Patients with Suspected NCGS Not Able to Identify When Challenged with Gluten

gluten challengeThe effect of a controlled gluten challenge in a group of patients with suspected non-coeliac gluten sensitivity: A randomized, double-blind placebo-controlled challenge.

  • John Wiley & Sons Ltd, Neurogastroenterology & Motility 1


  1. Twenty patients (14F/6M, age range: 21-62 years) with suspected NCGS, without coeliac disease and wheat-allergy, were included while on a gluten-free diet.
  2. All patients went through four periods of double-blinded provocation, two with gluten and two with placebo in randomized order.
  3. They consumed two muffins a day (11/0 g gluten) for 4 days, followed by a 3-day wash-out.
  4. Gastrointestinal symptoms were recorded with questionnaires at baseline and after each provocation.
  5. We also investigated whether patients were able to correctly identify periods with gluten-exposure.


  1. Collectively the whole group reported the most severe symptoms after placebo (P = .012).
  2. Four out of twenty patients correctly identified the two periods when they received gluten, hence were diagnosed with NCGS.
  3. The diagnosed-group tended to show higher symptom scores than the not-diagnosed group both at baseline, after gluten exposure and after placebo, but no clear difference was seen between provocation with gluten and placebo.
  4. The not-diagnosed group showed more severe symptoms with placebo than with gluten (P = .029).


  • The present study showed that the majority of patients with suspected NCGS are not able to identify when challenged with gluten in a double-blind placebo-controlled food challenge, indicating that gluten is not the cause of their symptoms.


The effect of a controlled gluten challenge in a group of patients with suspected non‐coeliac gluten sensitivity: A randomized, double‐blind placebo‐controlled challenge

First published: 15 March 2018 –