Gut brain reaction – finding your food allergies and intolerances - Food for the Brain

Gut brain reaction – finding your food allergies and intolerances

If you are suffering from bloating, belching, indigestion, heartburn, abdominal pain, IBS and any other digestive complaint, or brain fog and headaches but after meals, you might be wondering if there’s something you are eating that you are intolerant or allergic to.

If you’ve ruled out indigestion and dysbiosis the next most likely contributor to your digestive problems is a food allergy or intolerance. Allergies are caused by the immune system producing antibodies that ‘attack’ certain food proteins because it considers them as aliens. The most extreme type of allergic reaction involves a type of antibody called IgE. If you have a pin prick allergy test on your arm, in which a drop of potential allergens are put on a pin prick, if you react you get a red wheal. This immediate reaction, within ten minutes, is an IgE reaction. IgE allergy can also be tested from a blood sample.


But many reactions against food involve a different kind of antibody called IgG. Most people call these food intolerances even though they do fit the bill for the definition of an allergic reaction. IgG reactions don’t occur immediately so it isn’t always easy to know what you react to. For this reason it is worth having a test to find out what you may be reacting to. This can be done from a tiny amount of blood, collectable with a home test kit. The leading laboratory is called They send you a kit, you prick your finger (It isn’t painful) and send them the blood as instructed. They then measure the presence of IgG antibodies in your blood and give you a report that tells you how strongly your immune system is reacting against which foods.

Healing the gut

The first step is to avoid those foods you react strongly to. You can ‘rotate’ those foods which produce a mild reaction which means eaten then not more than every five days. (If you eat a reactive food every day your level of reactivity builds up.) Yorktest include a session with a nutritional therapist by phone, who can help you do it right.

The good news is that IgG antibody reactions often go away if you a) avoid the food strictly for 3 to 4 months and b) heal the gut. The same is not true for IgE based reactions. We often develop food intolerances because the gut wall becomes inflamed or damaged allowing incompletely digested food proteins to enter the body and bloodstream. The gut wall is also damaged by alcohol, painkillers, too much coffee and fried foods.

Certain foods irritate the gut wall. An example is wheat, containing gliadin. This is why a lot of people are somewhat intolerant of wheat.

Fortunately, the cells that line the gut wall heal and replenish very quickly, especially when you feed them an amino acid called l-glutamine. So, supplementing l-glutamine can speed up gut healing. If you want to heal a ‘leaky’ gut have 5 grams (a heaped teaspoon) of glutamine powder in cold water (hot water destroys this amino acid) last thing at night or at least half an hour before eating.

In summary, to reduce your immune sensitivity to foods and restore gut health

Some digestive supplements provide all three – digestive enzymes, probiotics and glutamine – in one.