Wheat-starch-based gluten-free products in the treatment of newly detected coeliac disease: prospective and randomized study

Gluten-free diet for pediatric patients with coeliac disease: A position paper from the ESPGHAN gastroenterology committee, special interest group in coeliac disease

BACKGROUND AND OBJECTIVE

Coeliac disease is a chronic, immune-mediated disorder for which the only treatment consists of lifelong strict adherence to gluten-free diet (GFD). However, there is a lack of evidence-based guidelines on the GFD dietary management of coeliac disease. This position paper, led by the Special Interest Group in coeliac disease of the European Society of Pediatric, Gastroenterology Hepatology, and Nutrition, supported by the Nutrition Committee and the Allied Health Professionals Committee, aims to present evidence-based recommendations on the GFD as well as how to support dietary adherence.

METHODS

A wide literature search was performed using the MeSH Terms: "diet, gluten free," "gluten-free diet," "diets, gluten-free," "gluten free diet," and "coeliac disease" in Pubmed until November 8th, 2022.

RESULTS

The manuscript provides an overview of the definition of the GFD, regulations as basis to define the term "gluten-free," which foods are naturally gluten-free and gluten-containing. Moreover, it provides recommendations and educational tips and infographics on suitable food substitutes, the importance of reading food labels, risk of gluten cross-contact at home and in public settings, nutritional considerations as well as factors associated to dietary adherence based on available evidence, or otherwise clinical expertise.

CONCLUSIONS

This position paper provides guidance and recommendations to support children with coeliac disease to safely adhere to a GFD.

ESPEN guideline on hospital nutrition

In hospitals through Europe and worldwide, the practices regarding hospital diets are very heterogeneous. Hospital diets are rarely prescribed by physicians, and sometimes the choices of diets are based on arbitrary reasons. Often prescriptions are made independently from the evaluation of nutritional status, and without taking into account the nutritional status. Therapeutic diets (low salt, gluten-free, texture and consistency modified, …) are associated with decreased energy delivery (i.e. underfeeding) and increased risk of malnutrition. The European Society for Clinical Nutrition and Metabolism (ESPEN) proposes here evidence-based recommendations regarding the organization of food catering, the prescriptions and indications of diets, as well as monitoring of food intake at hospital, rehabilitation center, and nursing home, all of these by taking into account the patient perspectives. We propose a systematic approach to adapt the hospital food to the nutritional status and potential food allergy or intolerances. Particular conditions such as patients with dysphagia, older patients, gastrointestinal diseases, abdominal surgery, diabetes, and obesity, are discussed to guide the practitioner toward the best evidence based therapy. The terminology of the different useful diets is defined. The general objectives are to increase the awareness of physicians, dietitians, nurses, kitchen managers, and stakeholders towards the pivotal role of hospital food in hospital care, to contribute to patient safety within nutritional care, to improve coverage of nutritional needs by hospital food, and reduce the risk of malnutrition and its related complications.

Gluten Detection Methods and Their Critical Role in Assuring Safe Diets for Celiac Patients

Celiac disease, wheat sensitivity, and allergy represent three different reactions, which may occur in genetically predisposed individuals on the ingestion of wheat and derived products with various manifestations. Improvements in the disease diagnostics and understanding of disease etiology unveiled that these disorders are widespread around the globe affecting about 7% of the population. The only known treatment so far is a life-long gluten-free diet, which is almost impossible to follow because of the contamination of allegedly "gluten-free" products. Accidental contamination of inherently gluten-free products could take place at any level from field to shelf because of the ubiquity of these proteins/grains. Gluten contamination of allegedly "gluten-free" products is a constant threat to celiac patients and a major health concern. Several detection procedures have been proposed to determine the level of contamination in products for celiac patients. The present article aims to review the advantages and disadvantages of different gluten detection methods, with emphasis on the recent technology that allows identification of the immunogenic-gluten peptides without the use of antibodies. The possibility to detect gluten contamination by different approaches with similar or better detection efficiency in different raw and processed foods will guarantee the safety of the foods for celiac patients.

Dietary Factors and Mucosal Immune Response in Celiac Disease Patients Having Persistent Symptoms Despite a Gluten-free Diet

GOALS

The aim of this study was to investigate the role of dietary factors, distinct small-bowel mucosal immune cell types, and epithelial integrity in the perpetuation of gastrointestinal symptoms in treated celiac disease patients.

BACKGROUND

For unexplained reasons, many celiac disease patients suffer from persistent symptoms, despite a strict gluten-free diet (GFD) and recovered intestinal mucosa.

STUDY

We compared clinical and serological data and mucosal recovery in 22 asymptomatic and 25 symptomatic celiac patients on a long-term GFD. The density of CD3 and γδ intraepithelial lymphocytes (IELs), CD25 and FOXP3 regulatory T cells, and CD117 mast cells, and the expression of tight junction proteins claudin-3 and occludin, heat shock protein 60, interleukin 15, and Toll-like receptor 2 and 4 were evaluated in duodenal biopsies.

