If you’ve been battling with a dodgy belly then you might have removed gluten from your diet before getting tested for coeliac disease. In this article, we’re going to discuss how to get an accurate test for coeliac disease by doing a low FODMAP gluten challenge.
Did you know that coeliac disease affects approximately 1-2% of people across the globe?
Despite this, gluten-containing foods have become some of the most commonly avoided foods by people wanting to manage their gut symptoms. While lots of people get an improvement in IBS symptoms when they remove gluten, more often than not, it’s actually the fructans in the wheat that are the issue and not the gluten.
This means if it is the fructans in wheat that are to blame for your symptoms, then you may find you get better results with a low FODMAP diet (and more food freedom) than you get with a gluten free diet.
What is the difference between fructans and gluten?
Wheat is a complex grain with many components. It contains a protein, known as Gluten, and a carbohydrate component known as Fructans. These are two very different molecules that are often in the same foods.
By switching to a gluten free diet, you will also lower the amount of fructans that you are eating. Which leaves the question, is it the removal of gluten or the removal of fructans that is making you feel better?
We need to figure out which one is causing issues for you.
What’s more, you need to remember that not all gluten free foods are low in fructans. For example, onion, garlic, legumes and dried fruit are gluten free but they contain fructans. Similarly, many foods (hello soy sauce and sourdough bread) are not gluten free, but are low in FODMAPs.
This means that if you are on the wrong diet for you, then you could end up restricting foods unnecessarily and are likely to get unexplained symptom flares too.
What is the difference between coeliac disease & IBS?
Coeliac disease is a serious autoimmune condition where the body reacts abnormally to the gluten protein found in wheat, barley, rye and oats, resulting in damage to the lining of the small intestine. This damage interferes with the absorption of nutrients resulting in digestive upset, iron deficiency, osteoporosis, fertility problems and if left untreated, even lymphoma. Currently, the only treatment for coeliac disease is a strict gluten free diet.
IBS affects approx. 20% of people globally and is far more common than Coeliac Disease. Up to 90% of people with IBS know that food is involved with triggering their symptoms and will modify their diet to help find relief. Although IBS does cause digestive symptoms, it does not cause damage to the intestine nor medical complications. Managing IBS is all about identifying the foods that trigger your symptoms and where your threshold for them is.
Once you know how much or how little of those foods you can eat, you can then find the right balance between managing your symptoms and what food you can enjoy. It’s okay if this balance is different on different days.
How do you know if you need to limit gluten or fructans?
Symptoms of IBS and coeliac disease can be identical, but managing them is very different. Knowing which approach is best for you is the key to getting maximum variety and minimal symptoms.
The first step is talking to your doctor and getting a proper diagnosis. Part of this process will be ruling out that you don’t have coeliac disease.
Testing For Coeliac Disease
Testing for coeliac disease is a two-step process:
- Blood test for coeliac antibodies tTg-IgA and DGP
- If the blood test is positive, the next step is to have a gastroscopy that looks at the small intestine to see if there is damage caused by coeliac disease.
The tricky part of testing for coeliac disease is that both the blood test and the gastroscopy look for antibodies produced and damage caused when someone with coeliac disease eats gluten. So, if you are already on a gluten free diet, you can get a false negative.
If you have already removed gluten from your diet, then you need to reintroduce gluten back into your diet to get an accurate coeliac disease testing result.
However, if you have had a significant improvement on a gluten free diet, then the thought of doing a gluten challenge can be scary.
Low FODMAP Gluten Challenge
The good news is that you can do a gluten challenge while still following a low FODMAP diet. In many cases introducing low FODMAP serves of wheat is very well tolerated and will give you an accurate result from the coeliac blood test while keeping your belly calm.
Requirements for a gluten challenge vary depending on which resource you look at, but most indicate that you need to eat about 3g of gluten per day for a 6 week period.
This works out to be about 2-4 slices of wheat bread per day or two serves of the foods in the list below. If this feels tricky for you, then work with your doctor and dietitian to create a personalized plan as they can modify the challenge to suit your individual needs.
Do you want to radically improve your gut symptoms?
No thanks, my gut is perfect.
The foods in the following list each contain about 1.5g of gluten and equal a low FODMAP serve. To meet a gluten challenge, you need to include at least two serves of these foods per day for 6 weeks. Note that you can have multiple low FODMAP serves of the same food each day as long as you leave 3-4 hours before eating the next serving of the food.
Gluten challenge foods:
- 1 slice of regular wheat bread
- 1 slice of low FODMAP certified wheat breadg. Alpine Bread, Brumby’s, Bakers Delight lowFOD loaf, Cobbs LowFOD loaf
- 2 slices of wheat or spelt sourdough bread
- ½ cup regular wheat pasta
- Approximately 30g of Lo-Fo pantry flour (you can turn this into baking)
- 2g Bobs Red Mill Vital wheat gluten (can be added to a smoothie)
There is a lot of cross over between IBS and coeliac disease and symptoms can be identical. They both however are very different conditions with different trigger foods. Given the seriousness of coeliac disease, it’s important to know if you have it or not. If you have IBS and not coeliac disease, then avoiding gluten is unnecessarily over-restrictive and unlikely to give you the best results when managing symptoms.
So talk to your doctor about doing a gluten challenge and get an accurate coeliac disease test.
About The Writer
Joanna Baker is a dietitian who loves food. She specialises in helping people with IBS and food intolerances calm their gut and identify their symptom triggers so that they can learn to love food and life again.
Joanna is trained and experienced in low FODMAP, RPAH, histamine sensitivities, gluten, dairy sensitivities and more. If you’ve had enough and it’s time for professional guidance, you can find out more about Joanna and contact her via Everyday Nutrition