Gluten-related gut disorders

ConditionMechanism (simplified)Key tests
Celiac diseaseAutoimmune enteropathy triggered by gluten in HLA-DQ2/DQ8 carriersTTG-IgA, total IgA, confirmatory biopsy if serology positive
Wheat allergyIgE or non-IgE immune response to wheat proteinsAllergy workup
Non-coeliac gluten/wheat sensitivity (NCGWS)Symptom recurrence on gluten/wheat challenge without celiac markersDiagnosis of exclusion; supervised challenge

Barrier and microbiome

  • Celiac: strong literature on increased permeability, zonulin pathway research, recovery on gluten-free diet (see intestinal barrier).
  • NCGWS: barrier changes reported in subsets; mechanisms not settled (immune, FODMAP overlap, amylase-trypsin inhibitors).
  • Healthy volunteers: gliadin can trigger transient permeability signals in research models, clinical significance differs from celiac.

FODMAP overlap

Wheat contains fructans (FODMAP), not just gluten. Symptom improvement on wheat avoidance may reflect FODMAP reduction rather than gluten immunity, see FODMAPs.


Context if you're reading a report

"Avoid gluten for leaky gut" advice often skips celiac serology. Missing celiac disease has long-term health consequences; unnecessary lifelong gluten avoidance has social and nutritional costs.

Microbiome panels do not diagnose celiac disease. TTG-IgA and total IgA (clinical) come first when celiac is suspected.

That a microbiome report proves gluten sensitivity; that non-celiac symptoms require gluten elimination; or that gluten causes barrier dysfunction in everyone.