Gluten contamination in foods labeled as "gluten free" in the United States

Gluten-Free Diet Adherence Evaluation in Adults with Long-Standing Celiac Disease

BACKGROUND

Celiac disease (CD) is an autoimmune disease that results from the interaction of genetic, immune, and environmental factors. According to the 2020 European Society for Pediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) guidelines, an elimination diet (i.e., excluding products that may contain gluten) is the basic method of treating celiac disease. Following a gluten-free diet is extremely problematic, and patients often make unconscious deviations from the diet. According to the current Oslo definitions for celiac disease, depending on the clinical picture and adequate tests, several forms of celiac disease have been identified: typical, atypical, asymptomatic, potential, and refractory.

OBJECTIVE

The aim of the study was to assess the frequency of conscious diet mistakes and unconscious deviations from a gluten-free diet in a group of patients with long-standing celiac disease and their impact on the frequency of typical and atypical symptoms.

METHODS

The study included 57 people diagnosed with celiac disease between 1980 and 2010. After verifying the history of the disease according to the ESPGHAN guidelines from 2020, we excluded 19 patients who had Marsh grade 1 at the time of diagnosis or those without HLA DQ2 or DQ8 haplotypes detected. After verification, the study included 38 patients, 30 women and 8 men, with a verified diagnosis of typical celiac disease. The effectiveness of the gluten-free diet was assessed in all participants. Blood was collected to determine IgA anti-tissue transglutaminase II antibodies (anti-tTG) and IgG antibodies against deamidated gliadin peptides by ELISA. All survey participants provided data concerning current gastrointestinal and systemic symptoms, bowel habits, comorbidities, dietary habits, physical activity, and socioeconomic conditions.

RESULTS

A total of 25 patients (65.78%) declared strict adherence to the gluten-free diet. However, in this group, seven (18.4%) patients had significantly increased levels of anti-tTG antibodies (mean 82.3 RU/mL ± 78.9 SD at N < 20 RU/mL). Among the patients who consciously made dietary mistakes, six (46.2%) demonstrated increased levels of anti-tTG antibodies. The analysis did not reveal any difference between the frequency of intestinal and extraintestinal symptoms in patients making dietary mistakes and following the gluten-free diet.

CONCLUSIONS

More than half of celiac patients unconsciously or consciously make dietary mistakes, which indicates an urgent need to increase their general knowledge of CD and the appropriate diet. Regardless of whether the gluten-free diet is followed, both typical and atypical symptoms of the disease have been observed among celiac patients.

Unauthentic Information About Celiac Disease on Social Networking Pages: Is It a Matter of Concern in Celiac Disease Management?

BACKGROUND

Facebook (FB) is the most popular online networking platform. Many celiac disease Facebook (CD-FB) pages spread awareness about celiac disease (CD). To get the latest information, patients with CD frequently follow such pages. However, little is known about whether such pages provide authentic and reliable information.

AIMS

This study aims to investigate whether CD-FB pages spread misleading information to patients with CD.

METHODS

On the Facebook social networking platform, CD-FB pages created in three celiac-prevalent countries (Italy, the USA, and India) were explored using different combinations of keywords. The type/category of the CD-FB page, country of origin, purpose, page web link, and number of followers/members were documented in a Microsoft spreadsheet. All posts distributed on selected CD-FB pages in the last 3 years were thoroughly screened.

RESULTS

From August 2022 to March 2023, a total of 200 CD-FB pages from Italy, the USA, and India were explored. Out of these 200 pages, 155 CD-FB (Italy 70; the USA 46; India 39) were found eligible. Of them, 20 (13%) CD-FB pages (Italy 4; the USA 5; India 11) shared misleading information about CD. Surprisingly, 11 (8%) of these 20 pages (Italy 0; the USA 2; India 9) supported alternative treatment options for CD.

CONCLUSIONS

CD-FB pages are useful for disseminating celiac-disease-related information. While most such pages provide useful information, 13% of CD-FB pages allow misleading information. Patients with CD should consult their treating unit before following any uncertain information posted on CD-FB pages.

Celiac Disease, Gluten Sensitivity, and Diet Management

PURPOSE OF REVIEW

Celiac disease is a common chronic inflammatory condition of the small bowel triggered by gluten in wheat, rye and barley in the diet. Non-celiac gluten sensitivity presents with symptoms similar to celiac disease with the ingestion of gluten or other components of wheat. In this article, we review challenges presented by a gluten free diet for the treatment of both disorders.

RECENT FINDINGS

Wheat is ubiquitous in the diet and medications/products. A registered dietitian is mandatory for patient education on the gluten free diet. Naturally gluten free foods provide a healthy diet for those with celiac disease. Whole grains labelled gluten free, including oats, are encouraged in the diet as refined grains may be deficient in fiber, protein, and micronutrients, particularly folate. Gluten contamination is the most common cause of persistent symptoms in celiac disease though shared equipment of food preparation may not be as large a problem as suspected. Most with celiac disease on a gluten free diet will fully recover and gain weight that poses a problem for those overweight to start. The gluten free diet may have a negative impact on quality of life for both celiac patients and their families. Those with hypervigilance of the gluten free diet and avoidance of dining out have the lowest quality of life. The gluten free diet is currently the only effective treatment for celiac disease. A registered dietitian is needed to educate patients on the complexity of the gluten free diet with a goal of healthy eating, maintaining a healthy weight, and avoiding disordered eating or diet hypervigilance; key to a good quality of life.

