Table 1.
Overview about functional gastrointestinal disorders caused by grain components.
| Celiac disease | Wheat allergy* | Non-celiac wheat sensitivity | IBS | |
|---|---|---|---|---|
| Prevalence | ||||
| ~1% | 0.2–1% | ~10% | 7–21% | |
| Pathogenesis | Autoimmune | IgE-induced | Unspecific, partially immune-based | Diverse and not clear (low-grade inflammation and immunological alterations) |
| Marker | IgA anti-EMA, IgA anti-tTG, IgG anti-DGP, IgA anti-gliadin | Specific IgE antibodies | No biomarker, IgA/IgG anti-gliadin in 50% of cases | No biomarker |
| Genetic preposition | More than 95% DQ2-DQ8 HLA positive | About 50% DQ2-DQ8 HLA positive | DQ2-DQ8 HLA negative | Not clear |
| In/uptake | Oral | Oral, respiratory & percutaneous | Oral | Oral |
| Source/trigger | Peptides from gliadins and glutelins | Depending on type of allergy gliadins, glutelins and/or non-gluten proteins (e.g., ATIs) | ATIs, possibly gluten and FODMAPs, predominately fructans | FODMAPs, ATIs and gluten are potential triggers |
| Therapy | Gluten-free diet | Wheat-free diet | Wheat-free or strong reduction of wheat in diet | Gluten-free and low FODMAP diet |