The effect of starch-protein interaction in wheat on the glycemic response and rate of in vitro digestion

To determine the effect on blood glucose of removal of protein from wheat products, healthy volunteers took test meals of white bread made from either regular or gluten-free flour. After bread made from gluten-free flour, the blood-glucose rise was significantly greater. This corresponded with a significantly more rapid rate of digestion in vitro and reduced starch malabsorption in vivo as judged by breath-H2 measurements. Addition of gluten to the gluten-free bread mix did not reverse these effects. Factors associated with unprocessed wheat flour, such as the natural starch-protein interaction, may therefore be important in wheat products in reducing both their rate of absorption and glycemic response. They may have implications in the dietary management both of diabetes and of diseases where small intestinal absorptive capacity is impaired.     

Quality Properties of a Gluten-Free Bread with Buckwheat

The demand for gluten-free food due to allergic autoimmune diseases and sensitivity keeps growing. Usually, the treatment is a strictly gluten-free diet. In the absence of gluten, bread making becomes a technological challenge since wheat is the only cereal able to develop a viscoelastic dough. The objective of this research was to develop a gluten-free bread using buckwheat, rice, and cassava flours. Increasing buckwheat flour causes an increase of insoluble fiber, crumb cell circularity, and loaf specific volume. A sensory test showed that buckwheat flour has a positive impact on bread quality.     

Maize Prolamins Could Induce a Gluten-Like Cellular Immune Response in Some Celiac Disease Patients

Celiac disease (CD) is an autoimmune-mediated enteropathy triggered by dietary gluten in genetically prone individuals. The current treatment for CD is a strict lifelong gluten-free diet. However, in some CD patients following a strict gluten-free diet, the symptoms do not remit. These cases may be refractory CD or due to gluten contamination; however, the lack of response could be related to other dietary ingredients, such as maize, which is one of the most common alternatives to wheat used in the gluten-free diet. In some CD patients, as a rare event, peptides from maize prolamins could induce a celiac-like immune response by similar or alternative pathogenic mechanisms to those used by wheat gluten peptides. This is supported by several shared features between wheat and maize prolamins and by some experimental results. Given that gluten peptides induce an immune response of the intestinal mucosa both in vivo and in vitro, peptides from maize prolamins could also be tested to determine whether they also induce a cellular immune response. Hypothetically, maize prolamins could be harmful for a very limited subgroup of CD patients, especially those that are non-responsive, and if it is confirmed, they should follow, in addition to a gluten-free, a maize-free diet.     

Oats can diversify a gluten-free diet in celiac disease and dermatitis herpetiformis

Finnish celiac disease and dermatitis herpetiformis patients have used oat-containing gluten-free diets since 1997. The aim of this study was to evaluate how the use of oats has been adopted. The use of oats and the effect of oats on symptoms and quality of life were investigated in 1,000 randomly selected members of the Celiac Society. Altogether, 710 patients responded: 423 (73%) with celiac disease and 70 (55%) with dermatitis herpetiformis were currently consuming oats. Patients appreciated the taste, the ease of use, and the low costs; 94% believed that oats diversified the gluten-free diet; 15% of celiac disease and 28% of dermatitis herpetiformis patients had stopped eating oats. The most common reasons for avoiding oats were fear of adverse effects or contamination. There is a market demand for oats, and celiac societies and dietitians should make efforts to promote the development of products free of wheat contamination.     

Hydrocolloids in gluten-free breads: a review

Bread is a traditional food generally prepared from wheat flour. The main wheat component responsible for bread quality is gluten, which is an essential structure-binding protein. Although important, this protein can cause health problems in predisposed individuals, and is avoided in the diet of celiac disease patients. As diagnosis methods are improved, revealing the high incidence of gluten-intolerance in the western world, the demand for novel, nutritious and high-quality gluten-free foods also ascends. However, for the production of gluten-free breads the absence of gluten is critical and challenging in regards to the bread structure. Various gluten-free formulations have applied hydrocolloids to mimic the viscoelastic properties of gluten. They comprise a number of water-soluble polysaccharides with varied chemical structures providing a range of functional properties that make them suitable to this application. This paper reviews some actual facts about celiac disease and focuses on the reported applications of hydrocolloids in gluten-free breads.     