Adherence to the Gluten-Free Diet Role as a Mediating and Moderating of the Relationship between Food Insecurity and Health-Related Quality of Life in Adults with Celiac Disease: Cross-Sectional Study

This cross-sectional study aimed to estimate the relationship between food insecurity (FI) and health-related quality of life (HRQoL) in patients with celiac disease (CD) and assess whether this relationship is mediated or moderated by adherence to the gluten-free diet (GFD). The results of 1162 samples of patients diagnosed with CD showed that 8.3% of individuals who have a combined score of less than 13 exhibited excellent or very good adherence to the GFD. Furthermore, moderate and fair to poor adherence to the GFD was demonstrated, respectively and 71.9% of the patients had poor HRQoL levels. A significant and moderate positive correlation between FI and GFD adherence (r = 0.489) was found, indicating that 24% of the variance in FI is shared with GFD adherence. The patients' gender, marital status, and monthly income made statistically significant contributions to the prediction (p < 0.05). Females had significantly lower HRQoL scores than males (B = -4.619, 95% CL: -6.08, -3.16) after holding all other variables constant. In conclusion, FI is mediated by GFD adherence to HRQoL. Moreover, a significant total effect relation was found between HRQoL and both FI and GFD adherence, suggesting that lowering symptoms and complications associated with CD may reduce the impact of FI on HRQoL.

Performance assessment of a new G12/A1 antibody-based rapid ELISA using commercially available and gluten-spiked food samples

OBJECTIVE

Food products with <20 mg/kg gluten can be labeled 'gluten-free' according to international regulations. Several antibodies-based ELISAs have been develop to track gluten traces in food products. Among them, R5 and G12 antibody-based ELISAs are the frequently used methods. However, these antibodies have certain limitations. We evaluated the accuracy of G12/A1 antibody-based 'Glutentox ELISA Rapid G12' and compared the results with the current reference method i.e., R5 antibody-based 'Ridascreen R5 ELISA'.

METHODS

In the first step, the performance of Glutentox ELISA Rapid G12 kit was inspected by determination of the threshold value i.e., > or <20 mg/kg gluten in different food products. In the second step, quantification accuracy was assessed by quantification of gluten in gluten-free food products spiked with gliadin reference material.

RESULTS

In total 47 food products (naturally and labeled gluten-free, and food with traces of gluten) were included. Of them, 29 products were quantified with <20 mg/kg, and 18 with a low level of gluten by both the kits. Six out of 29 gluten-free products were used for the recovery test at different spike levels. Gluten concentration and mean recovery rates of individual kits showed consistency.

CONCLUSION

GlutenTox Rapid G12 ELISA could be an appropriate choice for detecting gluten in food products but needs more in-house validation and collaborative tests.

Does sourdough bread provide clinically relevant health benefits?

During the last decade, scientific interest in and consumer attention to sourdough fermentation in bread making has increased. On the one hand, this technology may favorably impact product quality, including flavor and shelf-life of bakery products; on the other hand, some cereal components, especially in wheat and rye, which are known to cause adverse reactions in a small subset of the population, can be partially modified or degraded. The latter potentially reduces their harmful effects, but depends strongly on the composition of sourdough microbiota, processing conditions and the resulting acidification. Tolerability, nutritional composition, potential health effects and consumer acceptance of sourdough bread are often suggested to be superior compared to yeast-leavened bread. However, the advantages of sourdough fermentation claimed in many publications rely mostly on data from chemical and in vitro analyzes, which raises questions about the actual impact on human nutrition. This review focuses on grain components, which may cause adverse effects in humans and the effect of sourdough microbiota on their structure, quantity and biological properties. Furthermore, presumed benefits of secondary metabolites and reduction of contaminants are discussed. The benefits claimed deriving from in vitro and in vivo experiments will be evaluated across a broader spectrum in terms of clinically relevant effects on human health. Accordingly, this critical review aims to contribute to a better understanding of the extent to which sourdough bread may result in measurable health benefits in humans.

Safety Assessment of Foods and Drinks Consumed by People on a Gluten-Free Diet

Naturally gluten-free foods and processed foods that do not contain information about the potential presence of gluten in them pose a hypothetical threat to people with food allergies and celiac disease. Patients who should follow a strict gluten-free diet do not always do so. Therefore, the aim of this research was to analyze certified “gluten-free” and naturally gluten-free products without labeled “may contain gluten” information in terms of their content of gluten proteins. The enzyme immunoassay AgraQuant Gluten G12 ELISA test kit was used for the analysis. Of all the products used in the research, only 5.8% were found to contain gluten above 20 ppm. Only one product labeled “gluten-free” was contaminated with gluten at 79.3 ppm (cider cake). In addition, our research also examined the gluten content of commercial beers containing barley malt not labeled as “gluten-free”. Research has shown that 60% of samples are not safe for those on a strict gluten-free diet. Our research clearly shows that many manufacturers, although they do not monitor their products for the presence of gluten in them, offer safe products, although they cannot be recommended in a gluten-free diet. Therefore, there is a strong need to increase the frequency of testing by food manufacturers for the presence of gluten in their products, so that the number of products approved for people on a gluten-free diet continues to increase.