RESULTS

All subjects kept a strict GFD and had negative celiac autoantibodies and recovered mucosal morphology. The asymptomatic patients had higher mean fiber intake (20.2 vs. 15.2 g/d, P=0.028) and density of CD3 IELs (59.3 vs. 45.0 cell/mm, P=0.045) than those with persistent symptoms. There was a similar but nonsignificant trend in γδ IELs (17.9 vs. 13.5, P=0.149). There were no differences between the groups in other parameters measured.

CONCLUSIONS

Low fiber intake may predispose patients to persistent symptoms in celiac disease. There were no differences between the groups in the markers of innate immunity, epithelial stress or epithelial integrity. A higher number of IELs in asymptomatic subjects may indicate that the association between symptoms and mucosal inflammation is more complicated than previously thought.

Adverse Reactions to Wheat or Wheat Components

Wheat is an important staple food globally, providing a significant contribution to daily energy, fiber, and micronutrient intake. Observational evidence for health impacts of consuming more whole grains, among which wheat is a major contributor, points to significant risk reduction for diabetes, cardiovascular disease, and colon cancer. However, specific wheat components may also elicit adverse physical reactions in susceptible individuals such as celiac disease (CD) and wheat allergy (WA). Recently, broad coverage in the popular and social media has suggested that wheat consumption leads to a wide range of adverse health effects. This has motivated many consumers to avoid or reduce their consumption of foods that contain wheat/gluten, despite the absence of diagnosed CD or WA, raising questions about underlying mechanisms and possible nocebo effects. However, recent studies did show that some individuals may suffer from adverse reactions in absence of CD and WA. This condition is called non-celiac gluten sensitivity (NCGS) or non-celiac wheat sensitivity (NCWS). In addition to gluten, wheat and derived products contain many other components which may trigger symptoms, including inhibitors of α-amylase and trypsin (ATIs), lectins, and rapidly fermentable carbohydrates (FODMAPs). Furthermore, the way in which foods are being processed, such as the use of yeast or sourdough fermentation, fermentation time and baking conditions, may also affect the presence and bioactivity of these components. The present review systematically describes the characteristics of wheat-related intolerances, including their etiology, prevalence, the components responsible, diagnosis, and strategies to reduce adverse reactions.

Gluten in Celiac Disease-More or Less?

To date, the only known effective treatment for celiac disease is a strict gluten-free diet for life. We reviewed the literature to evaluate the upper limit for gluten content in food, which would be safe for patients with celiac disease. Patients with celiac disease should limit their daily gluten intake to no more than 10-50 mg. Most health authorities define gluten-free products as containing less than 20 parts per million gluten.

Gluten-Free Diet in Celiac Disease-Forever and for All?

The gluten-free diet is the only effective treatment available for celiac disease. However, it is difficult to adhere to and a closer look on the diet’s implementation and indications reveals several ambiguities: Not only is there controversy on the threshold of gluten that can be tolerated in the frame of a strict gluten-free diet, but it is also unclear whether the gluten-free diet is an appropriate treatment in patient subgroups with asymptomatic or potential celiac disease. Reports from a number of research groups suggest that a certain proportion of patients may effectively develop tolerance to gluten and thus become suitable for gluten reintroduction over time. In this review, we set out to create an overview about the current state of research as regards the definition of a strict gluten-free diet in terms of the gluten thresholds considered tolerable and the indication for a gluten-free diet in the absence of histological abnormalities or symptoms. Furthermore, we discuss the concept that a gluten-free diet must be followed for life by all patients.

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.

Younger age at diagnosis predisposes to mucosal recovery in celiac disease on a gluten-free diet: A meta-analysis

Background and aims

Persistent intestinal damage is associated with higher complication rates in celiac disease. We aimed to assess the potential modifiers of mucosal recovery.

Materials and methods

We screened databases (PubMed, Embase, Cochrane Trials, and Web of Science) for papers on celiac disease. Papers discussing (1) celiac patients (2) follow-up biopsy and (3) mucosal recovery after commencement of a gluten-free diet were included. The primary outcome was to produce a comprehensive analysis of complete mucosal recovery (i.e., Marsh 0 on follow-up). We compared children’s recovery ratios to those of adults. Patients following a strict gluten-free dietary regimen were included in a subgroup. Summary point estimates, 95% confidence intervals (CIs), and 95% predictive intervals (PIs) were calculated. Heterogeneity was tested with I²-statistic. The PROSPERO registration number is CRD42016053482.

Results

The overall complete mucosal recovery ratio, calculated from 37 observational studies, was 0.36 (CI: 0.28–0.44, PI: -0.12–0.84; I²: 98.4%, p<0.01). Children showed higher complete mucosal recovery ratio than adults (p<0.01): 0.65 (CI: 0.44–0.85, PI: -0.10–1.39; I²: 96.5%, p<0.01) as opposed to 0.24 (CI: 0.15–0.33, PI: -0.19–1.08; I²: 96.3%, p<0.01). In the strict dietary adherence subgroup, complete mucosal recovery ratio was 0.47 (CI: 0.24–0.70, PI: -0.47–1.41; I²: 98.8%, p<0.001). On meta-regression, diagnostic villous atrophy (Marsh 3) ratio (-8.97, p<0.01) and male ratio (+6.04, p<0.01) proved to be a significant determinant of complete mucosal recovery, unlike duration of gluten-free diet (+0.01, p = 0.62). The correlation between complete mucosal recovery ratio and age on diagnosis is of borderline significance (-0.03, p = 0.05).

