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Tritordeum - a novel cereal for food processing with good acceptability and significant reduction in gluten immunogenic peptides in comparison with wheat: Tritordeum, a novel cereal with good acceptability and low coeliac peptides
Abstract
Background:
Tritordeum is a novel cereal obtained from the hybridisation between durum wheat and a wild barley. This study evaluates acceptance, digestibility and immunotoxic properties of tritordeum, a novel cereal for food processing. Nineteen healthy volunteers participated in a study with different diets to compare tritordeum bread with wheat and gluten-free breads.
Results:
Tritordeum breads had a similar acceptance to the wheat bread usually consumed and the acceptance was significantly higher than the gluten-free bread and the standardized wheat bread supplied in the study. There was no evidence for gastrointestinal symptoms among volunteers during the study. The reductions in the numbers of immunogenic epitopes in tritordeum in comparison with wheat were 78% for α-gliadins, 57% for γ-gliadins, and 93% for ω-gliadins. The analysis of gluten immunogenic peptides (GIP) in stool samples showed a significantly lower excretion in the tritordeum ingestion phase than in the wheat ingestion phase.
Conclusions:
These results suggest that tritordeum may be an option of interest for general food processing, and especially for those who want to reduce their intake of gluten. However, it is not suitable for celiac disease sufferers as it contains gluten.
... durum) and the perennial wild barley species Hordeum chilense (Martin et al. 1999). Tritordeum is adapted to the same Mediterranean environments as durum wheat but has rheological and baking performances similar to those of bread wheat (Martin et al., 1999) with good organoleptic properties and high consumer acceptability (Vaquero et al., 2017;Sánchez-León et al., 2020). It is typically grown as a winter-sown crop and is most competitive under Mediterranean-type conditions of relatively warm winters with rainfall in Autumn and Spring as it makes strong vegetative growth during the winter months. ...
... For example, it has been reported to have higher contents of a range of phytochemicals (carotenoids, xanthophylls, phenolic acids) (Atienza et al., 2007;Giordano et al., 2019;Suchowilska et al., 2021). Furthermore, it has been suggested to have a lower content of indigestible gliadin peptides and amylase trypsin inhibitors which may induce inflammation and intestinal barrier disfunction, and therefore to be more suitable for individuals suffering from adverse reactions to wheat (Vaquero et al., 2017;Sánchez-León et al., 2020;Haro et al., 2022;Nitride et al., 2022;Russo et al., 2022). However, only a few comparative studies of the grain compositions of tritordeum and wheat have been reported and further work is required to establish the extent of variation in composition between genotypes and grain samples grown under different conditions. ...
... Tritordeum is promoted as a novel cereal with health benefits. These claims are partly based on a reported reduction in gluten immunogenic peptides compared to bread wheat, although it is clearly not suitable for those with coeliac disease (Vaquero et al., 2017). However, they are also based on the higher contents of specific types of fibre, minerals and "beneficial phytochemicals" reported here and discussed above. ...
Three genotypes each of bread wheat, durum wheat and tritordeum were grown in randomized replicated field trials in Andalusia (Spain) for two years and wholemeal flours analysed for a range of components to identify differences in composition. The contents of all components that were determined varied widely between grain samples of the individual species and in most cases also overlapped between the three species. Nevertheless, statistically significant differences between the compositions of the three species were observed. Notably, tritordeum had significantly higher contents of protein, some minerals (magnesium and iron), total phenolics and methyl donors. Tritordeum also had higher levels of total amino acids (but not asparagine) and total sugars, including raffinose. By contrast, bread wheat and tritordeum had similar contents of the two major dietary fibre components in white flour, arabinoxylan and β-glucan, with significantly lower contents in durum wheat.
... Different strategies have been explored to eliminate or reduce the content of immunogenic proteins in wheat flour-related foods, ranging from treatment with specific proteases, supplemental intake of probiotics (i.e., live bacteria or yeasts with proteolytic activity) to the development of wheat varieties or interspecific hybrids by specific breeding of lines carrying desired traits that produce grains with a lower content of immunogenic peptides [13][14][15][16]. ...
... However, the samples taken at 24 h and 48 h from W. anomalus dough revealed a lower content of gliadins, consistent with partial hydrolysis of the gliadin proteins. Consistent with that already described by other authors, tritordeum gliadins (TF) displayed a different protein pattern than wheat flour [16]. As expected, gliadin proteins were not obtained from soybean (SF) ( Figure 5, last line) since soybean is a plant that cannot synthesize prolamin storage proteins [33]. ...
