Global prevalence of self-reported non-coeliac gluten and wheat sensitivity: a systematic review and meta-analysis

Background Non-coeliac gluten/wheat sensitivity (NCGWS) is characterised by gastrointestinal and extraintestinal symptoms related to gluten or wheat ingestion in individuals without coeliac disease or wheat allergy. Objective A systematic review and meta-analysis was conducted to estimate the global burden and clinical characteristics of self-reported NCGWS. Design We searched for studies evaluating the prevalence of self-reported NCGWS in the general population. Pooled prevalence estimates and odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated using random-effects meta-analysis. Results Twenty-five studies comprising 49 476 participants from 16 countries were included in the analysis. The pooled prevalence of self-reported NCGWS was 10.3% (95% CI 7.0% to 14.0%), with marked variations between countries. Among individuals reporting NCGWS, 40% (95% CI 25.2% to 55.0%) adhered to a gluten-free diet. The most common symptoms were bloating (71.0%; 95%CI 62.8% to 79.1%), abdominal discomfort (46.0%; 95%CI 39.0% to 52.7%), abdominal pain (36.0%; 95%CI 28.6% to 43.2%) and fatigue (32.1%; 95%CI 25.3% to 39.0%). Self-reported NCGWS was significantly more common in females than in males (OR 2.29; 95%CI 1.80 to 2.90; p<0.001). Individuals who self-reported NCGWS were significantly more likely to report anxiety (OR 2.95; 95%CI 1.56 to 5.57; p<0.001), depression (OR 2.42; 95%CI 1.80 to 3.24; p<0.001) and irritable bowel syndrome (OR 4.78; 95%CI 3.48 to 6.57; p<0.001) than controls. Conclusion Approximately one in 10 people worldwide self-report NCGWS, with a female predominance and a significant association with psychological distress and irritable bowel syndrome. Our findings suggest positioning NCGWS within the spectrum of disorders of gut–brain interaction once organic pathologies have been excluded.