Conclusions

There is considerable heterogeneity across studies concerning complete mucosal recovery ratios achieved by a gluten-free diet in celiac disease. Several celiac patients fail to achieve complete mucosal recovery even if a strict dietary regimen is followed. Younger age on diagnosis, less severe initial histologic damage and male gender predispose for achieving mucosal recovery.

Systematic review: patient-reported outcome measures in coeliac disease for regulatory submissions

BACKGROUND

New therapeutics are moving into phase 3 clinical trials for the treatment of coeliac disease, a condition with no established therapies other than gluten-free diet. These trials will require a meaningful, validated and fit for purpose patient-reported outcome measure (PROM) to quantify the symptomatic improvement of patients.

AIM

To evaluate existing PROMs for suitability in a Food and Drug Administration (FDA) approval trial for a coeliac disease therapeutic.

METHOD

We performed a systematic search in five online databases (MedLine, EmBase, Web of Science, CENTRAL, CINAHL) for studies that enrolled patients with coeliac disease and used PROMs. Studies included in this review had to measure some PROM concept, be patient administered and based upon a previously validated instrument with published measurement properties.

RESULTS

Our literature search identified 2706 unique records of which 199 ultimately qualified for abstraction. The majority of PROMs used in studies of coeliac disease was generic and did not measure numerous symptoms or concerns of interest to patients. Four PROMs were found to contain appropriate content for use in an FDA trial: the coeliac disease-specific modification of the Gastrointestinal Symptoms Rating Scale (CeD-GSRS), Psychological General Well-Being Index (PGWB), the Celiac Disease Symptom Diary (CDSD) and the Celiac Disease Patient Reported Outcome (CeD-PRO). The GSRS and PGWB are most often used together and are two of the most extensively used measures in coeliac disease. The CDSD and CeD-PRO were developed exclusively for trials in coeliac disease but have much less published information on their measurement properties.

CONCLUSIONS

While we did not find PROMs that currently meet the stated expectations of the FDA for regulatory purposes, four PROMs (CeD-GSRS, PGWB, CDSD and CeD-PRO) appear to contain appropriate content and with modest additional validation work could meet scientific standards for valid and sensitive measures of disease and treatment outcome. Specifically, what is needed for these instruments is an understanding of how sensitive they are to real changes in-patient condition, how stable they are over a period of time when health status should not have changed (test-retest reliability) as well as how they correlate with other measures of patient functioning such as intestinal biopsy. All of these objectives could feasibly be accomplished over a short cohort study of patients with biopsy-defined coeliac disease undergoing gluten challenge.

The gluten-free diet and its current application in coeliac disease and dermatitis herpetiformis

BACKGROUND

A gluten-free diet (GFD) is currently the only available therapy for coeliac disease (CD).

OBJECTIVES

We aim to review the literature on the GFD, the gluten content in naturally gluten-free (GF) and commercially available GF food, standards and legislation concerning the gluten content of foods, and the vitamins and mineral content of a GFD.

METHODS

We carried out a PubMed search for the following terms: Gluten, GFD and food, education, vitamins, minerals, calcium, Codex wheat starch and oats. Relevant papers were reviewed and for each topic a consensus among the authors was obtained.

CONCLUSION

Patients with CD should avoid gluten and maintain a balanced diet to ensure an adequate intake of nutrients, vitamins, fibre and calcium. A GFD improves symptoms in most patients with CD. The practicalities of this however, are difficult, as (i) many processed foods are contaminated with gluten, (ii) staple GF foods are not widely available, and (iii) the GF substitutes are often expensive. Furthermore, (iv) the restrictions of the diet may adversely affect social interactions and quality of life. The inclusion of oats and wheat starch in the diet remains controversial.

Mixture design of rice flour, maize starch and wheat starch for optimization of gluten free bread quality

Gluten-free bread production requires gluten-free flours or starches. Rice flour and maize starch are two of the most commonly used raw materials. Over recent years, gluten-free wheat starch is available on the market. The aim of this research was to optimize mixtures of rice flour, maize starch and wheat starch using an experimental mixture design. For this purpose, dough rheology and its fermentation behaviour were studied. Quality bread parameters such as specific volume, texture, cell structure, colour and acceptability were also analysed. Generally, starch incorporation reduced G* and increased the bread specific volume and cell density, but the breads obtained were paler than the rice flour breads. Comparing the starches, wheat starch breads had better overall acceptability and had a greater volume than maize-starch bread. The highest value for sensorial acceptability corresponded to the bread produced with a mixture of rice flour (59 g/100 g) and wheat starch (41 g/100 g).

Altered duodenal microbiota composition in celiac disease patients suffering from persistent symptoms on a long-term gluten-free diet

OBJECTIVES

A significant fraction of celiac disease patients suffer from persistent symptoms despite a long-term gluten-free diet (GFD) and normalized small bowel mucosa. The commonly suggested reasons, such as inadvertent gluten-intake or presence of other gastrointestinal disease, do not explain the symptoms in all these patients. Recently, alterations in intestinal microbiota have been associated with autoimmune disorders, including celiac disease. This led us to test a hypothesis that abnormal intestinal microbiota may be associated with persisting gastrointestinal symptoms in treated celiac disease patients.

