergy prevention. But right from the start, I said to George, "Look, I'm not taking anything away from the mighty peanut protein, but there's a lot more in a peanut than just the peanut protein."

And there's two things that I can say to support this. The one is, I actually wrote an editorial for the Journal of Allergy and Clinical Immunology with Marian Groetch, a very close colleague of mine, a dietitian from Mount Sinai. And we highlighted in the editorial that the children in the LEAP intervention arm, so the children that actually ate peanut, they also had a much healthier diet than the children in the control arm.

Dr. Bajowala: Mm-hmm.

Dr. Venter: Because they were filled up from the peanut butter and the peanuts, so they didn't eat cookies and chips, or crisps, as they call it in the UK. So I've always been interested and wondering if we can tease out the healthy eating aspect of the LEAP study, versus just the peanut protein intake.

And then the second thing that supports the fact that it's not just about that peanut protein, I've just recently published a paper with Liam O'Mahony. He's a professor of immunology at the University College Cork in Ireland. And we showed that when you actually feed children the whole peanut, which includes the fats and the protein and all the fibers, it has a much more beneficial effect on their gut microbiome than when you actually feed them peanut flour, where some of the fiber has been taken out and a lot of the fat has been removed. And so it really shows that it's not just about feeding babies allergens. It is important to think of the bigger picture and overall nutrition.

Venus: If I were to add to that, Dr. Venter, I think in your course, you had shared literature about responsiveness to diet therapy in eosinophilic esophagitis, and how in certain countries there was more responsiveness to the elimination diets. And in particular, in Spain, I could never find the paper again, but I had searched deep for it. But in Spain, where the children were eating a more whole foods diet, or some may call a Mediterranean diet, that they had much better responsiveness to the EoE elimination diet, whereas in the United States or maybe other more westernized countries, more standard American diet, they weren't having as great of a success rate. I feel like this is a theme across your career.

Dr. Venter: Yeah. So I'm a huge fan of Alfredo Lucendo and the work he's done, well, is still doing in Spain in eosinophilic esophagitis. And I can distinctly remember having this conversation with him at a conference. And I said, "Alfredo, how do you get people to follow your diet?" And he said, "It's very simple, Carina. We don't tell them necessarily what not to eat. We tell them to go home, cook fresh, and just avoid the allergens." But there's not hours and hours of discussions about the label reading because they go home and they have cornbread and tomato and orange juice for breakfast.

And my classic example is that when I did a study here in America in eosinophilic esophagitis, the Pop-Tart, the strawberry Pop-Tart is actually milk-free. So you can actually put a child with EOE on a milk-free diet, and they can have Pop-Tarts for breakfast. Now compare, just in your mind, that Pop-Tart for breakfast versus the child in Spain that's going to eat fresh tomatoes, freshly baked cornbread, and a glass of freshly squeezed orange juice. And again, that sort of highlights the importance of overall nutrition because Lucendo's work is very hard to replicate in more Westernized countries like the States.

Dr. Bajowala: Yeah. It sounds like if we were starting from scratch today, we would be emphasizing more of the holistic diet and lifestyle approach versus hyper-focusing on a particular food, or even taking it a step further and hyper-focusing on a particular protein within the food when it comes to thinking about reducing the risk of food allergies later on in our youngest, which are babies.

Dr. Venter: I know we're sort of stepping on many topics here, but when you look at the NIAID guidelines on food allergy management from around—And that's probably 10% of what I do. 90% of my consultation really goes on about what's left, and how can we address the rest of the overall diet to most beneficially affect the microbiome and the immune system.

Venus: Absolutely.

Dr. Bajowala: Yeah, absolutely. So even as an allergist in clinical practice, I feel like over the course of my career, the emphasis has very much changed away from telling people what they can't eat, and moving towards encouraging people to eat everything they can eat, right? And really encouraging dietary diversity and avoiding overly restrictive diets. Which leads us to that conversation then about what dietary diversity means for the microbiome.

Dr. Venter: Yeah. So in about 2013, Caroline Roduit from Switzerland published her first diet diversity paper, and its association with allergy outcomes. And I kept asking everybody, "What does diet diversity mean?" And they then said to me, "Well, you're the dietitian, you should know." So I got this group of experts around the world together, funded by the European Academy of Allergy and Clinical Immunology (EAACI) and we searched every single paper ever written on diet diversity and looked at the definitions. And in the end, we really concluded that diet diversity just means you're counting different foods.