Celiac disease: epidemiology, pathogenesis, diagnosis, and nutritional management.

Celiac disease (CD) is an inflammatory small intestinal disorder that can lead to severe villous atrophy, malabsorption, and malignancy. It is triggered by the gluten proteins of wheat, barley, and rye. All patients express the antigen-presenting molecules human leukocyte antigen-DQ2 (HLA-DQ2) and/or HLA-DQ8, which bind gluten peptides and thus activate destructive intestinal T cells. Patients with untreated CD have circulating IgA autoantibodies to the enzyme tissue transglutaminase (tTG), a component of endomysium. Testing for serum IgA tTG has a high predictive value. Therapy of CD is a lifelong gluten-free diet. Counseling by an expert dietitian and association with a celiac support group are important in helping the patient embark on a healthy gluten-free diet. Current research focuses on non-dietary therapies and treatment of refractory (diet-unresponsive) CD.     

Oral Consumption of Bread from an RNAi Wheat Line with Strongly Silenced Gliadins Elicits No Immunogenic Response in a Pilot Study with Celiac Disease Patients

Celiac disease (CD) is a genetically predisposed, T cell-mediated and autoimmune-like disorder caused by dietary exposure to the storage proteins of wheat and related cereals. A gluten-free diet (GFD) is the only treatment available for CD. The celiac immune response mediated by CD4+ T-cells can be assessed with a short-term oral gluten challenge. This study aimed to determine whether the consumption of bread made using flour from a low-gluten RNAi wheat line (named E82) can activate the immune response in DQ2.5-positive patients with CD after a blind crossover challenge. The experimental protocol included assessing IFN-γ production by peripheral blood mononuclear cells (PBMCs), evaluating gastrointestinal symptoms, and measuring gluten immunogenic peptides (GIP) in stool samples. The response of PBMCs was not significant to gliadin and the 33-mer peptide after E82 bread consumption. In contrast, PBMCs reacted significantly to Standard bread. This lack of immune response is correlated with the fact that, after E82 bread consumption, stool samples from patients with CD showed very low levels of GIP, and the symptoms were comparable to those of the GFD. This pilot study provides evidence that bread from RNAi E82 flour does not elicit an immune response after a short-term oral challenge and could help manage GFD in patients with CD.     

Challenges of Monitoring the Gluten-Free Diet Adherence in the Management and Follow-Up of Patients with Celiac Disease

Celiac disease (CD) is a chronic gluten-responsive immune mediated enteropathy and is treated with a gluten-free diet (GFD). However, a strict diet for life is not easy due to the ubiquitous nature of gluten. This review aims at examining available evidence on the degree of adherence to a GFD, the methods to assess it, and the barriers to its implementation. The methods for monitoring the adherence to a GFD are comprised of a dietary questionnaire, celiac serology, or clinical symptoms; however, none of these methods generate either a direct or an accurate measure of dietary adherence. A promising advancement is the development of tests that measure gluten immunogenic peptides in stools and urine. Causes of adherence/non-adherence to a GFD are numerous and multifactorial. Inadvertent dietary non-adherence is more frequent than intentional non-adherence. Cross-contamination of gluten-free products with gluten is a major cause of inadvertent non-adherence, while the limited availability, high costs, and poor quality of certified gluten-free products are responsible for intentionally breaking a GFD. Therefore, several studies in the last decade have indicated that many patients with CD who follow a GFD still have difficulty controlling their diet and, therefore, regularly consume enough gluten to trigger symptoms and damage the small intestine.     