METHODS

Duodenal microbiota was analyzed in 18 GFD-treated patients suffering from persistent symptoms and 18 treated patients without symptoms by 16S rRNA gene pyrosequencing. The celiac disease patients had been following a strict GFD for several years and had restored small bowel mucosa and negative celiac autoantibodies. Their symptoms on GFD were assessed with Gastrointestinal Symptom Rating Scale.

RESULTS

The results of several clustering methods showed that the treated celiac disease patients with persistent symptoms were colonized by different duodenal microbiota in comparison with patients without symptoms. The treated patients with persistent symptoms had a higher relative abundance of Proteobacteria (P=0.04) and a lower abundance of Bacteroidetes (P=0.01) and Firmicutes (P=0.05). Moreover, their microbial richness was reduced. The results indicated intestinal dysbiosis in patients with persistent symptoms even while adhering to a strict GFD.

CONCLUSIONS

Our findings indicate that dysbiosis of microbiota is associated with persistent gastrointestinal symptoms in treated celiac disease patients and open new possibilities to treat this subgroup of patients.

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

Gluten is the main storage protein in grains and consists of gliadin and glutenin occurring in the same ratio. Persons suffering from intolerances, including celiac disease, must avoid foods containing gluten or products containing wheat, barley, and rye. Accordingly, gluten detection is of high interest for the food safety of celiac patients. This study was designed to determine the concentrations of gluten in foods labeled "gluten free" available in the United States. Seventy-eight samples labeled gluten free were collected and analyzed using a gliadin competitive enzyme-linked immunosorbent assay. The gluten content was calculated based on the assumption of the same ratio between gliadin and glutenin. Forty-eight (61.5%) of the 78 samples contained less than the limit of quantification of 10 mg/kg for gluten. In addition, 14 (17.9%) of the 78 samples labeled gluten free contained less gluten than the guidelines established by the Codex Alimentarius for gluten-free labeling (20 mg/kg). However, 16 samples (20.5%) did contain gluten levels of ≥20 mg/kg, ranging from 20.3 to 60.3 mg/kg. In particular, five of eight breakfast cereal samples showed gluten contents higher than 20 mg/kg. These results may be of concern, as gluten sensitivity is known to vary among celiac disease patients.

Optimising delivery of care in coeliac disease - comparison of the benefits of repeat biopsy and serological follow-up

BACKGROUND

The majority of deleterious health consequences of coeliac disease (CD) are most likely to be secondary to intestinal inflammation; hence, mucosal recovery is a desirable goal of therapy. Follow-up in CD is controversial and serological response is often used as a surrogate for histological recovery.

AIMS

To inform the clinical management of CD using comparative serological and histological data from a biopsy-driven pathway of care.

METHODS

A retrospective analysis of the Cambridge Coeliac Clinic database of 595 patients routinely followed up by biopsy and serology.

RESULTS

Paired biopsy results were available for 391 patients (15% seronegative). Persisting villous atrophy (VA) occurred in 182 patients (47%). The sensitivity of anti-tissue transglutaminase (TTG) antibody for ongoing VA was only 43.6%. Information on dietetic management and further biopsy to assess response was available for 94 initially unresponsive patients, in whom targeted dietetic intervention by removal of identified gluten sources or avoidance of trace amounts of gluten led to resolution of persistent VA in 50%. The effects of institution of a formal care pathway are analysed in 298 patients. Discharge to primary care and clinical management was facilitated by the information derived from repeat biopsy.

CONCLUSIONS

Serology appears to be a poor surrogate marker for mucosal recovery on a gluten-free diet; dietary assessment fails to identify a potential gluten source in many patients with ongoing villous atrophy. The benefits of re-biopsy on diet include stratification of patients with coeliac disease suitable for early discharge from secondary care or those requiring more intensive clinical management.

Novel therapeutic/integrative approaches for celiac disease and dermatitis herpetiformis

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Gluten is a protein component in wheat and other cereals like rye and barley. At present, the only available treatment is a strict gluten-free diet. Recent advances have increased our understanding of the molecular basis for this disorder. Last decade has seen new scientific developments in this disease and led to the formulation of new concepts of pathophysiology that offer possible targets for new treatments or interventions integrative to the gluten-free diet.

Clinical practice : coeliac disease

Coeliac disease (CD) is an immune-mediated systemic condition elicited by gluten and related prolamines in genetically predisposed individuals and characterised by gluten-induced symptoms and signs, specific antibodies, a specific human leukocyte antigen (HLA) type and enteropathy. The risk of coeliac disease is increased in first-degree relatives, certain syndromes including Down syndrome and autoimmune disorders. It is thought to occur in 1 in 100-200 individuals, but still only one in four cases is diagnosed. Small-bowel biopsy is no longer deemed necessary in a subgroup of patients, i.e. when all of the following are present: typical symptoms or signs, high titres of and transglutaminase antibodies, endomysial antibodies, and HLA-type DQ2 or DQ8. In all other cases, small-bowel biopsy remains mandatory for a correct diagnosis. Therapy consists of a strictly gluten-free diet. This should result in complete disappearance of symptoms and of serological markers. Adequate follow-up is considered essential.

