Prebiotic Supplementation During Gestation Induces a Tolerogenic Environment and a Protective Microbiota in Offspring Mitigating Food Allergy

Food allergy is associated with alterations in the gut microbiota, epithelial barrier, and immune tolerance. These dysfunctions are observed within the first months of life, indicating that early intervention is crucial for disease prevention. Preventive nutritional strategies with prebiotics are an attractive option, as prebiotics such as galacto-oligosaccharides and inulin can promote tolerance, epithelial barrier reinforcement, and gut microbiota modulation. Nonetheless, the ideal period for intervention remains unknown. Here, we investigated whether galacto-oligosaccharide/inulin supplementation during gestation could protect offspring from wheat allergy development in BALB/cJRj mice. We demonstrated that gestational prebiotic supplementation promoted the presence of beneficial strains in the fecal microbiota of dams during gestation and partially during mid-lactation. This specific microbiota was transferred to their offspring and maintained to adulthood. The presence of B and T regulatory immune cell subsets was also increased in the lymph nodes of offspring born from supplemented mothers, suggestive of a more tolerogenic immune environment. Indeed, antenatal prebiotic supplementation reduced the development of wheat allergy symptoms in offspring. Our study thus demonstrates that prebiotic supplementation during pregnancy induces, in the offspring, a tolerogenic environment and a microbial imprint that mitigates food allergy development.

Cross-reactivity of each fraction among cereals in children with wheat allergy

Background: Cross-reactivity between wheat and other cereals is an essential issue in the management of wheat allergy. Few studies have reported in vitro cross-reactivity in immediate-type wheat allergy. This study aimed to examine cross-reactivity of the three fractions (albumin/globulin, gliadin, and glutenin fractions) among cereals in children with wheat allergy. Methods: Sera from 128 children with immediate-type wheat allergy were collected. We measured specific immunoglobulin E (sIgE) levels against each fraction of wheat, barley, and rye by using an enzyme-linked immunosorbent assay (ELISA). Cross-reactivities of each fraction among wheat, barley, and rye were examined via inhibition ELISA. Results: All subjects were sensitized to all the fractions of wheat, and also those of barley and rye. The wheat sIgE levels were significantly higher than those of barley and rye in all the fractions (p ≤ 0.001) and were significantly correlated with sIgE levels to them in each fraction (r = 0.887–0.969, p < 0.001). On inhibition ELISA, wheat inhibited the IgE binding to most of the solid phases at the lower protein levels compared to barley and rye in all fractions. Conclusions: In children with immediate-type wheat allergy, sensitization to all the three fractions of wheat was observed. In addition, they showed sensitization to barley and rye caused by in vitro cross-reactivity with wheat in each fraction. When managing children with wheat allergy, sensitization to barley and rye caused by the cross-reactivities should be considered.

Clinical Features of Wheat Allergy Are Significantly Different between Tri a 14 Sensitized Patients and Tri a 19 Sensitized Ones

<b><i>Introduction:</i></b> Wheat is the most important cereal for human nutrition but its high consumption is associated to an increasing complaint of wheat-related disorders, many of which are allergic in nature and different in respect to the involved allergens. In this study, we compared the clinical aspects of wheat allergy presented by patients sensitized to Tri a 19 in respect to those presented by patients sensitized to Tri a 14. <b><i>Methods:</i></b> With this aim, we selected patients sensitized to 1 or both of the 2 allergens, and among these we identified those who were really wheat allergic and reactive on the basis of a standardized methodology. We evaluated the clinical features such as the kind and severity of symptoms, the coexistence of triggering factors such as physical exercise and NSAIDs and alcohol consumption, and the association with other allergens and with various immunologic parameters. Wheat allergy in Tri a 19 sensitized patients was confirmed through a questionnaire while the patients sensitized to Tri a 14 underwent wheat challenge with 100 g of pasta followed by exercise on a treadmill. <b><i>Results:</i></b> Seventy-nine patients sensitized to Tri a 14 and 40 patients sensitized to Tri a 19 were recruited. The 2 sensitizations were independent with a significant inverse relation (<i>p</i> &#x3c; 0.00001). The Tri a 19 sensitized patients presented, in respect to the Tri a 14 sensitized ones, an older age (<i>p</i> = 0.0017), a higher risk to be wheat allergic (<i>p</i> &#x3c; 0.0001), a higher severity of the reactions (<i>p</i> &#x3c; 0.00001) and a higher association with some cofactors, namely alcohol (<i>p</i> &#x3c; 0.0005) and physical exercise (<i>p</i> = 0.003). On the contrary, Tri a 14 sensitization was associated with atopy (<i>p</i> &#x3c; 0.0001), with a higher probability of patients being asymptomatic (<i>p</i> &#x3c; 0.0001) and being sensitized to other foods, in particular to nuts and cereals (<i>p</i> &#x3c; 0.00001). <b><i>Conclusions:</i></b> Sensitization to Tri a 19 or Tri a 14 determines different clinical pictures. In particular, sensitization to Tri a 19 implies a higher probability of severe reactions, even dependent on daily triggers, while that to Tri a 14 implies a higher cross-reactivity with other foods but it’s more frequently asymptomatic, making a food challenge necessary to prevent useless food avoidance.

