Episode 4: Why Food Sensitivity Tests Confuse Everyone
In this Team Gut Girls episode, Drs. Whitney Baxter, ND, Dr. Christina Carew, ND and Dr. Dominique Vanier, ND discuss bloating and the popularity of IgG food sensitivity tests, contrasting them with IgE allergy testing and explaining that IgG reflects a delayed immune exposure signal rather than an immediate, potentially dangerous allergic reaction. They distinguish food intolerance as malabsorption/fermentation (e.g., lactose, fructose, fructans; low-FODMAP concepts) rather than an immune response.
They review a 2026 IBS literature review (13 studies, ~900 patients) where IgG-based elimination diets often improved symptoms, but note major study limitations and risks of broad restriction, fear, and malnutrition. They highlight concerns about test accuracy/reproducibility and cite European, Canadian, and American guidelines recommending against IgG testing for diagnosing food allergy/intolerance, suggesting antibodies may reflect oral tolerance. They advocate systematic evaluation (rule out celiac and true allergies, time-limited, planned eliminations with reintroduction, and avoiding unreliable testing (including hair-based tests).
00:00 Welcome and Topic Setup
00:20 Why IgG Tests Trend
02:59 IgG vs IgE Explained
06:03 Food Intolerance Basics
07:22 Leaky Gut and Testing Pitch
08:43 What Research Shows
10:32 Leaky Gut Nuance
13:00 Test Accuracy Concerns
16:42 Guidelines Say No
18:04 Other Causes of Bloating
20:48 Strategic Elimination Plans
24:06 Systematic Workup Approach
24:39 Practical Takeaways
26:11 Hair Testing and Pitfalls
29:03 How to Talk to Your Doctor
29:55 Final Thanks and Wrap
Team Gut Girls Transcript Episode Four: Why Food Sensitivity Tests Confuse Everyone
Dr. Whitney Baxter, ND: [00:00:00] Hello everyone. Today’s Gut Girls episode. We wanna talk about food sensitivities and bloating, specifically IgG food sensitivity reactions. So what do these mean? How are we testing for them and what are the guidelines recommending for their use for our patients? So when you think about bloating, it makes sense to think about the food that you’ve recently eaten that day.
If by 4:00 PM you feel like you wanna race home and rip off those jeans, or you’re starting to see a pattern with the food that you ate, and 30 minutes or even two hours after you are bloating, you’ll wanna avoid that food because it’s not the best feeling. It’s also pretty common, and I don’t know about you, Christina and Dominique, to patients per se.
My, my friend did this food sensitivity test and removed the foods and now feel so much better. Or they’re seeing people talk about this on social media. And it sounds great. There’s [00:01:00] like a root cause problem. There’s great tests that will just outline the exact plan that you need to do and that will cure your bloating, your brain fog, the loose stools, and these other weird symptoms that I’m having.
Do you guys find this a lot in your practice as well?
Dr. Christina Carew, ND: Yeah, actually I have a friend who, her birthday cake. There was a birthday cake in her office and it was like, there was a note on, it was like, gluten-free, egg free, la la, la. All these frees. And I was like, oh. I’m like,, oh, are you, are you anaphylactic?
And she was like, oh no. I did a food 15 years ago. And those came up and I’ve never eaten them since. Oh. And we had a whole discussion in sheets, eggs, now.
Dr. Whitney Baxter, ND: Yay. Yay.
Dr. Dominique Vanier, ND: It is so common to see people who’ve done this test like a long time ago, and then they’re still following it. Right. And I don’t think that’s really the intention of the test and certainly not the intention of the practitioner.
I think [00:02:00] doing it, like there should always be a conversation about reintroduction. But then there’s also like the whole thing. Fears behind that part too. Like the test itself is like this one thing that you can do to then give you all this insight. Right? Which it kind of, I think it kind of simplifies really somebody’s digestion.
Dr. Whitney Baxter, ND: Yeah. And that’s exactly what we wanna talk about is how this is. Likely an oversimplification. Our bodies are fascinating and complex, and there’s often a lot of things going on, so we wanna talk about this immune response. That’s what food. Sensitivity or this IgG is, it’s an immune response. So we wanna talk to you about this.
Christina brought up anaphylaxis, so why you would want to avoid foods forever. So we’ll kind of differentiate those two pieces. And before we dive in, I’ll introduce who’s here. So I’m Dr. Whitney Baxter, and I’m joined with Dr. Christina Carew. And Dr. Dominique Vanier. And welcome to the Gut Girls Podcast.
Okay, so we’re gonna [00:03:00] dive in and talk about the myth are food sensitivities causing my bloating, so specifically IgG food sensitivities. Let’s explain the difference between IgG versus IgE, and we’ll give you some context into what these mean. Christina, do you wanna explain the difference between the two?
Dr. Christina Carew, ND: Sure. So when we think about our immune system, there’s all these different responses that can happen. So there’s an IgG, an IGM, an IgE, A IGA response. So there are all these different activations the way I often explain it to people is like around messaging. So the first messenger, the person that kind of looks out the door and sees what’s going on is called the IGM, and that isn’t a very specific reaction.
It just tells us like, Hey, something’s going on, and it sends some information back to the body. An IgG reaction is a secondary reaction. And so that information was taken and then a more [00:04:00] specific immune system response goes out. And so in the case of these food sensitivity tests, the body’s like, Hey, I saw some peanut I’m gonna send a response back to the body.
Or, Hey, I saw some strawberry, or maybe there is some. Mustard over there. And so that kind of sends a response back to the body. It’s seeing something that is in a place where it shouldn’t necessarily be. And so these immune system reactions aren’t happening inside your intestinal tract. They’re kind of happening outside your intestinal tract.
And so it’s immune response to the item that was seen. It doesn’t necessarily mean you have an anaphylactic reaction. It just means that it was seen in a place that we don’t expect it to be. And so the difference between that and going to an allergist and getting an IgE type test, those scratch tests that you may have had an experience with or heard about that test doesn’t say.
You know, is this [00:05:00] out of place that says if I have an exposure to this thing, will I get a swelling rash? Could the potential for my airway to be blocked is that sort of the reaction I can have? And so these are the people in your lives who have EpiPens who are sensitive to fish or to peanuts or to dogs that may have to use that to prevent their immune system from going into overdrive.
