We have read with great interest the systematic review and meta-analysis by Shiha et al, which estimated the self-reported prevalence of non-coeliac gluten/wheat sensitivity (NCGWS) globally at 10.3%.1 We appreciate the authors’ contribution of important global evidence for this clinically ambiguous disease; however, some data consistency and reporting details require clarification.

First, we are concerned that the high rate of self-initiated gluten-free diets may lead to a ‘dead end’ in the diagnosis of coeliac disease (CeD). The diagnostic efficacy of serological and histological tests for CeD may decline when symptomatic individuals reduce or stop gluten intake before evaluation, and definitive diagnosis often requires a gluten challenge test, which has limited acceptability and may increase the burden of symptoms. Current guidelines clearly recommend that CeD testing should be performed while patients are on a gluten-containing diet and that a structured diagnostic pathway (such as selective HLA-DQ2/DQ8 typing and, if necessary,…