Gluten contamination in labelled gluten-free, naturally gluten-free and meals in food services in low-, middle- and high-income countries: a systematic review and meta-analysis

The gluten-free diet is based on the consumption of foods without gluten, which aims to manage celiac disease. The concern of celiac patients is that these foods should be safe. However, gluten contamination can affect these foods. The objectives of this review and meta-analysis were first, to identify articles that detected gluten contamination in gluten-free foods using validated methods. Second, to quantify the overall prevalence of gluten contamination of naturally gluten-free foods, labelled gluten-free products, and meals prepared in food services. Third, to highlight the influence of the country's income and the period of study on this prevalence. The studies were identified in Scopus, Science Direct, Web of Science, PubMed, and Google Scholar. Forty articles were included according to PRISMA guidelines. The statistical meta-analysis was performed using MedCalc 19 software. The results show that in the gluten-free foods analysed, the overall prevalence of gluten contamination was estimated at 15.12% (95% CI: 9.56%-21.70%), with more than 20 mg/kg of gluten. Naturally gluten-free foods were significantly more contaminated than labelled gluten-free products and than meals in food services (28.32%; 9.52%; 4.66% respectively; p < 0.001). Moreover, it was noticed that oats were the most contaminated food. In addition, the prevalence of gluten contamination has significantly decreased over time. The majority of the studies were carried out in upper-middle-income and high-income countries, while only one study was conducted in lower-middle income countries. Therefore, it is necessary to implement preventive actions to reduce gluten contamination, ensuring safe gluten-free foods for celiac patients, including low-income countries.

The global burden of coeliac disease: opportunities and challenges

Coeliac disease is a systemic disorder characterized by immune-mediated enteropathy, which is caused by gluten ingestion in genetically susceptible individuals. The clinical presentation of coeliac disease is highly variable and ranges from malabsorption through solely extra-intestinal manifestations to asymptomatic. As a result, the majority of patients with coeliac disease remain undiagnosed, misdiagnosed or experience a substantial delay in diagnosis. Coeliac disease is diagnosed by a combination of serological findings of disease-related antibodies and histological evidence of villous abnormalities in duodenal biopsy samples. However, variability in histological grading and in the diagnostic performance of some commercially available serological tests remains unacceptably high and confirmatory assays are not readily available in many parts of the world. Currently, the only effective treatment for coeliac disease is a lifelong, strict, gluten-free diet. However, many barriers impede patients' adherence to this diet, including lack of widespread availability, high cost, cross-contamination and its overall restrictive nature. Routine follow-up is necessary to ensure adherence to a gluten-free diet but considerable variation is evident in follow-up protocols and the optimal disease management strategy is not clear. However, these challenges in the diagnosis and management of coeliac disease suggest opportunities for future research.

Byproducts from the Vegetable Oil Industry: The Challenges of Safety and Sustainability

Food loss and food waste are a global challenge as about one third of all food produced around the globe is lost or wasted at some point in the food supply chain, from the farm to the fork. Vegetable oils generate a considerable amount of waste and byproducts, and such byproducts represent valuable opportunities for the food industry. Given the obvious benefits of using byproducts, special attention should be paid to the safety issues, especially when it comes to reintroducing them into the food chain. In this study, the quality and safety of several vegetable oil industry byproducts were evaluated in order to further consider them as potential ingredients in functional foods. Microbiological tests, mycotoxin assessments, and a heavy metal analysis were performed. The microbiological analysis showed reduced contamination with spoilage microorganisms, and a lack of contamination with pathogenic bacteria. All of the samples noted levels of deoxynivalenol, and, with a few exceptions, the heavy metal levels were below the maximum allowed limits. This study also notes the lack of regulation for this category of products. This not only puts the possibility of capitalizing on many food byproducts at risk, but also their widespread use as ingredients for the production of new functional products and their safe consumption.

Determination of Urinary Gluten Immunogenic Peptides to Assess Adherence to the Gluten-Free Diet: A Randomized, Double-Blind, Controlled Study

INTRODUCTION

The adherence to a gluten-free diet (GFD) is a trending topic in the management of celiac disease. The aim of our study was to evaluate the diagnostic performance of urinary gluten immunogenic peptides (GIP) determination to detect gluten contamination of the GFD.

METHODS

In study A, 25 healthy adults on a standard GFD performed 6 gluten challenges (0, 10, 50, 100, 500, and 1,000 mg) with quantification of urinary GIP before (T0) and during the following 24 hours. In study B, 12 participants on a gluten contamination elimination diet underwent urinary GIP determination at T0 and after challenge with 5 or 10 mg gluten. Urine GIP concentration was determined by an immunochromatographic assay.