Dr. Whitney Baxter, ND: Yeah. Awesome. So it’s just two different types of immune response, immediate emergent IgE versus the delayed, Hey, I found this thing, IgG response. And these immune responses are handy for bacteria and viruses that are dangerous and our body needs to protect ourselves against. And sometimes these foods are an inappropriate response but IgG still have to avoid it.
It’s gonna send you to the emerge if you don’t. Whereas IgG. It’s, it’s showing up in different [00:06:00] ways. So this is what we’ll dive into. And then another thing we wanna talk about too is just the definition of a food intolerance. Because this is where the guidelines and the research is pretty accurate and it does make sense to.
Do kind of elimination diet or a discussion around this if you are getting a lot of bloating or other digestion type symptoms. So a food intolerance is not an immune response. It’s more of a malabsorption. So when you eat, your digestive enzymes are incomplete, breaking down and absorbing this food.
So it’s getting to your gut in as a larger. Molecule component and your microbiome is having a bit of a party. So it’s fermenting, it’s eating this food and causing gas in the process. So this can really cause in terms of like excess gas fermentation is gas production. In some cases there’s an osmotic pull of water into the colon, so people are getting symptoms.
So [00:07:00] these are typically to the carbohydrate components of food. So like fructose, lactose, obviously lactose intolerance. You’ve heard this term before. Other things like sucrose, fructans, and then you’ve heard of the FODMAPS. So this is different than an IgG. Food sensitivity response. So we just wanted to bring that up.
Okay, so back to the food sensitivities. In the bloating world, they’re often described as, okay, so a leaky gut is happening where the the gut lining should be kind of a closed off compartment, so it can selectively bring things into the bloodstream. However, for some reason it’s, there’s more gaps and things are leaking through triggering an immune response, and this IgG mediated delayed onset of symptoms like bloating, brain fog, digestion changes, et cetera.
The solution. Do a food [00:08:00] sensitivity test. We’ll draw your blood. We’ll test for these IgG complexes. We’ll eliminate all those foods so you don’t get those symptoms. We’ll heal that leaky gut and then we will slowly reintroduce the foods. So this is what I was taught in school a lot, and this is what I hear about a lot and a lot of people come into my practice asking for these types of tasks.
I used to do them. And then. I’ll talk, maybe talk about later, but why I’ve since stopped. But we wanna talk about are these tests accurate? Are they picking up what the patient is experiencing? Is it truly that food leading to the bloating? Do we have to eat like this forever, which we talked about earlier.
So if, if we look at the data, there was recently a 2026 review of IgG elimination diets for IBS. I couldn’t find anything specifically for bloating, but it did talk about some bloating in these people. So there are 13 studies involving 900 patients with IBS. [00:09:00] So they were following the Rome four criteria.
So overall they did IgG based elimination diets and they did find that in general they improved symptoms including abdominal pain, pain, bloating, so expansion, distension, bowel habits, stool consistency and subjective ratings of quality of life. So some studies noted other improvements in anxiety, migraines, fatigue.
However, there were substantial differences in the study designs, how they were, what the control groups looked like. Sometimes the two groups were, okay, this group is going to remove the food, s food sensitivities that came up on their test, and the other group is going to remove the things that didn’t come up on their test versus other types of controls.
Additionally, and this is talked about in every single study that I look at for [00:10:00] IgG, there were concerns raised regarding the risk associated with excluding multiple foods, which may lead to altered E eating habits, increasing malnutrition risk, which is huge if we can’t always guarantee that these tests are gonna work or be accurate.
Is it safe in best practice to be recommending them with the risk of causing food? Fear? So yes, they may improve IBS symptoms, but there’s a lot of limitations in the studies and how they’re designed. So let’s talk about this. Let’s break this down a little bit. I wanna go back to this concept of leaky gut.
And Christina, do you think this is oversimplified? What’s a more realistic way to describe this, or how do you talk to your patients about this?
Dr. Christina Carew, ND: Yeah. So the reason that the food sensitivity test might be showing positive is because there’s these escape valves that Whitney sort of alluded to, or these, like, I always think about them as pinholes.
So the way I describe a [00:11:00] gut to my patient’s is to imagine like a brick house. And so a brick house has this cement in between the bricks. That stop the outside from coming onto the inside and your body in between their cells. And the intestinal tract also has zonulin, which is the glue in between the cells.
And so when something irritates the cell and causes it to be inflamed, then the glue in between gets dislodged, and that’s what creates these little tiny pinholes. It could be a food, so it could be something like celiac disease where the body has inflammation, but it could also be an infection. It could be something in their environment.
So we see that commonly with people that have a. Mold toxicity or environmental exposures. There was a study that was released yesterday that talked about people with diabetes type one, that this is a very common symptom that they have. We certainly can see it with food sensitivities, but it’s not.
Only from food [00:12:00] sensitivities. And so when I think about a food sensitivity test, we’re really just measuring one thing that has potentially escaped or created this inflammation in the system. And we’re sort of disregarding everything else. It’s the same reason why we started this podcast. We came up with more than 20 reasons why people have bloating.
And each week we’re gonna talk about, you know, what are those different things to consider. It isn’t just like one test equals one solution for every person.
Dr. Whitney Baxter, ND: Exactly, and I think that’s where it gets exciting is the body is so complex and that’s where we need to find individualized approaches in medicine as opposed to doing these very specific tests to find the root cause. We need to look at the person and kind of evaluate it from that perspective. Yeah.
Okay. So that, thank you. That makes a lot of [00:13:00] sense. And then are these food sensitivity tests accurate? So I’ve read about studies where they draw the blood from the same person and they send it off to two different labs and they’ve tested it and it comes up with different results. That makes me feel uncomfortable if I’m recommending a test that can cost up to $400 for somebody.
So Dominique, can you talk a little bit about the, the accuracy of these tests?
Dr. Dominique Vanier, ND: Yeah. If you take a step back, like when you do a test, there’s something called specificity and sensitivity, right? Which is like, basically that just refers to like, is this a true positive? So if, if a test result comes back positive, is it actually a true positive?
Could it be a false positive, right? Or is it a true negative when a test result comes back negative? So you want, like when you’re doing a medical test. It needs to have that degree, like that high degree of accuracy, we’ll call it like high sensitivity, high specificity, you know, not, not to get into like [00:14:00] further kind of nitty gritty details there, ’cause we can talk a lot about that.
