Publications & Research

Publications & Research

Use of the LEAP Mediator Release Test to Identify Non-IgE Mediated Immunologic Food Reactions that Trigger Diarrhea Predominant IBS Symptoms Results in Marked Improvement of Symptoms Through Use of an Elimination Diet

American College of Gastroenterology, Annual Scientific & Educational Meeting, Orlando, Florida, November 2004, Fred H. Williams, MD, Department of Gastroenterology, St. John’s Mercy Medical Center, St. Louis, Missouri, United States


Diarrhea predominant IBS (D-IBS) is a common condition that is often refractory to standard therapy. Though some treatments may improve certain symptoms, there is no treatment that has been shown to result in the improvement of global D-IBS symptoms. The Lifestyle Eating and Performance Mediator Release Test (LEAP MRT) is an in vitro test that detects non-IgE mediated food reactions that can trigger D-IBS symptoms. We report on our early experience with this dietary modification program.


Ten patients who met Rome II criteria for D-IBS are reported in this study. These patients presented to our community-based gastroenterology practice and were evaluated by a gastroenterologist. Evaluation for other causes of their symptoms was based on the patient’s previous evaluation and the discretion of the gastroenterologist. Typically, if not already employed in the past, a trial of standard therapy such as fibre and anti-spasmodic agents was attempted. If the patient didn’t improve, they were then offered LEAP MRT testing. Using an in vitro assay, the patient’s blood was tested for non-IgE mediated reactivity to 150 foods and food additives. A specific elimination diet that omitted the reactive foods was then designed for the patient. A Symptom Survey was employed to follow the patients for improvement in D-IBS as well as systemic symptoms. The survey graded multiple GI and systemic symptoms on a scale of 0-4 with increasing severity represented by a higher number. The maximum number of points possible for the entire survey was 236 and for the GI portion was 36.


Prior to beginning the LEAP MRT-based elimination diet, the average score for the entire survey was 56.9 and for the GI portion was 19.1. After at least one month on the diet, the average scores had decreased to 26.3 and 6.3 respectively. Patients generally reported a marked improvement in their D-IBS symptoms, decreased systemic symptoms, and an overall increase in their feeling of well-being.


The LEAP MRT identifies non-IgE mediated immunologic food reactions that trigger D-IBS symptoms. Elimination of these foods from the diet results in a marked improvement in D-IBS and other systemic symptoms.

