No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates.

Patients with non-celiac gluten sensitivity (NCGS) do not have celiac disease but their symptoms improve when they are placed on gluten-free diets. We investigated the specific effects of gluten after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates (fermentable, oligo-, di-, monosaccharides, and polyols [FODMAPs]) in subjects believed to have NCGS. We 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. Participants were randomly assigned 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. We assessed serum and fecal markers of intestinal inflammation/injury and immune activation, and indices of fatigue. Twenty-two participants then crossed over to groups given gluten (16 g/d), whey (16 g/d), or control (no additional protein) diets for 3 days. Symptoms were evaluated by visual analogue scales. In all participants, 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. Gluten-specific effects were observed in only 8% of participants. There were no diet-specific changes in any biomarker. During the 3-day rechallenge, participants' symptoms increased by similar levels among groups. Gluten-specific gastrointestinal effects were not reproduced. An order effect was observed. 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 diets low in FODMAPs.

Biesiekierski JR ，Peters SL ，Newnham ED ，Rosella O ，Muir JG ，Gibson PR ... -  《-》

A diet low in FODMAPs reduces symptoms of irritable bowel syndrome.

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) often is used to manage functional gastrointestinal symptoms in patients with irritable bowel syndrome (IBS), yet there is limited evidence of its efficacy, compared with a normal Western diet. We investigated the effects of a diet low in FODMAPs compared with an Australian diet, in a randomized, controlled, single-blind, cross-over trial of patients with IBS. In a study of 30 patients with IBS and 8 healthy individuals (controls, matched for demographics and diet), we collected dietary data from subjects for 1 habitual week. Participants then randomly were assigned to groups that received 21 days of either a diet low in FODMAPs or a typical Australian diet, followed by a washout period of at least 21 days, before crossing over to the alternate diet. Daily symptoms were rated using a 0- to 100-mm visual analogue scale. Almost all food was provided during the interventional diet periods, with a goal of less than 0.5 g intake of FODMAPs per meal for the low-FODMAP diet. All stools were collected from days 17-21 and assessed for frequency, weight, water content, and King's Stool Chart rating. Subjects with IBS had lower overall gastrointestinal symptom scores (22.8; 95% confidence interval, 16.7-28.8 mm) while on a diet low in FODMAPs, compared with the Australian diet (44.9; 95% confidence interval, 36.6-53.1 mm; P < .001) and the subjects' habitual diet. Bloating, pain, and passage of wind also were reduced while IBS patients were on the low-FODMAP diet. Symptoms were minimal and unaltered by either diet among controls. Patients of all IBS subtypes had greater satisfaction with stool consistency while on the low-FODMAP diet, but diarrhea-predominant IBS was the only subtype with altered fecal frequency and King's Stool Chart scores. In a controlled, cross-over study of patients with IBS, a diet low in FODMAPs effectively reduced functional gastrointestinal symptoms. This high-quality evidence supports its use as a first-line therapy. ACTRN12612001185853.

Halmos EP ，Power VA ，Shepherd SJ ，Gibson PR ，Muir JG ... -  《-》

Evaluation of Non-Celiac Gluten Sensitivity in Patients with Previous Diagnosis of Irritable Bowel Syndrome: A Randomized Double-Blind Placebo-Controlled Crossover Trial.

Barone M ，Gemello E ，Viggiani MT ，Cristofori F ，Renna C ，Iannone A ，Di Leo A ，Francavilla R ... -  《Nutrients》

Fructan, Rather Than Gluten, Induces Symptoms in Patients With Self-Reported Non-Celiac Gluten Sensitivity.

Non-celiac gluten sensitivity is characterized by symptom improvement after gluten withdrawal in absence of celiac disease. The mechanisms of non-celiac gluten sensitivity are unclear, and there are no biomarkers for this disorder. Foods with gluten often contain fructans, a type of fermentable oligo-, di-, monosaccharides and polyols. We aimed to investigate the effect of gluten and fructans separately in individuals with self-reported gluten sensitivity. We performed a double-blind crossover challenge of 59 individuals on a self-instituted gluten-free diet, for whom celiac disease had been excluded. The study was performed at Oslo University Hospital in Norway from October 2014 through May 2016. Participants were randomly assigned to groups placed on diets containing gluten (5.7 g), fructans (2.1 g), or placebo, concealed in muesli bars, for 7 days. Following a minimum 7-day washout period (until the symptoms induced by the previous challenge were resolved), participants crossed over into a different group, until they completed all 3 challenges (gluten, fructan, and placebo). Symptoms were measured by Gastrointestinal Symptom Rating Scale Irritable Bowel Syndrome (GSRS-IBS) version. A linear mixed model for analysis was used. Overall GSRS-IBS scores differed significantly during gluten, fructan, and placebo challenges; mean values were 33.1 ± 13.3, 38.6 ± 12.3, and 34.3 ± 13.9, respectively (P = .04). Mean scores for GSRS-IBS bloating were 9.3 ± 3.5, 11.6 ± 3.5, and 10.1 ± 3.7, respectively, during the gluten, fructan, and placebo challenges (P = .004). The overall GSRS-IBS score for participants consuming fructans was significantly higher than for participants consuming gluten (P = .049), as was the GSRS bloating score (P = .003). Thirteen participants had the highest overall GSRS-IBS score after consuming gluten, 24 had the highest score after consuming fructan, and 22 had the highest score after consuming placebo. There was no difference in GSRS-IBS scores between gluten and placebo groups. In a randomized, double-blind, placebo-controlled crossover study of individuals with self-reported non-celiac gluten sensitivity, we found fructans to induce symptoms, measured by the GSRS-IBS. Clinicaltrials.gov no: NCT02464150.

Skodje GI ，Sarna VK ，Minelle IH ，Rolfsen KL ，Muir JG ，Gibson PR ，Veierød MB ，Henriksen C ，Lundin KEA ... -  《-》

[Non-celiac gluten sensitivity: a critical review of current evidence].

Non-celiac gluten sensitivity (NCGS) is an emerging disorder characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food in non-celiac patients. Its prevalence has been estimated to be six to ten-times higher than that of celiac disease (CD). A gluten-free diet is the most widely recommended therapy, but the causative agent remains unknown and there are no consensus diagnostic criteria. Recent studies on NCGS have included patients with possibly overlooked minor CD and diarrhea-predominant irritable bowel syndrome without self-reported gluten intolerance, but showing a response to a gluten-free diet. Furthermore, FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols) have recently been postulated as the culprit component for NCGS in wheat, instead of gluten. This review updates evidence on the pathophysiology of NCGS and the efficacy of different dietary interventions in its treatment, stressing the need for proper screening for CD before a diagnosis of NCGS is made.

Molina-Infante J ，Santolaria S ，Montoro M ，Esteve M ，Fernández-Bañares F ... -  《-》