Non-Celiac Gluten/Wheat Sensitivity: Clinical Characteristics and Microbiota and Mycobiota Composition by Response to the Gluten Challenge Test

Abstract

The aims of this observational “proof-of-concept” study were to analyze the clinical/psychological characteristics and gut microbiota/mycobiota composition of individuals with suspected non-celiac gluten/wheat sensitivity (NCGS/WS) according to responses to the double-blind-placebo-controlled (DBPC) crossover gluten challenge test. Fifty individuals with suspected NCGS/WS were subjected to the DBPC challenge test; anthropometric measurements, psychometric questionnaires, and fecal samples were collected. Twenty-seven (54%) participants were gluten responsive (NCGS), and 23 were placebo responsive, with an order effect. NCGS individuals displayed a significantly lower risk of eating disorders and a higher mental health score when compared to placebo-responsive participants, confirmed by multiple logistic regression analyses (OR = 0.87; 95% CI 0.76–0.98, p = 0.021, and OR = 1.30; 95% CI 1.06–1.59, p = 0.009, respectively). Principal coordinate analyses based on microbiota composition showed a separation by the DBPC response (p = 0.039). For Bacteroides (p = 0.05) and Parabacteroides (p = 0.007), the frequency of amplicon sequence variants was lower, and that for Blautia (p = 0.009) and Streptococcus (p = 0.004) was higher in NCGS individuals at multiple regression analyses. No difference in the mycobiota composition was detected between the groups. In conclusion, almost half of the individuals with suspected gluten sensitivity reported symptoms with placebo; they showed lower mental health scores, increased risk for eating disorders, and a different gut microbiota composition.

Effects of Gluten on Gut Microbiota in Patients with Gastrointestinal Disorders, Migraine, and Dermatitis

“…The bacterial composition was dominated by the phyla Bacteroidetes and Firmicutes in both study groups, with very subtle changes after the intervention ( Figure 3 ). This is consistent with a study that investigated the effect of gluten sensitivity on the microbiota, with the principal coordinate analysis (PCoA) based on gut microbiota composition showing a prevalence of the phylum Bacteroides [ 27 ]. Other bacteria belonging to the phylum Firmicutes have also been implicated in gluten metabolism, mostly of the genus Lactobacillus , followed by Streptococcus , Staphylococcus , and Clostridium [ 28 ].…”

“…This implies that the diversity of fungal species increased in the gluten-free group. This can be due to the GFD and the low-FODMAP diet, which is also low in carbohydrates and fermented foods [ 27 ]. A linear increase was found at the end of the intervention when using Chao1 to compare the fungal and bacterial communities of the placebo group.…”

Skin gluten-related disorders: new and old cutaneous manifestations to be considered

“…In addition, intestinal dysbiosis may contribute to the pathogenesis of NCGS enhancing epithelial barrier dysfunction and associated inflammatory response to gluten, similarly to what has been shown in CD and other inflammatory bowel diseases ( 163 , 164 ). It is unclear whether gliadin is the real responsible of the disease, since other wheat component including amylase-trypsin inhibitors (ATIs), fermentable oligo-di-monosaccharides and polyols have been proposed as triggers ( 165 ).…”

Comparative Quality Assessment of Five Bread Wheat and Five Barley Cultivars Grown in Romania

“…According to the literature, in the case of wheat, non-gluten proteins represent 20–25% of the total mass of proteins, most of which are monomeric [ 43 ]. Albumins and globulins represent about 14% and 22%, respectively.…”