Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet

BACKGROUND The gluten-free diet(GFD)has limitations,and there is intense research in the development of adjuvant therapies.AIM To examine the effects of orally administered Aspergillus niger prolyl endopeptidase protease(AN-PEP)on inadvertent gluten exposure and symptom prevention in adult celiac disease(CeD)patients following their usual GFD.METHODS This was an exploratory,double-blind,randomized,placebo-controlled trial that enrolled CeD patients on a long-term GFD.After a 4-wk run-in period,patients were randomized to 4 wk of two AN-PEP capsules(GliadinX;AVI Research,LLC,United States)at each of three meals per day or placebo.Outcome endpoints were:(1)Average weekly stool gluten immunogenic peptides(GIP)between the run-in and end of treatments and between AN-PEP and placebo;(2)celiac symptom index(CSI);(3)CeD-specific serology;and(4)quality of life.Stool samples were collected for GIP testing by ELISA every Tuesday and Friday during run-ins and treatments.RESULTS Forty patients were randomized for the intention-to-treat analysis,and three were excluded from the per-protocol assessment.Overall,628/640(98.1%)stool samples were collected.GIP was undetectable(<0.08μg/g)in 65.6%of samples,and no differences between treatment arms were detected.Only 0.5%of samples had GIP concentrations sufficiently high(>0.32μg/g)to potentially cause mucosal damage.Median GIP concentration in the AN-PEP arm was 44.7%lower than in the run-in period.One-third of patients exhibiting GIP>0.08μg/g during run-in had lower or undetectable GIP after AN-PEP treatment.Compared with the run-in period,the proportion of symptomatic patients(CSI>38)in the AN-PEP arm was significantly lower(P<0.03).AN-PEP did not result in changes in specific serologies.CONCLUSION This exploratory study conducted in a real-life setting revealed high adherence to the GFD.The AN-PEP treatment did not significantly reduce the overall GIP stool concentration.However,given the observation of a significantly lower prevalence of patients with severe symptoms in the AN-PEP arm,further clinical research is warranted.

Advances in understanding and managing celiac disease:Pathophysiology and treatment strategies

In this editorial,we comment on an article published in the recent issue of the World Journal of Gastroenterology.Celiac disease(CeD)is a disease occurring in genetically susceptible individuals,which is mainly characterized by gluten intolerance in the small intestine and clinical symptoms such as abdominal pain,diarrhea,and malnutrition.Therefore,patients often need a lifelong gluten-free diet,which greatly affects the quality of life and expenses of patients.The gold standard for diagnosis is intestinal mucosal biopsy,combined with serological and genetic tests.At present,the lack of safe,effective,and satisfactory drugs for CeD is mainly due to the complexity of its pathogenesis,and it is difficult to find a perfect target to solve the multi-level needs of patients.In this editorial,we mainly review the pathological mechanism of CeD and describe the current experimental and improved drugs for various pathological aspects.

Digesting gluten with oral endopeptidases to improve the management of celiac disease

In our editorial,we want to comment on the article by Stefanolo et al titled“Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet”.Celiac disease is an immune-mediated disorder triggered by dietary gluten in genetically predisposed individuals.Although avoiding gluten can permit patients to live symptom-free,ongoing voluntary or involuntary exposure to gluten is common and associated with persistent villous atrophy in small bowel mucosa.As villous atrophy predisposes patients to life threatening complications,such as osteoporotic fractures or malignancies,therapeutic adjuncts to gluten-free diet become important to improve patients’quality of life and,if these adjuncts can be shown to improve villous atrophy,avoid complications.Oral administration of enzyme preparations,such as endopeptidases that digest gluten and mitigate its antigenicity to trigger inflam-mation,is one clinical strategy under investigation.The article is about the utility of one endopeptidase isolated from Aspergillus niger.We critique findings of this clinical trial and also summarize endopeptidase-based as well as other strategies and how they can complement gluten-free diet in the management of celiac disease.

Aspergillus niger prolyl endopeptidase in celiac disease

We comment here on the article by Stefanolo et al entitled“Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet”,published in the World Journal of Gastroenterology.Celiac disease is a well-recognized systemic autoimmune disorder.In genetically susceptible people,the most evident damage is located in the small intestine,and is caused and worsened by the ingestion of gluten.For that reason,celiac patients adopt a gluten-free diet(GFD),but it has some limitations,and it does not prevent re-exposure to gluten.Research aims to develop adjuvant therapies,and one of the most studied alternatives is supplementation with Aspergillus niger prolyl endopeptidase protease(AN-PEP),which is able to degrade gluten in the stomach,reducing its concentration in the small intestine.The study found a high adherence to the GFD,but did not address AN-PEP as a gluten immunogenic peptide reducer,as it was only tested in patients following a GFD and not in gluten-exposing conditions.This study opens up new research perspectives in this area and shows that further study is needed to clarify the points that are still in doubt.

