Gluten has become one of the most talked-about topics in nutrition, and one of the most misunderstood. Two very different things get lumped together in that conversation: coeliac disease, a diagnosed autoimmune condition, and gluten sensitivity, a much less clearly defined pattern of symptoms. They are not the same condition, they're not diagnosed the same way, and they don't need to be managed the same way either.
What is gluten?
Gluten is a group of proteins found in wheat, barley and rye. Most people eat it daily without any issue at all. A smaller group experience symptoms after eating it, or have a diagnosed medical condition that means they need to avoid it, and the two groups need quite different approaches.
What is coeliac disease?
Coeliac disease is an autoimmune condition. When someone with coeliac disease eats gluten, their immune system reacts by damaging the lining of the small intestine, which over time affects how well the gut absorbs nutrients. It's thought to affect around 1 in 100 people in the UK, but only around 36% of those are ever diagnosed, which means an estimated half a million people in the UK are living with undiagnosed coeliac disease [1][2].
Symptoms vary widely and can include bloating, diarrhoea, constipation and nausea, alongside less obviously digestive symptoms like fatigue, iron deficiency, headaches and brain fog. That range is part of why it so often goes unrecognised for years.
What is gluten sensitivity?
Non-coeliac gluten sensitivity describes people who get symptoms after eating gluten, without having coeliac disease or a wheat allergy. It's a real and recognised pattern, but it works differently to coeliac disease: there's no autoimmune damage to the intestine, and no single blood test or biopsy that confirms it [3]. It's more often identified by ruling coeliac disease and wheat allergy out first, then observing how symptoms respond to gluten.
Gluten sensitivity vs coeliac disease: the key differences
| Aspect | Coeliac Disease | Gluten Sensitivity | | --- | --- | --- | | Condition type | Autoimmune | Food-related sensitivity | | Diagnosis | Clinical testing: antibodies, sometimes genetic markers, GP-guided | No single definitive test | | Response to gluten | Immune damage to the small intestine | Symptoms without intestinal damage | | Management | Lifelong gluten-free diet, medically supervised | Individual dietary approach, guided by symptoms | | How it's investigated | Medical testing before any dietary change | Symptom tracking, food diaries, sometimes a structured elimination |
Why more people are investigating their response to food
Health has become more personalised and more proactive, and food is no exception. Rather than following generic advice, more people want a specific answer to a specific question: is this gluten, is this something else, or is this not diet-related at all. Testing and structured elimination give you a way to investigate that properly, rather than guessing your way through cutting out food after food.
How testing can help
If coeliac disease is a possibility, testing usually starts with a coeliac antibody blood test, which looks for markers your immune system produces in response to gluten. Our Coeliac Check tests for tissue transglutaminase (tTG) antibodies, the marker most commonly used for this. In some cases, a GP or specialist may also use genetic testing (HLA-DQ2/DQ8 typing) to help rule coeliac disease out, most useful for people who have already gone gluten-free before being tested, since it can't confirm the disease on its own but a negative result makes it very unlikely.
The critical point, and the one most worth remembering: don't remove gluten from your diet before antibody testing. Doing so can suppress the antibody response and produce a falsely reassuring result.
If coeliac disease and wheat allergy have been ruled out and symptoms persist, an IgG food intolerance test can help investigate a broader range of foods, as one part of an investigation with a practitioner rather than a standalone diagnosis. Where digestive symptoms are the main issue, FODMAP-related testing, such as our SIBO breath test (Lactulose + Fructose), can also be a useful complement.
Should you stop eating gluten before testing?
Not if coeliac disease is a possibility. Stopping gluten before an antibody test can affect its accuracy and lead to a false negative, potentially missing a diagnosis that needs ongoing medical management. If you're thinking about a major dietary change, it's worth talking to your GP first, particularly if coeliac disease hasn't been ruled out yet.
Looking at the wider picture
Gluten concerns rarely exist in isolation. Fatigue, bloating and digestive symptoms have plenty of other possible contributors, so it's often worth looking at the wider picture alongside a gluten-specific investigation; our gut health and digestion testing range, and nutritional or vitamin testing, can help build that fuller view where more than one thing might be contributing.
The bigger shift: from guesswork to information
The old approach to a suspected food problem was trial and error: cut something out, see how you feel, repeat. Testing, done in the right order, replaces some of that guesswork with actual information, so any dietary change you make is based on what's actually going on rather than a hunch.
Coeliac disease is a medical condition that requires clinical diagnosis and management by a healthcare professional. Food intolerance testing provides information about food-related responses but does not diagnose coeliac disease, gluten sensitivity, or any other medical condition. See your GP if you have persistent digestive symptoms, unexplained fatigue, or ongoing concerns about gluten, and particularly if you experience unintentional weight loss, rectal bleeding, iron deficiency anaemia, a change in bowel habit, or new-onset symptoms after age 50.
