Beyond Behavior: Autism, Nutrition, and Gut Health with Greer McGuiness

In this episode of Autism Explained, the host welcomes Greer McGuiness, a registered dietitian with nearly 20 years of experience, published researcher, autism practitioner, and mother of a 12-year-old son with autism and ARFID.

Greer discusses why autism cannot always be understood through genetics or behavior alone. Because every autistic child presents differently, she believes families and professionals may also need to examine nutrition, digestion, nutrient status, the gut microbiome, and other biochemical factors that can affect a child’s comfort, appetite, energy, and daily functioning.

The conversation explores the high prevalence of selective eating, sensory feeding challenges, and gastrointestinal issues among children on the spectrum. Greer explains how limited diets may create nutritional gaps and why behavioral changes can sometimes be connected to physical discomfort that a child may not be able to communicate clearly.

She also addresses popular dietary interventions, including gluten-free and dairy-free approaches. While some families report meaningful improvements, Greer emphasizes that restrictive diets should be introduced carefully and under the guidance of a licensed practitioner so children continue receiving appropriate nutrition.

The episode also examines supplements and testing. Rather than selecting products based on social-media testimonials, Greer encourages parents to work with qualified professionals and consider appropriate conventional or functional laboratory testing before introducing supplements to a developing child.

Greer makes an important distinction about the purpose of biomedical support: the goal is not to “cure” or “reverse” autism. Her own son remains autistic. Her focus is helping children feel as healthy, comfortable, nourished, and supported as possible.

Learn more and access Greer’s free educational resources at biomedicalhealingforkids.com.

The website includes 11 free e-books, including the Microbiome Workbook and the Autism and ADHD Biomedical Workbook, which discusses laboratory tests that may be covered by insurance.

You can also join the private Facebook group Biomedical Healing for Kids and follow @biomedicalhealingforkids on Instagram.

This episode is for educational purposes only and does not replace individualized medical or nutritional care. Consult a qualified healthcare professional before changing a child’s diet, supplements, medication, or treatment plan.