RESULTS

In study A, 51 of 150 baseline urine samples were GIP+ on GFD and 7 of 17 were GIP+ after the zero-gluten challenge, whereas only 55 of 81 were GIP+ after the 10-1,000 mg gluten challenges. There was no significant change in the 24-hour urinary GIP when increasing gluten from 10 to 1,000 mg. In study B, 24 of 24 baseline urine samples were GIP-, whereas 8 of 24 were GIP+ after 5 or 10 mg of gluten.

DISCUSSION

Traces of gluten in the standard GFD may cause positivity of urinary GIP determination, whereas a false negativity is common after a gluten intake of 10-1,000 mg. Owing to the impossibility of standardizing the test in normal conditions, it seems unlikely that urinary GIP determination may represent a reliable tool to assess the compliance to the GFD of patients with celiac disease or other gluten-related disorders.

Food Safety and Cross-Contamination of Gluten-Free Products: A Narrative Review

A gluten-free diet (GFD) is currently the only effective treatment for celiac disease (CD); an individual’s daily intake of gluten should not exceed 10 mg. However, it is difficult to maintain a strict oral diet for life and at least one-third of patients with CD are exposed to gluten, despite their best efforts at dietary modifications. It has been demonstrated that both natural and certified gluten-free foods can be heavily contaminated with gluten well above the commonly accepted threshold of 20 mg/kg. Moreover, meals from food services such as restaurants, workplaces, and schools remain a significant risk for inadvertent gluten exposure. Other possible sources of gluten are non-certified oat products, numerous composite foods, medications, and cosmetics that unexpectedly contain “hidden” vital gluten, a proteinaceous by-product of wheat starch production. A number of immunochemical assays are commercially available worldwide to detect gluten. Each method has specific features, such as format, sample extraction buffers, extraction time and temperature, characteristics of the antibodies, recognition epitope, and the reference material used for calibration. Due to these differences and a lack of official reference material, the results of gluten quantitation may deviate systematically. In conclusion, incorrect gluten quantitation, improper product labeling, and poor consumer awareness, which results in the inadvertent intake of relatively high amounts of gluten, can be factors that compromise the health of patients with CD.

Gluten content in labeled and unlabeled gluten-free food products used by patients with celiac disease

OBJECTIVE

Gluten-free (GF) diet is the only reliable treatment for patients with celiac disease (CeD), but data on the extent of gluten contamination in GF food available in India is scanty. We evaluated gluten content in labeled, imported, and non-labeled GF food products currently available in the Indian market.

METHODS

Overall, 794 processed and commercially available packaged GF products (labeled GF (n = 360), imported GF (n = 80), and non-labeled/naturally GF (n = 354)) were collected from supermarkets of National Capital Region of India. Those unavailable in stores were purchased from e-commerce sites or directly from the manufacturers. Gluten level in them was determined by Ridascreen Gliadin sandwich R5 enzyme-linked immunosorbent assay (R-Biopharm AG, Germany). As per Codex Alimentarius and Food Safety and Standard Authority of India, "gluten free" labeled products must not contain > 20 mg/kg of gluten.

RESULTS

Overall, 10.1% of 794 GF products including 38 (10.8%) of 360 labeled and 42 (11.8%) of 354 non-labeled/naturally GF food products had gluten content > 20 mg/kg (range: 24.43-355 and 23.2-463.8 mg/kg, respectively). None of the imported GF products had gluten more than the recommended limits. Contaminated products most commonly belonged to cereal and their products (flours, coarse grains, pasta/macaroni, snack foods) pulse flours, spices, and bakery items.

CONCLUSIONS

A substantial proportion (10.1%) of GF food products (both labeled and non-labeled) available in India have gluten content greater than the prescribed limits of <20 mg/kg. Physicians, dietitians, support group, and patients with CeD should be made aware of this fact and regulatory bodies should ensure quality assurance.

Quantification of Accidental Gluten Contamination in the Diet of Children with Treated Celiac Disease

A strict gluten-free diet is extremely difficult to maintain. Protracted ingestion of gluten traces (>10 mg/day) is sufficient to cause significant damage in the architecture of the small intestinal mucosa in patients on treatment for celiac disease. The aim of this study was to directly measure the level of contaminating gluten in the daily diet of celiac children following a gluten-free diet. From April 2019 to December 2019, celiac disease children (2-18 years old) on a gluten-free diet for ≥6 months were offered to participate in this prospective-observational study. Patients and their caregivers were invited to provide a representative portion (about 10 g) of all meals consumed during a 24-h period. Participants were requested to weigh all ingested food and report items in a 24-h food diary. The gluten content was quantified by the R5 sandwich enzyme-linked immunosorbent assay method. Sixty-nine children completed the protocol. Overall, 12/448 (2.7%) food samples contained detectable amounts of gluten; of them, 11 contained 5-20 ppm and 1 >20 ppm. The 12 contaminated food samples belonged to 5/69 enrolled patients. In these 5 children, the daily gluten intake was well below the safety threshold of 10 mg/day. The present findings suggest that in a country characterized by high celiac disease awareness, the daily unintended exposure to gluten of treated celiac children on regular follow-up is very low; reassuringly, the presence of gluten traces did not lead to exceed the tolerable threshold of 10 mg/day of gluten intake in the gluten-free diet.

