Just one-third of patients who fulfill criteria for non-celiac gluten sensitivity experienced recurrence of symptoms during a double blind gluten challenge in a recent study.
To evaluate the prevalence of non-celiac gluten sensitivity (NCGS) in patients who meet the clinical criteria, were already on a gluten-free diet and in whom celiac disease or wheat allergy was ruled out, researchers from Italy performed a prospective, randomized, double blind, placebo-controlled, crossover challenge study in 35 patients (31 women; mean age, 41 ± 2 years) diagnosed with NCGS between 2008 and 2013.
Participants were randomly assigned to one sachet per day with 10 g gluten-containing or gluten-free flour, which they were instructed to sprinkle over pasta or soup, for 10 days and were then crossed over to the other flour after a 2-week washout period. The primary outcome measure was their ability to identify which flour contained gluten based on their symptom recurrence, and secondary outcome measures included Gastrointestinal Symptoms Rating Scale (GSRS) scores.
Overall, 34% of participants correctly identified the gluten-containing flour, and their GSRS scores were higher after the gluten challenge, including pain (P = .005 vs. baseline), reflux (P = .019), indigestion (P < .001), diarrhea (P = .014) and constipation (P = .033). Conversely, 49% incorrectly identified the gluten-free flour as gluten-containing flour, and their GSRS scores were higher after the gluten-free flour challenge, including pain (P = .005), reflux (P = .006), indigestion (P < .002), diarrhea (P = .001) and constipation (P < .001). Visual Analogue Fatigue Scale scores also were increased after gluten challenge in those classified as having NCGS (P = .024) and after gluten-free flour challenge in those classified as sensitive to gluten-free flour (P < .001).
“In conclusion, our study has shown that gluten challenge leads to a recurrence of symptoms in only a third of patients fulfilling the recognized diagnostic criteria for the clinical diagnosis of NCGS,” the researchers concluded. “Consequently, NCGS is likely to be the correct diagnosis in only a minority of those who do not have [celiac disease], but whom themselves choose to follow a [gluten-free diet]. They are outnumbered by those sensitive to other components, such as FODMAPs, in cereal. The distinction between these patient groups is important clinically, as only patients with NCGS need to adhere strictly to a [gluten-free diet]. Meanwhile, the effectiveness of a low FODMAP diet in cereal intolerant patients, who are not gluten sensitive, deserves further investigation.” – by Adam Leitenberger
Disclosure: The researchers report no relevant financial disclosures.