Coeliac children on a gluten-free diet with or without oats display equal anti-avenin antibody titres

Systematic Review of the Effects of Oat Intake on Gastrointestinal Health

BACKGROUND

Oats are a food source with multiple health benefits that could support beneficial bacterial groups and provide important bioactive compounds for the gut.

OBJECTIVES

This review explores the association between oat intake, gastrointestinal (GI) symptoms, and microbial community changes in individuals with celiac disease (CeD), irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD) and without GI disease.

METHODS

Four databases and Google Scholar were systematically searched from inception until April 29, 2021. Clinical trials, observational studies, and in vitro studies with human gut-derived samples were included.

RESULTS

There were 84 articles [23 randomized controlled trials (RCTs), 21 nonrandomized trials, 8 observational studies, and 32 in vitro studies] included. Oat intake increased total bacterial count, Lactobacilli spp., and Bifidobacterium spp. in healthy individuals and those with CeD. There was an increased concentration of short-chain fatty acids and improved gut permeability with oat intake but with no significant quality-of-life difference. In some individuals with CeD, consumption of certain oat types was associated with worsening of GI symptoms. We found no studies reporting on IBS and only 3 for IBD. The quality of RCTs showed some concerns mostly in domains of randomization (73.9%), whereas the quality of evidence of non-RCTs, observational studies, and in vitro studies was satisfactory.

CONCLUSIONS

Oat intake was associated with the increase of beneficial bacterial groups in individuals without GI disease and those with CeD. Most studies showed no changes in GI symptoms with oat consumption. In vitro studies in CeD provide insight to oat-sensitive individuals and their GI mucosa, but the clinical studies remain limited, precluding our ability to draw firm conclusions. The prevalence of oat sensitivity in individuals with CeD should be further explored as this could improve clinical management and facilitate inclusion of oat in the diet for this population.

The Gluten Gene: Unlocking the Understanding of Gluten Sensitivity and Intolerance

Wheat flour is one of the most important food ingredients containing several essential nutrients including proteins. Gluten is one of the major protein components of wheat consisted of glutenin (encoded on chromosome 1) and gliadin (encoded on chromosome 1 and 6) and there are around hundred genes encoding it in wheat. Gluten proteins have the ability of eliciting the pathogenic immune responses and hypersensitivity reactions in susceptible individuals called “gluten-related disorders (GRDs)”, which include celiac disease (CD), wheat allergy (WA), and non-celiac gluten sensitivity (NCGS). Currently removing gluten from the diet is the only effective treatment for mentioned GRDs and studies for the appropriate and alternative therapeutic approaches are ongoing. Accordingly, several genetic studies have focused on breeding wheat with low immunological properties through gene editing methods. The present review considers genetic characteristics of gluten protein components, focusing on their role in the incidence of gluten-related diseases, and genetic modifications conducted to produce wheat with less immunological properties.

Probiotics, Prebiotics and Other Dietary Supplements for Gut Microbiota Modulation in Celiac Disease Patients

To date, the only available treatment for celiac disease (CD) patients is a life-lasting gluten-free diet (GFD). Lack of adherence to the GFD leads to a significant risk of adverse health consequences. Food cross-contamination, nutritional imbalances, and persistent gastrointestinal symptoms are the main concerns related to GFD. Moreover, despite rigid compliance to GFD, patients struggle in achieving a full restoring of the gut microbiota, which plays a role in the nutritive compounds processing, and absorption. Pivotal studies on the supplementation of GFD with probiotics, such as Bifidobacterium and Lactobacilli, reported a potential to restore gut microbiota composition and to pre-digest gluten in the intestinal lumen, reducing the inflammation associated with gluten intake, the intestinal permeability, and the cytokine and antibody production. These findings could explain an improvement in symptoms and quality of life in patients treated with GFD and probiotics. On the other hand, the inclusion of prebiotics in GFD could also be easy to administer and cost-effective as an adjunctive treatment for CD, having the power to stimulate the growth of potentially health-promoting bacteria strains. However, evidence regarding the use of prebiotics and probiotics in patients with CD is still insufficient to justify their use in clinical practice.