Nutritional Composition of Gluten-Free Labelled Foods in the Slovenian Food Supply

The market of gluten-free (GF) foods has been expanding in recent years. GF foods are consumed not only by those with medical predispositions for avoiding gluten, but also by a specific segment of consumers, searching for “healthier” food choices. For these, such practices can present a serious limitation in the variability of food choices. Considering that GF foods are commonly perceived as healthier alternatives, there is a lack of knowledge on the nutritional profile and content of specific nutrients of GF-labelled foods compared to general food supply. A comparison of nutritional composition of GF/non-GF packed foods in the Slovenian food supply was conducted. The nutrient profiling scoring criterion (NPSC) and content of specific nutrients/energy was compared between GF-labelled and regular foods. The highest proportion of GF-labelled products were found in food categories, which typically do not contain gluten (Cheese imitates, Milk imitates, Yoghurt imitates, Canned fish and seafood and Processed meat). Significant differences in the nutrient profile between GF-labelled and regular products were found in Cakes, muffins and pastry, Crisps and snacks, Desserts and Milk imitates. GF-labelled foods often had lower protein and sugar content. Energy value was comparable in most categories and no significant differences in salt content were found, compared to non-GF products. In conclusion, GF-labelled foods will unlikely bring health benefits to those who are not medically required to follow GF diet. Public health initiatives should aim towards promotion of consuming non-processed foods and provision of reliable information about who is required to consume GF foods.

Potential ways for gluten contamination of gluten-free grain and gluten-free foods: the buckwheat case

Buckwheat has been reported to be responsible for gluten contamination in manufactured gluten-free foods (mGFFs) although it is inherently gluten-free (GF). It could happen through buckwheat grains contacting gluten-containing (GC) grains and surfaces contacted by GC grains during pre-manufacturing practices. To simulate grain contact, whole and broken GC grains (wheat, rye, barley, and oat) were mixed into buckwheat grains at the ratio of 2.5-10.0%. Grains were agitated in vessels with inner surfaces covered with buckwheat grain. Gluten was not detected in buckwheat grains contacting whole GC grains at all mixing ratios. It was not detected in the case of broken GC grains at the mixing ratio of 2.5% and oat grains at all mixing ratios. Gluten concentration increased with the increasing mixing ratio and the natural gluten concentration of broken GC grains. To simulate surface contact, GC grains were first agitated in galvanised steel vessels and then buckwheat grains were agitated together under the same conditions. Gluten was detected on galvanised steel surfaces contacted by whole and broken GC grains. It was not detected in buckwheat grains contacting the surfaces contaminated by whole GC grains. Gluten was detected in buckwheat grain in the case of the broken GC grains except for oats. Gluten concentrations increased with increasing natural gluten concentration of GC grains. Contamination of mGFFs could be linked to potential contact with buckwheat grain. This contamination issue could be resolved through regulations mandating the proof of being GF for ingredients used in the production of mGFFs.

Gluten contamination in labelled and naturally gluten-free grain products in southern India

Consumption of a gluten-free diet or avoiding exposure to gluten is the only feasible and effective treatment available for coeliac patients to date. Although many grains and their products are naturally gluten-free, the possibility of gluten cross-contamination must be considered. Since such data are not available for Indian markets, we carried out this pilot study (n = 160) to assess gluten contamination in various grain-based food products from the category of breakfast products, flours, and batters made from grain that are naturally gluten free. The gluten was extracted from samples using 60% ethanol and gluten analysis was carried out using a commercially available competitive ELISA, which utilises a monoclonal antibody. Nearly 9.8% of the products labelled as gluten-free and 36.7% of the products made from naturally gluten-free grain were found to contain gluten above 20 mg/kg. Among products made from naturally gluten-free grain, 35.9% of the flour samples and 85% of the oat samples (11.67-1830 mg/kg) were contaminated with gluten. In the case of flours, unbranded samples collected from local markets (70%) and directly from local mills (30%) showed gluten content above Codex safety levels (20-400 mg/kg). Among products labelled as gluten free (n = 51), only 5 samples showed gluten contamination above 20 mg/kg although levels were well within 100 mg/kg (32.5 ± 5.8). Our study suggests that there is a likelihood of gluten contamination in products that are sourced from local retailers and millers.