But when I did a deep dive in the literature for IgG testing. We actually didn’t have any, there was no data that I could find on the specific diagnostic type of like method that was used for IgG testing. So that’s called the ELISA method or the enzyme linked Immunosorbent assay.
So we actually don’t even have like information. On it in that way. So when it comes to the reproducibility of a test, so for example, doing, your IgG test one day and then doing again the week later I don’t have an answer for that. And so when you know you’re recommending a test for somebody and then also expecting them to take out large.
Large food groups from their diet based on the test that where they may actually have different results if they had done it the week later. I don’t, I wouldn’t actually call that good medicine and I’m gonna be very, like, straightforward there. So I personally did use to recommend this test and for, you know, various reasons when I looked into it a little bit further including how [00:15:00] robust the research was.
Behind this type of testing method? I felt less and less confident using it with patients for a number of reasons.
Dr. Whitney Baxter, ND: Yeah. Yeah. We care about our patients and we really love when we can find clear evidence for things.
Dr. Christina Carew, ND: Did you ever have a test where something weird showed up
Dr. Whitney Baxter, ND: like a random food? Yeah,
Dr. Dominique Vanier, ND: many
Dr. Christina Carew, ND: times.
I had a patient came in from a different practitioner and the only two things on the test were jalapenos and lettuce as the two primary foods that they’re reactive to. And so I was like, oh, do you eat a lot of tacos? And he is I’ve never eaten a jalapeno ever before in my life. I was like, say.
Dr. Dominique Vanier, ND: And I think like when it comes to a test, it’s also important to evaluate is there a different method that can be used that’s like less invasive, less costly, that would get us to the same outcome, right? Like the same outcome, which is like [00:16:00] reduction in bloating, identification of foods. And we’ll talk more about that.
But there are,
Dr. Whitney Baxter, ND: yeah. Yeah, there for sure are. Yeah. And I’ve read articles where they’re like, okay, these IgG complexes were found in healthy people. Where they’re not noting symptoms. So do they just exist in the bloodstream as our immune system? Hey, I found this. Are they then leading onto immune response or inflammatory symptoms or triggering all these things?
And at one point, are we thinking more, is this a disorder of gut brain interaction, which we’ll get into in other episodes, but is this pertinent person’s sensitivity to think heightened? So it just brings up a lot of questions. So if we think about what our guidelines are recommending, so what is the gastroenterology guidelines recommending?
What are the allergy associations recommending? So from European, Canadian, and American, they all maintain strong positions against the clinical use of these food, specific IGG [00:17:00] testing and diagnosing food allergies or intolerances. So it’s pretty clear in all of the major guidelines that we follow. They emphasize that these antibodies most likely represent a physiological consequence of oral tolerance.
So basically saying that the immune system just says, Hey, they’re there. It’s not a causative factor of disease or bloating. So we like to follow the guidelines. It makes us feel more confident, especially because as naturopathic doctors, we’re working often with the patient’s medical doctor and they’ve maybe seen an allergist and they’ve received some allergy testing.
So we like to all be on the same page. And then the studies aren’t great, which I talked about before. There’s limitations. There’s different study methods, non-standardized IgG, cutoff thresholds, lack of placebo controls, small sample sizes, which doesn’t improve confidence. So if we go back to this idea of like [00:18:00] pain and bloating and like the physiology behind it and what’s happening.
So you, Christina, and John, I’m curious, do you see this in your practice from other things? Like could other things be triggering these symptoms like mast cells, histamine, other immune responses?
Dr. Christina Carew, ND: Yeah, you can still have a response from food that creates bloating, but it may not be from 35 different foods that may show up on the test. It might be that you haven’t. Been checked for celiac disease, so that’s a very common reason why someone could get bloated or you are having a food reaction.
There’s an episode coming up that talks about mast cell activation, and mast cell activation is about 30 minutes after eating. You’re gonna get a series of symptoms, some of which could be in the gut, depending on the person, which may include bloating, which starts to make you think, actually talked to someone earlier today about [00:19:00] that.
That there’s a food that they’re reacting to because it’s causing all these gastro symptoms when the actual issue is that eating is causing the reaction. And so it’s just a body that feels like it’s on fire or inflamed. And so it, it’s not as simple as remove strawberries and things get better.
Dr. Dominique Vanier, ND: A hundred percent. Yeah. Like this kind of like didactic approach. It’s really not do this input and then therefore this output will happen. Definitely. At least I haven’t seen it that straightforward. Sometimes it’s that straightforward. If somebody has a very basic, like lactose intolerance, right? But truly like y Celiac, there are many conditions that.
That we can see bloating in. Right? And like when we talk about that visceral hypersensitivity piece, like part of that is where somebody who has this hypersensitivity, they’re gonna feel their digestive processes so much more acutely than somebody else who let’s say, doesn’t have a disorder of gut brain interaction.
But there’s also like that pain, pain disinhibition that happens with the visceral [00:20:00] hypersensitivity. So like. We’re getting these signals from our, our gut, like that’s sensing, like bloating and, and speaking about like, you know, um, discomfort and, and then pain. And then the brain through the central nervous system is not dampening those signals like the way it should.
So we can see like this bloat, this non-specific bloating really sprinkle through so many different digestive conditions.
Dr. Christina Carew, ND: Mm-hmm. And, and other conditions we see at post COVID. There’s lots of people that are getting more. Leaky gut or more hypersensitivity because their immune system’s just been like overwhelmed.
We see it in mold, we see it in Lyme disease. So it’s not that you necessarily have those things because you have bloating, it’s just that bloating can be caused by so many different things.
Dr. Whitney Baxter, ND: And that brings up a good point are you ever, is there ever a time where you’re recommending reduction? Of foods for those types of things, if they have a super leaky gut.
Are you [00:21:00] reducing the, like inflammatory foods, I guess, like wheat, gluten, dairy? Do you ever talk about that with patients?
Dr. Christina Carew, ND: I don’t know what you guys do, but I often will do like a 30 day gut reset with my patients, where I will take out some of those foods. But it’s a very limited time and it’s a very strategic reintroduction.
