Celiac disease treatment: gluten-free diet and beyond

IDP Force Fields Applied to Model PPII-Rich 33-mer Gliadin Peptides

The 33-mer gliadin peptide and its deamidated metabolite, 33-mer DGP, are the immunodominant peptides responsible for the adaptive immune response in celiac disease (CD). CD is a complex autoimmune chronic disorder triggered by gluten ingestion that affects the small intestine and affects ∼1% of the global population. The 33-mers are polyproline II-rich (PPII) and intrinsically disordered peptides (IDPs), whose structures remain elusive. We sampled the conformational ensembles of both 33-mer peptides via molecular dynamics simulations employing two force fields (FFs) (Amber ff03ws and Amber ff99SB-disp) specifically validated for other IDPs. Our results show that both FFs allow the extensive exploration of the conformational landscape, which was not possible with the standard FF GROMOS53A6 reported before. Clustering analysis of the trajectories showed that the five largest clusters (78-88% of the total structures) present elongated, semielongated, and curved conformations in both FFs. Large average radius of gyration and solvent-exposed surfaces characterized these structures. While the structures sampled are similar, the Amber ff99SB-disp trajectories explored folded conformations with a higher probability. In addition, PPII secondary structure was preserved throughout the trajectories (58-73%) together with a non-negligible content of β structures (11-23%), in agreement with previous experimental results. This work represents the initial step in studying further the interaction of these peptides with other biologically relevant molecules, which could lead to finally disclose the molecular events that lead to CD.

Starch Characteristics Linked to Gluten-Free Products

The increasing prevalence of coeliac disease (CD) and gluten-related disorders has led to increasing consumer demand for gluten-free products with quality characteristics similar to wheat bread. The replacement of gluten in cereal-based products remains a challenge for scientists, due to its unique role in network formation, which entraps air bubbles. When gluten is removed from a flour, starch is the main component left. Starch is used as gelling, thickening, adhesion, moisture-retention, stabilizing, film forming, texturizing and anti-staling ingredient. The extent of these properties varies depending on the starch source. The starches can additionally be modified increasing or decreasing certain properties of the starch, depending on the application. Starch plays an important role in the formulation of bakery products and has an even more important role in gluten-free products. In gluten-free products, starch is incorporated into the food formulation to improve baking characteristics such as the specific volume, colour and crumb structure and texture. This review covers a number of topics relating to starch; including; an overview of common and lesser researched starches; chemical composition; morphology; digestibility; functionality and methods of modification. The emphasis of this review is on starch and its properties with respect to the quality of gluten-free products.

Administration of Bifidobacterium breve Decreases the Production of TNF-α in Children with Celiac Disease

BACKGROUND

Increasing evidence suggests that not only genetics, but also environmental factors like gut microbiota dysbiosis play an important role in the pathogenesis of celiac disease (CD).

AIM

The aim of our study was to investigate the effect of two probiotic strains Bifidobacterium breve BR03 and B. breve B632 on serum production of anti-inflammatory cytokine interleukin 10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) in children with CD.

METHODS

The study was a double-blinded, placebo-controlled trial that included 49 children with CD on gluten-free diet (GFD) randomized into two groups and 18 healthy children in the control group. The first group (24 children with CD) daily received B. breve BR03 and B632 (2 × 10(9) colony-forming units) and the second group (25 children with CD) received placebo for 3 months.

RESULTS

TNF-α levels were significantly decreased in the first group after receiving B. breve for 3 months. On follow-up, 3 months after receiving probiotics, TNF-α levels increased again. Children with CD who were on GFD for less than 1 year showed similar baseline TNF-α levels as children who were on GFD for more than 1 year. IL-10 levels were in all groups of patients below detection level.

CONCLUSIONS

Probiotic intervention with B. breve strains has shown a positive effect on decreasing the production of pro-inflammatory cytokine TNF-α in children with CD on GFD.

Gluten-free diet or alternative therapy: a survey on what parents of celiac children want

OBJECTIVES

Celiac disease (CD) is treated by life-long gluten-free diet (GFD). Novel therapies are under development. Willingness of CD children's parents to alternative therapies and GFD impact were evaluated.