CONCLUSION

Although small-bowel biopsy may be omitted in a minority of patients, small-bowel biopsy is essential for a correct diagnosis of CD in all other cases. Diagnostic work-up should be completed before treatment with gluten-free diet instituted.

Review article: coeliac disease, new approaches to therapy

BACKGROUND

Coeliac disease is managed by life-long gluten withdrawal from the diet. However, strict adherence to a gluten-free diet is difficult and is not always effective. Novel therapeutic approaches are needed to supplement or even replace the dietary treatment.

AIM

To review recent advances in new therapeutic options for coeliac disease.

METHODS

A literature search was performed on MEDLINE, EMBASE, Web of Science, Scopus, DDW.org and ClinicalTrials.gov for English articles and abstracts. The search terms used included, but not limited to, 'Celiac disease', 'new', 'novel', 'Advances', 'alternatives' and 'Drug therapy'. The cited articles were selected based on the relevancy to the review objective.

RESULTS

Several new therapeutic approaches for coeliac disease are currently under development by targeting its underlying pathogenesis. Alternative therapies range from reproduction of harmless wheat strains to immunomodulatory approaches. Some of these therapies such as enzymatic cleavage of gluten and permeability inhibitors have shown promise in clinical studies.

CONCLUSIONS

Gluten-free diet is still the only practical treatment for patients with coeliac disease. Novel strategies provide promise of alternative adjunctive approaches to diet restriction alone for patients with this disorder.

Diet improves perception of health and well-being in symptomatic, but not asymptomatic, patients with celiac disease

BACKGROUND & AIMS

The benefits of serologic screening and early diagnosis of celiac disease in asymptomatic patients are not known. We investigated the impact of a gluten-free diet on self-perceived health and well-being in symptomatic and asymptomatic patients with celiac disease.

METHODS

We performed a prospective study of 698 consecutive adults newly diagnosed with celiac disease because of classic (n = 490) or extraintestinal (n = 62) symptoms or through screening of at-risk groups (n = 146; 23 were asymptomatic and analyzed separately). The survey included questions on health and well-being; quality of life was evaluated by the psychological general well-being (PGWB) questionnaire. Patients were followed for 1 year of treatment; 110 healthy subjects served as controls.

RESULTS

On a gluten-free diet, self-perceived health improved significantly among patients with classic symptoms and those detected by screening. Patients in all groups were equally concerned about their health before the diagnosis, but anxiety was alleviated by the gluten-free diet. At diagnosis, the quality of life reduced among all 3 groups but improved significantly among patients on the diet. Among the 23 asymptomatic patients, perception of health worsened and concern about health increased while they were on the diet.

CONCLUSIONS

Self-perceived health and well-being were low among patients at the time they were diagnosed with celiac disease. Most patients benefited from a gluten-free diet, so it is important to identify patients with celiac disease. Perception of health decreased among asymptomatic cases, which discourages population-based screening.

Systematic review: adherence to a gluten-free diet in adult patients with coeliac disease

BACKGROUND

Coeliac disease is increasingly diagnosed in adult patients who present with atypical symptoms or who are asymptomatic and detected by case screening. Its treatment, a gluten-free diet, can have a considerable impact on daily living. Understanding the factors associated with non-adherence is important in terms of supporting patients with their condition.

AIM

To investigate factors associated with adherence to a gluten-free diet in adults with coeliac disease.

METHODS

A literature search of multiple electronic databases using a pre-determined search string for literature between 1980 and November 2007 identified a possible 611 hits. After checking for relevance, 38 studies were included in this review.

RESULTS

Rates for strict adherence range from 42% to 91% depending on definition and method of assessment and are the lowest among ethnic minorities and those diagnosed in childhood. Adherence is most strongly associated with cognitive, emotional and socio-cultural influences, membership of an advocacy group and regular dietetic follow-up. Screen and symptom-detected coeliac patients do not differ in their adherence to a gluten-free diet.

CONCLUSIONS

The existing evidence for factors associated with non-adherence to a gluten-free diet is of variable quality. Further and more rigorous research is needed to characterize those individuals most likely to be non-adherent to assist them better with their treatment.

Clinical trial: gluten microchallenge with wheat-based starch hydrolysates in coeliac disease patients - a randomized, double-blind, placebo-controlled study to evaluate safety

BACKGROUND

Wheat-based starch hydrolysates such as glucose syrups, dextrose and maltodextrins are found in more than 50% of European processed food. These products contain low amounts of residual gluten and it has been questioned whether they are safe for coeliac disease patients.

AIM

To investigate whether coeliac disease patients can safely consume wheat-based starch hydrolysate products.

METHODS

This randomized, double-blind, placebo-controlled, prospective follow-up study involved 90 coeliac disease patients in remission randomized to consume glucose syrups, maltodextrins or placebo for 24 weeks. Small bowel mucosal morphology and inflammation, symptoms, coeliac serology and malabsorption laboratory data were evaluated at baseline and at the end of the study.