Gluten contamination in manufactured gluten-free foods in Turkey

Gluten contamination in manufactured gluten-free foods (mGFFs) is a major health, well-being and economic issue worldwide for both mandatory and voluntary GFF-consumers. Although scarce, a number of surveys have shown that up to 21.5 % of mGFFs in circulation in the market are contaminated with gluten. However, at the present time there is no published work reporting gluten contamination in mGFFs produced in Turkey. In this paper miscellaneous mGFFs produced in Turkey were analysed for gluten concentration (G) to fill this knowledge gap, and to compare the situation in Turkey with worldwide efforts on this issue. A total of 200 mGFFs from 8 product categories (snack, pasta, bread, cookie, cracker, farina, traditional and others), and manufactured using 7 main ingredients (cereal mixture, buckwheat, corn, rice, locust bean, potato, and others) were analysed. A significant portion of mGFFs (17.5 %) were contaminated with gluten and therefore unacceptable as being GFF. The results point to buckwheat as the main cause of this contamination. If buckwheat is excluded, the ratio of unacceptable mGFFs dramatically decreases to 6.3 % and probably to 1.8 %, which are comparable figures to those reported for other countries. Almost all countries are subjected to the same regulations on GFFs, and the problem of gluten contamination could readily be solved to a great extent if pre-market measures are mandated. Enforcing mGFF-producers to screen their raw materials and final products to detect the presence of gluten, and preventing the release of contaminated mGFFs into the market would be a practical measure in favour of all stakeholders involved in GFF-consumption.

Accidental Gluten Contamination in Traditional Lunch Meals from Food Services in Brasilia, Brazil

This study aimed to evaluate the occurrence of gluten contamination in naturally gluten-free meals from food services in the Federal District, Brazil. This is an exploratory cross-sectional quantitative study in which a total of 180 samples of naturally gluten-free dishes were collected from 60 food services in Brazil. The enzyme-linked immunosorbent assay was used for the quantification of gluten. As established by the Codex Alimentarius, the threshold of 20 ppm of gluten was considered as the accepted upper gluten level for gluten-free food. A total of 2.8% (95% CI: 0.3-5.2%) gluten contamination was found in the samples. Among the 60 food services, 6.7% (95% CI: 2.7-10.6%) displayed at least one contaminated food in our sample. The occurrence of gluten contamination in naturally gluten-free preparations was uncommon and low on a quantitative basis.

Gluten immunogenic peptide excretion detects dietary transgressions in treated celiac disease patients

BACKGROUND

Life-long removal of gluten from the diet is currently the only way to manage celiac disease (CeD). Until now, no objective test has proven useful to objectively detect ingested gluten in clinical practice. Recently, tests that determine consumption of gluten by assessing excretion of gluten immunogenic peptides (GIP) in stool and urine have been developed. Their utility, in comparison with conventional dietary and analytical follow-up strategies, has not been fully established.

AIM

To assess the performance of enzyme-linked immunosorbent assay (ELISA) and point-of-care tests (PoCTs) for GIP excretion in CeD patients on gluten-free diet (GFD).

METHODS

We conducted an observational, prospective, cross-sectional study in patients following a GFD for at least two years. Using the Gastrointestinal Symptom Rating Scale questionnaire, patients were classified at enrollment as asymptomatic or symptomatic. Gluten consumption was assessed twice by 3-d dietary recall and GIP excretion (by ELISA in stool and PoCTs (commercial kits for stool and urine) in two consecutive samples. These samples and dietary reports were obtained 10 day apart one from the other. Patients were encouraged to follow their usual GFD during the study period.

RESULTS

Forty-four patients were enrolled, of which 19 (43.2%) were symptomatic despite being on a GFD. Overall, 83 sets of stool and/or urine samples were collected. Eleven out of 44 patients (25.0%) had at least one positive GIP test. The occurrence of at least one positive test was 32% in asymptomatic patients compared with 15.8% in symptomatic patients. GIP was concordant with dietary reports in 65.9% of cases (Cohen´s kappa: 0.317). PoCT detected dietary indiscretions. Both ELISA and PoCT in stool were concordant (concomitantly positive or negative) in 67 out of 74 (90.5%) samples. Excretion of GIP was detected in 7 (8.4%) stool and/or urine samples from patients considered to be strictly compliant with the GFD by dietary reports.

CONCLUSION

GIP detects dietary transgressions in patients on long-term GFD, irrespective of the presence of symptoms. PoCT for GIP detection constitutes a simple home-based method for self-assessment of dietary indiscretions.

Improving gluten free diet adherence by youth with celiac disease

INTRODUCTION

Celiac disease (CD) is a gluten-triggered autoimmune disorder of the small intestine, which can occur in genetically susceptible individuals at any age. A strict life-long gluten free diet (GFD) is the only medically approved treatment, and non-adherence is associated with significant morbidity. However, gluten use is widespread, complicating efforts to follow the diet. Youth with CD are especially challenged with dietary adherence, as they strive for peer acceptance and personal autonomy in the context of managing a chronic disease.

METHODS

A scoping review was conducted to identify mechanisms to assist youth with remaining gluten free.

RESULTS

There is a paucity of literature regarding best approaches to improve diet adherence by youth, however, lessons can also be learned by borrowing ideas from self-management approaches of other chronic diseases. Several mechanisms for improving GFD adherence among youth are identified, including regular engagement of the youth with CD and their family with an experienced multidisciplinary team, electronic tool utilization and awareness of accurate resources for self-guided education and resources.

CONCLUSIONS

Improvement in GFD adherence by youth is achievable and may influence long-term health outcomes.

