Many people who suffer from distressing gut symptoms such as bloating, constipation and/or diarrhoea identify gluten-containing foods (such as bread and pasta) as a trigger, and are quick to eliminate all gluten from their diet, often unnecessarily.
Gut symptoms can be triggered by any number of dietary components (such as naturally-occurring chemicals in foods), stress, and anxiety, but gluten-containing foods are commonly problematic as the protein they contain causes symptoms in people with Coeliac disease (a relatively common autoimmune disease), and they are also rich in fermentable carbohydrates (known as 'FODMAPs') which can be problematic for people with Irritable Bowel Syndrome (IBS).
What should you do if you think gluten is causing your symptoms?
The most important thing is to keep wheat and other sources of gluten (such as rye, barley and oats) in your diet, and have a blood test to rule out Coeliac disease as a potential cause of your symptoms. Coeliac disease is relatively common in Australia (approximately 1 in 70 ), and because of the severity of the disease, it’s important to rule it out as a cause of your gut symptoms. There are two different tests performed to screen for Coeliac disease: an antibody test (the most common, which requires you to keep gluten in your diet), and a genetic test.
Coeliac antibody tests
If you do have Coeliac disease and you are eating gluten, your body will generate antibodies as a response, which can be measured by the blood test. If you've already eliminated gluten from your diet, your body won't be producing these antibodies and could result in a false negative result (i.e. the test would be negative, but it really should have been positive), which is why it is so important to keep gluten in your diet for this test.
Coeliac genetic testing
The second blood test available is a genetic test, which can't be used to diagnose Coeliac Disease (as 30-40% of the general population have the genes), but can be useful to exclude Coeliac Disease a diagnosis. If you don’t don't have the Coeliac-associated genes (HLA-DQ2/8) it's highly unlikely that you have or will ever develop Coeliac disease. For this test you do not need to be eating gluten, as it's looking at your genetic makeup, which is unaffected by your diet.
If you do have the genes, you'll still need to include gluten in your diet for 4-6 weeks and then have an antibody test to determine whether you have Coeliac disease. For an official diagnosis of Coeliac disease, you'll need to have a procedure known as an endoscopy, which will take a sample (a biopsy) from the lining of your small intestine to confirm the presence of pathology (damage to the lining of the small intestine caused by gluten).
This test can be useful for people who experience highly-distressing gut symptoms and are absolutely unwilling to include gluten if their diet, but be aware that there will likely be an out of pocket expense of around $100. Please speak to your GP about it if you are interested in having this test done.
What should you do if you’ve had Coeliac disease ruled out, but still have gut symptoms?
If you have ongoing gut issues and have had Coeliac Disease excluded, the next step is to speak to your regular GP and seek a referral to a Gastroenterologist, if your GP thinks it is necessary. Many people assume they ‘just have IBS’, but it’s incredibly important to eliminate other potential causes of your symptoms (such as inflammatory bowel disease or ovarian cancer) which can mimic the symptoms of IBS. IBS has long been considered a 'diagnosis of exclusion' (i.e. if you can't be diagnosed with anything else, you must just have IBS), but the formal criteria for diagnosis (as per Rome IV) are:
'Recurrent abdominal pain on average at least 1 day per week in the last 3 months, associated with 2 or more of the following:
1. Pain is related to defaecation, meaning the pain can be better or worse after having a bowel movement;
2. Pain is associated with a change in frequency of stool, meaning you now suffer from constipation or diarrhoea, or both;
3. Pain is associated with a change in form (appearance) of stool .
What should you do if you’ve been diagnosed with IBS?
If you’ve been diagnosed with IBS, I would definitely recommend trialling a low FODMAPs diet, which is the best dietary strategy for managing IBS. Keep in mind that dietary strategies are just one approach - you could also try psychological support if your symptoms worsen with stress or anxiety.
If you do want to try the low FODMAPs diet, it’s best to do this under the guidance of an experienced dietitian. You can find dietitians with a special interest in IBS using the ‘Find a Dietitian’ search function of the Dietitian’s Association of Australia website (search for 'Gastrointestinal disorders' under 'Area of Practice'). The Monash University app and blog are excellent resources too.
Why not just go gluten-free?
Gluten free diets are only essential for people with Coeliac Disease. Even if you have been diagnosed with IBS, you may find that you can tolerate gluten-containing foods such as spelt sourdough bread, which is low in FODMAPs.
The FODMAPs found in gluten-containing products such as wheat, rye and spelt breads, wholegrain wheat pasta and oats are incredibly beneficial for gut health, as they feed the good gut bacteria, improving the health of the bowel. In turn, gluten-free diets have actually been shown to reduce the diversity (the number of different species) of good bacteria in the gut, which negatively affects gut health .
Nutritional aspects of gluten-free diets
Gluten-free grains (such as corn and rice) are generally lower in protein and fibre than gluten-containing grains, and many of the ingredients used to make gluten-free products (such as breads and pastas) are made from highly-refined starches (such as corn flour and rice flour) which are known to have a high Glycemic Index (GI), and are lower in nutrients such as iron and zinc.
If you have Coeliac Disease or are gluten-free by personal choice, I would recommend that you:
- Choose whole grains such as brown rice, buckwheat and quinoa over refined grain products (such as white rice noodles and corn pastas)
- For breakfast, try a porridge made from whole grains (such as buckwheat or quinoa) instead of refined gluten-free cereals
- Choose starchy vegetables such as potatoes and sweet potatoes for carbohydrates with main meals
- If you are having pasta, try a 50:50 mix of a gluten-free pasta and a pasta made from legumes such as San Remo’s pulse pasta to boost the protein and fibre content of the meal
Feel free to ask any questions below.
1. Coeliac Australia. Coeliac Disease [Internet]. [cited 2017 Jul 5]. Available from: http://www.coeliac.org.au/coeliac-disease/
2. Palma GD, Nadal I, Collado MC, Sanz Y. Effects of a gluten-free diet on gut microbiota and immune function in healthy adult human subjects. British Journal of Nutrition. 2009;102:1154–60.