RESULTS

Daily ingestion of wheat-based starch hydrolysates, glucose syrups and maltodextrins, had no deleterious effect on small-bowel mucosal villous architecture or inflammation in coeliac disease patients when compared to the placebo group. Neither were there any significant differences in gastrointestinal symptoms, serology or malabsorption parameters after 24 weeks.

CONCLUSIONS

Wheat-based starch hydrolysates, glucose syrups and maltodextrins did not have harmful effect on coeliac disease patients. Coeliac patients can thus safely continue to consume these products.

Surface-associated proteins of wheat starch granules: suitability of wheat starch for celiac patients

Wheat starch is used to make baked products for celiac patients in several European countries but is avoided in the United States because of uncertainty about the amounts of associated grain storage (gluten) proteins. People with celiac disease (CD) must avoid wheat, rye, and barley proteins and products that contain them. These proteins are capable of initiating damage to the absorptive lining of the small intestine in CD patients, apparently as a consequence of undesirable interactions with the innate and adaptive immune systems. In this study, starch surface-associated proteins were extracted from four commercial wheat starches, fractionated by high-performance liquid chromatography and gel electrophoresis, and identified by tandem mass spectrometry analysis. More than 150 proteins were identified, many of which (for example, histones, purothionins, and glutenins) had not been recognized previously as starch-associated. The commercial starches were analyzed by the R-5 enzyme-linked immunosorbent assay method to estimate the amount of harmful gluten protein present. One of these starches had a low gluten content of 7 ppm and actually fell within the range proposed as a new Codex Alimentarius Standard for naturally gluten-free foods (maximum 20 ppm). This low level of gluten indicates that the starch should be especially suitable for use by celiac patients, although wheat starches with levels up to 100 ppm are deemed safe in the proposed Codex standards.

Systematic review: tolerable amount of gluten for people with coeliac disease

BACKGROUND

The threshold amount of gluten in 'gluten-free' products that can be tolerated by people with coeliac disease is unclear.

AIM

To investigate the threshold amount of gluten and the threshold concentration of gluten in food products that can be tolerated by people with coeliac disease.

DESIGN

Systematic review of studies published between 1966 and May 2007.

METHODS

The data sources used were MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL, and reference lists of retrieved articles. We included studies that evaluated the amount of dietary gluten or the concentrations of gluten in food products that can be tolerated by people with coeliac disease whatever their design, method or language of publication.

RESULTS

Thirteen studies (three randomized controlled, one cohort, two crossover, and seven cross-sectional) met the inclusion criteria. The daily amount of tolerable gluten varied widely between studies. Whilst some patients tolerated an average of 34-36 mg of gluten per day, other patients who consumed about 10 mg of gluten per day developed mucosal abnormalities. The effect of the consumption of 'gluten-free' products with different degrees of gluten contamination was also inconsistent.

CONCLUSIONS

The amount of tolerable gluten varies among people with coeliac disease. Although there is no evidence to suggest a single definitive threshold, a daily gluten intake of <10 mg is unlikely to cause significant histological abnormalities.

Reduced chemokine receptor 9 on intraepithelial lymphocytes in celiac disease suggests persistent epithelial activation

BACKGROUND & AIMS

Celiac disease is caused by an inappropriate immune response to dietary gluten, with increased epithelial lymphocyte infiltration in the duodenum/jejunum as a hallmark. The chemokine receptor 9 (CCR9) is a small intestinal homing receptor normally found on most mucosal T cells in this organ. Because CCR9 expression appears to be activation dependent, we examined CCR9 on duodenal T cells from untreated and treated (gluten-free diet) patients with celiac disease and healthy controls.

METHODS

Duodenal biopsy specimens and blood samples were obtained for histologic analysis and flow-cytometric CCR9 analysis of isolated lymphocytes. CCR9 expression after activation was studied in peripheral blood T cells from healthy volunteers.

RESULTS

The median number of CCR9(+) cells among CD3(+) T cells in epithelium and lamina propria, respectively, was 56% and 48% in controls, 11% and 40% in treated patients, and 1% and 8% in untreated patients. Significant differences occurred between controls and treated or untreated patients in the epithelium but only between controls and untreated patients in the lamina propria (P=.008, all comparisons). No such differences were seen in peripheral blood, but stimulation with phorbol myristate acetate and ionomycin and, to a lesser extent, stimulation via NKG2D reduced the CCR9 expression on blood T cells.

CONCLUSIONS

CCR9 expression is reduced on epithelial and lamina propria T cells in untreated celiac disease. Down-regulation of CCR9 persists in intraepithelial T cells from well-treated patients. This suggests ongoing immune activation preferentially within the epithelium.

A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease

BACKGROUND

Treatment of celiac disease (CD) is based on the avoidance of gluten-containing food. However, it is not known whether trace amounts of gluten are harmful to treated patients.

OBJECTIVE

The objective was to establish the safety threshold of prolonged exposure to trace amounts of gluten (ie, contaminating gluten).

DESIGN

This was a multicenter, double-blind, placebo-controlled, randomized trial in 49 adults with biopsy-proven CD who were being treated with a gluten-free diet (GFD) for > or =2 y. The background daily gluten intake was maintained at < 5 mg. After a baseline evaluation (t0), patients were assigned to ingest daily for 90 d a capsule containing 0, 10, or 50 mg gluten. Clinical, serologic, and histologic evaluations of the small intestine were performed at t0 and after the gluten microchallenge (t1).