So it’s not forever. It’s to kind of. Make the process happen faster because we’re not also, I always say it’s trying to get rid of the mice by having mouse traps and then leaving your food on the counter. Like you can’t that’s a good analogy. Get rid of both things at the same time as easily.
Right. And so if we can reduce leaving the food on the counter and just direct everything towards the mass traps, we can just get further ahead fast. So instead of a patient being on a treatment for three months, maybe they can be on a treatment for 30 days. So there are some strategic [00:22:00] reasons why we might reduce foods or take out certain foods.
Dr. Dominique Vanier, ND: Yeah,
Dr. Whitney Baxter, ND: and that’s such a good point, like that clear timeline because that’s that’s so freeing. To have okay, we can do this for four weeks. We’re gonna reduce the fire in your system. And then this is the plan because there is immune reactions happening, especially in individuals who have these postviral things or mold or NCAs mast cell activation syndromes.
So it’s helpful to reduce that input, but for a short period of time as you’re working on the immune and gut healing and all those good things.
Dr. Dominique Vanier, ND: Well, even some of the research on the low FODMAP diet, which is like the most common diet, right? And that does involve some elimination with a very structured reintroduction schedule.
Is when it can, it can like basically calm the system, we’ll call it, calm the system, which we can see changes even in in like the visceral hypersensitivity aspect too. So from [00:23:00] like a scientific standpoint, like there, there is rationale behind trying to f. Approach it from a food angle in addition to other, other angles.
’cause like we said, there’s multiple things happening. Um, right. Yeah. It can be, it can be very helpful. I’ve seen it Very helpful for patients. Yeah. With again, like a plan. Yeah. A plan to arrange with a
Dr. Whitney Baxter, ND: plan.
Dr. Dominique Vanier, ND: Yeah.
Dr. Whitney Baxter, ND: Yeah.
Dr. Christina Carew, ND: And then I would say if you are going to. Test for celiac disease, even though it’s gonna be a whole nother episode.
Mm-hmm. Please make sure that you are not stopping your wheat before taking the test, because more often than not, we see people that have a negative test and think they’re clear, but we actually don’t know because you, similar to these food sensitivity tests, the foods that can show up are only the foods that you’re currently consuming.
And part of that is, is a piece of the puzzle is like you can’t measure [00:24:00] something that we don’t have any exposure to.
Dr. Whitney Baxter, ND: Yeah, that’s a good point. And that brings up the point of systematically approaching someone’s bloating. So while, so when we meet our patients, we’re hearing their symptoms and there are some things we need to rule out.
A celiac disease, we’ll talk about that test, how to do it properly. What other symptoms are going on? We need to do some blood work. And then in between that blood work coming back on our next appointment, we wanna make you feel better, so we’re gonna do a low FOD map or what has the best research for outcomes.
Usually it’s a low FOD map, so we’ll talk about that with our patients too. Okay. Thanks guys. That was awesome. Let’s talk about some practical takeaways from this episode. So first of all, we do wanna look at bloating and how there are so many causes and it’s not just food and the guidelines. I could actually don’t recommend cutting out foods as the first step.
So we wanna systematically work through your bloating unless it’s pretty [00:25:00] obvious and there is a clear connection, we can start to talk about that. Definitely roll out celiac disease and true allergies. And then also discovering your unique food to tolerance or intolerances. It takes time. So there’s often a systematic elimination period.
We’re gonna work together frequently through this, so you’re not on your own. There’s gonna be a clear plan With recipes, we just are truly not wanting to cause fear around food or causing making you think that you have to do this long term. It can take time to figure out your unique intolerance or what’s triggering your system.
And food elimination may cause more harm good than good if it’s not introduced this way. There could be nutrient gaps, nutrient deficiencies. We’re restricting your lifestyle. We don’t wanna make you afraid to just go with your friends or have to eat outside of the home. , The, the guidelines are great. The studies aren’t great for these food [00:26:00] sensitivity, IgG tests and all the guidelines recommend against them. So that’s just something to keep in mind. And anything else to add to this piece ladies?
Dr. Christina Carew, ND: I think before we forget, we should also include the hair testing for foods in this.
I don’t know if you guys have seen them. They have ads often on some of the social media platforms.
Dr. Whitney Baxter, ND: I’ve seen it more for like mineral testing. I don’t know about food sensitivity. So do go on.
Dr. Christina Carew, ND: I had a patient come in with it. It, the test was $25. And she snipped off some of her hair and sent it away and they came back in.
The number one thing that she was sensitive to was duck blood.
Dr. Whitney Baxter, ND: Oh my gosh.
Dr. Christina Carew, ND: And so we had a good laugh about it, but but just like sometimes the. The responses when they come back help to understand like why that test ISN ineffective. But we also can see [00:27:00] the exact opposite happened. So I had a patient who was already on a very restrictive diet and her son was on a restrictive diet and they did the test and all of the items they were eating were the items that came up because of sort of the idea of leaky gut and all the things that were sort of.
Exposed to them. And it wasn’t that they were sensitive to all those 60 foods. It was like really scary because this child was like six, seven years old and his mom was controlling his diet and now we’re at a point where like there already were missing a lot of foods out of their diet. And so now there’s many, many more.
So just to keep in mind, as much as the internet tells us they’re amazing things, they may not be anything for you.
Dr. Dominique Vanier, ND: My little one agrees with that baby here agrees with that. I think, I think to your, to your question, Whitney it’s the investigation part with a skilled practitioner is super important because yes, like on one hand we wanna be.
[00:28:00] Ruling out are there more kind structural things going on, right? Was the colonoscopy performed, like celiac testing done accurately, et cetera, et cetera. And then figuring out, okay, well if, if we’ve ruled out kind of more serious issues, is like, where does that leave us? And can we even hone down a little bit further as to what’s happening?
And for a lot of patients there’s like multiple things happening that’s causing the bloating, but then matching, you know, what like the best available TR treatment is to that rather than just I’m gonna take out these foods and just hope for the best.
Dr. Whitney Baxter, ND: Yeah. Yeah. And the longer some something takes, the more sustainable it usually is.
If you’re doing a quick test with quick results and it’s giving you a tiny plan. That’s all you’ve got, right? And as opposed to having a really comprehensive assessment, testing discussion, and then like you’ve got this toolbox and you understand your body so much more, isn’t that more valuable than, you know, a one size fits all approach?[00:29:00]
Dr. Dominique Vanier, ND: Good for thought.
