A new global study published in Gut has found that around one in ten people report symptoms after eating gluten or wheat, despite not having coeliac disease or a wheat allergy.
The research, a large systematic review and meta-analysis of 25 studies involving nearly 50,000 participants from 16 countries, shows that self-reported gluten or wheat sensitivity, known as non-coeliac gluten/wheat sensitivity (NCGWS) affects approximately 10% of people worldwide.
The study found that NCGWS appears to be more common among women and those with irritable bowel syndrome (IBS), anxiety or depression. Symptoms typically improve when gluten or wheat is removed from the diet and return when these foods are reintroduced, although the biological cause of NCGWS remains unclear. Unlike coeliac disease or wheat allergy, the condition has no specific blood markers and is diagnosed mainly by excluding other causes of symptoms.
Participants most frequently reported bloating (71%), abdominal discomfort (46%), abdominal pain (36%) and fatigue (32%), with other symptoms including diarrhoea, constipation, headache and joint pain. The analysis also revealed striking geographical differences in prevalence, ranging from 0.7% in Chile to 23% in the UK and 36% in Saudi Arabia. Four in ten people reporting NCGWS said they followed a gluten-free diet, often without medical advice or formal diagnosis.
Lead author Dr Mohamed Shiha, Gastroenterology Fellow, PhD, University of Sheffield and Specialist Registrar in Gastroenterology said: “Our study shows that about one in ten people worldwide believe they react to gluten or wheat, even though they do not have coeliac disease or wheat allergy. We found strong links between these self-reported symptoms and conditions such as anxiety, depression and irritable bowel syndrome.
"This suggests that what many people experience may not be caused by gluten itself, but by how the gut and brain interact. Recognising this connection can help people move away from unnecessary dietary restriction and towards a more holistic, evidence-based approach to understanding and managing their symptoms.”
Co-author Dr Imran Aziz, Senior Lecturer and Consultant Gastroenterologist, University of Sheffield added: “This is an important piece of work that brings much-needed clarity to a controversial area of gastroenterology, which has drawn significant public interest over the past decade. It will influence how we assess and support patients who believe they have gluten sensitivity.”
Non-coeliac gluten/wheat sensitivity is increasingly recognised as part of the broader group of gut–brain interaction disorders, which emphasise the two-way communication between the gut and the nervous system. Understanding the condition in this context may help develop more accurate, symptom-based diagnostic criteria and guide personalised management approaches that focus on individual symptom patterns and dietary triggers, helping to avoid unnecessary dietary restrictions.
Although the evidence relies largely on self-reported data and studies with differing methodologies, the findings indicate that non-coeliac gluten/wheat sensitivity is a common condition that varies considerably across populations and countries, highlighting the need for continued clinical and research attention.