Two conditions, one trigger
Both conditions flare after eating gluten, which is why they're so often confused. The difference lies underneath: in coeliac disease the immune system attacks the gut lining itself, flattening the villi that absorb nutrients. In non-coeliac gluten sensitivity (NCGS), symptoms are genuine — bloating, brain fog, fatigue, joint aches — but the intestinal lining stays intact and antibodies stay normal.
Why the distinction matters
- Strictness: coeliacs must avoid even trace gluten for life; many with NCGS find a personal tolerance threshold.
- Monitoring: coeliac disease brings follow-up needs — bone density, iron, B12; NCGS does not.
- Family: coeliac disease runs in families and first-degree relatives should be screened; NCGS shows no such inheritance pattern.
Getting tested — in the right order
The cardinal rule: don't go gluten-free before testing. The coeliac blood test (tTG-IgA) and confirmatory biopsy both rely on active gluten exposure; remove it first and results turn falsely negative. If the coeliac panel is negative and wheat allergy is ruled out, but a supervised elimination-and-reintroduction clearly links symptoms to gluten, NCGS is the working diagnosis.
It might also be the fructans
Some people who feel better off wheat are reacting to fructans — fermentable carbohydrates in wheat — rather than gluten itself. A dietitian-guided low-FODMAP trial can untangle the two.
The shared good news
Whichever diagnosis lands, the modern gluten-free shelf means neither condition costs you real bread, pizza night or weekend bagels anymore.