To Be Oats or Not to Be? An Update on the Ongoing Debate on Oats for Patients With Celiac Disease

To date, the only known effective treatment for celiac disease (CD) is a strict gluten-free diet (GFD) for life. Patients with CD often find it difficult to adhere to strict GFD. Oats, compared with wheat, barley, and rye, contain less amounts of prolamins. Inclusion of oats in a GFD might be valuable due to their nutritional and health benefits and increase of food variety. Therefore, they may potentially improve feeding diversity for these children and improve taste and satiety. We reviewed the literature to evaluate the safety of oats in CD patients. We have searched PUBMED, societal guidelines and national health authorities' recommendations. The following aspects were reviewed: gastrointestinal symptoms, malabsorption, serology including specific avenin antibodies, mucosal changes, avenin toxicity, immunogenicity of oats, and quality of life. We also referred to wheat contamination of oat products, the safe amount of oats for CD patients and the type of oats recommended. Data support that pure oats are well-tolerated by most CD patients, at moderate amounts (20-25 g/day dry rolled oats for children; 50-70 g/day for adults). Nevertheless, since the potential for sensitivity/toxicity exists, oats should be added with caution to a GFD, only after all CD symptoms including weight loss and growth disturbances have resolved, after at least 6 months of conventional GFD and probably also after normalization of serology. The need for pre exposure biopsy is unclear and should be considered on an individual basis.

All that a physician should know about gluten-free diet

Gluten-free diet (GFD) is the only definitive treatment for patients with celiac disease (CeD). Strict adherence to GFD improves the symptoms, nutritional deficiencies, and the overall well-being of the patients. The management of CeD is truly different and unique from the treatment of other medical or surgical diseases. While prescribing a GFD is easy, the key to the success lies in the dietary counseling by a nutrition specialist/physician and maintenance of adherence to the prescribed diet by the patient. When restricting gluten from all possible sources, it is pertinent to recommend a diet that is healthy and balanced for patients with celiac disease. Those following GFD must be counseled properly on the ways of balancing their diets and of avoiding cross contamination. They should be taught how to read food labels properly and given tips for dining out or during traveling. Regular follow up with patients is required for assessing the compliance and monitoring growth and the status of recovery. In this review article, we have compiled, for the physicians and gastroenterologists, the relevant information about GFD including counseling, adherence, nutritional adequacy, and many other related issues.

Safety of Oats in Children with Celiac Disease: A Double-Blind, Randomized, Placebo-Controlled Trial

OBJECTIVE

To evaluate the long-term validity and safety of pure oats in the treatment of children with celiac disease.

STUDY DESIGN

This noninferiority clinical trial used a double-blind, placebo-controlled, crossover design extended over 15 months. Three hundred six children with a biopsy-proven diagnosis of celiac disease on a gluten-free diet for ≥2 years were randomly assigned to eat specifically prepared gluten-free food containing an age-dependent amount (15-40 g) of either placebo or purified nonreactive varieties of oats for 2 consecutive 6-month periods separated by washout standard gluten-free diet for 3 months. Clinical (body mass index, Gastrointestinal Symptoms Rating Scale score), serologic (IgA antitransglutaminase antibodies, and IgA anti-avenin antibodies), and intestinal permeability data were measured at baseline, and after 6, 9, and 15 months. Direct treatment effect was evaluated by a nonparametric approach using medians (95% CI) as summary statistic.

RESULTS

After the exclusion of 129 patients who dropped out, the cohort included 177 children (79 in the oats-placebo and 98 in the placebo-oats group; median, 0.004; 95% CI, -0.0002 to 0.0089). Direct treatment effect was not statistically significant for clinical, serologic, and intestinal permeability variables (body mass index: median, -0.5; 95% CI, -0.12 to 0.00; Gastrointestinal Symptoms Rating Scale score: median, 0; 95% CI, -2.5 to 0.00; IgA antitransglutaminase antibodies: median, -0.02; 95% CI, -0.25 to 0.23; IgA anti-avenin antibodies: median, -0.0002; 95% CI, -0.0007 to 0.0003; intestinal permeability test: median, 0.004; 95% CI, -0.0002 to 0.0089).

CONCLUSIONS

Pure nonreactive oat products are a safe dietary choice in the treatment of children with celiac disease.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00808301.

The Gluten-Free Diet: Can Oats and Wheat Starch Be Part of It?