RESULTS

At t0, the median villous height/crypt depth (Vh/Cd) in the small-intestinal mucosa was significantly lower and the intraepithelial lymphocyte (IEL) count (x 100 enterocytes) significantly higher in the CD patients (Vh/Cd: 2.20; 95% CI: 2.11, 2.89; IEL: 27; 95% CI: 23, 34) than in 20 non-CD control subjects (Vh/Cd: 2.87; 95% CI: 2.50, 3.09; IEL: 22; 95% CI: 18, 24). One patient (challenged with 10 mg gluten) developed a clinical relapse. At t(1), the percentage change in Vh/Cd was 9% (95% CI: 3%, 15%) in the placebo group (n = 13), -1% (-18%, 68%) in the 10-mg group (n = 13), and -20% (-22%, -13%) in the 50-mg group (n = 13). No significant differences in the IEL count were found between the 3 groups.

CONCLUSIONS

The ingestion of contaminating gluten should be kept lower than 50 mg/d in the treatment of CD.

Consumption of gluten-free products: should the threshold value for trace amounts of gluten be at 20, 100 or 200 p.p.m.?

OBJECTIVE

The threshold of gluten contamination in gluten-free products of both dietary and normal consumption is under debate. The objective of this study was to gather information on consumption of gluten-free products intended for dietary use of people under a gluten-free diet. This information is essential to ascertain the exposure of coeliac patients to gluten through their diet and deduce the maximum gluten content that these products should contain to guarantee a safe diet.

METHODS

A diet diary of consumption of gluten-free products intended for dietary use was distributed to the coeliac societies of two typical Mediterranean countries (Italy and Spain) and two Northern countries (Norway and Germany). The diet diary included a self-weigh table of the selected food items and a 10-day consumption table. Results were reported in percentiles as distributions were clearly right skewed.

RESULTS

The respondents included in the study accounted for 1359 in Italy, 273 in Spain, 226 in Norway and 56 in Germany. Gluten-free products intended for dietary use contributed significantly to the diet of coeliac patients in Italy, Germany and Norway and to a lesser degree in Spain. The most consumed gluten-free product in all countries was bread, and it was double consumed in the Northern countries (P<0.001). Mediterranean countries showed consumption of a wider variety of gluten-free foods and pasta was eaten to a large degree in Italy.

CONCLUSIONS

The differences between Northern and Mediterranean countries were not in the total amount of gluten-free products but in the type of products consumed. The observed daily consumption of gluten-free products results in the exposure to rather large amounts of gluten, thus the limit of 200 p.p.m. should be revised. A limit of 20 p.p.m. for products naturally gluten-free and of 100 p.p.m. for products rendered gluten-free is proposed to guarantee a safe diet and to enable coeliac patients to make an informed choice. These limits should be revised as new data become available.

Coeliac disease: a diverse clinical syndrome caused by intolerance of wheat, barley and rye

Coeliac disease is a lifelong intolerance to the gluten found in wheat, barley and rye, and some patients are also sensitive to oats. The disease is genetically determined, with 10% of the first-degree relatives affected and 75% of monozygotic twins being concordant. Of the patients with coeliac disease 95% are human leucocyte antigen (HLA)-DQ2 or HLA-DQ8 positive. Characteristically, the jejunal mucosa becomes damaged by a T-cell-mediated autoimmune response that is thought to be initiated by a 33-mer peptide fragment in A2 gliadin, and patients with this disorder have raised levels of anti-endomysium and tissue transglutaminase antibodies in their blood. Coeliac disease is the major diagnosable food intolerance and, with the advent of a simple blood test for case finding, prevalence rates are thought to be approximately 1:100. Classically, the condition presented with malabsorption and failure to thrive in infancy, but this picture has now been overtaken by the much more common presentation in adults, usually with non-specific symptoms such as tiredness and anaemia, disturbance in bowel habit or following low-impact bone fractures. Small intestinal biopsy is necessary for diagnosis and shows a characteristically flat appearance with crypt hypoplasia and infiltration of the epithelium with lymphocytes. Diet is the key to management and a gluten-free diet effectively cures the condition. However, this commitment is lifelong and many aisles in the supermarket are effectively closed to individuals with coeliac disease. Compliance can be monitored by measuring antibodies in blood, which revert to negative after 6-9 months. Patients with minor symptoms, who are found incidentally to have coeliac disease, often ask whether it is necessary to adhere to the diet. Current advice is that dietary adherence is necessary to avoid the long-term complications, which are, principally, osteoporosis and small bowel lymphoma. However, risk of these complications diminishes very considerably in patients who are on a gluten-free diet.