Dr. Whitney Baxter, ND: So we always like to leave our listeners with some ways of talking to your practitioners. So. Instead of, I would like to do a food sensitivity test. You could bring up, Hey, I am feeling this sensation. I’m feeling bloated. Describe that feeling to your practitioner. Let them know when it happens.
If it happens right after eating, how long after eating is there pain? Is there any association with stools or nausea? So just get really clear on what you’re feeling. And then you can even go on to ask could this be a food? Could this be a food intolerance? Could I have an allergy? Or could I have a visceral hypersensitivity?
You could get really scientific with it. Mm-hmm. But just be more curious and with your own gut and your digestion too to.
Team Gut Girls Transcript Episode Four: Why Food Sensitivity Tests Confuse Everyone
Dr. Whitney Baxter, ND: [00:00:00] Hello everyone. Today’s Gut Girls episode. We wanna talk about food sensitivities and bloating, specifically IgG food sensitivity reactions. So what do these mean? How are we testing for them and what are the guidelines recommending for their use for our patients? So when you think about bloating, it makes sense to think about the food that you’ve recently eaten that day.
If by 4:00 PM you feel like you wanna race home and rip off those jeans, or you’re starting to see a pattern with the food that you ate, and 30 minutes or even two hours after you are bloating, you’ll wanna avoid that food because it’s not the best feeling. It’s also pretty common, and I don’t know about you, Christina and Dominique, to patients per se.
My, my friend did this food sensitivity test and removed the foods and now feel so much better. Or they’re seeing people talk about this on social media. And it sounds great. There’s [00:01:00] like a root cause problem. There’s great tests that will just outline the exact plan that you need to do and that will cure your bloating, your brain fog, the loose stools, and these other weird symptoms that I’m having.
Do you guys find this a lot in your practice as well?
Dr. Christina Carew, ND: Yeah, actually I have a friend who, her birthday cake. There was a birthday cake in her office and it was like, there was a note on, it was like, gluten-free, egg free, la la, la. All these frees. And I was like, oh. I’m like,, oh, are you, are you anaphylactic?
And she was like, oh no. I did a food 15 years ago. And those came up and I’ve never eaten them since. Oh. And we had a whole discussion in sheets, eggs, now.
Dr. Whitney Baxter, ND: Yay. Yay.
Dr. Dominique Vanier, ND: It is so common to see people who’ve done this test like a long time ago, and then they’re still following it. Right. And I don’t think that’s really the intention of the test and certainly not the intention of the practitioner.
I think [00:02:00] doing it, like there should always be a conversation about reintroduction. But then there’s also like the whole thing. Fears behind that part too. Like the test itself is like this one thing that you can do to then give you all this insight. Right? Which it kind of, I think it kind of simplifies really somebody’s digestion.
Dr. Whitney Baxter, ND: Yeah. And that’s exactly what we wanna talk about is how this is. Likely an oversimplification. Our bodies are fascinating and complex, and there’s often a lot of things going on, so we wanna talk about this immune response. That’s what food. Sensitivity or this IgG is, it’s an immune response. So we wanna talk to you about this.
Christina brought up anaphylaxis, so why you would want to avoid foods forever. So we’ll kind of differentiate those two pieces. And before we dive in, I’ll introduce who’s here. So I’m Dr. Whitney Baxter, and I’m joined with Dr. Christina Carew. And Dr. Dominique Vanier. And welcome to the Gut Girls Podcast.
Okay, so we’re gonna [00:03:00] dive in and talk about the myth are food sensitivities causing my bloating, so specifically IgG food sensitivities. Let’s explain the difference between IgG versus IgE, and we’ll give you some context into what these mean. Christina, do you wanna explain the difference between the two?
Dr. Christina Carew, ND: Sure. So when we think about our immune system, there’s all these different responses that can happen. So there’s an IgG, an IGM, an IgE, A IGA response. So there are all these different activations the way I often explain it to people is like around messaging. So the first messenger, the person that kind of looks out the door and sees what’s going on is called the IGM, and that isn’t a very specific reaction.
It just tells us like, Hey, something’s going on, and it sends some information back to the body. An IgG reaction is a secondary reaction. And so that information was taken and then a more [00:04:00] specific immune system response goes out. And so in the case of these food sensitivity tests, the body’s like, Hey, I saw some peanut I’m gonna send a response back to the body.
Or, Hey, I saw some strawberry, or maybe there is some. Mustard over there. And so that kind of sends a response back to the body. It’s seeing something that is in a place where it shouldn’t necessarily be. And so these immune system reactions aren’t happening inside your intestinal tract. They’re kind of happening outside your intestinal tract.
And so it’s immune response to the item that was seen. It doesn’t necessarily mean you have an anaphylactic reaction. It just means that it was seen in a place that we don’t expect it to be. And so the difference between that and going to an allergist and getting an IgE type test, those scratch tests that you may have had an experience with or heard about that test doesn’t say.
You know, is this [00:05:00] out of place that says if I have an exposure to this thing, will I get a swelling rash? Could the potential for my airway to be blocked is that sort of the reaction I can have? And so these are the people in your lives who have EpiPens who are sensitive to fish or to peanuts or to dogs that may have to use that to prevent their immune system from going into overdrive.
Dr. Whitney Baxter, ND: Yeah. Awesome. So it’s just two different types of immune response, immediate emergent IgE versus the delayed, Hey, I found this thing, IgG response. And these immune responses are handy for bacteria and viruses that are dangerous and our body needs to protect ourselves against. And sometimes these foods are an inappropriate response but IgG still have to avoid it.
It’s gonna send you to the emerge if you don’t. Whereas IgG. It’s, it’s showing up in different [00:06:00] ways. So this is what we’ll dive into. And then another thing we wanna talk about too is just the definition of a food intolerance. Because this is where the guidelines and the research is pretty accurate and it does make sense to.
Do kind of elimination diet or a discussion around this if you are getting a lot of bloating or other digestion type symptoms. So a food intolerance is not an immune response. It’s more of a malabsorption. So when you eat, your digestive enzymes are incomplete, breaking down and absorbing this food.