Transcript

SPEAKER_00 0:04

When you get an autism diagnosis, I feel many times it hits you so hard and you kind of don't realize where you need to go. And I felt the same exact way. When my son was diagnosed with autism, I really felt like I was drowning. I felt like I didn't have the support that I needed. If autism is truly genetic, how come we can't figure out which genes are causing autism? Research has shown that about 37% of children who were once diagnosed with autism under the age of three no longer meet the diagnosis when they get to the ages of five to seven years of age. That's a pretty big jump. So what happened. So as I said, I'm an autism mom. I have a 12-year-old boy, um, and I'm also a practitioner. I've been a registered dietitian for nearly 20 years now, and autism was not a part of our plan. And I'm sure a lot of you feel the exact same way. When you become a mom, there are so many emotions and so many things that are going on in your body and your brain and all the expectations you have of your child. And when you get an autism diagnosis, I feel many times it hits you so hard and you kind of don't realize where you need to go. And I felt the same exact way. When my son was diagnosed with autism, I really felt like I was drowning. I felt like I didn't have the support that I needed. And as much as everyone in our journey was so amazing and helped us tremendously and helped my son, I felt like I still was looking for more. I felt as a parent I should be doing more. And that's how I started really diving and understanding that there was an entire different world out there to help children with autism that nobody ever explained to me. And I thought as a practitioner for nearly 10 years at that point, how come nobody told me about this? How come nobody explained to me that there were other labs or nutrition and supplements that could be helping my child to thrive? And that was something that I thought was a great disservice, not only to me as an autism mom, but also as a practitioner that I was never taught this. So what I started doing was understanding that there was more research out there than I expected. And I have to say thank you to all the moms who came before me and created Facebook groups and Instagrams and who were really trying to get the word and the message out over 10 years ago when social media was just starting. These moms were sharing labs and supplements and tips that I didn't even realize were an option for us. So I want to first say thank you to all those moms and practitioners who have been doing this for so long and really trying to help and get the word out and support our families as we evolve. And as someone who's worked in research for nearly 15, 20 years of my life, it's one of those things that I'm very passionate about today. And that brings me to one of the first things of explaining is how the research has been evolving. We look at autism as only a genetic disorder. And unfortunately, we can't really say that anymore because research has evolved. We've learned more about the brain in the last 10 years than ever before. So while we understand that there could be a genetic component, I'm sure many of you, just like me, went to a geneticist, maybe did some gene mapping. And unfortunately, when we got the results, everything was what they would consider normal. There were no genetic abnormalities. And so we're left scratching our heads as parents of how did we still get here? If autism is truly genetic, how come we can't figure out which genes are causing autism? And yes, we do have genetic variants that we have identified. I do work with many families who have had a positive genetic abnormality. And I'm not saying that that's not always the case, but for our case and for many of my patients, it was one of those things that made me question and wonder what else is going on. Diving more into the research, I realized that there is so much more than what we've been told or what we've had somebody explain to us. And so that's one of the things where if we're looking at autism and no two kids are the same, and autism is a spectrum, we shouldn't be treating every child the same. So if we're just doing the same therapies, speech therapy, occupational therapy, maybe ABA, it might not be really helping every single kid the way we hoped because every single kid is completely different on the spectrum. So looking at research and understanding the human body, one of the best things that I did was I actually left healthcare and I started working for functional lab companies. I started diving into looking at research and labs and lab values and understanding how the person's human body was actually functioning. And that's where a lot of the research kind of always questions or leads to more research is needed, or this can't be conclusive enough because what works for one might not work for another. These tests and a person's body is not like working with somebody who has elevated cholesterol or elevated blood pressure, and we can see how interventions can move down labs or decrease blood pressure. Autism is a behavioral assessment and understanding how that perfect person's brain works and how they respond to things. So I think what the most important thing is understanding your child at a biochemical level and just saying, what is going on inside your body? How is your nutrition? What specific diet do you need? What specific supplement do you need? How do we support your body so your body can go off and continue to thrive? When I started working with my son, it was something that I didn't expect to really see happen. And within the first few weeks of working on his gut and helping to support his body, it was like I opened a floodgate. And I know I've seen this with many of my families too, where it's once you start rebalancing the system, it starts to work. If we are looking at autism, what we know with autism is so many, up to 80 to 90 percent, could have selective eating issues, uh, they could have sensory issues when it comes to feeding, they could have GI issues too, that could be impacting so many things, not only behavior, but also their appetite and how they take in food. So if we're looking at that as a possibility of if we're restricting their nutrition or they are restricting nutrition, but not by choice, how does that impact their body, their brain, and their entire system? Now, biomedical is not a one size fits all. And I really always try to advocate to make sure that my families are aware that just because one thing worked for one child doesn't mean it's gonna work for another. And I've been in those shoes too with certain things of why didn't this work for my child? Because my child was similar to that person's child, but they didn't, I didn't see the same results that they did. And it really comes down to the biochemical differences for every single child. So when we're looking at nutrition and the gut and diets, we want to be mindful and meaningful when we're doing nutrition and interventions. There are a lot of restrictive diets out there, and we want to make sure that the child has better nutrition. If your child, if we're trying to do a gluten and dairy-free diet, but your child then withers down to only eating three things, that's not helpful at all. And I understand the concept of, you know, saying, well, we know gluten and dairy-free could really help a child, but if we're getting to the point where that child isn't eating anymore, we need to revisit the situation and say, okay, maybe we don't start there, maybe we start someplace else. And I have a son with RFID, and which is avoidant restrictive feeding intake disorder. And we have done a lot of feeding therapy over the years with different specialists and programs. We are on a gluten-free diet, but it took us time to get there. And I didn't push and I didn't rush it. I made sure that we maintained nutrition throughout the entire process, which is why working with somebody who's a licensed practitioner in this area is really beneficial and helpful for so many families so that we can help guide you and I help you identify the gaps that we need to provide so that your child stays in their optimal nutritional intake. So just because something, you know, works for everybody doesn't mean it's gonna always work for your child. And that's perfectly okay. There's so many diets out there, there's over 20 different types of therapeutic diets for kids with autism. So that's why parents can get so confused and overwhelmed when it comes to picking the right diet for their child. And sometimes the testing honestly truly helps. But I also always feel that my families should feel with their gut instinct. That gut instinct that you have as a parent will never steer you wrong. So if there's something that's pulling at you saying that there's something that you should try, maybe that is something you should try because you know your child better than anyone and you're so in tune with your child. So, and I've I've felt that the entire time I've worked with my son, that I've always had that inkling and feeling when something just felt right to do. And one of the first things for us was I always thought gluten was a real big issue for my son. And once I started doing testing, I was right. Even though all the practitioners told all