... However, this effect has not been explicitly reported before, although Brzozowski´s works seem to infer some contribution from the baking process to proteolysis in the bread samples [55]. Also, Vaquero et al. (2018) [16] found a marked decrease in gliadins in wheat and tritordeum bread after baking, although they did not analyze gliadin content before. Therefore, it is impossible to know if the decrease in gliadins was due only to baking or fermentation. ...
Gliadins proteins make up around 30% of total wheat flour proteins. They are involved in many immune disorders affecting an increasing number of people who eat foods made with wheat flour. The triggering factor is the accumulation in the gut of immunogenic peptides derived from incomplete degradation of gliadins by gastric proteases. Previous research has revealed the effectiveness of sourdough-fermentation technology or related lactic acid bacteria in reducing wheat flour allergenic proteins. However, there are no single yeast cultures for producing reduced allergenicity wheat products. This study evaluated sourdough-related yeast Wickerhamomyces anomalus strains for their ability to hydrolyze gliadin proteins. All yeast strains were able to degrade gliadins and use them as carbon and nitrogen sources. The proliferation of the yeast strains depended on the gliadin addition; complete hydrolysis was observed after 24 h. The strain showing higher proteolytic activity fermented, acceptably wheat flour dough. The gliadin content of the leavened dough was reduced by 50%. Bread made from the W. anomalus-fermented dough showed a 78% reduction in immunogenic α-gliadins. 50% of the decrease was attributed to the proteolytic activity of the yeast cells, and the other 35% to the baking process. These results show the potential of the yeast W. anomalus as a starter for reducing immunogenicity wheat products.
... We have shown that pseudogenes were strongly ligated to the subgenomes A and B, mainly for the alpha-gliadins. The high rate of pseudogenes detected in durum wheat and tritordeum could contribute to explaining the lower immunogenicity reported for these genotypes (Auricchio et al., 1982;Vaquero et al., 2018). However, both durum wheat and tritordeum are cereals containing gluten and therefore not suitable for celiac patients. ...
... Overall, there is a strong relationship between the CD epitope subgenomes and their immunogenicity, those with the highest immunogenic potential the ones from the A-and, mainly, the D-subgenome (Halstead-Nussloch et al., 2021). Thus, durum wheat and tritordeum genotypes would have a lower immune response in CD patients and fewer gluten immunogenic peptides (GIPs) are expected in the excretion of healthy individuals (Auricchio et al., 1982;Vaquero et al., 2018). However, there was a high heterogeneity of the alpha-gliadin amplicon abundance profile from the three subgenomes in bread wheat, so there are genotypes with a low-immunogenic potential as they have clustered together with the durum wheat and tritordeum: Relmo Siriri and THA85, for example. ...
The development of low-gluten immunogenic cereal varieties is a suitable way to fight the increment of pathologies associated with the consumption of cereals. Although RNAi and CRISPR/Cas technologies were effective in providing low-gluten wheat, the regulatory framework, particularly in the European Union, is an obstacle to the short- or medium-term implementation of such lines. In the present work, we carried out a high throughput amplicon sequencing of two highly immunogenic complexes of wheat gliadins in a set of bread and durum wheat, and tritordeum genotypes. Bread wheat genotypes harboring the 1BL/1RS translocation were included in the analysis and their amplicons successfully identified. The number of CD epitopes and their abundances were determined in the alpha- and gamma-gliadin amplicons, including 40k-γ-secalin ones. Bread wheat genotypes not containing the 1BL/1RS translocation showed a higher average number of both alpha- and gamma-gliadin epitopes than those containing such translocation. Interestingly, alpha-gliadin amplicons not containing CD epitopes accounted for the highest abundance (around 53%), and the alpha- and gamma-gliadin amplicons with the highest number of epitopes were present in the D-subgenome. The durum wheat and tritordeum genotypes showed the lowest number of alpha- and gamma-gliadin CD epitopes. Our results allow progress in unraveling the immunogenic complexes of alpha- and gamma-gliadins and can contribute to the development of low-immunogenic varieties within precision breeding programs, by crossing or by CRISPR/Cas gene editing.