Review article: safe amounts of gluten for patients with wheat allergy or coeliac disease

For both wheat allergy and coeliac disease the dietary avoidance of wheat and other gluten-containing cereals is the only effective treatment. Estimation of the maximum tolerated amount of gluten for susceptible individuals would support effective management of their disease. Literature was reviewed to evaluate whether an upper limit for gluten content in food, which would be safe for sufferers from both diseases, could be identified. When setting gluten limits for coeliac disease sufferers, the overall potential daily intake should be considered, while for wheat allergy limits should be based on single servings. For coeliac disease sufferers this limit should lie between 10 and 100 mg daily intake. For wheat allergy, lowest eliciting doses for children lie in the lower milligram range, while for adults they are most significantly higher. Gliadins (part of the gluten proteins) not only trigger coeliac disease, but are also major allergens in wheat allergy. Therefore, measurement of gliadins with validated enzyme-linked immunosorbent assay methods provides an appropriate marker for assessing gluten and/or wheat protein contents in food. Available data suggest that a maximum gluten content for 'gluten-free' foods could be set, which protects both wheat allergy sufferers and coeliac patients.

Celiac disease: is the atypical really typical? Summary of the recent National Institutes of Health Consensus Conference and latest advances

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Gluten is a protein component in wheat and other cereals, such as rye and barley. At present, the only available treatment is a strict gluten-free diet. Recent advances have increased our understanding of the molecular basis for this disorder. The past decade has seen new scientific developments in this disease and led to the formulation of new concepts of pathophysiology and clinical manifestations. There are several targets for new treatments. This article briefly summarizes the National Institutes of Health Consensus Statement and gives an overview of new findings in recent years and of future therapeutic options for CD.

Gluten-free diet--what is toxic?

The cornerstone of treatment of coeliac disease is a gluten-free diet devoid of proteins from wheat, rye, barley and related cereals. Oats are tolerated by most patients with coeliac disease but are not totally innocent. There are considerable differences between individual patients with respect to clinical and mucosal responses to gluten challenge. In vitro and in vivo testing has identified synthetic peptides that are toxic to the coeliac small intestinal mucosa. This toxicity overlaps at least partly to the known epitopes that are recognised by small intestinal T-cells. However, the clinical significance of several of these epitopes is unclear, as is the maximum level of gluten intake that can be recommended to be safe for patients with coeliac disease. Future efforts may lead to better understanding of the disease processes as well as possible new therapeutic options.

Dietary guidelines and implementation for celiac disease

Medical nutrition therapy is the only accepted treatment for celiac disease. This paper summarizes a review of scientific studies using the gluten-free diet, nutritional risk factors, controversial elements of the diet, and its implementation in treating celiac disease. Treatment for celiac disease requires elimination of the storage proteins found in wheat, rye, and barley. The inclusion of oats and wheat starch is controversial. Research supports that oats may be acceptable for patients with celiac disease and can improve the nutritional quality of the diet. However, use of oats is not widely recommended in the United States because of concerns of potential contamination of commercial oats. Studies assessing the contamination of commercial oats are limited. Research indicates no differences in patients choosing a strict wheat starch-containing, gluten-free diet vs. a naturally gluten-free diet. Factors other than trace gluten may be the cause of continued villous atrophy in some patients. The impact of nutrient malabsorption caused from untreated celiac disease is well documented. The diet and gluten-free products are often low in B vitamins, calcium, vitamin D, iron, zinc, magnesium, and fiber. Few gluten-free products are enriched or fortified, adding to the risk of nutrient deficiencies. Patients newly diagnosed or inadequately treated have low bone mineral density, imbalanced macronutrients, low fiber intake, and micronutrient deficiencies. Also troubling is the increased incidence of obesity seen in persons with celiac disease following a gluten-free diet. Because of the nutritional risks associated with celiac disease, a registered dietitian must be part of the health care team that monitors the patient's nutritional status and compliance on a regular basis.

The safe threshold for gluten contamination in gluten-free products. Can trace amounts be accepted in the treatment of coeliac disease?

BACKGROUND

Gluten contamination in gluten-free products cannot totally be avoided. The safe threshold for gluten remains obscure.

AIM

The purpose was to estimate a reasonable limit for residual gluten, based on current literature and measurement of gluten in gluten-free products on the market.

METHODS

The gluten content of 59 naturally gluten-free and 24 wheat starch-based gluten-free products were analysed by enzyme-linked immunosorbent assay. The daily intake of flours was calculated in 76 adults on gluten-free diet, and the intake compared with mucosal histology.

RESULTS

A number of both naturally gluten-free (13 of 59) and wheat starch-based gluten-free (11 of 24) products contained gluten from 20 to 200 ppm (=mg/kg). The median daily flour consumption was 80 g (range: 10-300). Within these limits, the long-term mucosal recovery was good.

CONCLUSIONS

The threshold for gluten-contamination can safely be set at 100 ppm. Provided that the daily flour intake is even 300 g, a level of 100 ppm results in 30 mg of gluten intake. This has been shown to be safe, when correlated to histology, in clinical and challenge studies. The level can be achieved by the industry, and does not make the diet too cumbersome.

Advances in celiac disease

PURPOSE OF REVIEW

The number of diagnoses of celiac disease, especially "silent" forms continues to rise world-wide. This review aims to summarize critically recent research in celiac disease.

RECENT FINDINGS

New proteomic approaches with the development of a possible powerful animal model have potentially furthered the isolation of the epitopes within gliadin, and other related proteins, that are critical for the development of celiac disease.

SUMMARY

The number of potential disease-triggering gliadin components remains large. Small bowel biopsies remain the gold-standard for both diagnosis and monitoring of treatment.