Food Sensitivities
—MRT Food Sensitivity Testing · Included in Every program
You've been eating carefully for years.
You're gut still isn't cooperating.
The foods triggering your symptoms aren’t always the obvious ones. Food sensitivities can take 48-72 hours to show up — which is exactly why elimination diets based on guesswork never work long term. The MRT test finds what’s actually causing the reaction so you can stop avoiding everything and start knowing exactly what foods work best for you.
176 Foods & Chemicals | 94.5% Sensitivity | 91.7% Specificity | Included in Every Program
176
foods and chemicals tested in a single blood draw
94.5%
sensitivity — the most accurate food sensitivity test available
48-72h
how long a food sensitivity reaction can take to show up — why you never connect the dots
—What is MRT Testing?
Most food sensitivity tests miss 90% of the reaction.
This one doesn't.
Most food sensitivity tests only measure IgG antibodies — one single pathway of your immune response. However, food sensitivities can trigger reactions through multiple immune pathways, and IgG is often not even the primary one driving your symptoms.
The MRT — Mediator Release Test — measures something different and far more comprehensive. It measures the actual release of chemical mediators from your immune cells regardless of which pathway triggered the reaction. That includes prostaglandins, leukotrienes, cytokines, thromboxanes, platelet activating factor, and histamine — the full downstream inflammatory cascade, not just one marker.
When your immune system reacts to a food, those cells shrink and release mediators that drive inflammation, disrupt your gut lining, and create the symptoms you’ve been trying to trace for years. MRT captures that response across 176 foods and chemicals — giving us a precise, comprehensive map of what’s actually triggering your immune system.
What MRT actually measures
The Mediator Release Test measures the release of chemical mediators — like cytokines and histamines — from your white blood cells when exposed to specific foods and chemicals. When your immune system reacts, those cells release inflammatory mediators. MRT quantifies that reaction across 176 different items, giving us a precise map of your immune triggers.
Why it's different from other sensitivity tests
Most food sensitivity tests measure IgG antibodies — which can show up even for foods you tolerate well. MRT measures the actual downstream inflammatory response, making it far more clinically relevant and accurate. With 94.5% sensitivity and 91.7% specificity, it’s the most reliable test of its kind available — and it’s not something your doctor orders.
What happens after the test
MRT results alone aren’t enough — you need someone who knows how to implement them. That’s where the LEAP protocol comes in. As a Certified LEAP Therapist, I guide you through a structured elimination diet built entirely around your specific results — not a generic protocol, but a plan designed around what your immune system is actually reacting to.
How long does it take
The test is a simple blood draw — a kit ships to your door and gets sent to the lab. Results come back in 10-14 days. From there we build your personalized LEAP diet, walk through your results together in plain language, and start implementing changes immediately. Most clients notice meaningful improvement within the first two to three weeks.
—What food sensitivities can drive
Your digestive symptoms could have a food connection
you haven't identified yet.
Food sensitivities not only cause gut symptoms — but the inflammatory cascade they trigger can affect almost every system in your body.
IBS
Bloating & Gas
Constipation
Diarrhea
Leaky Gut
Reflux & GERD
IBD
Stomach Pain
Colitis
Eczema & Skin Issues
Migraines
Brain Fog & Fatigue
Autoimmune Conditions
Anxiety & Depression
Joint Pain
—How it works
From blood draw to
real relief — step by step.
At-home test kit ships to your door
The MRT test kit arrives at your home. You take it to a local lab for a simple blood draw and ship the sample directly to the MRT lab.
Results in 10-14 days
Your results come back showing your immune reactivity to 176 foods and chemicals — ranked from most to least reactive. We review every result together in plain language connected directly to your symptoms.
Your personalized LEAP diet begins
I build your elimination diet around your specific results — starting with your lowest-reactive foods and expanding systematically. You’ll start recording in your Food & Symptom journal. You get weekly check ins to keep you on track.
Shopping lists, recipes, and real-life support
You get grocery product recommendations, recipe ideas, a menu planner, and ongoing coaching to make the changes actually liveable — not just theoretically correct.