... Tritordeum brings together the nutritional content of durum wheat and barley (Suchowilska et al., 2021) to become as one of the most sustainable food ingredients, which can withstand climate change without impacting the environment ("Tritordeum," 2018). Recently, Tritordeum was introduced in the European market as novel cereal and also proposed as a suitable cereal for the reduction of gluten sensitivity compared to wheat (Vaquero et al., 2018). Tritordeum flour has a low gluten content and this can be further reduced through gluten degradation during sourdough fermentation Dingeo et al., 2020). ...
... This result is consistent with the dominance of LAB from day 5 onwards, which have been recognized for their esterase activity and ability to hydrolyze complex phenolic compounds and their glycosylated forms into the corresponding phenolic acids (Nionelli et al., 2014). Tritordeum has been reported as a rich source of dietary fibers attributed to its barley component (Vaquero et al., 2018), and the brewer's spent grain (BSG) derived from Tritordeum has been used to increase the nutritional content of durum pasta (Nocente et al., 2021). The total dietary fiber content increased during propagations, with IDF content higher than SDF. ...
The novel cereal ‘Tritordeum’ was employed in sourdough fermentation for bread making using a traditional backslopping procedure over 10 days. Culture-dependent and culture-independent approaches were used to characterize microbial ecology during sourdough preparation and propagation. Sourdough reached the highest microbial diversity after three days of propagation. Microbial diversity decreased as sourdough reached maturity (day 5). Microbiota dominance shifted from Weisella to Lactiplantibacillus genera after 5 days of propagation. Lactic acid bacteria (LAB) showed a constant increase throughout the propagations starting from 3.9 ± 0.24 log CFU g⁻¹ on day 0 up to 8.0 ± 0.39 log CFU g⁻¹ on day 5. Weisella confusa/cibaria and Weissella paramesenteroides were the most prevalent LAB species until day 5 of propagation, while Lactiplantibacillus plantarum was the most prevalent thereafter. Yeasts were present in low cell density (2.0 ± 0.11 log CFU g⁻¹) until the fourth backslopping (day 4) and then gradually increased until day 10 (5.0 ± 0.29 log CFU g⁻¹), with Saccharomyces cerevisiae being the most prevalent and dominant species. Lactic and acetic acid concentrations increased throughout Tritordeum sourdough propagations, indicative of a proportional decrease of fermentation quotient (lactic acid/acetic acid) from 13.54 ± 1.29 to 4.08 ± 0.15. Utilization of glucose, fructose and sucrose was observed, followed a progressive increase in mannitol concentrations beginning from day 4. The nutritional potential (total phenol content, antioxidant activity, dietary fiber content and total free amino acids) remained elevated during sourdough propagations. Antinutritional factors (phytic acid and raffinose) were reduced to minimal concentrations by day 10. Finally, texture analysis of Tritordeum sourdough bread was demonstrated to have better cohesiveness, resilience and firmness compared to baker's yeast bread, confirming its potential to improve functionality and use in sourdough biotechnology.
... This crop was developed in 1977 by the Spanish National Research Council and was recently commercialized due to its interesting nutritional profile and higher resilience to hot and dry climates than wheat. 34,35 Triticale, a hybrid crop obtained by crossing Triticum and Secale with the intent to combine the yield potential and quality of wheat with the environmental tolerance of rye, also presented a frequent incidence of contamination, in agreement with previous results. 32,33 This may indicate for both hybrids a susceptibility tract inherited from the parent lines. ...
Ergot alkaloids (EAs), mycotoxins produced mainly by fungi of the Claviceps genus, have been frequently reported in rye, while their increasingly frequent occurrence in other cereals is likely related to weather conditions, with the incidence of ergot sclerotia in winter grains being related to heavy rainfall and moist soils at critical periods. However, compared to other regulated mycotoxins, data about the prevalence and occurrence of EAs in major and minor cereals harvested in the Mediterranean growing areas are still scant. In this regard, the current study reported the occurrence of EAs in 18 genotypes of winter cereals harvested over 3 years from an experimental field located in North Italy which were analyzed by HPLC−MS/MS. Results indicate a widespread occurrence of all the major EAs in all the considered cereal crops, especially under supportive meteorological conditions. EA contamination was dependent on the harvest year (p < 0.0001) which was particularly high in 2020 for all the considered species. The results also demonstrated a large co-occurrence of EAs with 98 cereal samples out of 162 contaminated with at least one of the 12 EAs (60% positive samples) in the range LOD: 15,389 μg/kg (median value: 2.32 μg/kg), expressed as the sum of the EAs. Rye was confirmed to be the crop more susceptible to the fungal infection (EAs content up to 4,302 μg/kg). To the best of our knowledge, we have reported the accumulation of EAs in tritordeum (LOD: 15,389 μg/kg) and in emmer (LOD: 1.9 μg/kg) for the first time.