Objective and Conclusion: Uncertainty still exists about the use of oats and wheat starch as part of a gluten-free diet in patients with celiac disease (CD). This review should help to clarify the issues at hand. Whereas uncontaminated (from gluten/gliadin) oats and oats from cultivars not containing celiac-activating sequences of proline and glutamine can be used without risk of intestinal damage, wheat starch should not be used, unless it is free of gluten-that is, deglutinized-because even small amounts of gluten over time are able to induce small intestinal mucosal damage.

Safety of Adding Oats to a Gluten-Free Diet for Patients With Celiac Disease: Systematic Review and Meta-analysis of Clinical and Observational Studies

BACKGROUND & AIMS

Patients with celiac disease should maintain a gluten-free diet (GFD), excluding wheat, rye, and barley. Oats might increase the nutritional value of a GFD, but their inclusion is controversial. We performed a systematic review and meta-analysis to evaluate the safety of oats as part of a GFD in patients with celiac disease.

METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE databases for clinical trials and observational studies of the effects of including oats in GFD of patients with celiac disease. The studies reported patients' symptoms, results from serology tests, and findings from histologic analyses. We used the GRADE approach to assess the quality of evidence.

RESULTS

We identified 433 studies; 28 were eligible for analysis. Of these, 6 were randomized and 2 were not randomized controlled trials comprising a total of 661 patients-the remaining studies were observational. All randomized controlled trials used pure/uncontaminated oats. Oat consumption for 12 months did not affect symptoms (standardized mean difference: reduction in symptom scores in patients who did and did not consume oats, -0.22; 95% CI, -0.56 to 0.13; P = .22), histologic scores (relative risk for histologic findings in patients who consumed oats, 0.24; 95% CI, 0.01-4.8; P = .35), intraepithelial lymphocyte counts (standardized mean difference, 0.21; 95% CI, reduction of 1.44 to increase in 1.86), or results from serologic tests. Subgroup analyses of adults vs children did not reveal differences. The overall quality of evidence was low.

CONCLUSIONS

In a systematic review and meta-analysis, we found no evidence that addition of oats to a GFD affects symptoms, histology, immunity, or serologic features of patients with celiac disease. However, there were few studies for many endpoints, as well as limited geographic distribution and low quality of evidence. Rigorous double-blind, placebo-controlled, randomized controlled trials, using commonly available oats sourced from different regions, are needed.

Identification and molecular characterization of oat peptides implicated on coeliac immune response

BACKGROUND

Oats provide important nutritional and pharmacological properties, although their safety in coeliac patients remains controversial. Previous studies have confirmed that the reactivity of the anti-33-mer monoclonal antibody with different oat varieties is proportional to the immune responses in terms of T-cell proliferation. Although the impact of these varieties on the adaptive response has been studied, the role of the dendritic cells (DC) is still poorly understood. The aim of this study is to characterize different oat fractions and to study their effect on DC from coeliac patients.

METHODS AND RESULTS

Protein fractions were isolated from oat grains and analyzed by SDS-PAGE. Several proteins were characterized in the prolamin fraction using immunological and proteomic tools, and by Nano-LC-MS/MS. These proteins, analogous to α- and γ-gliadin-like, showed reactive sequences to anti-33-mer antibody suggesting their immunogenic potential. That was further confirmed as some of the newly identified oat peptides had a differential stimulatory capacity on circulating DC from coeliac patients compared with healthy controls.

CONCLUSIONS

This is the first time, to our knowledge, where newly identified oat peptides have been shown to elicit a differential stimulatory capacity on circulating DC obtained from coeliac patients, potentially identifying immunogenic properties of these oat peptides.

Role of oats in celiac disease

A gluten-free diet is currently the only effective means of treating individuals with celiac disease. Such a diet enables celiac patients to control their symptoms and avoid various complications associated with this condition. However, while the quality of gluten-free foods has significantly improved during recent decades, maintenance of a gluten-free diet does not necessarily ensure adequate nutritional intake. Because oats are an important source of proteins, lipids, vitamins, minerals, and fibre, their inclusion in a gluten-free diet might improve the nutritional status of a celiac patient. Although oats are included in the list of gluten-free ingredients specified in European regulations, their safety when consumed by celiac patients remains debatable. Some studies claim that pure oats are safe for most celiac people, and contamination with other cereal sources is the main problem facing people with this disease. However, it is necessary to consider that oats include many varieties, containing various amino acid sequences and showing different immunoreactivities associated with toxic prolamins. As a result, several studies have shown that the immunogenicity of oats varies depending on the cultivar consumed. Thus, it is essential to thoroughly study the variety of oats used in a food ingredient before including it in a gluten-free diet.