So, you may be counting different fruits, you may be counting different vegetables. You may be counting everything somebody has eaten over the last week. So you just need to be clear about what you're counting.

Dr. Bajowala: Mm-hmm.

Dr. Venter: But I think for the most of it, we all count everything healthy that somebody has eaten over the last week.

And then data from both Caroline's work and also other studies not really focusing on allergy have clearly shown that as you increase diet variety or number of foods over the first year of life.

Dr. Bajowala: And I think this kind of leads us to that question about how important is it for us to encourage dietary diversity rather than dietary restriction in our clinical practice, right? Because even in my allergy practice, I've found over the years that I spend much more time talking to my patients about what they can eat and what they should eat rather than the foods I want them to avoid for their safety.

Dr. Venter: Well, that's amazing, because I think that really should be the focus of what we do. But talking about diet diversity, which really is just the number of different foods somebody eat over the course of the week, and hopefully the number of healthy foods somebody eats over the course of a week or perhaps a month, and what we've shown in studies is that in infancy and also really even in pregnancy, as the number of foods that people eat over the course of a week or over the course of pregnancy increase, so does diversity of the gut microbiome increase.

And so I'm really summarizing a complex science, but for the most part, as the diversity of the gut microbiome increase, we also see an increase in all the good bacteria. These good bacteria make a chemical which is called butyrate, and butyrate actually just tells the immune system to calm down. And so that's really why we want a diverse diet, because to cut a long story short, if you have more variety in your diet, your gut microbiome looks healthier. You make more of the important bacteria that's going to make chemicals that's going to tell the immune system to calm down.

Venus: That is amazing, and I feel like if you were to tell a child that fruits and vegetables talk to the gut and then tell their immune system to behave properly, I think their mind would be blown. On the topic of butyrate and just short chain fatty acids in general, how central of a role do they play in immune tolerance in general, but particularly in early life when we're working with babies? Or do you think it's not even about the short chain fatty acids at all? It's more about, again, like that big picture that has this really laser-focused impact? What are your thoughts?

Dr. Venter: Butyrate is definitely important, but also so is particular bacteria. So butyrate in the studies from Caroline Roduit from Switzerland, she showed that if you have a healthier, more diverse diet in infancy, the children have more butyrate. We have more of the messengers like TGF-beta and IL-10, and these messengers go and say to the immune system that they have to make more cells that keeps everything calm and everything in balance than making cells that's going to cause allergies. So we really know that butyrate is important, but there's two other short-chain fatty acids as well, the valerate and the acetate, and they also play an important role to just calm the immune system down.

So that's the butyrate side, but there's also specific bacteria that's important. So we know that when we feed children peanut, they make a bacteria called blautia.

And somehow blautia directly talks to the immune system not to cause peanut allergy. Because when we took blautia out of the gut of mice, they developed peanut allergy.

And when we put the blautia back, the peanut allergy resolved. So it's sort of like the overall microbiome that's important because we need those chemicals, but we're also learning more and more about particular bacteria that may be important to prevent specific food allergies.

Dr. Bajowala: Yeah. Leads me to another question. What you're talking about here is really emphasizing the importance of getting all of the macro and micronutrients that are in foods all at once while you're eating them to get the full benefit of that food, rather than necessarily isolating out the peanut protein and feeding it, or isolating out a probiotic and giving it as a supplement, right? Do you feel like in medicine and even nutrition today, have we been over-reliant on kind of filling the gap with supplementation rather than just trying to get everything from the diet itself?

Dr. Venter: I think so. But I think sometimes in a food allergy clinic, there's just so much to deal with that if there's a shortcut to something like rather than now having to talk to you for 30 minutes about getting a more diverse diet, I'm just going to recommend a probiotic because that's going to take me two minutes. But I think more and more we come back to the basics that we have to eat a healthy diet. Apologies. We have to cook from scratch. We have to try and stay away from ultra-processed foods.

And when we talk about healthy eating, we really need to think about having freshly cooked food at home. I know people get sensitive when I talk about ultra-processed food. I understand. We can't always cook. Even I heat something up that's coming out of a box on occasion. But there's really good data that show that as we're eating more ultra-processed food, which is devoid of all the nutrients we need, it's got a lot of emulsifiers, which is really not great for the gut microbiome, we see more allergies. And so I think it's really trying to get a balance. Understand we all have a life to live, and sometimes we're going to take the shortcut. But we really need to try at least 80% of the time to give our children a healthy, varied diet from home-cooked food.