Reintroduction and long-term freedom
Reactive foods aren’t removed forever. As your immune system resets over 3-6 months, we systematically reintroduce foods so you can eat as broadly as possible — with confidence.
—What Your MRT Results Look Like
Color coded data.
Easy to understand.
Your MRT results come back as a color-coded report showing your immune reactivity to each of the 176 foods and chemicals tested. The color coding makes it immediately clear where to start.
When we review your results, I’ll walk through exactly how we’re going to use this information to build your LEAP diet.
Red- high reactivity, eliminate for 6 months
Yellow- moderate reactivity, eliminate for 3 months
Green- low reactivity, where your healing diet starts
—The research behind MRT
This isn't a wellness trend.
It's backed by clinical evidence.
Here’s what the research actually shows — in plain language, with links to the full studies if you want to go deeper.
American College of Gastroenterology · 2004
MRT-guided diet dramatically reduced IBS symptoms in clinical trial
In a study of patients with diarrhea-predominant IBS, GI symptom scores dropped from 19.1 to 6.3 after just one month on an MRT-guided LEAP diet. That’s a two-thirds reduction in symptoms — in 30 days.
✔️ Symptom scores decrease from 19.1 → 6.3 in 30 days
Nature Reviews Gastroenterology · 2021
Local immune activation drives food-triggered gut symptoms in IBS
Research published in Nature confirmed that specific foods trigger a localized immune response in the gut wall that directly causes the pain and symptoms of IBS — validating the immune-mediated mechanism that MRT testing is designed to identify.
✔️ Confirms immune-mediated food reactions in IBS
Journal of Nutrition · 2024
MRT-LEAP significantly improved IBS symptoms and quality of life
A 2024 study found that patients following an MRT-guided LEAP elimination diet showed significant improvements in IBS symptom severity, quality of life, and psychological wellbeing compared to a standard low-FODMAP approach.
✔️ Superior outcomes vs. Low FODMAP diet
American Journal of Gastroenterology · 2022
Food-triggered symptoms in IBS involve immune and barrier mechanisms
This review confirmed that food-triggered gut symptoms in IBS involve specific immune activation, gut barrier dysfunction, and visceral hypersensitivity — exactly the mechanisms that MRT testing identifies and the LEAP protocol addresses.
✔️ Validates the immune-gut-food connectionon
Annals of Allergy, Asthma & Immunology · 2021
Non-IgE food reactions drive real gut damage — and standard allergy testing misses all of it
This review confirmed that food reactions don’t require IgE antibodies to cause significant gut damage. Non-IgE reactions trigger multiple immune pathways — TH1, TH17, innate immunity, and gut barrier breakdown — causing chronic inflammation, altered motility, and diarrhea. The research also found that gut dysbiosis and its metabolites directly stimulate serotonin production, disrupting gut motility and brain function — the same gut-brain disruption at the core of IBS symptoms.
✔️ Non-IgE pathways drive IBS — none detectable by standard allergy testing
Digestive Diseases & Sciences · 2025
Food triggers IBS symptoms through immune activation in the gut — a new clinical framework
This landmark review proposed a new paradigm for understanding why IBS and functional gut symptoms are so often food-related. Research found strong evidence that low-grade duodenal inflammation driven by eosinophils and mast cells is present in a major subset of IBS patients — caused by food interacting with gut bacteria to switch on immune activation in the small intestine. Critically, these immune responses are not IgE-mediated, meaning standard food allergy testing completely misses them. The authors proposed that removing the specific food antigens triggering this immune response — exactly what MRT identifies — may provide a symptom cure in affected patients.
✔️ Food-triggered immune activation in the gut drives IBS — invisible to standard allergy testing
Nature Reviews Gastroenterology & Hepatology · 2019
Your gut microbiome determines which foods trigger a reaction — and why it changes over time
This landmark review from Nature explained a critical piece of the food sensitivity puzzle — it’s not just the food itself that drives the reaction, it’s the interaction between the food and your gut microbiome. Gut infections and microbiome imbalances break down oral tolerance to food antigens, causing the immune system to begin reacting to foods it previously had no issue with. This explains why food sensitivities develop later in life, why they worsen during periods of gut disruption, and why the same foods don’t cause reactions in everyone. The microbiome also directly metabolizes dietary proteins — altering how the immune system sees and responds to them.