Urinary nitric oxide metabolites in children with celiac disease after long-term consumption of oats-containing gluten-free diet

OBJECTIVE

Oats are accepted in the gluten-free diet (GFD) for children with celiac disease (CD). Some reports have indicated, however, that not all celiac patients tolerate oats. We have previously shown that some children still have high levels of urinary nitric oxide (NO) metabolites as markers of intestinal inflammation after 1 year on GFD with oats. In this study, we measured urinary NO metabolites in CD children who had been consuming oats-containing GFD for an extended, 2-6-year period, also taking into consideration ordinary consumption of nitrite/nitrate-rich foods close to the urine sampling.

MATERIALS AND METHODS

Morning urinary nitrite/nitrate concentrations were measured in 188 pediatric CD patients. A questionnaire was used to elucidate factors possibly affecting the urinary levels, for example, dietary factors, asthma, or urinary tract infection.

RESULTS

Oats were consumed by 89.4% of the patients for a median time of 3 years. The median nitrite/nitrate level was 980 μM. The majority (70.2%) who consumed oats had low levels of urinary nitrite/nitrate, that is, <1400 μM, while 29.8% demonstrated high levels, that is, >1400 μM. Nitrite/nitrate-rich foods did not significantly influence the urinary concentrations.

CONCLUSION

The urinary levels of NO metabolites revealed two subpopulations, one with high and one with low levels. The high levels could be possibly due to poor adherence to the GFD, sensitivity to oats, or some unknown factor(s). Nitrate-rich foods, asthma, or urinary tract infection did not affect the result. The elevated levels of NO metabolites could indicate mucosal inflammation and pinpoint the need of careful follow-up of children on oats-containing GFD.

Noncontaminated dietary oats may hamper normalization of the intestinal immune status in childhood celiac disease

OBJECTIVES:

Life-long, strict gluten-free diet (GFD) is the only treatment for celiac disease (CD). Because there is still uncertainty regarding the safety of oats for CD patients, the aim was to investigate whether dietary oats influence the immune status of their intestinal mucosa.

METHODS:

Paired small intestinal biopsies, before and after >11 months on a GFD, were collected from children with CD who were enrolled in a randomized, double-blind intervention trial to either of two diets: standard GFD (GFD-std; n=13) and noncontaminated oat-containing GFD (GFD-oats; n=15). Expression levels of mRNAs for 22 different immune effector molecules and tight junction proteins were determined by quantitative reverse transcriptase (RT)-PCR.

RESULTS:

The number of mRNAs that remained elevated was higher in the GFD-oats group (P=0.05). In particular, mRNAs for the regulatory T cell (Treg) signature molecules interleukin-10 (IL-10) and transforming growth factor-β1 (TGF-β1), the cytotoxicity-activating natural killer (NK) receptors KLRC2/NKG2C and KLRC3/NKG2E, and the tight junction protein claudin-4 remained elevated. Between the two groups, most significant differences were seen for claudin-4 (P=0.003) and KLRC3/NKG2E (P=0.04).

CONCLUSIONS:

A substantial fraction of pediatric CD patients seem to not tolerate oats. In these patients, dietary oats influence the immune status of the intestinal mucosa with an mRNA profile suggesting presence of activated cytotoxic lymphocytes and Tregs and a stressed epithelium with affected tight junctions. Assessment of changes in levels of mRNA for claudin-4 and KLC3/NKG2E from onset to after a year on oats containing GFD shows promise to identify these CD patients.

The effects of oats on the function of gut microflora in children with coeliac disease

BACKGROUND

Faecal short chain fatty acids (SCFAs) are produced by the gut microflora. We have previously reported high faecal SCFA levels in children with coeliac disease (CD), indicating alteration in gut microfloral metabolism. Data accumulated over recent decades by us and others suggest that wheat-free oats can safely be included in a gluten-free diet (GFD). However, concerns have been raised with respect to the safety of oats in a subset of coeliacs.

AIM

To describe faecal SCFA patterns in children with newly diagnosed CD treated for 1 year with a GFD with or without oats.

