Predictivity of Autoimmune Stigmata for Gluten Sensitivity in Subjects with Microscopic Enteritis: A Retrospective Study

Doubtful Justification of the Gluten-Free Diet in the Course of Hashimoto's Disease

The popularization of the gluten-free diet brings with it a fashion for its use, which can harm the treatment of Hashimoto's disease. The few studies in this regard do not confirm positive changes resulting from a gluten-free diet. At the same time, the presence of other comorbid autoimmune diseases in this group of patients is increasing. This may have important implications for the interpretation of test results and the need for a gluten-free diet in some patients. In this review, the PubMed database was searched for links between a gluten-free diet, Hashimoto's disease, and autoimmune diseases. When analyzing the available literature, we found no basis for introducing a gluten-free diet for the standard management of Hashimoto patients. The recommended diet is instead an anti-inflammatory diet that levels the supply (to compensate for deficiencies) of vitamin D, iodine, and selenium, which are found in plant products rich in polyphenols, antioxidants, and omega-3 fatty acids, as illustrated in this article.

Autoimmunity Features in Patients With Non-Celiac Wheat Sensitivity

INTRODUCTION

Nonceliac wheat sensitivity (NCWS) is characterized by intestinal and extraintestinal manifestations consequent to wheat ingestion in subjects without celiac disease and wheat allergy. Few studies investigated the relationship between NCWS and autoimmunity. The aim of this study is to evaluate the frequency of autoimmune diseases (ADs) and autoantibodies in patients with NCWS.

METHODS

Ninety-one patients (13 men and 78 women; mean age of 40.9 years) with NCWS, recruited in a single center, were included. Seventy-six healthy blood donors (HBD) and 55 patients with a diagnosis of irritable bowel syndrome (IBS) unrelated to NCWS served as controls. Autoantibodies levels were measured. Human leukocyte antigen haplotypes were determined, and duodenal histology performed in all patients carrying the DQ2/DQ8 haplotypes. Participants completed a questionnaire, and their medical records were reviewed to identify those with ADs.

RESULTS

Twenty-three patients with NCWS (25.3%) presented with ADs; autoimmune thyroiditis (16 patients, 17.6%) was the most frequent. The frequency of ADs was higher in patients with NCWS than in HBD (P = 0.002) and in patients with IBS (P = 0.05). In the NCWS group, antinuclear antibodies tested positive in 71.4% vs HBD 19.7%, and vs patients with IBS 21.8% (P < 0.0001 for both). The frequency of extractable nuclear antigen antibody (ENA) positivity was significantly higher in patients with NCWS (21.9%) than in HBD (0%) and patients with IBS (3.6%) (P = 0.0001 and P = 0.004, respectively). Among the patients with NCWS, 9.9% tested positive for antithyroglobulin, 16.5% for antithyroid peroxidase, and 14.3% for antiparietal cell antibodies; frequencies were not statistically different from controls. The presence of ADs was related to older age at NCWS diagnosis, female sex, duodenal lymphocytosis, and eosinophil infiltration.

DISCUSSION

One in 4 patients with NCWS suffered from AD, and serum antinuclear antibodies were positive in a very high percentage of cases. These data led us to consider NCWS to be associated to ADs.

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

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.

Current Evidence on the Efficacy of Gluten-Free Diets in Multiple Sclerosis, Psoriasis, Type 1 Diabetes and Autoimmune Thyroid Diseases

In this review, we summarize the clinical data addressing a potential role for gluten in multiple sclerosis (MS), psoriasis, type 1 diabetes (T1D) and autoimmune thyroid diseases (ATDs). Furthermore, data on the prevalence of celiac disease (CD) and gluten-related antibodies in the above patient groups are presented. Adequately powered and properly controlled intervention trials investigating the effects of a gluten-free diet (GFD) in non-celiac patients with MS, psoriasis, T1D or ATDs are lacking. Only one clinical trial has studied the effects of a GFD among patients with MS. The trial found significant results, but it is subject to major methodological limitations. A few publications have found beneficial effects of a GFD in a subgroup of patients with psoriasis that were seropositive for anti-gliadin or deamidated gliadin antibodies, but no effects were seen among seronegative patients. Studies on the role of gluten in T1D are contradictive, however, it seems likely that a GFD may contribute to normalizing metabolic control without affecting levels of islet autoantibodies. Lastly, the effects of a GFD in non-celiac patients with ATDs have not been studied yet, but some publications report that thyroid-related antibodies respond to a GFD in patients with concomitant CD and ATDs. Overall, there is currently not enough evidence to recommend a GFD to non-celiac patients with MS, psoriasis, ATDs or T1D.

Gluten Vehicle and Placebo for Non-Celiac Gluten Sensitivity Assessment

Non-celiac gluten sensitivity (NCGS) is a syndrome characterized by gastrointestinal and extraintestinal manifestations triggered after gluten ingestion in the absence of celiac disease and wheat allergy. Because of the lack of biomarkers for NCGS diagnosis, the cornerstone for its assessment is a single- or double-blind placebo-controlled (DBPC) gluten challenge. However, there are some non-standardized points in the diagnostic approach proposed by the experts. This complicate comparisons among the results published by different research groups. The gluten vehicle and placebo must be indistinguishable from each other, which entails sensory and technological evaluations of the designed gluten vehicle and placebo products. At the moment, there is no standardized method for the preparation of the gluten vehicle and placebo for carrying out DBPC gluten challenges for NCGS assessment. This review focuses on the challenges that researchers have to face, either for the development of an accepted gluten vehicle and placebo or for identifying NCGS cases on the basis of DBPC gluten challenges.