Monday, May 07, 2007

Food sensitivity and intolerance testing options include new mediator release testing (MRT)

As a gastroenterologist, I diagnose and treat many people with food allergies and intolerance, colitis, Crohn’s disease, reflux and irritable bowel syndrome or IBS. As a food allergy and food intolerance specialist – the Food Doc, I find food allergies are relatively easy to diagnose, as is Celiac disease, the worst form of a spectrum of gluten sensitivity. Crohn’s and colitis are also usually easily diagnosed though this requires an endoscopic examination of the colon, colonoscopy, with biopsies of abnormal appearing intestinal lining. Sometimes specific blood tests for colitis and Crohn's disease may screen for or help confirm ulcerative colitis and Crohn’s disease. More recently, biopsies of normal appearing intestine lining, has been found to reveal previously unsuspected microscopic forms of inflammation that may be due to food allergies or intolerance. These various forms of microscopic colitis, often misdiagnosed as IBS include lymphocytic, collagenous and mastocytic enterocolitis may be due to foods. However, food intolerance or sensitivity are often the cause of a myriad of symptoms but can be quite difficult to confirm. I am now using new testing from Signet Diagnostic Corporation that may end some of the frustration experienced by people who have symptoms suspected to be due to food sensitivities. You may take a take a symptom survey and register for secure communication on my on-line consultation site. On that site I also review MRT testing for those interested.

Frequently, the testing available and covered by insurance is very incomplete for determining the possible link between foods and symptoms of ill health. After excluding Celiac disease, non-celiac gluten sensitivity can often be diagnosed based on blood or stool tests for gliadin antibodies and response to a gluten free diet. Other food sensitivities may be suspected based on IgG antibody blood tests or IgA stool tests. Genetic testing for high-risk genes for Celiac disease and gluten sensitivity can also be of some help.

IgG antibody testing has proved to be of some help in linking symptoms to foods in patients with IBS but is not available in most labs or is not covered by many insurances in the U.S. At least two laboratories offer IgG tests for foods. The tests offered by US Biotech IgG food panel testing and the Optimum Health Resources Laboratories IgG ELISA Food Intolerance Test are not necessarily covered by insurance. They do provide testing for a large number of foods but only IgG antibodies and the relevance to symptoms continue to meet resistance by doctors in the U.S. The Enterolab testsEnterolab, though very popular within the gluten sensitivity and Celiac disease community, currently only test for stool IgA antibodies for gluten sensitivity (anti-gliadin and tissue transglutaminase), chicken egg, soy, cow’s milk (casein) and dietary yeast (saccharomyces cerevisiae). For those in whom parasites, abnormal levels of yeast or bacteria or looking for additional IgA antibody stool testing Doctor's Data laboratory's comprehensive gastrointestinal panels are another option but again the validity is questioned by some doctors and insurances, most of which do not cover the tests. People failing to respond adequately to elimination of limited foods tested or who cannot afford the out of pocket expense of these tests often must resort to a strict elimination diets, followed by food challenge as the only way to try to link specific foods to their symptoms.

Food sensitivities or intolerance are a common cause of many chronic conditions. Though only about 8% of people have true food allergies confirmed by allergy testing, food allergies are only a subset of a larger problem of food reactions. The difference between food allergy and intolerance are explained in my Food Doc video and website. Food intolerance and sensitivity affect 15-20% of the population by conservative estimates and possibly affect as many as 60-80%. Food sensitivity or intolerance that is not due to the immediate immune response or IgE antibody reactions cannot be diagnosed by testing based on that reaction. Skin tests and food allergy blood tests or RAST IgE antibody tests will be negative if you are not allergic to a food or foods but you can still have an abnormal immune response to foods and food additives. The immune system can be triggered to release chemicals as a reaction to food or chemicals in foods resulting in various symptoms and feeling sick.

When the immune system perceives foods as a foreign invader or potentially harmful like most bacteria, viruses, parasites or toxic chemicals, various defensive measures are triggered by the body. Some foods or protein products produced from those foods, such as various lectins, may in fact be harmful or toxic to the human digestive and immune system. However, other times it may be a case of mistaken identity. Either way, the results of the body’s perception of a food or food protein as foreign can lead to production of various immunoglobulin antibodies (Ig) and the release of toxic chemicals from infection fighting cells. These chemicals are called "mediators".

The immune mediators include numerous substances such as histamine, cytokines, tumor necrosis factor, and prostaglandins that are being studied vigorously. Recent research is focusing on the role of these mediators and their effects, including the resulting leaky gut, in the presence of altered levels and types of bacteria and yeast. Such interactions are being investigated in the context of how they result in various diseases especially those that are autoimmune in the genetically predisposed. Though many medications have been discovered that are effective blocker of these mediators, like anti-histamines and various cytokine blockers like Remicade.

However, once these mediators are released, the inflammatory and pain-inducing effects of these chemicals give rise to the various symptoms that make us feel sick. The toxic effects of these chemical mediators can also cause damage to our bodies, not just in the gut, where their effects usually result in a leaky gut that predisposes to even more risk of food sensitivity and entry of bad bacteria and yeast into our body. When the mediators or foreign bacteria, yeast or food proteins, get into the blood stream they can travel to remote parts of the body resulting in damage and symptoms in the muscles, bones, nerves, brain, skin and glands.

Research is accumulating indicating patients with irritable bowel syndrome (IBS), migraine headaches, fibromyalgia, chronic depression, chronic fatigue, diabetes, thyroid problems, and chronic inflammatory bowel diseases (IBD) have higher than normal levels of these mediators circulating throughout their bodies. For many people, the "trigger" that causes these mediators to be released can be linked to foods or chemicals in their diet.

Food sensitivity symptoms are often chronic because the mediators are released every time we reactive foods that we frequently habitually exposing ourselves in our diet. So, how do you identify the foods your body is recognizing as foreign and triggering mediator release to so that you can avoid those particular foods? This is done testing for mediator release to specific foods. That is what MRT testing, Signet Diagnostic Corporation, provides. However, they also go one step further by providing an elimination diet followed by a rotation diet based on the specific test results. Further, they provide about three hours of personalized dietary education, counseling, and coaching from a trained dietician.

This combined with a physician experienced in food sensitivity has resulted in some dramatic results in patients who previously had given up getting better. I consider this testing a powerful new weapon in the war against food related illness. If you are in need of consultation and a doctor to order the testing for you please visit my secure on-line consultation website. After you register for secure communication you may request on online consultation. I can review your symptoms and previous testing before making recommendations regarding further evaluation and testing.

Copyright © 2007, The Food Doc, LLC, All Rights Reserved.

No comments:

Visit the Virtual Practice of Dr. Scot Lewey on HealthTap