Venus: That makes perfect sense to me, and I think it nods to the theme of having diversity, taking this more holistic approach, not getting stuck on any one particular supplement and prescription. On one hand, in the clinic, I can see the benefit of having the probiotic or the prebiotic supplement, for example, especially if it gives assurance to the clinician that it will happen, and therefore it'll give that benefit. Versus diet and lifestyle, it's so nebulous. It's influenced by so many externalities as well, too, that it can be hard to give the counseling and absolutely know that the therapy that you've communicated, which is a lifestyle, is going to therefore change.

Dr. Venter: Yeah. But I do want to say there is also a place for supplements.

Venus: Yeah.

Dr. Venter: And I use them in my clinical practice, and I'm aware that some of my patients may be listening. We do know that it doesn't matter whether you look at cow's milk allergy or IgE-mediated food allergies, or FPIES or EoE, children with food allergies across the spectrum often lack Lactobacillus and Bifidobacteria.

We also have data currently unpublished, so I don't want to go in too much detail, but showing that children with food allergies may not be able to digest fibers well because they lack the bacteria that breaks down the fiber. So there may be a group of children with food allergies where a short-term supplementation of the bacteria that they're lacking may definitely help them to best utilize the foods and the fibers they're eating.

I don't think we know enough about the microbiome or about nutrition and the microbiome of children with food allergies to say, "This is the magic supplement, and this is the dose everybody needs to take." But if I have a family that really invested into buying a probiotic, I will definitely give them, to my opinion, a few options of probiotics that I think could be beneficial.

Dr. Bajowala: All right. So there's going to be a lot of our viewers who see this conversation, and they are going to immediately think that their baby requires supplementation of vitamins and minerals and prebiotics and fiber and synbiotics because they are just not eating that much food yet.

Dr. Venter: Yeah.

Dr. Bajowala: Right? So how do we counsel these families who are like, "Ah, my baby doesn't have everything"? I generally tell my patients, "Listen, I only go down this road if a child is on a restricted diet for some reason." But if your child is kind of learning to eat and gradually adding new foods, even if they're not eating a large volume, I generally don't worry about additional supplementation. How do you guys feel about that?

Dr. Venter: Well, I think it's important that you highlight that because there's sort of the baby that's beginning to eat and perhaps not eating a lot. And for that baby, it's a balance between how much they're eating, whether they are still being breastfed, whether they're taking a formula, and very rarely in those very young babies, we will be needing a nutritional supplement because they're just beginning to eat, and nutrition is not the main source of— or food is not the main source of their nutrition. There's the other side of food allergy when you are dealing with a two, two and a half-year-old that's clearly a very picky eater, not wanting to take our hypoallergenic formula anymore, not taking sufficient plant-based beverages if they have a milk allergy. Those are the kind of children where I would start to consider using supplements. I will always first try to address the diet before I go for a supplement. That's always my last resort. But in these little babies that's really just starting to eat, there's definitely no need to say, "You're only having two or three teaspoons or tablespoons of certain foods, and therefore we now need to bombard you with iron."

Venus: I think an important point to make. Absolutely. I agree. There are different scenarios that call for different types of interventions, and I think in the case of a baby, as long as baby's making progress, too, and showing good potential to get there in time, that's really reassuring to me, versus a baby who might be at nine months and no interest in food and kind of struggling to make that progress. That might be a baby who we want to keep a closer eye on, and maybe they do need iron supplements down the line or at the present moment.

Dr. Venter: Yeah.

Venus: But also, every baby has their own timeline, too. They progress differently, hit milestones at different points, and we don't want to add any more stress to modern parenthood than we absolutely need to.

Dr. Venter: Yeah. And that brings me to another sort of side effect of early introduction of allergens. When we had growth faltering or the children not growing well, there was always this sort of desperate struggle to get more protein and fats into the children so that they can grow. Well, I don't have that anymore in clinic because when I have a child that's not growing well and I do early introduction of allergens and all these nut butters, and the baby loves it and eat it, the next time I do growth monitoring, that child is back on their percentiles.

And so that's something I really like about early introduction of allergens. It fixes a lot of my nutrition concerns. And of course, there's some iron in these nut butters, but definitely a lot of zinc and all the good fats that the children need. So yeah, I must say, there's a place for supplementation, but most definitely not the norm in my clinical practice.

I wonder, Venus, could you put a percentage on that? How many children do you think that you see would leave your office on a supplement, a nutritional supplement?

