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IgE-mediated food allergies and the gut

The topic of allergies is a huge subject that I couldn’t possibly cover in one blog post so I will keep coming back to it to address various aspects. In today’s post I will be covering why it is important to address digestive health when it comes to suffering from IgE-mediated food allergies.

Firstly I want to break it down a little from the top because many people when they think of allergies don’t realise that they are not all the same. If you already experience or you have a child that has an allergy then you are probably already very well read on this so you can skip to the bit where I talk about the link between digestive health and IgE-mediated food allergies clicking here.

Allergies are increasing in developed countries incredibly quickly. Research from the U.S. Centres for Disease Control and Prevention shows that food allergies in children have increased approximately 50 percent between 1997 and 2011, now affecting 1 in 13 children in the United States. This translates to roughly two students in every classroom. Regular medications such as antihistamines and steroids are only effective at suppressing the symptoms of allergies, sometimes with unpleasant side effects.

There are three types of allergies affecting most people.

  1. Environmental or inhalant allergies

  2. Food allergies

  3. Chemical sensitivities (e.g food additives, medications, household cleaners and many other man-made products)

Allergies are over-reactions of the body to substances such as dust, pollens and foods that normally should not trigger a reaction in the body. The body mistakenly interprets the allergen as a threat to the body and mounts a strong immune defence against it. This is known as a hypersensitivity reaction. It is not a sign of a weak immune system but a sign of an over-reactive immune system. So simply “boosting” the immune system will not work to solve an allergy problem.

To make it more confusing there are four types of allergy. I am referring to Type I hypersensitivity which is a type of allergic reaction that occurs when the immune system overreacts to an otherwise harmless substance, such as pollen, dust, or certain foods. It is characterised by the rapid release of immunoglobulin E (IgE) antibodies in response to the allergen. The symptoms that occur during an allergic reaction will not always be the same. The nature of the symptoms and their severity depend upon several factors including the individual, the level of contact/ingestion, the tissue receptors that are affected, and the length of time since the previous exposure.

This is not to be confused with a type III food hypersensitivity which is when the immune system produces specific IgG antibodies (immune globulins of the subclass G). These antibodies can lead to inflammatory processes. The symptoms appear from several hours up to three days after the consumption of a trigger food. This is very different to the quick reaction of an IgE response. The symptoms are also quite different with IgE typically manifesting as swelling/inflammation/hives/rash/difficulty breathing/throat tightening and in severe cases anaphylactic shock. IgG reactions are usually more subtle and last longer. They can manifest in many different ways such as fatigue, joint aches, stool changes, nausea, headaches etc..I will discuss these types of responses in future posts.

Food allergy typically begins in the first 2 years of life. While some food allergies, such as cow’s milk and egg, are often outgrown, peanut and tree nut allergies are more likely to persist into adulthood. Although more common statistically with children, it is possible to develop a food allergy as an adult.

So what do IgE-mediated food allergies have to do with digestive health?

The development of food allergy has been reported to be related with the changes in the gut microbiome. The gut microbiome for those of you that don’t know is the trillions of microorganisms and their genetic material that live in your intestinal tract. These microorganisms, mainly comprising of bacteria, are involved in functions critical to your health and wellbeing.

A change in the composition, richness and balance of the microbiota that colonise the human gut during early infancy has been found to play a significant role in the development of IgE-mediated food allergy. The coexistence of the human gastrointestinal tract and its microorganisms has resulted in a interdependent relationship in which gut microbiota play a vital role in early life immune development and function, as well as maintenance of gut wall epithelial integrity. Since IgE mediated food allergy is associated with immune dysregulation and impaired gut epithelial integrity there is substantial interest and an increasing body of research into the link between gut microbiota and food allergy.

It has been demonstrated that in early life the gut microbiota influences immune development and balance of Treg cells (which act to suppress immune response, thereby maintaining homeostasis and self-tolerance) which may increase the risk of food allergy. Environmental factors that may affect gut microbiota patterns in early life include obstetric interventions in pregnancy, antibiotic exposure, infant feeding practices and a modern westernised lifestyle.

Researchers have observed significant differences in the gut microflora of people with and without a food allergy. Healthy gut flora is made up of a wide array of commensal bacteria, including Bacteroides, Enterobacteria, Bifidobacteria, and Lactobacilli. Interaction between these bacteria and the intestinal immune system “trains” the body to tolerate food triggers.

Scientists have made significant progress in identifying the connections between the gut microbial composition and predisposition to food allergy. Although in the case of IgE-mediated food hypersensitivity, the best first step is to remove the offending food-I don’t suggest it should be the only action taken. As part of Nutritional Therapy, supporting digestive health and the gut microbiome is an essential part of helping to build tolerance to allergens and support the immune response.

I am a registered Naturopathic Nutritional Therapist and Naturopath, specialising in clinical paediatric nutrition and digestive health. My goal is to empower families, supermums and kids towards improved health and well-being. If you are interested in starting Nutritional Therapy for yourself, your family or your child then please contact me for more information/FREE discovery call or you can check out my services on my website.

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