The newly-emerged clinical syndrome non-coeliac gluten sensitivity continues to puzzle gastroenterologists and other medical professionals, as scientists and clinicians grapple to understand the condition and how best to manage it. Professor David Sanders from the Sheffield Teaching Hospitals in Sheffield, UK, and Chairman of the Health Advisory Committee for the respected UK charity Coeliac UK, told journalists at the 21st United European Gastroenterology Week (UEG Week) in Berlin, Germany, that a careful diagnosis to exclude coeliac disease, good patient education and cautious use of a glutenfree diet may be key to effective symptom control in this condition. "Public awareness of gluten-related symptoms is rising, if not mushrooming," he said. "But we shouldn't rush into prescribing a gluten-free diet to everyone who reports gluten sensitivity. We are still on a learning curve ourselves about this condition and its natural history, and patients need to understand that."
What is non-coeliac gluten sensitivity?
Until relatively recently, the most well-known medical condition associated with gluten sensitivity was coeliac disease. This is caused by an immune response to the cereal protein gluten in susceptible people. Coeliac disease is a potentially serious condition that can cause intestinal symptoms such as weight loss and chronic diarrhoea and other health problems including anaemia, osteoporosis, joint pain, dermatitis and neurological symptoms. The condition affects around 1% of the general population and is diagnosed using a combination of a blood test for antibodies and a biopsy of the small intestine.1 A life-long gluten-free diet is currently the only treatment available.
It is now widely accepted that gluten sensitivity can also occur in people without coeliac disease. Non-coeliac gluten sensitivity (NCGS), as it is known, is associated with a similar range of acute symptoms to coeliac disease, making it difficult to differentiate between the two conditions based on symptoms alone. NCGS is diagnosed by a process of exclusion and currently there is no biomarker to detect it. It seems likely that NCGS is far more prevalent than coeliac disease, with a recent UK study2 suggesting that, out of every 100 patients with gluten sensitivity referred for specialist investigation, 10 will be diagnosed with coeliac disease and 90 will have NCGS.
"In this study, 13% of adults screened in the general population said they had gluten sensitivity, which is a significant number of people," said Prof. Sanders. "We were very interested to find that the vast majority of individuals referred to secondary care with gluten sensitivity were diagnosed with NCGS and that these people were far less likely to have nutritional deficiencies or autoimmune disorders than the patients diagnosed with coeliac disease."
Prof. Sanders thinks the best way for doctors to approach patients who present with symptoms relating to eating gluten is to focus on excluding coeliac disease using blood tests and, where necessary, gastroscopy with a biopsy of the small bowel. However, he says, physicians need to make sure patients are eating a normal diet at the time of diagnosis. "Any patient who presents saying they have gluten-related symptoms is likely to have placed themselves on a gluten-free diet," he says. "It is essential that these patients stop their gluten-free diet and eat a normal diet in order for us to exclude coeliac disease."
What role for a gluten-free diet in NCGS?
Gluten-free product sales far exceed the number of patients diagnosed with coeliac disease, suggesting that many individuals are deriving symptomatic benefit from a 2 of 2 gluten-free diet. However, says Prof. Sanders, in his opinion, a gluten-free diet should not be prescribed immediately to individuals diagnosed with NCGS.
"I believe we should reassure patients that they do not have coeliac disease and therefore their risk of complications is lower," he said. "We should explain that we, as doctors, are still learning about this condition before discussing with them the possible role of a gluten-free diet in the future. Depending on how symptoms progress after the diagnosis, patients may choose to reintroduce a gluten-free diet at a later date or they may be able to gradually increase their gluten intake."