... However, its benefits include tolerance to biotic [63] and abiotic [62] stresses, better performance under organic farming compared with conventional management than durum wheat [64], high nitrogen use efficiency [65], desirable brewing properties [66], and the potential of incorporating brewers' spent grain in durum wheat pasta to improve its nutritional value [67]. Its flour is more similar to bread wheat than to those of its progenitor durum wheat, being suitable for end-use products similar to those of bread wheat and with a considerable reduction in gluten content, and high levels of protein, carotenoids, and essential minerals [68][69][70]. Thus, tritordeum offers several advantages compared with durum and bread wheat, although it is desirable to increase its productivity by using high-yielding parental modern durum wheats in place of the original ones. ...
In recent decades, genetic advances in yield improvement in the major cereal crops, including wheat, has stagnated or proceeded at a slower rate than is required to meet future global food demand, particularly in the face of climate change. To reverse this situation, and in view of the future climate scenario, there is a need to increase the genetic diversity of wheat to increase its productivity, quality, stability, and adaptation to local agro-environments. The abundant genetic resources and literature are a basis for wheat improvement. However, many species, such as wild relatives, landraces, and old cultivars have not been studied beyond their agronomic characteristics, highlighting the lack of understanding of the physiological and metabolic processes (and their integration) associated with higher productivity and resilience in limiting environments. Retrospective studies using wheat ancestors and modern cultivars may identify novel traits that have not previously been considered, or have been underestimated, during domestication and breeding, but that may contribute to future food security. This review describes existing wheat genetic diversity and changes that occurred during domestication and breeding, and considers whether mining natural variation among wheat ancestors offers an opportunity to enhance wheat agronomic performance, spike architecture, canopy- and organ-level photosynthetic capacity, and responses to abiotic stress, as well as to develop new wheat hybrids.
... Beyond symptoms, TBD has been demonstrated to ameliorate a series of pathophysiological parameters in IBS-D patients, such as altered intestinal permeability, a proinflammatory immunological profile, and dysbiosis [15]. As reported elsewhere [15,16,29], the reduced contents of gliadin, fructans, and carbohydrates in this cereal seem responsible for the improved symptom profile. In the present study, our attention was focused on abdominal bloating. ...
Most female patients with irritable bowel syndrome (IBS) complain of abdominal bloating rather than abdominal pain and diarrhea. The higher incidence in women could be due to the so-called dysfunctional gas handling. Since diet seems the most effective and durable strategy for managing IBS symptoms, we aimed to evaluate the effects of a 12 week diet based on a relatively new cereal, Tritordeum (TBD), on gastrointestinal (GI) symptoms, anthropometric and bioelectrical impedance parameters, and psychological profiles in 18 diarrhea-predominant IBS (IBS-D) female patients with abdominal bloating as the dominant symptom. The IBS Severity Scoring System (IBS-SSS), the Symptom Checklist-90 Revised, the Italian version of the 36-Item Short-Form Health Survey, and the IBS-Quality of Life questionnaire were administered. The TBD reduces the IBS-SSS “Intensity of abdominal bloating” with a concomitant improvement in the anthropometric profile. No correlation was found between “Intensity of abdominal bloating” and “Abdominal circumference”. Anxiety, depression, somatization, interpersonal sensitivity, and phobic and avoidance manifestations were significantly reduced after TBD. Lastly, anxiety was correlated with “Intensity of abdominal bloating”. Overall, these results suggest the possibility of lowering abdominal bloating and improving the psychological profile of female IBS-D patients using a diet based on an alternative grain such as Tritordeum.
... Existen una serie de cereales que contienen gluten como el trigo, centeno, cebada y avena. Otros cereales pueden ver reducido su contenido en gluten mediante selección genética, como puede ser el caso del tritordeum (Vaquero et al., 2017). Además, otros cereales como el maíz, el arroz, el trigo sarraceno, mijo, sorgo, amaranto o quinoa, no lo contienen (Bascuñán et al., 2017). ...
... Grains of the WT and the E82 RNAi lines at harvest were collected and milled for proteomic data analysis. Protein digestion, liquid chromatographic and mass spectrometric analysis were performed as described in Vaquero et al. (2018) followed by custom Python scripts 1 for counting the number of unique peptides assigned to each wheat protein fraction. ...