So it’s getting to your gut in as a larger. Molecule component and your microbiome is having a bit of a party. So it’s fermenting, it’s eating this food and causing gas in the process. So this can really cause in terms of like excess gas fermentation is gas production. In some cases there’s an osmotic pull of water into the colon, so people are getting symptoms.
So [00:07:00] these are typically to the carbohydrate components of food. So like fructose, lactose, obviously lactose intolerance. You’ve heard this term before. Other things like sucrose, fructans, and then you’ve heard of the FODMAPS. So this is different than an IgG. Food sensitivity response. So we just wanted to bring that up.
Okay, so back to the food sensitivities. In the bloating world, they’re often described as, okay, so a leaky gut is happening where the the gut lining should be kind of a closed off compartment, so it can selectively bring things into the bloodstream. However, for some reason it’s, there’s more gaps and things are leaking through triggering an immune response, and this IgG mediated delayed onset of symptoms like bloating, brain fog, digestion changes, et cetera.
The solution. Do a food [00:08:00] sensitivity test. We’ll draw your blood. We’ll test for these IgG complexes. We’ll eliminate all those foods so you don’t get those symptoms. We’ll heal that leaky gut and then we will slowly reintroduce the foods. So this is what I was taught in school a lot, and this is what I hear about a lot and a lot of people come into my practice asking for these types of tasks.
I used to do them. And then. I’ll talk, maybe talk about later, but why I’ve since stopped. But we wanna talk about are these tests accurate? Are they picking up what the patient is experiencing? Is it truly that food leading to the bloating? Do we have to eat like this forever, which we talked about earlier.
So if, if we look at the data, there was recently a 2026 review of IgG elimination diets for IBS. I couldn’t find anything specifically for bloating, but it did talk about some bloating in these people. So there are 13 studies involving 900 patients with IBS. [00:09:00] So they were following the Rome four criteria.
So overall they did IgG based elimination diets and they did find that in general they improved symptoms including abdominal pain, pain, bloating, so expansion, distension, bowel habits, stool consistency and subjective ratings of quality of life. So some studies noted other improvements in anxiety, migraines, fatigue.
However, there were substantial differences in the study designs, how they were, what the control groups looked like. Sometimes the two groups were, okay, this group is going to remove the food, s food sensitivities that came up on their test, and the other group is going to remove the things that didn’t come up on their test versus other types of controls.
Additionally, and this is talked about in every single study that I look at for [00:10:00] IgG, there were concerns raised regarding the risk associated with excluding multiple foods, which may lead to altered E eating habits, increasing malnutrition risk, which is huge if we can’t always guarantee that these tests are gonna work or be accurate.
Is it safe in best practice to be recommending them with the risk of causing food? Fear? So yes, they may improve IBS symptoms, but there’s a lot of limitations in the studies and how they’re designed. So let’s talk about this. Let’s break this down a little bit. I wanna go back to this concept of leaky gut.
And Christina, do you think this is oversimplified? What’s a more realistic way to describe this, or how do you talk to your patients about this?
Dr. Christina Carew, ND: Yeah. So the reason that the food sensitivity test might be showing positive is because there’s these escape valves that Whitney sort of alluded to, or these, like, I always think about them as pinholes.
So the way I describe a [00:11:00] gut to my patient’s is to imagine like a brick house. And so a brick house has this cement in between the bricks. That stop the outside from coming onto the inside and your body in between their cells. And the intestinal tract also has zonulin, which is the glue in between the cells.
And so when something irritates the cell and causes it to be inflamed, then the glue in between gets dislodged, and that’s what creates these little tiny pinholes. It could be a food, so it could be something like celiac disease where the body has inflammation, but it could also be an infection. It could be something in their environment.
So we see that commonly with people that have a. Mold toxicity or environmental exposures. There was a study that was released yesterday that talked about people with diabetes type one, that this is a very common symptom that they have. We certainly can see it with food sensitivities, but it’s not.
Only from food [00:12:00] sensitivities. And so when I think about a food sensitivity test, we’re really just measuring one thing that has potentially escaped or created this inflammation in the system. And we’re sort of disregarding everything else. It’s the same reason why we started this podcast. We came up with more than 20 reasons why people have bloating.
And each week we’re gonna talk about, you know, what are those different things to consider. It isn’t just like one test equals one solution for every person.
Dr. Whitney Baxter, ND: Exactly, and I think that’s where it gets exciting is the body is so complex and that’s where we need to find individualized approaches in medicine as opposed to doing these very specific tests to find the root cause. We need to look at the person and kind of evaluate it from that perspective. Yeah.
Okay. So that, thank you. That makes a lot of [00:13:00] sense. And then are these food sensitivity tests accurate? So I’ve read about studies where they draw the blood from the same person and they send it off to two different labs and they’ve tested it and it comes up with different results. That makes me feel uncomfortable if I’m recommending a test that can cost up to $400 for somebody.
So Dominique, can you talk a little bit about the, the accuracy of these tests?
Dr. Dominique Vanier, ND: Yeah. If you take a step back, like when you do a test, there’s something called specificity and sensitivity, right? Which is like, basically that just refers to like, is this a true positive? So if, if a test result comes back positive, is it actually a true positive?
Could it be a false positive, right? Or is it a true negative when a test result comes back negative? So you want, like when you’re doing a medical test. It needs to have that degree, like that high degree of accuracy, we’ll call it like high sensitivity, high specificity, you know, not, not to get into like [00:14:00] further kind of nitty gritty details there, ’cause we can talk a lot about that.
But when I did a deep dive in the literature for IgG testing. We actually didn’t have any, there was no data that I could find on the specific diagnostic type of like method that was used for IgG testing. So that’s called the ELISA method or the enzyme linked Immunosorbent assay.
So we actually don’t even have like information. On it in that way. So when it comes to the reproducibility of a test, so for example, doing, your IgG test one day and then doing again the week later I don’t have an answer for that. And so when you know you’re recommending a test for somebody and then also expecting them to take out large.
Large food groups from their diet based on the test that where they may actually have different results if they had done it the week later. I don’t, I wouldn’t actually call that good medicine and I’m gonna be very, like, straightforward there. So I personally did use to recommend this test and for, you know, various reasons when I looked into it a little bit further including how [00:15:00] robust the research was.
