Celiac.com 09/23/2013 - Patients with non-celiac gluten sensitivity (NCGS) do not have celiac disease, but see an improvement in symptoms when they adopt gluten-free diets.
A team of researchers recently investigated the specific effects of gluten after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates (fermentable, oligo-, di-, monosaccharides, and polyols [FODMAPs]) in patients with suspected NCGS.
The team performed a double-blind cross-over trial of 37 subjects (aged 24−61 y, 6 men) with NCGS and irritable bowel syndrome (based on Rome III criteria), but not celiac disease.
They assigned study participants randomly to groups given a 2-week diet of reduced FODMAPs, and were then placed on 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) diets for 1 week, followed by a washout period of at least 2 weeks.
The researchers then evaluated serum and fecal markers of intestinal inflammation/injury and immune activation, and indices of fatigue.
The team then crossed twenty-two participants over to groups receiving gluten (16 g/d), whey (16 g/d), or control (no additional protein) diets for 3 days, using visual analogue scales to evaluate symptoms.
They found that gastrointestinal symptoms consistently and significantly improved for all patients during reduced FODMAP intake, but significantly worsened to a similar degree when their diets included gluten or whey protein.
The team saw gluten-specific effects in just 8% of study subjects. They saw no diet-specific changes in any biomarker. During the 3-day re-challenge, participants’ symptoms increased by similar levels among groups. Gluten-specific gastrointestinal effects were not reproduced. An order effect was observed.
A placebo-controlled, cross-over re-challenge study showed no evidence of specific or dose-dependent effects of gluten in patients with NCGS placed diets low in FODMAPs.