Wheat Starch, Gliadin, and the Gluten-free Diet

Individuals with celiac disease generally are advised to follow a lifelong gluten-free diet and avoid consumption of the prolamins gliadin (wheat), secalin (rye), and hordein (barley). Although the designation of the diet as gluten free may imply that the diet contains zero gluten, this is not necessarily true. In some countries (eg, United States, Canada), the gluten-free diet is completely devoid of gluten and is based on foods such as rice and corn that are naturally gluten free. In others (eg, Scandinavia, United Kingdom), the gluten-free diet may include foods such as wheat starch that have been rendered gluten free but nonetheless contain small amounts of toxic prolamins. The discrepancy in the use of foods rendered gluten free exists because the amount of toxic prolamins that individuals with celiac disease may consume without damaging the mucosa of the small intestine is unknown. Minimal research has been conducted on the toxicity of foods rendered gluten free, and there are no definitive data about whether the small amount of prolamin found in these products is safe to consume. Nonetheless, the Codex Alimentarius Standard for gluten-free foods allows a certain amount of prolamin in foods designated gluten free, and these products have been used in many countries for several decades. Well-designed, scientifically sound studies are needed to help determine the amount of toxic prolamins, if any, that may be safely consumed by individuals with celiac disease. Until this research is conducted, dietitians in the United States should continue to advise their patients against the use of wheat starch and other foods rendered gluten free. J Am Diet Assoc. 2001; 101:1456-1459.     

Coeliac disease. Following the diet and eating habits of participating individuals in the Federal District, Brazil

The western diet includes several food items based on wheat. Adherence and obedience to a gluten-free diet requires self-determination on the part of the person with Coeliac disease, as well as their family members. The objective of this research is to identify the main difficulties noted by people with Coeliac disease in their eating habits, the frequency of consumption and their satisfaction with gluten-free products. We employed an adapted already validated questionnaire, with open, closed, and multiple choice questions. Of the 105 participants with Coeliac disease, 90.38% of them followed, where possible, a gluten-free diet; 67.12% consumed food with gluten inadvertently or because of a lack of alternatives and/or information in food found in public places. Seventy percent affirmed that their diet provided all the energy and nutrients they need; 77.67% of the Coeliac participants prepared their meals by themselves or this task was assumed by their caregivers; 77.14% read the manufacturers labels on products, and, 74.49% expressed dissatisfaction regarding the price and availability of gluten-free products. The data show an association only between the energy and nutrients needed for good health and gluten-free dietary tracking (p = 0.0315). That is, people with Coeliac disease who avoided gluten consumed more calories and were more likely to have adequate nutrients in their diet.     

Wheat Starch Intolerance in Patients With Celiac Disease

Objective Evaluate in patients with celiac disease the tolerance of prolonged consumption of small amounts of gliadin contained in products containing wheat starch. Design Open 1-year trial of the addition of wheat starch to a gluten-free diet in a cohort of adult patients with biopsy-proven celiac disease who had never consumed wheat starch. The control group consisted of patients with celiac disease who tolerated wheat starch.Subjects Seventeen patients with celiac disease and 14 control patients, all diagnosed according to criteria of the European Society of Pediatric Gastroenterology and Nutrition, were recruited from the Canadian Celiac Association and the Quebec Celiac Foundation.Setting The study was conducted in the outpatient clinic of the Gastroenterology and Nutrition Service of Ste Justine Hospital, Montreal, Quebec, Canada. Interventions Patients were asked to consume four to six portions daily of a wheat starch-containing product, mainly bread, for up to 1 year.Main outcome measures The gliadin content of the wheat starch product used in this trial was quantified by enzyme linked irnmunosorbent assay. Patient outcome measures included symptoms, nutritional parameters (anthropometric data, complete blood count, serum folate and iron levels), and immunologic parameters (antigliadin antibody and antiendomysium antibody titers).Results A quantifiable amount of immunoreactive gliadin (0.75 mg/100 g) was found in the wheat starch. The majority of the patients with celiac disease (11 of 17) who had never consumed wheat starch previously developed symptoms, which resolved within weeks of discontinuing the product. Relapse of skin lesions was seen in two of three patients with coexisting dermatitis herpetiformis. No weight loss or biochemical changes were observed. Despite the presence of symptoms, antigliadin antibody and antiendomysium antibody determinations were not useful to detect the clinical intolerance.Applications The innocuousness of the long-term ingestion of “gluten-free” products containing wheat starch is still unproven, and prolonged use of such products by patients with celiac disease cannot be recommended.     