Behind this type of testing method? I felt less and less confident using it with patients for a number of reasons.
Dr. Whitney Baxter, ND: Yeah. Yeah. We care about our patients and we really love when we can find clear evidence for things.
Dr. Christina Carew, ND: Did you ever have a test where something weird showed up
Dr. Whitney Baxter, ND: like a random food? Yeah,
Dr. Dominique Vanier, ND: many
Dr. Christina Carew, ND: times.
I had a patient came in from a different practitioner and the only two things on the test were jalapenos and lettuce as the two primary foods that they’re reactive to. And so I was like, oh, do you eat a lot of tacos? And he is I’ve never eaten a jalapeno ever before in my life. I was like, say.
Dr. Dominique Vanier, ND: And I think like when it comes to a test, it’s also important to evaluate is there a different method that can be used that’s like less invasive, less costly, that would get us to the same outcome, right? Like the same outcome, which is like [00:16:00] reduction in bloating, identification of foods. And we’ll talk more about that.
But there are,
Dr. Whitney Baxter, ND: yeah. Yeah, there for sure are. Yeah. And I’ve read articles where they’re like, okay, these IgG complexes were found in healthy people. Where they’re not noting symptoms. So do they just exist in the bloodstream as our immune system? Hey, I found this. Are they then leading onto immune response or inflammatory symptoms or triggering all these things?
And at one point, are we thinking more, is this a disorder of gut brain interaction, which we’ll get into in other episodes, but is this pertinent person’s sensitivity to think heightened? So it just brings up a lot of questions. So if we think about what our guidelines are recommending, so what is the gastroenterology guidelines recommending?
What are the allergy associations recommending? So from European, Canadian, and American, they all maintain strong positions against the clinical use of these food, specific IGG [00:17:00] testing and diagnosing food allergies or intolerances. So it’s pretty clear in all of the major guidelines that we follow. They emphasize that these antibodies most likely represent a physiological consequence of oral tolerance.
So basically saying that the immune system just says, Hey, they’re there. It’s not a causative factor of disease or bloating. So we like to follow the guidelines. It makes us feel more confident, especially because as naturopathic doctors, we’re working often with the patient’s medical doctor and they’ve maybe seen an allergist and they’ve received some allergy testing.
So we like to all be on the same page. And then the studies aren’t great, which I talked about before. There’s limitations. There’s different study methods, non-standardized IgG, cutoff thresholds, lack of placebo controls, small sample sizes, which doesn’t improve confidence. So if we go back to this idea of like [00:18:00] pain and bloating and like the physiology behind it and what’s happening.
So you, Christina, and John, I’m curious, do you see this in your practice from other things? Like could other things be triggering these symptoms like mast cells, histamine, other immune responses?
Dr. Christina Carew, ND: Yeah, you can still have a response from food that creates bloating, but it may not be from 35 different foods that may show up on the test. It might be that you haven’t. Been checked for celiac disease, so that’s a very common reason why someone could get bloated or you are having a food reaction.
There’s an episode coming up that talks about mast cell activation, and mast cell activation is about 30 minutes after eating. You’re gonna get a series of symptoms, some of which could be in the gut, depending on the person, which may include bloating, which starts to make you think, actually talked to someone earlier today about [00:19:00] that.
That there’s a food that they’re reacting to because it’s causing all these gastro symptoms when the actual issue is that eating is causing the reaction. And so it’s just a body that feels like it’s on fire or inflamed. And so it, it’s not as simple as remove strawberries and things get better.
Dr. Dominique Vanier, ND: A hundred percent. Yeah. Like this kind of like didactic approach. It’s really not do this input and then therefore this output will happen. Definitely. At least I haven’t seen it that straightforward. Sometimes it’s that straightforward. If somebody has a very basic, like lactose intolerance, right? But truly like y Celiac, there are many conditions that.
That we can see bloating in. Right? And like when we talk about that visceral hypersensitivity piece, like part of that is where somebody who has this hypersensitivity, they’re gonna feel their digestive processes so much more acutely than somebody else who let’s say, doesn’t have a disorder of gut brain interaction.
But there’s also like that pain, pain disinhibition that happens with the visceral [00:20:00] hypersensitivity. So like. We’re getting these signals from our, our gut, like that’s sensing, like bloating and, and speaking about like, you know, um, discomfort and, and then pain. And then the brain through the central nervous system is not dampening those signals like the way it should.
So we can see like this bloat, this non-specific bloating really sprinkle through so many different digestive conditions.
Dr. Christina Carew, ND: Mm-hmm. And, and other conditions we see at post COVID. There’s lots of people that are getting more. Leaky gut or more hypersensitivity because their immune system’s just been like overwhelmed.
We see it in mold, we see it in Lyme disease. So it’s not that you necessarily have those things because you have bloating, it’s just that bloating can be caused by so many different things.
Dr. Whitney Baxter, ND: And that brings up a good point are you ever, is there ever a time where you’re recommending reduction? Of foods for those types of things, if they have a super leaky gut.
Are you [00:21:00] reducing the, like inflammatory foods, I guess, like wheat, gluten, dairy? Do you ever talk about that with patients?
Dr. Christina Carew, ND: I don’t know what you guys do, but I often will do like a 30 day gut reset with my patients, where I will take out some of those foods. But it’s a very limited time and it’s a very strategic reintroduction.
So it’s not forever. It’s to kind of. Make the process happen faster because we’re not also, I always say it’s trying to get rid of the mice by having mouse traps and then leaving your food on the counter. Like you can’t that’s a good analogy. Get rid of both things at the same time as easily.
Right. And so if we can reduce leaving the food on the counter and just direct everything towards the mass traps, we can just get further ahead fast. So instead of a patient being on a treatment for three months, maybe they can be on a treatment for 30 days. So there are some strategic [00:22:00] reasons why we might reduce foods or take out certain foods.
Dr. Dominique Vanier, ND: Yeah,
Dr. Whitney Baxter, ND: and that’s such a good point, like that clear timeline because that’s that’s so freeing. To have okay, we can do this for four weeks. We’re gonna reduce the fire in your system. And then this is the plan because there is immune reactions happening, especially in individuals who have these postviral things or mold or NCAs mast cell activation syndromes.
So it’s helpful to reduce that input, but for a short period of time as you’re working on the immune and gut healing and all those good things.