METHODS

This report is part of a randomised, double-blind study on the effect of a GFD containing oats (GFD-oats) vs. a standard GFD (GFD-std). Faecal samples were received from 34 children in the GFD-oats group and 37 in the GFD-std group at initial diagnosis and/or after 1 year on a GFD. Faecal SCFAs were analysed.

RESULTS

The GFD-std group had a significantly lower total faecal SCFA concentration at 12 months compared with 0 months (P < 0.05). In contrast, total SCFA in the GFD-oats group remained high after 1 year on the GFD. The children in the GFD-oats group had significantly higher acetic acid (P < 0.05), n-butyric acid (P < 0.05) and total SCFA concentration (P < 0.01) after 1-year diet treatment compared to the GFD-std group.

CONCLUSIONS

Our results indicate that oats do affect the gut microflora function, and that some coeliac children receiving oats may develop gut mucosal inflammation, that may present a risk for future complications.

Nutrition and celiac disease

Celiac disease affects about 1% of the European and North American population. The classical clinical presentation is with symptoms of malabsorption. Serologic studies demonstrate that most celiac patients present with oligosymptomatic (silent), latent, potential, and extraintestinal forms. The disease is defined as an immune-mediated systemic disorder of genetically disposed individuals (HLA-DQ2/8) induced by the alcohol-soluble fractions of cereals and characterized by gluten-dependent symptoms, celiac-specific antibodies (against tissue transglutaminase 2), and a Marsh 2-3 enteropathy. In the last 60 years, a strict and lifelong gluten-free diet has been demonstrated to be effective and safe, preventing most potential complications of the disease, including autoimmune disease, osteoporosis, infertility, prematurity, and malignancy. Among patients with celiac disease, the toxicity of oats seems to be less than wheat, barley, and rye. The introduction of oats into the diet of patients with celiac disease should increase taste, fiber content, diversity, compliance with the diet, and quality of life. The clinical studies provide limited results in favor of a general harmlessness of oats for celiac disease patients. Patients with celiac disease who consume oats (20-25 g/d for children, 50-70 g/d for adults) need proper follow-up.

Celiac disease, gluten-free diet, and oats

Oats in a gluten-free diet increase the diet's nutritional value, but their use remains controversial. Contamination with prolamins of other cereals is frequent, and some clinical and experimental studies support the view that a subgroup of celiac patients may be intolerant to pure oats. Thus, this issue is more complex than previously suggested. In order to produce oats that are safe for all celiac patients, the following topics should be addressed: selection of oat cultivars with low avenin content, research on such recombinant varieties of oats, development of assay methods to detect avenins in oat products, guidelines for the agricultural processing of oats and the manufacture of oat products, as well as guidelines for following up with celiac patients who consume oats.

Intestinal permeability in irritable bowel syndrome patients: effects of NSAIDs

Intestinal permeability and the effect of NSAIDs on permeability were investigated in 14 irritable bowel syndrome (IBS) patients and 15 healthy subjects. In the study, 24-h urinary recoveries of orally administered polyethylene glycols (PEGs 400, 1500, and 4000) were not significantly different in healthy subjects and IBS patients before or after NSAID ingestion. Lactulose mannitol ratios in healthy subjects and IBS patients were not significantly different. Only time-dependent monitoring of PEG excretion showed that NSAIDs enhanced intestinal permeability for PEG 4000 in healthy subjects (P = 0.050) and for PEGs 400, 1500, and 4000 in IBS patients (P = 0.012, P = 0.041, and P = 0.012, respectively). These results show that intestinal permeability in IBS patients is not different from that in healthy subjects; NSAIDs compromise intestinal permeability in IBS patients to a greater extent than in healthy subjects, which suggests that IBS is associated with an altered response of the intestinal barrier to noxious agents.

Oats do not induce systemic or mucosal autoantibody response in children with coeliac disease

OBJECTIVES

A gluten-free diet omitting wheat, rye, and barley is the only effective treatment for coeliac disease. The necessity of excluding oats from the diet has remained controversial. We studied the toxicity of oats in children with coeliac disease during a 2-year follow-up by investigating jejunal transglutaminase 2 (TG2)-targeted IgA-class autoantibody deposits, a potentially more sensitive disease marker than serum antibodies or conventional histology.