Gluten contamination in food services and industry: A systematic review

Gluten-related disorders (GRD) affects approximately 10% of the general population. The only treatment for GRD is still so far is the lifelong complete exclusion of gluten from the daily diet. The correct information about the presence/absence of gluten in food is very important to this group. The present study aimed to evaluate the prevalence of gluten contamination in gluten-free industrial and non-industrial products. In this systematic review, 24 cross-sectional studies were analyzed. The authors developed specific search strategies for Science Direct, Scopus, Web of Science, Google Scholar and ProQuest Dissertations & Theses Global. The authors evaluated the methodological quality of the included studies using criteria from Meta-analysis of Statistics Assessment and Review Instrument (MASTARI). We performed the statistical meta-analysis by metafor package of R program. 95.83% (n = 23) of the studies presented positive results for contamination (over 20 ppm). In industrial food products, studies showed a contamination prevalence of 13.2% (95% CI: 10.8%-15.7%). In non-industrial food products, studies showed a contamination prevalence of 41.5% (95% CI: 16.6%-66.4%). Despite the non-industrial products presented higher contamination prevalence than the industrial products, the difference was not significant (p = 0.072). The findings indicate cross-contamination in industrialized and non-industrialized products. As expected, industrial products labeled as gluten-free showed a lower percentage of gluten-contamination than non-industrialized. Despite that, any contaminated sample found in this group present greater relevance than non-labeled foods. It indicates that foods labeled as "gluten-free" should not be considered safe for patients with GRD since information on the label regarding the presence/absence of gluten is unreliable. Therefore, any gluten-contamination in products labeled as gluten-free is a serious problem to whom present GRD. Further studies are needed to estimate gluten cross-contamination in food service meals and industry better.

Analysis of Gluten Content in Gluten-Free Pizza from Certified Take-Away Pizza Restaurants

Currently, a strict gluten-free diet is the only treatment for celiac disease. In Italy, food service establishments and restaurants can be certified for providing gluten-free foods, including pizza restaurants that make both gluten-free pizza and traditional wheat-based pizza. With this study we analyzed the gluten content in samples of gluten-free pizza prepared and purchased at certified restaurants in the Turin metropolitan area. All samples, from 28 pizzas and 28 cooked dough bases, produced results below the test limit of detection, except for one sample of cooked dough, that tested positive for gluten but still below the warning level for celiac consumers (<20 ppm). Gluten-free pizza, as advertised in the restaurants surveyed, can be considered a safe option for gluten-free consumption. Attention to and compliance with good manufacturing practices, a requisite for obtaining gluten-free certification for restaurants, were noted to have a positive effect on the final product.

Gluten-Free Diet: From Development to Assessment of a Check-List Designed for the Prevention of Gluten Cross-Contamination in Food Services

Gluten cross-contamination in gluten-free food may jeopardize treatment of celiac patients. Considering the deficit of appropriate instruments to enable the implementation of safe production practices for gluten-free food, this study aimed to evaluate the application of a check-list elaborated for gluten cross-contamination prevention in food services. The instrument was applied in 60 Brazilian food services. Interobserver reproducibility and internal consistency of the check-list were tested. A score classification was created for establishments according to the food contamination risk assessment. Subsequent to the application and statistical analysis, the original instrument was reduced to a 30-item check-list. In the reproducibility analysis, none of the 30 items showed significant divergence among the evaluators (p > 0.05 in the Cochran Q test). The 30-item version of the check-list presented Kuder–Richardson Formula 20 (KR-20) = 0.771, indicating good internal consistency. The proposed classification score is obtained by adding 1 point for each item with an “adequate” response; therefore, the final score may vary between 0 and 30 points. Establishments with up to 15 points exhibit risk of gluten contamination, while establishments with a score above 16 points exhibit low risk of contamination. The check-list displayed good reproducibility and internal consistency, suggesting that it could be a useful gluten contamination control instrument in food services.

The feasibility of harmonizing gluten ELISA measurements

Many publications have highlighted that routine ELISA methods do not give rise to equivalent gluten content measurement results. In this study, we assess this variation between results and its likely impact on the enforcement of the EU gluten-free legislation. This study systematically examines the feasibility of harmonizing gluten ELISA assays by the introduction of: a common extraction procedure; a common calibrator, such as a pure gluten extract and an incurred matrix material. The comparability of measurements is limited by a weak correlation between kit results caused by differences in the selectivity of the methods. This lack of correlation produces bias that cannot be corrected by using reference materials alone. The use of a common calibrator reduced the between-assay variability to some extent, but variation due to differences in selectivity of the assays was unaffected. Consensus on robust markers and their conversion to "gluten content" are required.

AGY, a Novel Egg Yolk-Derived Anti-gliadin Antibody, Is Safe for Patients with Celiac Disease

BACKGROUND

Celiac disease (CD) is a gluten-triggered autoimmune disorder of the small intestine. A lifelong gluten-free diet (GFD) is the only approved treatment; however, strict adherence is difficult and many suffer from inadvertent gluten exposure. Oral egg yolk anti-gliadin antibody (AGY) is a novel treatment to neutralize gluten and may improve the efficacy of the GFD.