Dr. Dominique Vanier, ND: Well, even some of the research on the low FODMAP diet, which is like the most common diet, right? And that does involve some elimination with a very structured reintroduction schedule.
Is when it can, it can like basically calm the system, we’ll call it, calm the system, which we can see changes even in in like the visceral hypersensitivity aspect too. So from [00:23:00] like a scientific standpoint, like there, there is rationale behind trying to f. Approach it from a food angle in addition to other, other angles.
’cause like we said, there’s multiple things happening. Um, right. Yeah. It can be, it can be very helpful. I’ve seen it Very helpful for patients. Yeah. With again, like a plan. Yeah. A plan to arrange with a
Dr. Whitney Baxter, ND: plan.
Dr. Dominique Vanier, ND: Yeah.
Dr. Whitney Baxter, ND: Yeah.
Dr. Christina Carew, ND: And then I would say if you are going to. Test for celiac disease, even though it’s gonna be a whole nother episode.
Mm-hmm. Please make sure that you are not stopping your wheat before taking the test, because more often than not, we see people that have a negative test and think they’re clear, but we actually don’t know because you, similar to these food sensitivity tests, the foods that can show up are only the foods that you’re currently consuming.
And part of that is, is a piece of the puzzle is like you can’t measure [00:24:00] something that we don’t have any exposure to.
Dr. Whitney Baxter, ND: Yeah, that’s a good point. And that brings up the point of systematically approaching someone’s bloating. So while, so when we meet our patients, we’re hearing their symptoms and there are some things we need to rule out.
A celiac disease, we’ll talk about that test, how to do it properly. What other symptoms are going on? We need to do some blood work. And then in between that blood work coming back on our next appointment, we wanna make you feel better, so we’re gonna do a low FOD map or what has the best research for outcomes.
Usually it’s a low FOD map, so we’ll talk about that with our patients too. Okay. Thanks guys. That was awesome. Let’s talk about some practical takeaways from this episode. So first of all, we do wanna look at bloating and how there are so many causes and it’s not just food and the guidelines. I could actually don’t recommend cutting out foods as the first step.
So we wanna systematically work through your bloating unless it’s pretty [00:25:00] obvious and there is a clear connection, we can start to talk about that. Definitely roll out celiac disease and true allergies. And then also discovering your unique food to tolerance or intolerances. It takes time. So there’s often a systematic elimination period.
We’re gonna work together frequently through this, so you’re not on your own. There’s gonna be a clear plan With recipes, we just are truly not wanting to cause fear around food or causing making you think that you have to do this long term. It can take time to figure out your unique intolerance or what’s triggering your system.
And food elimination may cause more harm good than good if it’s not introduced this way. There could be nutrient gaps, nutrient deficiencies. We’re restricting your lifestyle. We don’t wanna make you afraid to just go with your friends or have to eat outside of the home. , The, the guidelines are great. The studies aren’t great for these food [00:26:00] sensitivity, IgG tests and all the guidelines recommend against them. So that’s just something to keep in mind. And anything else to add to this piece ladies?
Dr. Christina Carew, ND: I think before we forget, we should also include the hair testing for foods in this.
I don’t know if you guys have seen them. They have ads often on some of the social media platforms.
Dr. Whitney Baxter, ND: I’ve seen it more for like mineral testing. I don’t know about food sensitivity. So do go on.
Dr. Christina Carew, ND: I had a patient come in with it. It, the test was $25. And she snipped off some of her hair and sent it away and they came back in.
The number one thing that she was sensitive to was duck blood.
Dr. Whitney Baxter, ND: Oh my gosh.
Dr. Christina Carew, ND: And so we had a good laugh about it, but but just like sometimes the. The responses when they come back help to understand like why that test ISN ineffective. But we also can see [00:27:00] the exact opposite happened. So I had a patient who was already on a very restrictive diet and her son was on a restrictive diet and they did the test and all of the items they were eating were the items that came up because of sort of the idea of leaky gut and all the things that were sort of.
Exposed to them. And it wasn’t that they were sensitive to all those 60 foods. It was like really scary because this child was like six, seven years old and his mom was controlling his diet and now we’re at a point where like there already were missing a lot of foods out of their diet. And so now there’s many, many more.
So just to keep in mind, as much as the internet tells us they’re amazing things, they may not be anything for you.
Dr. Dominique Vanier, ND: My little one agrees with that baby here agrees with that. I think, I think to your, to your question, Whitney it’s the investigation part with a skilled practitioner is super important because yes, like on one hand we wanna be.
[00:28:00] Ruling out are there more kind structural things going on, right? Was the colonoscopy performed, like celiac testing done accurately, et cetera, et cetera. And then figuring out, okay, well if, if we’ve ruled out kind of more serious issues, is like, where does that leave us? And can we even hone down a little bit further as to what’s happening?
And for a lot of patients there’s like multiple things happening that’s causing the bloating, but then matching, you know, what like the best available TR treatment is to that rather than just I’m gonna take out these foods and just hope for the best.
Dr. Whitney Baxter, ND: Yeah. Yeah. And the longer some something takes, the more sustainable it usually is.
If you’re doing a quick test with quick results and it’s giving you a tiny plan. That’s all you’ve got, right? And as opposed to having a really comprehensive assessment, testing discussion, and then like you’ve got this toolbox and you understand your body so much more, isn’t that more valuable than, you know, a one size fits all approach?[00:29:00]
Dr. Dominique Vanier, ND: Good for thought.
Dr. Whitney Baxter, ND: So we always like to leave our listeners with some ways of talking to your practitioners. So. Instead of, I would like to do a food sensitivity test. You could bring up, Hey, I am feeling this sensation. I’m feeling bloated. Describe that feeling to your practitioner. Let them know when it happens.
If it happens right after eating, how long after eating is there pain? Is there any association with stools or nausea? So just get really clear on what you’re feeling. And then you can even go on to ask could this be a food? Could this be a food intolerance? Could I have an allergy? Or could I have a visceral hypersensitivity?
You could get really scientific with it. Mm-hmm. But just be more curious and with your own gut and your digestion too to.
All right, everybody, thank you so much for listening. [00:30:00] That’s all we got for today.All right, everybody, thank you so much for listening. [00:30:00] That’s all we got for today.
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