The clinical cross-reactivity and immunological cross-antigenicity of wheat and barley

Background: Some patients with a wheat allergy have been reported to show clinical cross-reactivity to barley. However, it is not clear whether the development of barley allergy in patients with a wheat allergy is due to cross-antigenicity between wheat and barley. In our study, we aimed to determine the clinical cross-reactivity and immunological cross-antigenicity of wheat and barley. Methods: We compared the results of barley oral food challenges (OFCs) before oral immunotherapy (OIT) for wheat with those after OIT in nine patients with a wheat allergy to estimate the clinical cross-reactivity of wheat and barley. Moreover, we performed enzyme-linked immunosorbent assay (ELISA) inhibition and immunoblotting inhibition using serum from seven patients allergic to wheat and barley. Results: Nine patients who had positive barley-OFC results performed before OIT for wheat were all negative on barley-OFC performed after OIT. In ELISA inhibition, preincubation of serum from patients allergic to wheat and barley with a high barley extract concentration inhibited binding of IgE to wheat extract by less than 10%. On the other hand, wheat and barley extracts equally inhibited binding to barley sIgE at high concentrations. In the immunoblotting inhibition test, the spots of wheat were inhibited but weakly by barley extracts, and most of the spots of barley were inhibited even by low concentrations of the wheat and barley extract. Conclusion: We showed that barley allergy associated with wheat allergy is caused by cross-reactivity from wheat. The OIT for wheat was one of the promising options for barley allergy.

Non-Celiac Gluten Sensitivity in Children: Controversial Role of Gluten and Diagnostic Enigma

Non-celiac gluten sensitivity (NCGS) is a debatable condition that affects less than 6% of children. The absence of specific diagnostic markers and standardized diagnostic procedures make the diagnosis of NCGS challenging, covering patients with different and varied symptoms. Generally, the parents of small and younger children introduce a gluten-free diet (GFD) based on their personal experiences and expectations. Additionally, a “fad component” exists, contributing to the recent rise in the popularity of GFD. Thus, celiac disease (CD) and wheat allergy (WA) must be excluded as these also appear in individuals experiencing symptoms similar to those of NCGS, improving and worsening with gluten withdrawal and consumption, respectively. The role of gluten inducing gastrointestinal symptoms in individuals with self-reported NCGS has been skeptically assessed based on evidence in recent years. However, currently, it is unknown whether a strict GFD is necessary for patients with NCGS. Thus, the placebo-controlled gluten challenge remains the gold standard for a challenging diagnosis like NCGS. The present review evaluates the published studies based largely on the adult population and describes the key elements in diagnosing NCGS and differential diagnosis with CD and WA.

Profiling serum antibodies with a pan allergen phage library identifies key wheat allergy epitopes

Allergic reactions occur when IgE molecules become crosslinked by antigens such as food proteins. Here we create the ‘AllerScan’ programmable phage display system to characterize the binding specificities of anti-allergen IgG and IgE antibodies in serum against thousands of allergenic proteins from hundreds of organisms at peptide resolution. Using AllerScan, we identify robust anti-wheat IgE reactivities in wheat allergic individuals but not in wheat-sensitized individuals. Meanwhile, a key wheat epitope in alpha purothionin elicits dominant IgE responses among allergic patients, and frequent IgG responses among sensitized and non-allergic patients. A double-blind, placebo-controlled trial shows that alpha purothionin reactivity, among others, is strongly modulated by oral immunotherapy in tolerized individuals. AllerScan may thus serve as a high-throughput platform for unbiased analysis of anti-allergen antibody specificities.

Gluten-related disorders

Gluten-related disorders are a heterogeneous group of clinical entities caused by intolerance of wheat, rye, and barley flour components. They occur in 3-5% of genetically predisposed persons and based on pathogenic and clinical features are classified into celiac disease, non-celiac gluten sensitivity, and wheat allergy. There are also specific entities such as dermatitis herpetiformis or gluten ataxia, which can occur either within the celiac disease or independently. This article based on the current knowledge shows the basic details of the pathogenesis, clinical expression, diagnosis, and treatment of these disorders.