PATIENTS AND METHODS

Twenty-three coeliac children in remission were randomized to undergo oat or gluten challenge with wheat, rye, barley, and oats. When jejunal histological relapse was evident after gluten challenge, patients excluded wheat, rye, and barley but continued with oats. Mucosal morphology and TG2-targeted autoantibody deposits were studied in jejunal biopsies taken at baseline and after 6 and 24 months. Furthermore, serum IgA-class TG2 antibodies were measured.

RESULTS

At baseline, serum TG2 antibodies were negative in all 23 patients, but 7 of them had minor mucosal deposits. In the oats group, there was no significant change in the intensity of the deposits within 2 years. In contrast, during the gluten challenge, the intensity of the deposits clearly increased and decreased again when wheat, rye, and barley were excluded but consumption of oats was continued; this was in line with serum autoantibodies. The intensity of the mucosal deposits correlated well with both villous morphology and serum autoantibody levels.

CONCLUSIONS

Consumption of oats does not induce TG2 autoantibody production at mucosal level in children with coeliac disease. Measurement of small-intestinal mucosal autoantibody deposits is suitable for monitoring treatment in coeliac patients.

Introduction of oats in the diet of individuals with celiac disease: a systematic review

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 only treatment for celiac disease is a strict gluten-free diet for life. This paper presents a systematic review of the scientific literature on the safety of pure oats for individuals with celiac disease, which historically has been subject to debate. Limitations identified within the scientific database include: limited data on long-term consumption, limited numbers of participants in challenge studies, and limited reporting about the reasons for withdrawals from study protocols. Furthermore, some evidence suggests that a small number of individuals with celiac disease may be intolerant to pure oats and some evidence from in vitro studies suggests that an immunological response to oat avenins can occur in the absence of clinical manifestations of celiac disease as well as suggesting that oat cultivars vary in toxicity. Based on the majority of the evidence provided in the scientific database, and despite the limitations, Health Canada and the Canadian Celiac Association (CCA) concluded that the majority of people with celiac disease can tolerate moderate amounts of pure oats. The incorporation of oats into a gluten-free diet provides high fiber and vitamin B content, increased palatability, and beneficial effects on cardiovascular health. However, it is recommended that individuals with celiac disease should have both initial and long-term assessments by a health professional when introducing pure oats into a gluten-free diet.

Unkilned and large amounts of oats in the coeliac disease diet: a randomized, controlled study

OBJECTIVE

There is evidence for the long-term safety of oats as part of a gluten-free diet in coeliac disease (CD). Oats is generally processed by kilning, which theoretically may change its antigenic properties and be the reason that it is tolerated by patients with CD. The aim of this study was to investigate the suitability of large amounts of unkilned oats, comparing its use with kilned oats in adult coeliac patients.

MATERIAL AND METHODS

The study group included 13 men and 19 women with CD in remission. The goal of daily intake of oats was 100 g during one year. These patients using oats as part of their gluten-free diet were randomized to two treatment groups. One group used regular oats and the other unkilned oats. After 6 months the patients changed the treatment groups. Food intake, symptoms, histology of the small intestine and the levels of endomysial antibodies were noted.

RESULTS

No marked changes were found in the duodenal biopsies, in the levels of endomysial antibodies or in the well-being of the patients. Compliance with the diet did not change during the follow-up.

CONCLUSIONS

Large amounts of both unkilned and regular kilned oats are well tolerated by adult patients with CD. Oats is therefore not harmful, even in its unkilned form, which indicates that its antigenic nature is not changed by common industrial food processing in such a way that would prevent the provoking of CD.

No induction of anti-avenin IgA by oats in adult, diet-treated coeliac disease

OBJECTIVE

Coeliac disease is effectively treated with a gluten-free diet devoid of wheat, rye, barley and related cereals. Oats has until recently also been considered harmful but is now allowed in several countries. We have, however, identified three adult coeliac disease patients who developed a flare of active coeliac disease after ingestion of oats, which suggests that oats might not be entirely innocent in coeliac disease. It is known that patients with untreated coeliac disease have elevated IgA antibodies to oat prolamins. The objective of this study was to investigate whether levels of IgA against oats were increased in treated, adult coeliac disease patients.