Venus: Yeah. I would probably say the minority as well, 25, maybe 30%, like a third of my patients, but most of them had bandwidth, capacity, motivation, and interest that they could make changes to diet and lifestyle in a way that made sense for that family unit. And then there were some that fell into those niche scenarios like dairy allergy but also soy intolerant or had these scenarios where they weren't getting enough calcium and really did need a supplement and didn't want to take a formula. Scenarios where the family might be vegan and really is iron deficient, and they just need to have an iron supplement on board all the time, or maximizing those iron-fortified foods. So it's not the norm. It's not for the majority. It's usually these niche nutritional populations or nutritionally vulnerable populations, as we call them, who need a little extra support. But it doesn't require a massive overhaul of their life. It's just small tweaks to make sure they stay safe in the long term.

Dr. Bajowala: Yeah. And of course, this is for both you, Venus, and you, Carina. You guys frequently are seeing kids in your practices who require extra nutritional support.

Venus: Right.

Dr. Bajowala: But kind of just going back to a kid who doesn't require that level of additional support. If that family is saying, "Gosh, as we go down this solid foods journey and dietary expansion," they recognize the importance of doing a lot of different things. But if you had some favorite, quote-unquote, super foods that you could start with, what is your shortlist? I heard you really like blueberries.

Dr. Venter: Oh, yes. I was going to say, I don't really have to think for a long time. Blueberries, definitely my favorite food. I've also published two papers where we did a study, and we showed that if you feed babies blueberries over the first six months after they start eating, that we change their gut microbiome, and they made more of these bacteria that's going to make more butyrate. And so they had more of the immune cells that just calm down the immune system. So blueberries, definitely one of my first foods.

Of course, if you do baby-led weaning, I have to say, you can't just feed the whole blueberry. You have to either squish it down or cut it up. But make sure we're not feeding babies whole blueberries.

And then my second food, which is actually my second favorite food as well, is peanut butter. And so we have blueberries, we have peanut butter, yogurt. I think yogurt, even plant-based yogurt if your kid is milk allergic, is such a wonderful way to get protein and calcium into a child, and also the good bacteria without then having to go for a supplement because you've got the good bacteria in the yogurt. So I'm on food number three. I'm going to get Venus or Vanise to do the next two foods so we have a nice five first weaning foods.

Venus: Oh my gosh. I'm definitely a person who loves to put it back on the family when they ask me, "Well, what is it that I should be eating?" I always want to know, what are you eating at home? What's inherent to your culture? So I always love to lead with that, but if I were to pick my favorite foods, I would probably say mango is a top favorite. Beta carotene, fiber, the mango pit is wonderful to also teethe on for babies. There's so many different kinds, more sour kinds, sweeter kinds. There's just so much you can do with mango.

And if I were to do a fifth one, hmm, I want to do something green. I think celery is a fantastic one. Also very baby-led weaning friendly, easy to grab. Makes a fantastic teether when baby is having teething pains as well. I think there's some type of plant compound in celery that has pain-relieving properties. I can't remember the name of the compound, but it makes it a really nice all-in-one type of vegetable for babies. And just the flavor is so unique and different too compared to other vegetables, so I think that's a really fun and accessible option.

Dr. Bajowala: Yeah. Now, Dr. Venter, I have a question for you about going back to blueberries. I know you mentioned it has positive impacts on the gut microbiome, but I'm also curious to know, is it about the fiber, directly about the fiber and the gut microbiome impact? Is it about polyphenols, other plant compounds, antioxidants, other sort of between microbe interactions, or something else entirely? And I just want to plant this here, could there be too much or too little of a good thing like blueberries? So I'm curious for your take on kind of the underlying mechanism, and when are we kind of going into the zone of too much?

Venus: If there is such a thing.

Dr. Venter: Yeah, so I definitely think the fibers are important because we know the fibers feed the gut microbiome. But there are many scientists who's built a career on studying polyphenols and how that positively affect the gut microbiome as well as the immune system. So I normally say to the parents, my bias is blueberries, but without having studied other berries, I think they probably do something very similar because they're all high in fiber, and they all have the polyphenols. I think that is the two main compounds.

There may be some other things that we just haven't studied yet. And is there too much of a good thing? Well, we all know that if we eat too much fiber, we're going to get diarrhea. So perhaps you can feed your baby too much blueberries. But again, getting back to baby-led weaning, I definitely do a combination of the two in my clinics.