Peer-Reviewed Manuscripts
    1. Zarini GG, McLean MA, Delgado SI. Is Personalized Dietary Therapy Effective for Individuals With Irritable Bowel Syndrome? Am J Lifestyle Med. 2022 Jul 6;17(2):317-325. doi: 10.1177/15598276221112309. PMID: 36896039; PMCID: PMC9989498.
    2. Zarini GG, Masters J, McLean MA, Strobel CT. Clinical and Anthropometric Improvements with a Tailored Dietary Approach in Pediatric Crohn’s Disease. Altern Ther Health Med. 2021 Mar 13:AT6717.
    3. Pasula MJ, Nowak J. Particle size measurement in suspensions: Part 1–A laboratory. method for exploring food allergies and sensitivities in illness. Am Clin Lab. 1999;18(4):16-18.
    4. Pasula MJ. Particle size measurement in suspensions. Part 2: An in vitro procedure for screening adverse reactions to foods and chemicals. Am Clin Lab. 1999;18(9):14-15.
    5. Kaczmarski M, Pasula M, Sawicka E, Werpachowska I. MRT test – New generation of tests for food hypersensitivity in children and adults. PrzegladPediatryczny.1997(SUPLEMENT 1):61-65.
Published Abstracts
    1. Zarini, G, McLean M, Delgado S, Lee L, Ondreyka J, Lee C, Linke S. Clinical Response to Personalized Dietary Therapy for Irritable Bowel Syndrome (IBS). Journal of the Academy of Nutrition and Dietetics, Volume 123, Issue 9, A24.
    2. McLean M, Zarini G, Delgado S, Lee L, Lee C, Ondreyka J, Patenaude J. P08-012-23. Evaluation of the Lifestyle Eating and Performance (LEAP) Program To Manage Symptoms and Quality of Life for Irritable Bowel Syndrome (IBS). Current Developments in Nutrition, Volume 7, 101147. Published in issue: July 2023.
    3. Zarini G, McLean M. Effectiveness of the Lifestyle Eating and Performance (LEAP) program for Irritable Bowel Syndrome (IBS). Am J Lifestyle Med. 2023; 17 (Suppl 1).
    4. Zarini G, McLean M. S572. A Pilot Study for Precision Nutrition in Irritable Bowel Syndrome: In-Vitro Stimulation of Pro-and Anti-inflammatory Cytokine Release. The American Journal of Gastroenterology: October 2022 – Volume 117 – Issue 10S – p e406. doi: 10.14309/01.ajg.0000858928.65055.a2.
    5. McLean M, Zarini GG, Linke S. Personalized Dietary Intervention for Women with Depression and Anxiety. Journal of the Academy of Nutrition and Dietetics. Vol. 122 Issue 9 Supplement A23. Published in issue: September 2022.
    6. Zarini G, McLean M. Study Protocol: Effectiveness of the Lifestyle Eating and Performance (LEAP) Program for the Treatment of Irritable Bowel Syndrome (IBS), Current Developments in Nutrition, Volume 6, Issue Supplement_1, June 2022, Page 1162,
    7. Linke S, Zarini G, McLean M. Personalized Dietary Approach for Rhinitis and Sinusitis. Journal of the Academy of Nutrition and Dietetics, Volume 121, Issue 9, A28. Published in issue: September 2021.
    8. Linke S, Zarini G, McLean M, Hogan J, Hogan P, Patenaude J. Tailored Dietary Approach for Individuals with Migraine. Current Developments in Nutrition, Volume 5, Issue Supplement_2, June 2021, Page 849,
    9. Patenaude J, Zarini G, McLean M, Linke S. Effectiveness of a Tailored Dietary Program in Subjects with Fibromyalgia. Current Developments in Nutrition, Volume 5, Issue Supplement_2, June 2021, Page 856,
    10. Braunstein N, Hogan M, Diaz Escamilla R. The Lifestyle Eating and Performance (LEAP) Program for Improving Quality of Life in Women With PCOS: A Pilot Study of Dietitian-Directed Therapy. Current Developments in Nutrition, Volume 5, Issue Supplement_2, June 2021, Page 1123,
    11. Patenaude J & Bright D. Clinical improvement of IBS, migraine, fibromyalgia and arthritis using elimination diets based on mediator release blood testing. Journal of the American Dietetic Association, Volume 109, Issue 9, Supplement, 2009, Page A32, ISSN 0002-8223, (
    12. Williams F. Use of the LEAP mediator release test to identify non-IgE mediated immunologic food reactions that trigger diarrhea predominant IBS symptoms results in marked improvement of symptoms through use of an elimination diet. American Journal of Gastroenterology: October 2004 – Volume 99 – Issue – P S277-S278. (