METHODS

Parents of celiac children on GFD were investigated on need and preference for novel CD therapies, children's enrolment in trials, compliance to and personal judgment on GFD, health status (HS) and quality of life (QoL).

RESULTS

About 59.5% surveyed parents expressed the need for alternative therapies with a preference for vaccine-based strategy (39.9%). About 37.7% would accept enrollment in an ad hoc trial, 20.3% would agree to endoscopy during the trial. GFD compliance was 97.4% and well accepted by 93.8%. HS and QoL significantly improved during GFD (p < 0.001).

CONCLUSIONS

The introduction of novel therapies for CD is desirable for over half of parents, with preference for vaccines. Parents frown upon enrolment in new clinical trials and the subsequent need for additional endoscopy.

The prevention of coeliac disease

Primary prevention of coeliac disease is currently not possible. Previously, a 'window of opportunity' was suggested for primary prevention, by introducing gluten between four and six months of age. However, results from recent prospective studies establish that the timing of gluten introduction and the duration or maintenance of breastfeeding do not influence the development of the disease. Secondary prevention is possible through early diagnosis and treatment. Since coeliac disease is severely underdiagnosed, the only way to achieve large-scale secondary prevention is by mass screening. Prospective studies indicate that important health problems, such as reduced foetal growth and birth weight, delayed growth in height and weight in children, and reduced bone mineral density in both children and adults can be prevented by mass screening. Adherence to a strict gluten-free diet may be considered as tertiary prevention.

The diagnosis and treatment of dermatitis herpetiformis

Dermatitis herpetiformis (DH) is an inflammatory cutaneous disease with a chronic relapsing course, pruritic polymorphic lesions, and typical histopathological and immunopathological findings. According to several evidences, DH is considered the specific cutaneous manifestation of celiac disease, and the most recent guidelines of celiac disease have stated that, in celiac patients with a proven DH, a duodenal biopsy is unnecessary for the diagnosis. In this review, the most recent data about the diagnosis and the management of DH have been reported and discussed. In particular, in patients with clinical and/or histopathological findings suggestive for DH, the finding of granular IgA deposits along the dermal–epidermal junction or at the papillary tips by direct immunofluorescence (DIF) assay, together with positive results for anti-tissue transglutaminase antibody testing, allows the diagnosis. Thereafter, a gluten-free diet should be started in association with drugs, such as dapsone, that are able to control the skin manifestations during the first phases of the diet. In conclusion, although DH is a rare autoimmune disease with specific immunopathological alterations at the skin level, its importance goes beyond the skin itself and may have a big impact on the general health status and the quality of life of the patients.

Celiac disease: prevention in children

Several studies have suggested a protective role of breastfeeding and/or the timing and quantity of gluten introduction in the subsequent development of celiac disease. Especially, prolonged breastfeeding during the introduction of gluten-containing feeding has been associated with a reduced risk of developing celiac disease in infancy. The mentioned results suggest the existence of a 'window of opportunity' between 4 and 6 months of age in which gluten can be introduced in small amounts. Therefore, the European Society for Pediatric Gastroenterology Hepatology and Nutrition recommends avoiding gluten introduction before the age of 4 months and after the age of 7 months and that gluten should be preferably introduced during ongoing breastfeeding. However, the influence of breastfeeding in the development of celiac disease is not clear, since some studies report prevention and others do not, and the studies reporting a protective effect of breastfeeding do not make clear if it concerns prevention of the disease or delays the onset of symptoms. In addition, most of the studies on this topic have been observational and retrospective. For these reasons, prospective studies are needed to understand the relationship between early nutrition in particular and environmental factors in general, concerning the development and possible prevention of celiac disease. Some of these studies are ongoing. One example is the European multicenter PreventCD project (www.preventcoeliacdisease.com) among infants with a first-degree family member with celiac disease carrying HLA-DQ2 and/or -DQ8, randomized to a double-blind dietary intervention with 100 mg of gluten daily or placebo between the age of 4-6 months. All included children are already 3 years old, and the first analyses are being prepared (http://www.trialregister.nl).