MATERIAL AND METHODS

Serum was collected from 136 adult patients with treated coeliac disease and 139 controls. Eighty-two of the coeliac disease patients had been taking oats as part of their gluten-free diet for 6 months or more. IgA against oats avenin, wheat gliadin and tissue transglutaminase was tested with ELISA.

RESULTS

No significant differences were found in IgA against oats in oats-eating and non-oats-eating coeliac disease patients. Both groups had increased levels of IgA against wheat, oats and tissue transglutaminase compared to healthy controls. A significant positive correlation was found between anti-avenin and antigliadin IgA (p<0.0001), and between anti-avenin and anti-tissue transglutaminase IgA (p=0.0012).

CONCLUSIONS

Ingestion of oats does not cause increased levels of IgA against oats in adult coeliac disease patients on a gluten-free diet. The findings support the notion that most adult coeliac disease patients can tolerate oats.

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.

Consumption of pure oats by individuals with celiac disease: a position statement by the Canadian Celiac Association

The treatment of celiac disease is a strict adherence to a gluten-free diet for life. In the past, oats were considered to be toxic to individuals with celiac disease and were not allowed in a gluten-free diet. However, recent evidence suggests that oats that are pure and uncontaminated with other gluten-containing grains, if taken in limited quantities, are safe for most individuals with celiac disease. For adults, up to 70 g (1/2 to 3/4 cup) of oats per day and for children, up to 25 g (1/4 cup) per day are safe to consume. These oats and oat products must fulfill the standards for a gluten-free diet set by the Canadian Food Inspection Agency and Health Canada. The Canadian Celiac Association, in consultation with Health Canada, Agriculture & Agri-Food Canada and the Canadian Food Inspection Agency, has established requirements for growing, processing, and purity testing and labelling of pure oats. These strategies have led to the production of pure, uncontaminated oats for the first time in Canada. Oats and oat products that are safe for consumption by individuals with celiac disease and dermatitis herpetiformis are now commercially available in Canada.

Can oats be taken in a gluten-free diet? A systematic review

OBJECTIVE

There has long been doubt about the need to exclude oats from a gluten-free diet (GFD). The objective of this study was to review the literature in order to arrive at a firm recommendation.

MATERIAL AND METHODS

Electronic databases were searched up to February 2006 using the terms "oats" and "coeliac disease".

RESULTS

Twenty relevant studies were found and presented. Early studies were small and uncontrolled and mostly indirect. In 10 studies involving 165 patients, only 1 patient was shown to have histological damage as a result of consuming oats.

CONCLUSIONS

Coeliac patients can, to some advantage, include oats in a GFD although there may be the occasional patient who is also oats sensitive. Previous conflicting results may have been partly due to contamination of oats by wheat. Lest contamination is present and exceeds the safe threshold, we recommend that coeliac patients should only add oats to their GFD when they are established on a conventional GFD, and stop eating oats if they develop any symptoms.

Urinary nitric oxide during one year of gluten-free diet with or without oats in children with coeliac disease

OBJECTIVE

Although in both adults and children with coeliac disease (CD) it is now recommended that oats be added to their gluten-free diet, there is still some controversy concerning the possible harmful effects of oats in some individuals. In this study concentrations of nitric oxide metabolites were repeatedly measured in the urine of children under investigation for CD, when on a gluten-free diet with or without oats.

MATERIAL AND METHODS

The study included 116 children, randomized to a standard gluten-free diet (GFD-std) or a gluten-free diet supplemented with wheat-free oat products (GFD-oats), over a one-year period. Small-bowel biopsy was performed at the beginning and end of the study. Morning urine samples were collected from 87 children and urinary nitrite/nitrate concentrations were monitored at 0, 3, 6, 9 and 12 months.

RESULTS

All patients were in clinical remission after the study period. There was a rapid decline in urinary nitrite/nitrate concentrations in both groups as early as after 3 months. No differences were seen between the study groups at any of the checkpoints. However, at the end of the study, the nitrite/nitrate values of 9 children in the GFD-oats group and 8 children in the GFD-std group had not normalized.

CONCLUSIONS

Children with CD on a gluten-free diet with oats display a similar reduction in urinary nitrite/nitrate as those on a traditional gluten-free diet. Some children, however, still demonstrate high nitrite/nitrate excretion after one year on either diet, indicating that long-term follow-up studies of children on an oats-containing diet are needed.