Gluten proteins are responsible for the unique viscoelastic properties of wheat dough, but they also trigger the immune response in celiac disease patients. RNA interference (RNAi) wheat lines with strongly silenced gliadins were obtained to reduce the immunogenic response of wheat. The E82 line presents the highest reduction of gluten, but other grain proteins increased, maintaining a total nitrogen content comparable to that of the wild type. To better understand the regulatory mechanisms in response to gliadin silencing, we carried out a transcriptomic analysis of grain and leaf tissues of the E82 line during grain filling. A network of candidate transcription factors (TFs) that regulates the synthesis of the seed storage proteins (SSPs), α-amylase/trypsin inhibitors, lipid transfer proteins, serpins, and starch in the grain was obtained. Moreover, there were a high number of differentially expressed genes in the leaf of E82, where processes such as nutrient availability and transport were enriched. The source-sink communication between leaf and grain showed that many down-regulated genes were related to protease activity, amino acid and sugar metabolism, and their transport. In the leaf, specific proline transporters and lysine-histidine transporters were down- and up-regulated, respectively. Overall, the silencing of gliadins in the RNAi line is compensated mainly with lysine-rich globulins, which are not related to the proposed candidate network of TFs, suggesting that these proteins are regulated independently of the other SSPs. Results reported here can explain the protein compensation mechanisms and contribute to decipher the complex TF network operating during grain filling.
This review paper provides an in-depth analysis of × Tritordeum [(Ascherson et Graebner)], a novel cereal crop with promising agronomic, nutritional, and economic potential. Through a comprehensive examination of the crop's agronomic characteristics and management requirements, we highlight its adaptability to Mediterranean climates, resilience under changing environmental conditions, and potential applications in the food industry, such as breadmaking and pasta production. We also discuss the role of digital agriculture technologies in optimizing tritordeum cultivation and their potential impact on agricultural practices. Furthermore, we assess the opportunities and challenges associated with tritordeum's integration into the agricultural economy and production systems, emphasizing its potential to contribute to a more sustainable and health-conscious food system. By offering a holistic understanding of tritordeum's attributes, this review serves as a valuable resource for researchers, agronomists, food manufacturers, and policymakers interested in exploring the potential of this innovative cereal grain.
Objectives
Treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). Patients should be followed-up with dietary interviews and serology as CD markers to ensure adherence to the diet. However, none of these methods offer an accurate measure of dietary compliance. Our aim was to evaluate the measurement of gluten immunogenic peptides (GIP) in stools as a marker of GFD adherence in CD patients and compare it with traditional methods of GFD monitoring.
Methods
We performed a prospective, nonrandomized, multicenter study including 188 CD patients on GFD and 84 healthy controls. Subjects were given a dietary questionnaire and fecal GIP quantified by enzyme-linked immunosorbent assay (ELISA). Serological anti-tissue transglutaminase (anti-tTG) IgA and anti-deamidated gliadin peptide (anti-DGP) IgA antibodies were measured simultaneously.
Results
Of the 188 celiac patients, 56 (29.8%) had detectable GIP levels in stools. There was significant association between age and GIP in stools that revealed increasing dietary transgressions with advancing age (39.2% in subjects ≥13 years old) and with gender in certain age groups (60% in men ≥13 years old). No association was found between fecal GIP and dietary questionnaire or anti-tTG antibodies. However, association was detected between GIP and anti-DGP antibodies, although 46 of the 53 GIP stool-positive patients were negative for anti-DGP.
Conclusions
Detection of gluten peptides in stools reveals limitations of traditional methods for monitoring GFD in celiac patients. The GIP ELISA enables direct and quantitative assessment of gluten exposure early after ingestion and could aid in the diagnosis and clinical management of nonresponsive CD and refractory CD. Trial registration number NCT02711397.
Celiac disease is the most common oral intolerance in Western countries. It results from an immune response towards gluten proteins from certain cereals in genetically predisposed individuals (HLA-DQ2 and/or HLA-DQ8). Its pathogenesis involves the adaptive (HLA molecules, transglutaminase 2, dendritic cells, and CD4+ T-cells) and the innate immunity with an IL-15-mediated response elicited in the intraepithelial compartment. At present, the only treatment is a permanent strict gluten-free diet (GFD). Multidisciplinary studies have provided a deeper insight of the genetic and immunological factors and their interaction with the microbiota in the pathogenesis of the disease. Similarly, a better understanding of the composition of the toxic gluten peptides has improved the ways to detect them in food and drinks and how to monitor GFD compliance via non-invasive approaches. This review, therefore, addresses the major findings obtained in the last few years including the re-discovery of non-celiac gluten sensitivity.