But if you're going to feed blueberries through baby-led weaning, that baby's not going to eat three bowls full. And getting back to what Sakina also said, is that babies don't have to eat volumes to have a healthy diet. It's little bites here and there that teaches them a varied diet and teaches them to love food. So I don't think a baby naturally will just overdo it, but yeah, clearly, I don't suggest bowls full of any food for a baby that's learning to eat.

And I want to get back to the diet diversity as well because, in our studies, we showed that the children that ate more than 11 foods, 10 or 11 foods by six months, they had less allergies. Now, that sounds like an incredible amount of food if you're going to think a six-month-old baby need to eat 11 bowls of food a day. But it was little bites and little tastes. And so I think we always need to remember that we can talk huge variety with babies, but it doesn't necessarily mean—

Dr. Bajowala: Yeah. And I think people hear, oh, 11 foods by six months of age, not only are they thinking that might be a lot of volume, but they're just wondering how they're ever going to get to that number in that amount of time, because there's this misconception that when we're expanding a baby's diet and introducing new foods, we have to be on one food for three to five days, and only then can we move on to the next food. But to be honest, if we took that approach, we would never get anywhere, right? So what is your philosophy on how quickly the diet can be diversified?

Dr. Venter: Oh, I was so hoping you're going to ask me that because every time I talk about diet diversity, somebody in the audience will say, "Well, excuse me, Carina, do you know that the AAP say we have to wait three to five days between each new food?" But the thing is, even if you start solids introduction at six months, if you wait three to five days between each new food, you can cut the variety down to about 45 foods in the first year of life. But if you do one new food every day, you can get to 180 foods. Now, I personally have never met a baby eating 180 foods at 12 months, but there is the potential. And so what do I do? The AAP also in their book, "Caring for Your Young Child" say, in the past we used to say wait between new foods. Now, new evidence suggests you can introduce multiple foods at once.

Dr. Bajowala: Exactly.

Dr. Venter: So this is what I do... practically is I do like the child to taste a food for the first time without being in a mix. But I don't actually wait days between foods. So it could be blueberry today, it could be banana tomorrow. And let's talk about vegetables as well. If the mother wanted to do blueberry for breakfast and try some softly cooked carrot batons for lunch, then that's as well fine. I think when it comes to the allergens, this is just my personal practice, I like to do one allergen for two days before I go to the next one. Now, we know that if they're going to have an allergic reaction, it's going to be within two hours. So I may be wrong, and it might be perfectly okay to do one allergen every day. I just think for me, I feel two days are good. I feel the parents that I work with normally would like the two days as well as just one new allergen a day. But definitely waiting days between new foods and weeks between new allergens is not necessary.

What do you do, Sakina? And do you—

Dr. Bajowala: Yeah. My approach in clinic and in how we advise Solid Starts families is three exposures, but they don't have to be over the course of three different days, right? You could have multiple exposures in the same day. You could do it in the morning, then wait a few hours, do a little bit more in the afternoon. Then the next day, have another serving, and now you've got three. And so it really does line up very similarly to what you're recommending, and I think it just goes to show that even when we are following guidelines and following the evidence, there's a lot of room for minor variation and stylistic differences in how things are done. It doesn't need to be exactly the same or super regimented all the time. The goal is just to get it in, keep it in, right? And keep going and then add more, right? So I think that I try to be kind of relaxed about it because I think otherwise families can feel very overwhelmed by just the concept of, "Oh, I have to do this this many times in this order, and then I have to do this, and then I have to do this. And if I don't do it exactly right, my baby is going to develop a life-threatening allergy." Right? And so I really try to talk people off the ledge a little bit with those concerns and say, "Do your best."

Dr. Venter: Absolutely. And Venus already referred to this, you work with the family in front of you. I have some families that's just ready to go. They just want to feed the baby. Then I have other families that's slightly more reluctant, slightly more hesitant. I have babies that just love food from the word go, and then I have other babies that takes a lot of time to get their heads around this whole concept of now having to eat. And so I think we have to just work with that. But definitely the one thing I say to my families, "Do not get a calendar." I do not want to hear Mondays are cashew days, and Tuesdays are egg days.

Dr. Bajowala: Yeah.

Dr. Venter: And call me on a Thursday because you forgot on Wednesday it was walnut day. I'm like, "This is not..." We have to allergens and food, just food. You know?

Dr. Bajowala: Yeah.

Dr. Venter: We don't want to over-medicalize allergy prevention.

Dr. Bajowala: Yeah.