✔️ Microbiome imbalances cause the immune system to react to foods it previously tolerated
Gut — BMJ Publishing · 2016
IBS isn’t just functional — mast cell activation in the gut lining is driving your symptoms
This review published in Gut — one of the world’s leading gastroenterology journals — challenged the long-held view that IBS is a purely functional disorder with no physical cause. Research confirmed that low-grade mucosal inflammation and immune activation are present in the gut lining of IBS patients, dominated by mast cells, eosinophils, and intraepithelial lymphocytes. Mast cell activation was shown to directly generate epithelial dysfunction, disrupt the gut lining, promote visceral hypersensitivity, and alter motility patterns — the exact mechanisms behind bloating, pain, urgency, and unpredictable bowel habits. IBS affects up to 16–26% of the worldwide population and this research points to a measurable organic substrate — not just stress or anxiety — as the driver.
✔️ Mast cell activation in the gut lining directly causes IBS pain, hypersensitivity, and altered motility
Nature Reviews Gastroenterology & Hepatology · 2019
Food sensitivity-guided elimination diet cut GERD symptoms in half — in patients who didn’t respond to PPIs
This randomized controlled trial enrolled 38 GERD patients who were partially or completely non-responsive to proton pump inhibitor medications — the standard prescription for reflux. Patients were divided into two groups: one following a food intolerance test-guided elimination diet, the other a control diet. After just one month, the group on the food sensitivity-guided diet saw their GERD symptom scores drop by 50%. The control group saw only a 26.9% reduction. When the control group then switched to the food sensitivity-guided diet, their scores dropped by a further 44.9%. Every single patient in the study reacted to at least one food.
✔️ Food sensitivity-guided diet cut GERD symptoms by 50% in patients PPI medications failed
Int Immunopharmacol · 2021
A damaged gut lining is what turns food sensitivities into full-blown intestinal inflammation
This study identified a critical two-step mechanism behind how food sensitivities cause gut damage. When the intestinal mucosal barrier is compromised — by NSAIDs like ibuprofen or aspirin, stress, infections, or dysbiosis — food antigens that would normally stay in the gut can cross into the intestinal tissue and directly interact with the immune system. Once inside, those food antigens triggered a significant Th1-dominant immune response, increased intestinal permeability, and drove sustained gut inflammation. The study also confirmed that a compromised gut barrier is a prerequisite for food antigen-driven intestinal inflammation — meaning food sensitivities and leaky gut don’t just coexist, they actively make each other worse. Identifying and removing the food antigens driving immune activation is a direct strategy for breaking that cycle.
✔️ A damaged gut lining is the prerequisite that allows food antigens to drive intestinal inflammation
Gastroenterology · 2019
More than half of IBS patients have food reactions — all of them tested negative for food allergies on standard tests
In this prospective study of 155 IBS patients, researchers used real-time confocal laser endomicroscopy to observe what actually happens inside the gut when food is introduced. Every patient had already tested negative for food allergies on standard IgE serology and skin prick tests. Yet 70% showed an immediate reaction to at least one food — with instant disruption of the intestinal barrier, increased intraepithelial lymphocytes, eosinophil degranulation, and gut lining permeability changes visible within minutes of food exposure. 61% of those who reacted did so to wheat. Excluding the identified trigger foods led to long-term symptom relief. This study demonstrated in real time what standard allergy testing is completely blind to — a non-IgE food reaction happening directly in the gut wall.