Celiac disease is a multisystem immune based disorder that is triggered by the ingestion of gluten in genetically susceptible individuals. The prevalence of celiac disease has risen in recent decades and is currently about 1% in most Western populations. The reason for this rise is unknown, although environmental factors related to the hygiene hypothesis are suspected. The pathophysiology of celiac disease involves both the innate and adaptive immune response to dietary gluten. Clinical features are diverse and include gastrointestinal symptoms, metabolic bone disease, infertility, and many other manifestations. Although a gluten-free diet is effective in most patients, this diet can be burdensome and can limit quality of life; consequently, non-dietary therapies are at various stages of development. This review also covers non-celiac gluten sensitivity. The pathophysiology of this clinical phenotype is poorly understood, but it is a cause of increasing interest in gluten-free diets in the general population.
Cereals are considered a basic food. Through the development of cooking, the human being has produced high- gluten-content food, so that it could make the most of its nutritional properties. Wheat is becoming one of the key elements of the Mediterranean diet. Amongst gluten- intake-related pathologies- gluten is present mainly in wheat, barley and rye- celiac disease (CD) is the most well-known. CD is a chronic inflammatory condition which affects gastrointestinal tract which develops in genetically predisposed individuals. The most common manifestation of CD is nutrients malabsorption. This protein trigger other pathology, wheat allergy (WA), which is an adverse immunological effect to gluten due to E immunoglobulin. A recent increased in non celiac gluten sensitivity (NCGS) has also been noticed, defined as the emergence of a range of gluten-intake related symptoms in patients for which celiac disease and wheat allergy have been ruled out. This article discusses these three conditions with their phatogenic mecanisms and the different clinic manifestations.
Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
the adaptive immune system is central to the development of coeliac disease. Adaptive immune responses are, however, controlled by a preceding activation of the innate immune system. We investigated whether gliadin, a protein present in wheat flour, could activate an innate as well as an adaptive immune response in patients with coeliac disease.
Methods: duodenal biopsy samples from 42 patients with untreated coeliac disease, 37 treated patients, and 18 controls, were cultured in vitro for 3 h or 24 h, in the presence of either immunodominant gliadin epitopes (pα-2 and pα-9) or a non-immunodominant peptide (p31–43) known to induce small intestine damage in coeliac disease. We also incubated biopsy samples from nine untreated and six treated patients with a non-immunodominant peptide for 3 h, before incubation with immunodominant gliadin epitopes. Different combinations of interleukin-15 or signal transduction inhibitors were added to selected incubations.
Findings: only the non-immunodominant peptide induced rapid expression of interleukin-15, cd83, cyclo-oxygenase (COX)-2, and CD25 by CD3– cells (p=O005 vs medium alone) and enterocyte apoptosis (p<0·0001). Only the non-immunodominant peptide induced p38 MAP kinase activation in CD3– cells. Pre-incubation with the non-immunodominant peptide enabled immunodominant epitopes to induce T-cell activation (p=0·001) and enterocyte apoptosis. Inhibition of interleukin-15 or of p38 MAP kinase controlled such activity.
Interpretation: a gliadin fragment can activate the innate immune system, affecting the in situ T-cell recognition of dominant gliadin epitopes. Although our findings emphasise the key role of gliadin-specific T cells, they suggest a complex pathogenic situation, and show that inhibition of interleukin-15 or p38 MAP kinase might have the potential to control coeliac disease.