Dr. Venter: We don't want to over-medicalize infant feeding, which should just be joyous and fun time rather than a stressful time. Although, of course, there's some stress involved with any stage of infant development.

Dr. Bajowala: Yeah. Yeah.

Dr. Venter: And that's why we're all here.

Venus: Yeah. Absolutely.

Dr. Venter: But then, having said that, I have moms that say, "I hear what you say about the calendar. Calendar works for me. I want to write down what my baby's eating, how well they did." And I'm saying, "You know what? I'd love to see your calendar next time."

Venus: Yeah.

Dr. Venter: But just, I'm not going to impose that on you. And I think this is why I love working with families with young children, because every family teaches me something.

Venus: Absolutely. I think kind of what you're saying is that the calendar and different approaches, they're options. They're not obligations. So you don't have to introduce a new allergen every single day if that feels a little overwhelming. And maybe you need the two days, or maybe you do need the three days even, just to build up that confidence. And I think the reluctant families, once they go through the motions one or two times and they see that it's going to go well, the risk of a reaction is actually quite low. If it does happen, they'll know what resources they have and what it is that they need to do, so that when it comes to the second, the third, or fourth foods, it feels more like routine versus this big, scary, daunting task that they need to overcome. The sustainability of it, we can take the calendar method, or we can sit down together and identify family foods that we enjoy that naturally have those foods or can be slightly tweaked so that we're not, again, overhauling the diet in a way that's not sustainable or reflective of a family's food culture either. So I love that all of us are kind of saying the same thing from our different areas of practice, that it's really about the family and we have these guidelines as a North Star to move us forward.

Dr. Venter: Yeah.

Dr. Bajowala: And when we—

Dr. Venter: So we've talked about fiber and we've talked about antioxidants and polyphenols and butyrate, and tons— We've talked a lot about protein and vitamins and minerals. Let's circle back to a conversation about fat, because I think there might be some opportunity for myth-busting here.

Dr. Bajowala: Very true.

Dr. Venter: What do you think about fat?

So the first thing is that particularly for children under one, we have no recommended intake or dietary guidelines, but we do know that babies need fat. And my data, which I'm just finally now writing up, really show that the skin of babies with eczema, in particular, likes fat. And so it absorbs the fat, and then it helps to just restore this. And this new drug, Dupixent or dupilumab, whichever way you want to call it, it does exactly that. It changed the cytokines and the lipid profile of the skin, and so we see improvement in eczema. So wouldn't it be amazing, and I'm not saying it will work, but wouldn't it be amazing by just feeding babies the right fat, we can get their skin better? So just getting back to a simple answer, like you've just said earlier on, there's no goodies and baddies.

And when it comes to fat, I say to parents as well, babies need saturated fat. I love ghee because ghee is actually one of the only food sources of butyrate. So it's a good source of butyrate. It's a good source of saturated fat. Skin loves saturated fat. There's always a place for some monounsaturated fat if you have a more Mediterranean diet. But now, again, now that we're eating all these nuts and nut butters, they get all their polyunsaturated fats from that. And so sort of for my normal diet consultation would say, we're definitely not going to call any fat a bad fat when it comes to babies and young children. We're going to let them eat all kinds of fat and a little bit of butter on a slice of toast is also great for babies to have. I'm not going to say seed oils are terrible. They also have a place in the diet, nut oils as well. So yeah. So I think children needs calories. Children needs to grow. Children have small tummies. Sometimes it's difficult to get all that calories in a big volume, and that's a very shortcut way to get calories into a baby without needing volume is by just feeding them fats. And of course, avocado. How can I forget the avocado?

Dr. Bajowala: Yeah. I look at the Solid Starts guidance. I send that link or advice to almost every family I see because, no baby can hold an avocado or a slice, but your advice about rolling it in some grain or oatmeal flakes, and all the parents go, "Aha!" So, definitely one of—

Venus: I also have read literature that suggests that it's not necessarily that omega-6 fats are pro-inflammatory, but they're not as anti-inflammatory as omega-3s, which is a really intriguing reframe compared to the pro-inflammatory and anti-inflammatory, and I think that helps. That sort of points to the nuance that you mentioned, Dr. Venter, about its role in tight junction support and supporting the different type of barriers in the body that is not necessarily—

Dr. Venter: And I think about this whole concept of the tight junctions in the gut. For the longest time, we've been saying that eczema is a disease of leaky skin. Answers to this, and I totally agree. So the one is, I think even myself, I sort of start to stutter and stumble over my words when leaky gut comes into my brain.