Advances in celiac disease and gluten-free diet

Celiac disease is becoming an increasingly recognized autoimmune enteropathy caused by a permanent intolerance to gluten. Once thought to be a rare disease of childhood characterized by diarrhea, celiac disease is actually a multisystemic disorder that occurs as a result of an immune response to ingested gluten in genetically predisposed individuals. Screening studies have revealed that celiac disease is most common in asymptomatic adults in the United States. Although considerable scientific progress has been made in understanding celiac disease and in preventing or curing its manifestations, a strict gluten-free diet is the only treatment for celiac disease to date. Early diagnosis and treatment, together with regular follow-up visits with a dietitian, are necessary to ensure nutritional adequacy and to prevent malnutrition while adhering to the gluten-free diet for life. The purpose of this review is to provide clinicians with current updated information about celiac disease, its diverse clinical presentation and increased prevalence, the complex pathophysiology and strong genetic predisposition to celiac disease, and its diagnosis. This review focuses in detail on the gluten-free diet and the importance of intense expert dietary counseling for all patients with celiac disease. Recent advances in the gluten-free diet include food allergen labeling as well as the US Food and Drug Administration's proposed definition of the food-labeling term gluten-free. The gluten-free diet is complex and patients need comprehensive nutrition education from a skilled dietitian.     

Two prolamin peptides from durum wheat preclude celiac disease-specific T cell activation by gluten proteins

Purpose  

Celiac disease (CD) is a permanent intolerance to wheat prolamins and related proteins displayed by genetically susceptible individuals. Blocking or modulation of CD-specific T cell response by altered prolamin peptides are currently considered as a potential alternative to the only effective therapy of CD based on a life-long gluten-free diet. Two prolamin peptides, the 9-mer ASRVAPGQQ and the 10-mer GTVGVAPGQQ sequences, were identified by mass spectrometry in the peptic/tryptic digest of prolamins (PTP) from durum wheat (Triticum turgidum ssp. durum) cv. Adamello, and investigated for their ability to preclude the stimulation of CD-specific mucosal T cells by gluten proteins.     

Long Term Follow Up of Celiac Disease—Is Atherosclerosis a Problem?

Celiac disease (CD) is a lifelong condition and it often involves impaired nutrition, wide spectrum of symptoms and it requires constant dietetic treatment. The impact of the gluten-free diet on patients’ nutritional status and on the other biochemical parameters is being widely investigated. In this article we looked into particular risk factors that might lead to increased prevalence of atherosclerosis in CD patients, including nutritional status, gluten-free diet, lipids profile and concomitant disease—type 1 diabetes mellitus. Here, we present the current data and research on these risk factors of atherosclerosis with respect to celiac disease.     

Green banana pasta: an alternative for gluten-free diets

The objective of this study was to develop and analyze a gluten-free pasta made with green banana flour. The study was divided into five steps: preparation/selection, chemical, sensory, technological, and statistical analysis. The modified sample presented greater acceptance (84.5% for celiac individuals and 61.2% for nonceliac) than standard samples (53.6% for nonceliac individuals). There was no significant difference between the modified and the standard samples in terms of appearance, aroma, flavor, and overall quality. The modified pastas presented approximately 98% less lipids. Green bananas are considered a subproduct of low commercial value with little industrial use. The possibility of developing gluten-free products with green banana flour can expand the product supply for people with celiac disease and contribute to a more diverse diet.     