the specialists told me that he was fine, I knew something was wrong. And the further tests that I did, I realized gluten not only was really hurting his stomach, but it was really hurting his brain. And when we removed gluten, it was an it was night and day for him on so many different levels. So take what I'm saying as there are things that we could do to help your child, especially in nutrition, but it doesn't have to be an overnight success, or it doesn't have to be an overnight get rid of everything and start again. We can make meaningful changes and get to a goal if we work together. Now, that also leads me into nutrition and supplements because natural doesn't always mean that it's safe or that it's not going to potentially harm or cause issues with your child. And with social media today, there is so much information that's out there, and every mom has a testimonial and a story and maybe a product that really moved the needle for them, which I think is amazing. And I always say that products have a time and a place. But one thing we have to understand is a child's body is not like an adult body, especially their microbiome, their brain, and how they are developing. So we can't recommend or use all supplements to do the same thing for an adult that we do for a child. And that's something that we have to understand that supplements really do help bridge the gap and they have a time and a place. And this is where testing comes in. How do we know what supplements to put a child on or what to recommend? Is usually we're doing testing. And we could do testing with your pediatrician or your neurologist, and we can also do functional lab tests that also give us guidance and clues on to what's gonna work best for your child. And what we're wanting to do is bridge the gap and eventually have the diet take over and not have to supplement forever. But sometimes our kiddos need supplements. The analogy I typically use for kids with autism is unfortunately, sometimes their body, picture it like a car in a ditch. If you drive off the road and in a ditch, you as a one person aren't going to be able to push that car out onto the road to let it take off again. Sometimes we need a tow truck, sometimes we need extra support to help get the car back on the road so you can continue your drive and your journey. And that's exactly how the nutrition and the supplement world works for your child as well. There shouldn't be any red, there shouldn't be any guarantees or, you know, say that this product can do this or that. There's a lot of red flags in this community. And that's one thing that I try to really advocate against is making bold claims and statements. If we're looking at autism as behavior, and that is how we assess and diagnose children on the spectrum, is it is a behavioral assessment. They're checking a box of things that they're doing or not doing, but we're not looking at the root cause. And for every child, it can be gravely different. So if we're looking at autism as just behavior, we can see how some kids can improve dramatically. Believe it or not, research has shown that about 37% of children who were once diagnosed with autism under the age of three no longer meet the diagnosis when they get to the ages of five to seven years of age. That's a pretty big jump. So, what happened if we had children meeting the autism criteria early on, and now several years later, they no longer meet those criteria. Or did they meet the behavioral criteria, but it was related to something completely different? Maybe a nutritional deficiency, maybe a gut microbiome imbalance, maybe some toxins in their system that were impacting their brain. There can be a lot of different variations to autism and what causes autism. And that's why it's important to understand where your child is at, not only just physically, but also biochemically. No different than when you go for a physical every single year. Unfortunately, many pediatricians are not running specific labs that are more autism-based because we don't have that knowledge in healthcare yet for providers to understand where to go and what type of tests to run. I've created many free guides, which is something that I am passionate about and I love on top of publishing research. So if you ever go to my website, biomedicalhealingforkids.com, you can get one of the 11 free ebooks that I have. And one of the free ebooks I have is my microbiome workbook. I love making free guides. That's one of my favorite things to do in the entire world is create free content, but also creating research for my families. So if you go to my website, you can grab one of my 11 free ebooks. And one that I particularly am going to suggest is my autism and ADHD biomedical workbook. And in that workbook, I have lists of labs that your pediatrician can run that is covered by insurance that can give us clues and identify what's going on inside your child that go beyond just the regular cookie cutter, blood CMP, BMP, basic blood work your pediatrician would run every year as a physical. I also have in that ebook other functional lab tests that you can run too, and what which ones are my favorite and what we're looking for in terms of that. But I also kind of help my parents start off the process. What test should you look for first? What should you look for, what should we be identifying first and what should we be focusing on? This world is huge. The biomedical world is continuing to grow every single year, which is absolutely amazing. And I absolutely love that we're growing and research is evolving and we're learning so much more. But what we have to understand is that in the medical world, working with mainstream doctors, they are still very much behind when it comes to the functional side or the other types of research that are in working with kids with autism and ADHD, which is why I created these free guides for my parents so that they can really start understanding all the other research. I've had many parents gift and uh print out and give these things to their pediatricians, and it really helps make a difference once they are aware and understand that there's so much more that we can do for our children. And that's the biggest clue is that there are so many tests out there, which one is best for your child? So, what a practitioner is going to work with you on, especially in the biomedical world, is taking a history, understanding your child, running some functional lab tests and maybe some conventional lab tests, and then trying to understand what is going on inside your child so that we can create a perfect plan that works for both you and your child. We want children to be safe. We want children to thrive. And this is one of the biggest things that I can say has been a big blessing for not only my family, but thousands of families that I've worked with and thousands of practitioners that are helping kids every single day. Autism isn't just genetic anymore. We can't use that and say that that's the only cause of autism. It's so much more complex than just that. And there's so many things that you could do to help your child if you take the time to just learn one little thing at a time. That's why I'm here. That's why a lot of practitioners are here. And we're trying to figure out how we can best help your child and continue to grow the biomedical world. As someone who has published research in this area, I can tell you I get overwhelmed with the amount of information that I find every single day. I'm constantly reading and learning and trying to publish research so that not only I can help other practitioners, but other families and understand more about what's going on inside an autism body and a brain. Everyone is going to have one way of trying to work with your child. And one of the most important things is again, this is not a one-size-fits-all approach. We need to peel back the onion layer and figure out what is we're gonna work best for you and your child. Don't let anyone tell you that this isn't going to help or that you may not see improvements. And that is always a possibility. We may not see the meaningful improvements that you're hoping for. But I can honestly say my goal with working with families is never to cure or reverse autism. That's not what I stand for, and that's not what I do. My son is still diagnosed with autism, and that's perfectly fine. But my goal is always to make kids feel as happy and as healthy as they possibly can and however that looks for them. We want our kids to thrive. We want the best life that we can for our child. And I feel as a parent, we're always trying to uncover every stone and every rock. And in the biomedical world, there's a lot of rocks to overturn, but we're gonna be here to support you, and I'm gonna be here to support you. If you're looking for more information and you need a supportive community, please come and join my private Facebook group, which is Biomedical Healing for Kids, or join me on Instagram. I try to post a lot of free content for my families so that they can start making decisions and figuring out how to best help their child in this amazing world that is very complex, but one of the most fulfilling things in the entire world, I can honestly say this world has meant a lot to me. And I hope it can mean a lot to you and your family as well.