Dr. Bajowala: Yeah. Yeah.

Dr. Venter: Because I try not to use the term.

Dr. Bajowala: Yeah, same. Yeah.

Dr. Venter: And I think because really a lot of non-medical people made a lot of money and got a lot of people sick in the past because they were treating their leaky gut when we really didn't understand what was going on. But the latest data from Cezmi Akdis, he's one of the world's top 1% immunologist from Switzerland as well, shows that when you eat emulsifiers, that when it gets into the gut, it turns into a soap. And this is now animal models, of course, we don't do this to babies, but when you actually then feed the mice that emulsifiers, you literally strip the epithelial barrier, and they do develop, which I hate to call a leaky barrier.

And then the allergens slip through as well. And so the whole thing about getting back to why do we want a good gut microbiome is other than making these chemicals, when you have a healthy gut microbiome, you also produce more mucus, and mucus is also sort of like a barrier. It's sort of smeared across the epithelial barrier, and it helps to keep it more thicker and healthier so that allergens can't slip through. I know that Cezmi refers to a barrier disease rather than a leaky gut.

But on that note, I also want to say, I always feel like I'm always talking about healthy eating and looking after your gut, but it's important for me that parents understand I have allergies in my family, too, and I do not say it directly means that they eat unhealthy, and they have a really bad gut microbiome because they eat unhealthy. I think we're all trying to do our best. We all can probably do better. I can have a better diet. I try my best. But it's interesting to look at the research. It's important to make the best we can out of nutritional intake, but we're not actually saying that families have done something wrong, and therefore this is happening to them.

Dr. Bajowala: Oh, yes.

Dr. Venter: No blame game.

I often get told that I'm doing the blame game, so I've learned to say, "This is what my research is showing, but it doesn't necessarily mean you've done something wrong, or because your child's not naturally outgrowing their peanut allergy doesn't mean it's because he's not eating healthy. Somehow peanut allergies just seem to stick unless we do SLIT or oral immunotherapy."

Dr. Bajowala: Yeah.

Venus: I really appreciate you saying that because I think so many families feel immense guilt when they've done everything right and their children develop food allergies, or their children develop food allergies and they feel like, "Oh, I should have done so much more. I should have done the pre and probiotic supplements. I should have started early introduction at four months. I should have done this and that." But I think what you're trying to say a little bit, Dr. Venter, is that biology is strange. It's very weird, and you can do everything right and control every variable, and sometimes these certain outcomes that we couldn't anticipate still do happen. And even in those scenarios, we do our best, and we give ourselves permission to have a lot of grace and to release that guilt and try to look forward on how we can still live life with food allergies, and allergies in general, as fully as we can, having a wonderful diet and lifestyle, but also really prioritizing that quality of life and having joy at the table and outside of the table as well.

Dr. Bajowala: And that kind of leads us into a quick discussion about the role of the maternal diet as it relates to allergic outcomes in their babies. Now, the party line in the allergy community has been that we just don't have enough data one way or the other to say that it makes a difference. So in that environment, what are you telling moms who come to you for prenatal dietary counseling?

Dr. Venter: Yeah. That is true. All the guidelines, and I was a part of them, they're not really helpful because all we say is, "There's no need to avoid food allergens." But we also don't know enough to say, "You have to eat them." So really what we're saying is, "Do what you're doing."

And so I've really spent the last 20 years, done so many systematic reviews looking at maternal diet and pregnancy from so many different angles. No answer. But then here in Colorado, I was able to look at a cohort, and we, to some extent, replicated the data in a cohort from Sweden. And what we showed was that, again, just increasing healthy diet diversity in pregnancy. So the more healthy foods you eat, the lower the risk of allergies in your baby.

If you really want to know which was the top two foods, the more vegetables you eat, the more yogurt you eat.

And I feel like if I did this study in Turkey, it might have been a different kind of fermented food. But I think in America, we eat yogurt. So really vegetables, fermented food. We also found then the baddies. So we saw more allergies, and I'm talking about food allergy, eczema, allergic rhinitis, and asthma when the mothers had more fried foods, when they had more red meat. But it wasn't no red meat at all. It was just that the more red meat you ate, the higher the risk. But there's definitely a place for red meat. Also, the more sugar you ate. So again, some sugar allowed, but increased sugar, low fiber foods.

And then the other interesting thing which is always tricky to explain was we saw more allergies when the mothers ate fruit juice rather than eating the fruit.

