Non-celiac gluten sensitivity's existence questioned

(HealthDay)—There is no evidence that gluten is a trigger in patients with non-celiac gluten sensitivity (NCGS) placed on a low fermentable, oligo-, di-, monosaccharides, and polyols (FODMAP) diet, according to a study published in the August issue of Gastroenterology.

Jessica R. Biesiekierski, Ph.D., from Monash University in Box Hill, Australia, and colleagues randomly assigned 37 subjects (aged 24 to 61 years; six men) with NCGS and irritable bowel syndrome (based on Rome III criteria), but not celiac disease, to a two-week diet of reduced FODMAPs followed by placement on either a high-gluten (16 g gluten/d), low-gluten (2 g gluten/d and 14 g whey protein/d), or control (16 g whey protein/d) diet for one week, followed by a washout period of at least two weeks. Serum and fecal markers of intestinal inflammation/injury and immune activation were assessed, as were indices of fatigue. Subsequently, 22 participants crossed over to groups given gluten (16 g/d), whey (16 g/d), or control (no additional protein) diets for three days.

The researchers found that gastrointestinal symptoms consistently and significantly improved during reduced FODMAP intake, but significantly worsened to a similar degree when their diets included gluten or whey protein. Only 8 percent of participants had gluten-specific effects. No changes in any biomarkers were diet-specific. Participants' symptoms increased by similar levels among groups during the three-day rechallenge, but gluten-specific gastrointestinal effects were not reproduced. The researchers observed an order effect.

"In a placebo-controlled, cross-over rechallenge study, we found no evidence of specific or dose-dependent effects of gluten in patients with NCGS placed [on] diets low in FODMAPs," the authors write.

One author has published a book on a diet for irritable bowel syndrome.