Gluten Intolerance Symptoms: Is It Actually Gluten or FODMAPs?
Are you struggling with bloating, gas or notice a change in bowel habits after eating bread or pasta and wondering if your gut symptoms are caused by a gluten intolerance? For many people, the culprit isn’t actually the protein gluten itself, but fructans - a type of fermentable carbohydrate (FODMAP) found in wheat and many gluten-containing foods (1).
By understanding the difference between gluten vs fructans, you can better identify your specific triggers, find gut symptom relief and avoid unnecessary dietary restrictions.
Digestive symptoms are often influenced by multiple factors, including diet, the gut microbiome and digestive sensitivity. If you’d like to explore this further, you may find our guide on why gut health matters useful.
Quick Click Contents
· Why can wheat trigger symptoms?
· What does the research say about fructans vs gluten?
What is gluten?
Gluten is a protein naturally present in wheat, barley and rye (2). It gives dough elasticity and helps bread maintain its structure.
For some people, gluten must be avoided completely due to specific medical conditions.
Wheat Allergy
A wheat allergy is an immune reaction to wheat proteins, like other food allergies (2).
Symptoms can occur shortly after eating wheat and may include hives, swelling, nausea or breathing difficulties.
Management typically involves avoiding wheat-containing foods under medical guidance (2).
You can find more details about allergies and intolerances in our article about food intolerance testing.
Coeliac Disease
Coeliac disease is an autoimmune condition in which the immune system reacts to gluten, which can damage the lining of the small intestine (3).
This can interfere with nutrient absorption and cause symptoms such as bloating, diarrhoea, fatigue and anaemia, to name a few.
It is important not to remove gluten from your diet before testing for Coeliac Disease, as this can affect the accuracy of diagnostic tests.
If you suspect you may have Coeliac Disease, speak with a healthcare professional.
People diagnosed with Coeliac Disease must follow a lifelong strict gluten-free diet and lifestyle to prevent intestinal damage and long-term health complications (3).
For further information about symptoms and diagnosis, see the NHS guide to coeliac disease and summary from Coeliac Australia.
Non-coeliac gluten sensitivity
In addition to gluten-specific conditions, some people also experience symptoms after eating gluten despite testing negative for Coeliac Disease.
This is often referred to as non-coeliac gluten sensitivity, although the exact cause of symptoms is still being studied (2), we know there is often an overlap with disorders of gut–brain interaction like IBS (9).
What are fructans?
Fructans are a type of FODMAP carbohydrate (fermentable oligosaccharides, disaccharides, monosaccharides and polyols).
These carbohydrates are poorly absorbed in the small intestine.
Instead, they are fermented by gut bacteria in the colon. This process can produce gas and draw water into the bowel, which may lead to digestive symptoms (4).
Common symptoms linked to fructans include:
Bloating
Abdominal pain
Excessive gas
Diarrhoea or changes in bowel habits
Fructans occur naturally in many everyday foods.
Wheat products are among the most common dietary sources, but they are also present in several vegetables and other plant foods (5).
Examples include:
Wheat-based foods such as bread, pasta and cereals
Rye-based breads and cereals
Onions and shallots
Garlic
Leeks and spring onions
Asparagus
Globe artichokes
Jerusalem artichokes
Brussels sprouts
Chicory root
Beans and pulses
For people with irritable bowel syndrome (IBS), these foods may trigger symptoms due to gut fermentation (5).
Why can wheat trigger symptoms?
Wheat contains both gluten and fructans, making it difficult to determine which component is responsible for symptoms (6).
When people remove gluten from their diet, they often reduce their intake of wheat-based foods.
As a result, their fructan intake also decreases, which may explain why symptoms improve.
Because digestive symptoms can have multiple causes, it is important to be cautious about self-diagnosing food intolerances.
What does the research say about fructans vs gluten?
Research comparing gluten and fructans suggests that fructans is more likely to be the trigger for symptoms in people who believe they are gluten sensitive.
One double-blind crossover study found participants experienced significantly worse gastrointestinal symptoms after consuming fructans compared with gluten or a placebo (7).
More recent research suggests that symptoms attributed to gluten may sometimes involve other components of wheat, rather than gluten itself (9).
The role of the low FODMAP diet
If fructans are suspected as a trigger, a low or modified FODMAP diet, may help identify problematic foods (5).
This approach involves temporarily reducing high-FODMAP foods such as fructans before gradually reintroducing them to identify individual tolerance.
Many people with IBS experience symptom improvement with this structured approach (8,10).
Because the process can be restrictive, it is best undertaken under the guidance of a registered dietitian.
Key takeaway - Fructans vs Gluten
While many people believe gluten is responsible for digestive problems, fructans are more likely to be the cause for those with IBS or sensitive digestion.
Understanding your specific triggers can lead to more effective dietary management.
Recognising the difference between gluten and fructans allows for personalised dietary strategies.
This approach helps manage symptoms more effectively and minimises unnecessary food restrictions.
Get personalised support for your gut health
Consulting a dietitian can help you identify your unique food triggers and create a plan that supports your long-term digestive health. You can contact the Balanced Nutrition Co team or book a consultation with one of our dietitians for individual support.
Article written by Hannah Pritchard, Registered Dietitian - BSci (Hons), RD
Hannah is a HCPC Registered Dietitian based in the UK, specialising in gastroenterology and the low FODMAP diet. She has extensive experience helping patients manage IBS, coeliac disease and non-coeliac gluten sensitivity. Hannah is passionate about translating complex nutritional science into practical, everyday strategies to help her patients find long-term digestive comfort.
Expert Support in the UK & Australia: Balanced Nutrition Co provides specialist gut health support. Whether you are looking for an HCPC Registered Dietitian in the UK or an Accredited Practising Dietitian in Australia, our team offers online consultations to help you find relief from digestive discomfort.
References
Skodje, G. et al. (2018) Fructan, rather than gluten, induces symptoms in patients with self-reported non-celiac gluten sensitivity. Gastroenterology. Available at: https://pubmed.ncbi.nlm.nih.gov/29102613/
Celiac Disease Foundation (2019) Non-celiac gluten/wheat sensitivity. Available at: https://celiac.org/about-celiac-disease/related-conditions/non-celiac-wheat-gluten-sensitivity/
NHS (2023) Coeliac disease. Available at: https://www.nhs.uk/conditions/coeliac-disease/
Eswaran, S. et al. (2013) What role does wheat play in the symptoms of irritable bowel syndrome? Gastroenterology & Hepatology. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC3754775/
Monash University (2024) About FODMAPs and IBS. Available at: https://www.monashfodmap.com/
Algera, J. et al. (2021) Gluten and fructan intake and their associations with gastrointestinal symptoms in IBS. Clinical Nutrition. Available at: https://www.sciencedirect.com/science/article/pii/S0261561421004155
Skodje, G. et al. (2018) Fructan, rather than gluten, induces symptoms in patients with self-reported non-celiac gluten sensitivity. Gastroenterology. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0016508517363023
Usai Satta, P. et al. (2024) FODMAP diet in gluten-related disorders. Nutrients. Available at: https://www.mdpi.com/2072-6643/16/23/4190
Biesiekierski, J. et al. (2025) Non-coeliac gluten sensitivity. The Lancet. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0140673625015338
Gluten Intolerance Group (2019) Gluten sensitivity and FODMAPs. Available at: https://gluten.org/wp-content/uploads/2019/10/EDU_GS-and-FODMAP.pdf