An outstanding characteristic of tritordeum (Hordeum chilense x Triticum turgidum conv. durum) is its high protein concentration in the grain, which is substantially higher than that of its wheat parent. Nitrate uptake and nitrate reductase (NR; EC 1.6.6.1) activity in roots and leaves were investigated in two tritordeum lines (HT8 and HT31) and in the T. turgidum parental cultivar as possible factors related to protein accumulation in vegetative plants and in grain. Net NO3/- uptake was studied on nitrogen- starved seedlings that were pretreated with NO3/- to induce the NO3/- - uptake system. The apparent K(s) values for net NO3/- uptake in T. turgidum, tritorduem HT8 and tritordeum NT31 were 128, 112, and 90 μM, respectively, and the corresponding V(max) values were 54, 70 and 93 μmol h-1 g-1 dry weight, indicating that tritordeum lines, and specially HT31, absorb NO3/- more efficiently than the T. turgidum and parental cultivar. Nitrate reductase activity in roots after NO3/- induction ranged from 5 to 13 μmol h-1 g-1 dry weight. Therefore, NO3/- reduction to NO2/- appears to be the rate-limiting step of NO3/- assimilation. Tritordeum HT8, whose grain protein concentration is substantially higher than that of tritordeum BT31, exhibited higher NR activity both in roots and leaves but lower efficiency for NO3/- absorption than tritordeum NT31. Hence, protein accumulation appears to be more related to NO3/- reduction than to NO3/-- uptake rate. A positive relationship between NR activity and protein content in vegetative tissues of tritordeum HT8 and its wheat parent was found.
Nonceliac gluten sensitivity (NCGS) is the clinical term used to describe gastrointestinal (GI) and/or extraintestinal symptoms associated with gluten ingestion. The prevalence of NCGS is unknown. The condition has clinical features that overlap with those of celiac disease (CD) and wheat allergy (WA). The pathophysiologic process in NCGS is thought to be through an innate immune mechanism, whereas CD and WA are autoimmune- and allergen-mediated, respectively. However, dietary triggers other than gluten, such as the fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, have been implicated. Currently, no clinical biomarker is available to diagnose NCGS. Exclusion of CD and WA is necessary in the evaluation of a patient suspected to have NCGS. The onset of symptoms in patients with NCGS can occur within hours or days of gluten ingestion. Patients with NCGS have GI and extraintestinal symptoms that typically disappear when gluten-containing grains are eliminated from their diets. However, most patients suspected to have NCGS have already initiated a gluten-free diet at the time of an evaluation. A gluten elimination diet followed by a monitored open challenge of gluten intake to document recurrence of GI and/or extraintestinal symptoms can sometimes be helpful. If NCGS is strongly suggested, then a skilled dietitian with experience in counseling on gluten-free diets can provide proper patient education. Additional research studies are warranted to further our understanding of NCGS, including its pathogenesis and epidemiology, and to identify a biomarker to facilitate diagnosis and patient selection for proper management.
The ancient diploid Triticum monococcum is of special interest as a candidate low-toxic wheat specie for celiac disease patients. Here, we investigated how an in vitro gastro-intestinal digestion, affected the immune toxic properties of gliadin from diploid compared to hexaploid wheat.
Gliadins from Triticum monococcum, and Triticum aestivum cultivars were digested using either a partial proteolysis with pepsin-chymotrypsin, or an extensive degradation that used gastrointestinal enzymes including the brush border membrane enzymes. The immune stimulatory properties of the digested samples were investigated on T-cell lines and jejunal biopsies from celiac disease patients. The T-cell response profile to the Triticum monococcum gliadin was comparable to that obtained with Triticum aestivum gliadin after the partial pepsin-chymotrypsin digestion. In contrast, the extensive gastrointestinal hydrolysis drastically reduced the immune stimulatory properties of Triticum monococcum gliadin. Mass spectrometry-based analysis showed that several Triticum monococcum peptides, including known T-cell epitopes, were degraded during the gastrointestinal treatment, whereas many of Triticum aestivum gliadin survived the gastrointestinal digestion.
The pattern of Triticum monococcum gliadin proteins is sufficiently different from those of common hexaploid wheat to determine a lower toxicity in celiac disease patients following in vitro simulation of human digestion. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Celiac disease is an immune-mediated disease triggered in genetically susceptible individuals by ingested gluten from wheat, rye, barley, and other closely related cereal grains. The current treatment for celiac disease is life-long adherence to a strict gluten-exclusion diet. The replacement of gluten presents a significant technological challenge, as it is an essential structure-building protein, which is necessary for formulating high-quality baked goods. A major limitation in the production of gluten-free products is the lack of protein functionality in non-wheat cereals. Additionally, commercial gluten-free mixes usually contain only carbohydrates, which may significantly limit the amount of protein in the diet. In the recent past, various approaches are attempted to incorporate protein-based ingredients and to modify the functional properties for gluten-free product development. This review aims to the highlight functionality of the alternative protein-based ingredients, which can be utilized for gluten-free product development both functionally as well as nutritionally.
© The Author(s) 2014.