AIMS

To determine the safety, tolerability, and potential efficacy of AGY in patients with CD.

METHODS

This 6-week, open-label, single-arm study was conducted in adults with biopsy-proven CD on a GFD. Safety measures included adverse events, physical examination, and clinical laboratory tests. Additional measures included a daily Celiac Symptom Index, Health-Related Quality of life, anti-tissue transglutaminase and anti-gliadin IgA/IgG, and lactulose/mannitol excretion ratio (LMER). A 2-week run-in period to assess questionnaire compliance and acceptability of baseline safety laboratory results was followed by a 4-week treatment period with two AGY capsules taken before meals.

RESULTS

Ten patients completed the study (mean age 43.4 years, nine female). All followed a GFD for at least 6 months (mean 5 years). No safety concerns were identified. Most patients had fewer celiac symptoms (especially tiredness, headache, and bloating), improved quality of life, lowered antibodies, and lowered LMER when taking AGY compared to the run-in period.

CONCLUSION

In our cohort, AGY was safe and potentially associated with improved CD-related outcome measures in patients on a GFD. A larger study powered for further safety and efficacy evaluation is planned.

Gluten Contamination in Naturally or Labeled Gluten-Free Products Marketed in Italy

Background: A strict and lifelong gluten-free diet is the only treatment of celiac disease. Gluten contamination has been frequently reported in nominally gluten-free products. The aim of this study was to test the level of gluten contamination in gluten-free products currently available in the Italian market. Method: A total of 200 commercially available gluten-free products (including both naturally and certified gluten-free products) were randomly collected from different Italian supermarkets. The gluten content was determined by the R5 ELISA Kit approved by EU regulations. Results: Gluten level was lower than 10 part per million (ppm) in 173 products (86.5%), between 10 and 20 ppm in 9 (4.5%), and higher than 20 ppm in 18 (9%), respectively. In contaminated foodstuff (gluten > 20 ppm) the amount of gluten was almost exclusively in the range of a very low gluten content. Contaminated products most commonly belonged to oats-, buckwheat-, and lentils-based items. Certified and higher cost gluten-free products were less commonly contaminated by gluten. Conclusion: Gluten contamination in either naturally or labeled gluten-free products marketed in Italy is nowadays uncommon and usually mild on a quantitative basis. A program of systematic sampling of gluten-free food is needed to promptly disclose at-risk products.

Engineering of Kuma030: A Gliadin Peptidase That Rapidly Degrades Immunogenic Gliadin Peptides in Gastric Conditions

Celiac disease is characterized by intestinal inflammation triggered by gliadin, a component of dietary gluten. Oral administration of proteases that can rapidly degrade gliadin in the gastric compartment has been proposed as a treatment for celiac disease; however, no protease has been shown to specifically reduce the immunogenic gliadin content, in gastric conditions, to below the threshold shown to be toxic for celiac patients. Here, we used the Rosetta Molecular Modeling Suite to redesign the active site of the acid-active gliadin endopeptidase KumaMax. The resulting protease, Kuma030, specifically recognizes tripeptide sequences that are found throughout the immunogenic regions of gliadin, as well as in homologous proteins in barley and rye. Indeed, treatment of gliadin with Kuma030 eliminates the ability of gliadin to stimulate a T cell response. Kuma030 is capable of degrading >99% of the immunogenic gliadin fraction in laboratory-simulated gastric digestions within physiologically relevant time frames, to a level below the toxic threshold for celiac patients, suggesting great potential for this enzyme as an oral therapeutic for celiac disease.

The Role of Gluten in Celiac Disease and Type 1 Diabetes

Celiac disease (CD) and type 1 diabetes (T1D) are autoimmune conditions in which dietary gluten has been proven or suggested to play a pathogenic role. In CD; gluten is established as the instigator of autoimmunity; the autoimmune process is halted by removing gluten from the diet; which allows for resolution of celiac autoimmune enteropathy and subsequent normalization of serological markers of the disease. However; an analogous causative agent has not yet been identified for T1D. Nevertheless; the role of dietary gluten in development of T1D and the potentially beneficial effect of removing gluten from the diet of patients with T1D are still debated. In this review; we discuss the comorbid occurrence of CD and T1D and explore current evidences for the specific role of gluten in both conditions; specifically focusing on current evidence on the effect of gluten on the immune system and the gut microbiota.

The Gluten-Free Diet in the 3rd Millennium: Rules, Risks and Opportunities

The gluten-free diet has long been considered the standard treatment for celiac disease. However, a significant number of patients continue to experience persistent symptoms despite following a gluten-free diet. Inadvertent gluten ingestion, fermentable carbohydrates, cross-contamination, and social or financial burdens present obstacles to maintaining a gluten-free diet. Proper diet education and follow-up by an expert Registered Dietitian (RD) is essential to ensure adequate nutrition on the gluten-free diet. Patients may experience unintended weight gain or elevated cholesterol levels after initiating the gluten-free diet due to adequate absorption and healing of the intestines. This review deals with the evolving gluten-free diet, optimal recommendations while considering the overall health of patients, and multi-factorial aspects of the permanent lifestyle change.