What Is Gluten?

What Gluten Actually Is

Gluten is a group of proteins, not a single thing. The main culprits are gliadin and glutenin, found in wheat. Barley contains hordein, rye contains secalin. All three grains are off-limits if you have coeliac disease or non-coeliac gluten sensitivity (NCGS). Other grains like oats contain avenin, which is structurally similar but usually tolerated.

These proteins give dough its elasticity and help bread rise. Coeliac Australia notes that gluten provides the chewy texture you expect in good bread. Without it, you get crumbly, dense results, which is why gluten-free baking is genuinely harder.

Why Gluten Matters for Some People

If you have coeliac disease, your immune system treats gluten like an invader. It attacks your small intestine lining, damaging the villi that absorb nutrients. This is autoimmune, not an allergy. About 1 in 70 Australians have coeliac disease, but roughly 80% don't know they have it.

Non-coeliac gluten sensitivity (NCGS) is different: symptoms like bloating, fatigue, and brain fog without the gut damage. It's real but not autoimmune. A wheat allergy is an IgE-mediated immune response, similar to peanut allergies, and can be severe.

Coeliac Disease: The Autoimmune Condition

Coeliac disease is genetic. You need the HLA-DQ2 or HLA-DQ8 gene variant, but having the gene doesn't guarantee you'll develop the disease. About 30-40% of the population carry these genes, yet coeliac disease only affects around 1-3% of people globally.

Symptoms vary wildly: some people get diarrhoea and stomach pain, others experience anaemia, fatigue, or bone loss without any gut symptoms at all. The only treatment is strict, lifelong avoidance of gluten. Even tiny amounts (as little as 20 parts per million) can trigger an immune response in the intestines.

The Three Distinct Conditions

Coeliac disease is autoimmune and involves gut damage. Non-coeliac gluten sensitivity causes symptoms but no intestinal villous atrophy. Wheat allergy is an IgE-mediated reaction that can cause anaphylaxis. They're tested differently, managed differently, and have different long-term health implications.

About 80% of Australians with coeliac disease remain undiagnosed (Coeliac Australia). If you suspect you have any of these conditions, get tested while still eating gluten. A gluten-free diet will skew your test results.

Sources

FSANZ, Coeliac Australia, Celiac Disease Foundation, FDA, Beyond Celiac