Book Chapter

  1. Susan Linke. Chapter 23: Irritable Bowel Syndrome: The other Inflammatory Disease. AAPI’S Nutrition Guide to Optimal Health Using Principles of Functional Medicine & Nutritional Genomics Part III – 2017. ISBN: 978-1-5323-4393-3.
Magazine Publications
  1. Patenaude J. Behavioral Nutrition Health Roundtable. Obesity in the age of weight neutrality: How are registered dietitian nutritionists responding to the challenge? Academy of Nutrition and Dietetics. BH Newsletter, Spring 2020, Volume 37 No. 1, Page 5.
  2. Joy Manning. I Wondered If How I Felt Had Anything to Do with Food. Epicurious Magazine. November 11, 2019.
  3. Lindsey Getz. Today’s Dietitian Fifth Annual Showcase of 10 Incredible RDs Who Are Making a Difference. Today’s Dietitian, March 2014 Issue, Vol. 16 No. 3 P. 24
  4. Pasula M. The patented mediator release test (MRT): a comprehensive blood test for inflammation caused by food and food-chemical sensitivities. Townsend Letter – January 2014.
  5. Aglaée Jacob. Elimination Diet Protocols. Today’s Dietitian, July 2013 Issue, Vol. 15 No. 7 P. 10.
  6. Karen Appold. Migraine Headaches — Here’s How to Identify Food Triggers and Reduce Debilitating Symptoms. Today’s Dietitian. November 2012 Issue, Vol. 14 No. 11 P. 14.
  7. Patenaude J. Inflammation and food sensitivities — successful treatment begins with patient-centered care. Today’s Dietitian, November 2011 Issue, Vol. 13 No. 11 P. 18.
  8. Maura Keller. Food Intolerances vs. Food Allergies. Today’s Dietitian. October 2011 Issue, Vol. 13 No. 10 P. 52.
  9. Maura Keller M. Get Certified — Provide a Valuable Service by Adding Allergy Testing to Your Practice. Today’s Dietitian, August 2010 Issue, Vol. 12 No. 8 P. 18.
  10. Susan Linke. Food Sensitivities: The Hidden Cause of Your Health Problem? 2009. org.
  11. Alternative approach to IBS and migraine is winning over providers. Dis Manag Advis. 2004;10(1):6-1. 
Poster Presentations/Conferences
  1. Ceresnie M, Ondreyka J, Ezekwe N, Zarini G, McLean M, Hamzavi IH. Bridging the gap between personalized diet and dermatology in clinical trials: a prospective pilot study in patients with hidradenitis suppurativa. Integrative Dermatology Symposium, 2022.
  2. Ceresnie M, Ondreyka J, Ezekwe N, Zarini G, McLean M, Hamzavi IH. A prospective pilot study on the clinical outcomes of the LEAP program in HS patients. American Medical Association (AMA) Research Challenge, 2022.
  3. Ceresnie M, Ondreyka J, Ezekwe N, Zarini G, McLean M, Hamzavi IH. Hidradenitis suppurativa and the Lifestyle Eating and Performance program: A prospective pilot study. Symposium on Hidradenitis Suppurativa Advances (SHSA), 2022.
  4. Zarini GG, McLean Role, Ondreyka J. Tailored Dietary Approach for Inflammatory Skin Disorders. FASEB Conference: The Nutrition, Immunity, and Inflammation Conference: From Model Systems to Human Trials – VIRTUAL, July 2021.
  5. Linke S, Patenaude J, Zarini GG, McLean MA. Tailored Dietary Approach to Manage Irritable Bowel Syndrome. Lifestyle Medicine Conference. Virtual, October 2020.
  6. Bethel LJ. Self-assessment of frequency and severity of symptoms with chronic inflammatory conditions following a patient-specific elimination diet and food reintroduction plan. Florida Dietetic Association Annual Meeting. Orlando, FL, July 2010.
Publications in Progress/ Preparation
  1. Ceresnie M, Ondreyka J, Ezekwe N, Zarini G, McLean M, Hamzavi IH. The Lifestyle Eating and Performance (LEAP) program for patients with hidradenitis suppurativa Hurley stages I-II: a pilot study. In progress.


  1. Michael A. McLean. The Mediator Release Test (MRT): An Advanced and Innovative Diagnostic Tool Used to Unmask the Foods that Contribute to your Diet-Induced Inflammation. Functional Diagnostic Nutrition. April 2, 2022.
  2. Michael A. McLean. Quality of the MRT Food Sensitivity Test. Functional Diagnostic Nutrition. August 12, 2021.
  3. Jan Patenaude. Taking the Guesswork Out of Testing for Food Sensitivities. Webinar: Transformational Enzyme Corp. April 21, 2021.

Radio & Podcast Interviews

  1. Susan Linke. Food Sensitivities. Healthy by Nature, June 12, 2021.
  2. Susan Linke. The Complete Guide to Food Sensitivity Testing: FUELED | wellness + nutrition with Molly Kimball, October 10, 2020.
  3. Susan Linke. The Whole Scoop Radio Show. Naturally Nutrition Inc, A Holistic Approach. Episode 4. “Reversing Disease”; Episode 5: “Leaky Gut: No Need to Call a Plumber, Learn How to Fix Yourself”; Episode 14: “Inflammation and Chronic Illness: What’s Food Got to Do with it?”; Episode 64: Inflammation: “What you really need to know”; Episode 77: “Eating out – Do we have a choice?” August 21, 2019.
  4. Susan Linke. Allergies–how to help prevent them and reduce their impact. Healthy by Nature radio, April 8, 2017.
  5. Jan Patenaude. The Food Sommelier Podcast – LEAP Podcast July 22, 2016.
  6. Susan Linke. Leaky Gut, Your Microbiome, and Food Sensitivities., May 25, 2016.
  7. Susan Linke. Food sensitivities. Healthy by Nature radio, May 21, 2016.
  8. Jan Patenaude. Identifying Your Migraine Triggers. Real Food Radio. May 17, 2016.
  9. Jan Patenaude. Migraines: Triggers, Tests and Solutions. February 29, 2016.
  10. Jan Patenaude. Namaste Nutritionist- Migraines, Nutrition & Food Sensitivities. December 17, 2015.
  11. Susan Linke. Fun with food. Healthy by Nature radio, April 16, 2011.