And so then getting back, we actually have three positives. Eating your fruit, eating your vegetables, eating your fermented foods, and then just really cut down a little bit on too much red meat, too much sugary food, too much fried food, and too much low fiber food. And then we saw a reduction in all these allergies. So I'm desperate to do a randomized control trial to see if in a RCT setting we can prove that it really works. But at least in terms of observational data, that seems to be the case. But just really expanding, and just like in the babies, where I showed every food, every additional food bring the risk down, it's the same for pregnancy. And so if I have a mom that really struggles with nausea, I say, "If I can get you on six food rather than two, or I can get you on 20 foods rather than 18," we bring the risk down with every food.

I calculated this maternal diet index, which I call, in this cohort in Spain. And I looked at the baby's gut microbiome at one month, and the babies whose moms had a healthier diet, they had a lot more Bifidobacteria in their gut microbiome at one month, which is exactly what you want, even if we controlled for mode of delivery and breastfeeding or not.

And so not only does mom and baby share some microbiota or gut bacteria, but mom's diet can actually directly affect the baby's gut microbiome in a positive way. And isn't that amazing?

And you know what I say to the moms is, because many of us with babies, we did plan that water birth or that natural delivery at home, and then we did plan that breastfeeding was going to go well. I can remember saying to the midwife working with me, "Look, I've written up a PhD thesis as I was carrying this baby. Breastfeeding is going to be so easy." And then things don't go well. The delivery doesn't go as planned, or the breastfeeding is much more difficult than you would ever think.

And so I say to them, "The one thing you can control to some extent is what you eat." And like I said, even if you have hyperemesis, we can do one food at a time. What you cannot control is how that delivery's going to work out and how breastfeeding is going to work out. And so let's try and control what we can in a positive way.

Venus: Yeah.

Dr. Venter: So that's why I love working with pregnant women because I think we can help a little bit. We can do what we can. We can't control everything.

Dr. Bajowala: Yeah. So I know your time is limited, and we so appreciate you spending so much time talking with us today. So just to close, if we had to zoom out, right, like way up high, and think just purely because it's going to be allergy and asthma awareness month soon, so if we're thinking purely about allergy prevention, beyond the introduction and exposure of the allergenic proteins themselves, if you had to pick one thing, what would you say is the most influential dietary driver of tolerance development alongside allergen exposure? And do you think we're currently doing it?

Dr. Venter: So I can tell you what I think, but I can also tell you what I know because I have got a number of systematic reviews just about to come out. It doesn't matter whether you look at mom's diet, whether you look at early life diet, whether you look at diet later in life. The number one driver for prevention of allergy is keep your diet diverse. And so we have done a great job in the world of allergy. I've done that, too. I've done that to my sisters, telling them that certain foods are evil, and that we should be scared about eating them, and definitely scared about giving them to babies. And so the number one thing I would say is don't be scared of foods. Just relax. Let the babies eat. Let the pregnant ladies eat. And when we open up our diets and we diversify, I think we'll see a lot less allergy. But we have a lot of damage that we have to undo in the world of allergy.

Dr. Bajowala: Yeah, I agree.

Venus: I think in the baby feeding world at large, there's a lot of misconceptions, rules that babies need separate foods, that they shouldn't be eating what the family eats, again, with small modifications. That it needs to come out of a jar or a pouch. That they shouldn't introduce allergens at all until one year of age or no spices and herbs. So I think yes, definitely in the allergy space, but I think in the feeding space at large, all of us here have a lot of work left to do. But that's what keeps us going, I think.

Dr. Bajowala: Yeah.

Venus: And when we see progress and change and attitudes shift, I think that's what's really exciting and keeps folks like us showing up each day to do the work that we do.

Dr. Venter: Absolutely. Please, and I know we have to wrap up, but one of the quotes I use most often in clinical practice when... And I love having the dads in the clinic, too, because there's published data. The number one factor that determines what a boy eat is what he sees his dad eat.

And so really sitting as a family, let them watch us, is just so important, and relax about food.

Dr. Bajowala: Well, Dr. Venter, thank you. Thank you so, so much for joining us today. This was a lot of fun. And we will absolutely need to do it again. And Venus, thank you also for kind of co-hosting this session. We're really excited for audiences all over to be able to learn from your knowledge, Carina, and I hope you'll join us again.

Dr. Venter: Absolutely. I loved the discussion. Thanks for having me.

Dr. Bajowala: Of course.

Venus: Thank you for joining, and thank you, Dr. Bajowala.