✔️ 70% of IBS patients reacted to food in real time — every single one had tested negative on standard allergy panels
Scandinavian Journal of Gastroenterology · 2006
Chronic constipation that didn’t respond to any laxative resolved completely on a food elimination diet
This study documented the first clinical cases of refractory chronic constipation in adults caused by food hypersensitivity — patients who had failed high-dose laxative treatment for years. When placed on an elimination diet, bowel habits normalized in every single patient. When food triggers were reintroduced through double-blind placebo-controlled challenges, constipation returned every time. Duodenal and rectal biopsies showed lymphocyte and eosinophil infiltration in the gut lining — confirming an immune-mediated reaction, not a motility problem. Patients with food hypersensitivity-driven constipation had significantly longer duration of illness, lower body weight, higher rates of self-reported food intolerance, and nocturnal abdominal pain — a profile that will sound very familiar to many women who’ve been told their constipation is just something to manage with laxatives indefinitely.
✔️ Constipation unresponsive to all laxatives resolved completely when food triggers were identified and removed
Mark Pasula, PhD · Townsend Letter · 2014
MRT clinical reliability and real-world outcomes
The developer of MRT published data showing the test’s clinical validity and the real-world outcomes achieved when Certified LEAP Therapists use MRT results to guide elimination diets — including significant symptom reduction in complex cases.
✔️ 94.5% sensitivity · 91.7% specificity
David Publisher · Clinical Study
MRT-LEAP protocol effective in PCOS patients with gut symptoms
A clinical study found that women with PCOS who followed an MRT-guided LEAP diet experienced significant improvements in both digestive symptoms and metabolic markers — reinforcing the gut-hormone connection and the value of individualized food sensitivity testing.
✔️ Improvements in both gut and metabolic markers
—Want to go deeper before your call?
Download the clinical explanation of how food sensitivities trigger inflammation written by the researchers behind the MRT test.
—Real Results
What women say after
working with Sarah.
I was having intense abdominal pain on a daily basis, and while I knew it was food related, I simply couldn’t identify ‘which’ food(s). With a massive diet overhaul and rigorous testing, we found that many of my ‘go to’ foods were the culprit and my digestive systems was a hot mess! Sarah guided me through the process of healing my gut, and my mind, and I’m now pain free and DRUG FREE – no antispasmodics and no pain killers!
I spent years with terrible stomach pain that doctors never had an answer for. But through her process I have gained my life back. She helped me discover what foods and chemicals were causing my gut issues and taught me how to navigate eating without them.
I had NO idea that some of the healthy foods that I was eating were directly related to my gut issues. This testing is so individual, with details that only apply to you and your gut. I eliminated these “trigger” foods..and no bloat, no issues, all good.
Ready to Find Your Triggers?
Stop guessing what's setting your gut off.
Let's find out.
MRT food sensitivity testing is included in every Digestive Reset Program. Book a free call and we’ll talk through whether this is the right next step for you.
—Not ready to book? Start here free.
Two free resources to help you understand what’s going on before you spend a dime 👉
—From the Gut Health Blog
Want to go deeper on food sensitivities?
In-depth articles on how food sensitivities affect gut health.
Are Food Sensitivities Sabotaging Your Health?
You might be eating the healthiest diet you know how to eat — and your food sensitivities are still quietly driving inflammation, disrupting your gut, and making you feel terrible. Here’s how to tell if that’s what’s happening to you.
Perimenopause Diarrhea: A Functional Nutrition Guide to Calm Your Gut Naturally
If your digestion changed when your cycles did and diarrhea became part of your daily reality — this is for you. A functional nutrition breakdown of why it happens and what you can actually do about it.
About Sarah
Sarah Neumann Haske, MS, RDN, is a Registered Dietitian Nutritionist with over 20 years of experience, specializing in digestive health for the past decade. She holds a Master’s of Science in Human Nutrition, is a Certified Microbiome Analyst, and is the Owner of Neumann Nutrition & Wellness, LLC. Her practice helps clients heal their gut, using a root-cause approach to their digestive health. As a result of her program her clients are able to come off medications, feel more energized, and be more confident in their bodies again. If you're interested in being a partner in your own health journey and finding the direction and accountability you need to reach your digestive health goals, then schedule your digestive assessment call with Sarah here.