Making bread with sourdough improves mineral bioavailability from reconstituted whole wheat flour in rats

OBJECTIVE: We compared the effects of different kinds of bread fermentation on mineral bioavailability. METHODS: Wistar rats were fed one of the following experimental diets for 21 d: control, reconstituted whole wheat flour (white flour plus bran), yeast bread, and sourdough bread. The apparent mineral absorption and intestinal fermentation were measured in each animal. RESULTS: Phytate contents in yeast and sourdough bread were lower than in reconstituted whole wheat flour (-52% and -71%, respectively). Total cecal pool of short-chain fatty acids, in particular the butyrate pool, was significantly increased by the ingestion of unrefined products. Calcium homeostasis was not modified by these nutritional conditions, whereas magnesium absorption was significantly greater in rats fed the control and sourdough diets than in those consuming whole wheat flour and yeast bread. Magnesium kidney excretion was slightly stimulated by sourdough bread. Compared with the control diet, iron balance was significantly reduced by reconstituted whole wheat flour diet. Yeast bread making counteracted the deleterious effects of whole wheat on iron absorption, whereas sourdough bread making enhanced iron absorption. Further, liver and plasma iron and transferrin saturation levels were lower in rats adapted to the flour diet than in other groups. Zinc absorption was strongly depressed in the presence of unprocessed reconstituted whole wheat flour in the diet, but yeast fermentation afforded a zinc assimilation comparable to the control diet, whereas the sourdough bread led to maximal zinc absorption. Copper absorption increased significantly when rats were fed the sourdough bread, whereas unprocessed whole flour depressed copper absorption (-41% versus control diet). CONCLUSION: Mineral bioavailability from reconstituted whole wheat flour can be improved by bread making. Although yeast fermentation minimizes the unfavorable effects of phytic acid, sourdough bread is a better source of available minerals, especially magnesium, iron, and zinc.     

Determination of the gluten content of foods.

Coeliac disease affects 1:1,500 people in Europe. Treatment of the condition involves a gluten-free diet with avoidance of foods containing wheat, rye, barley or oats. Evidence suggests that individuals should adhere strictly to the diet as this reduces the increased incidence of malignancy observed in the condition. A large number of gluten-free products are currently available. Immunological assays have been developed to assess their suitability for patients with coeliac disease. Quantitative assays, based on both polyclonal antisera and monoclonal antibodies, methods of extraction and problems associated with interfering substances are reviewed in this paper.     

Probiotics Supplements Reduce ER Stress and Gut Inflammation Associated with Gliadin Intake in a Mouse Model of Gluten Sensitivity

Exposure to gluten, a protein present in wheat rye and barley, is the major inducer for human Celiac Disease (CD), a chronic autoimmune enteropathy. CD occurs in about 1% worldwide population, in genetically predisposed individuals bearing human leukocyte antigen (HLA) DQ2/DQ8. Gut epithelial cell stress and the innate immune activation are responsible for the breaking oral tolerance to gliadin, a gluten component. To date, the only treatment available for CD is a long-term gluten-free diet. Several studies have shown that an altered composition of the intestinal microbiota (dysbiosis) could play a key role in the pathogenesis of CD through the modulation of intestinal permeability and the regulation of the immune system. Here, we show that gliadin induces a chronic endoplasmic reticulum (ER) stress condition in the small intestine of a gluten-sensitive mouse model and that the coadministration of probiotics efficiently attenuates both the unfolded protein response (UPR) and gut inflammation. Moreover, the composition of probiotics formulations might differ in their activity at molecular level, especially toward the three axes of the UPR. Therefore, probiotics administration might potentially represent a new valuable strategy to treat gluten-sensitive patients, such as those affected by CD.     

Nutritional and sensory challenges of gluten-free bakery products: a review

There is a growing need for gluten-free bakery products. Currently, gluten-free bakery products deliver lower protein, fibre and mineral content and elevated glycaemic index (GI) than gluten-containing foods. Only a mixture of rice and buckwheat flour or a low addition of either egg white or whey protein, has shown potential for the improvement of both nutrition and sensory qualities. To increase the fibre content, isolated cereal fibre and soluble fibre isolates have been incorporated into gluten-free formulations with some sensory success. Studies have shown that the GI of modern gluten-free products is no longer a major concern with the improvement of ingredient formulations and processing methods. The currently low mineral content can be increased with the use of mineral-rich ingredients such as amaranth, buckwheat or flaxseed flour. Nonetheless, consumers still show a preference to refined, low fibre breads over wholegrain fibre-rich bread.