Beyond the gluten-free diet:Innovations in celiac disease therapeutics

Celiac disease(CD)is an autoimmune disorder exacerbated by the ingestion of gluten in genetically susceptible individuals,leading to intestinal inflammation and damage.This chronic disease affects approximately 1%of the world’s po-pulation and is a growing health challenge due to its increasing prevalence.The development of CD is a complex interaction between genetic predispositions and environmental factors,especially gluten,culminating in a dysregulated immune response.The only effective treatment at present is a strict,lifelong gluten-free diet.However,adherence to this diet is challenging and often incomplete,so research into alternative therapies has intensified.Recent advances in under-standing the molecular and immunological aspects of CD have spearheaded the development of novel pharmacologic strategies that should provide more effec-tive and manageable treatment options.This review examines the latest inno-vations in CD therapies.The focus is on drugs in advanced clinical phases and targeting specific signaling pathways critical to the disease pathogenesis.We dis-cuss both quantitative strategies such as enzymatic degradation of gluten,and qualitative approaches including immunomodulation and induction of gluten tolerance.Innovative treatments currently under investigation include transglu-taminase inhibitors,which prevent the modification of gluten peptides,and nano-particle-based therapies to recalibrate the immune response.These new therapies not only promise to improve patient outcomes but are also expected to improve quality of life by reducing the burden of dietary restrictions.The integration of these new therapies could revolutionize the treatment of CD and shift the para-digm from strict dietary restrictions to a more flexible and patient-friendly thera-peutic approach.This review provides a comprehensive overview of the future prospects of CD treatment and emphasizes the importance of continued research and multidisciplinary collab-oration to integrate these advances into standard clinical practice.

Prevalence of malignant neoplasms in celiac disease patients-a nationwide United States population-based study

BACKGROUND Celiac disease(CeD)is an autoimmune disorder triggered by the immune response to gluten in genetically predisposed individuals.Recent research has unveiled a heightened risk of developing specific malignant neoplasms(MN)and various malignancies,including gastrointestinal,lymphomas,skin,and others,in individuals with CeD.AIM To investigate the prevalence of MN in hospitalized CeD patients in the United States.METHODS Using data from the National Inpatient Sample spanning two decades,from January 2000 to December 2019,we identified 529842 CeD patients,of which 78128(14.75%)had MN.Propensity score matching,based on age,sex,race,and calendar year,was employed to compare CeD patients with the general non-CeD population at a 1:1 ratio.RESULTS Positive associations were observed for several malignancies,including small intestine,lymphoma,nonmelanoma skin,liver,melanoma skin,pancreas myelodysplastic syndrome,biliary,stomach,and other neuroendocrine tumors(excluding small and large intestine malignant carcinoid),leukemia,uterus,and testis.Conversely,CeD patients exhibited a reduced risk of respiratory and secondary malignancies.Moreover,certain malignancies showed null associations with CeD,including head and neck,nervous system,esophagus,colorectal,anus,breast,malignant carcinoids,bone and connective tissues,myeloma,cervix,and ovary cancers.CONCLUSION Our study is unique in highlighting the detailed results of positive,negative,or null associations between different hematologic and solid malignancies and CeD.Furthermore,it offers insights into evolving trends in CeD hospital outcomes,shedding light on advancements in its management over the past two decades.These findings contribute valuable information to the understanding of CeD’s impact on health and healthcare utilization.

Celiac disease screening in patients with cryptogenic cirrhosis

We write a letter to the editor commenting the article“Who to screen and how to screen for celiac disease”.We discuss the present literature on cirrhosis and celiac disease(CD)and recommend screening and treating CD in individuals with cryptogenic cirrhosis.

Risk of pancreatic cancer in individuals with celiac disease in the United States:A population-based matched cohort study

BACKGROUND Celiac disease(CD)has been associated with gastrointestinal malignancies.However,the magnitude of the risk of pancreatic cancer(PC)associated with CD is much less clear,and risks have not been estimated from large populations.AIM To assess the risk of PC in CD patients.METHODS We conducted a population-based,multicenter,propensity score-matched cohort study with consecutive patients diagnosed with CD using the TriNeTx research network platform.We examined the incidence of PC in patients with CD compared with a matched cohort of patients without CD(non-CD,controls).Each patient in the main group(CD)was matched to a patient in the control group using 1:1 propensity score matching to reduce confounding effects.The incidence of PC was estimated using a Cox proportional hazards model with a hazard ratio(HR)and 95%confidence interval(CI).RESULTS A total of 389980 patients were included in this study.Among them,155877 patients had a diagnosis of CD,and the remaining 234103 individuals without CD were considered a control cohort.The mean duration of follow-up for patients in the CD and control cohorts was 5.8±1.8 and 5.9±1.1 years,respectively.During the follow-up,309 patients with CD developed PC,whereas 240 patients developed PC in the control group(HR=1.29;95%CI:1.09-1.53).In the secondary analyses in the first year after diagnosis of CD,patients with CD were at a significant increase in risk for PC;151 patients with CD had an incidence of PC compared with 96 incidences of PC among the patients in the non-CD control group(HR=1.56;95%CI:1.20-2.01)and sensitivity analysis showed similar magnitude to the one generated in the primary and secondary analysis.CONCLUSION Patients with CD are at increased risk of PC.Risk elevation persists beyond the first year after diagnosis to reference individuals without CD from the general population.

Gut microbiota predicts the diagnosis of celiac disease in Saudi children

BACKGROUND Celiac disease(CeD)is a multisystem immune-mediated multifactorial condition strongly associated with the intestinal microbiota.AIM To evaluate the predictive power of the gut microbiota in the diagnosis of CeD and to search for important taxa that may help to distinguish CeD patients from controls.METHODS Microbial DNA from bacteria,viruses,and fungi,was isolated from mucosal and fecal samples of 40 children with CeD and 39 controls.All samples were sequenced using the HiSeq platform,the data were analyzed,and abundance and diversities were assessed.For this analysis,the predictive power of the microbiota was evaluated by calculating the area under the curve(AUC)using data for the entire microbiome.The Kruskal-Wallis test was used to evaluate the significance of the difference between AUCs.The Boruta logarithm,a wrapper built around the random forest classification algorithm,was used to identify important bacterial biomarkers for CeD.RESULTS In fecal samples,AUCs for bacterial,viral,and fungal microbiota were 52%,58%,and 67.7%respectively,suggesting weak performance in predicting CeD.However,the combination of fecal bacteria and viruses showed a higher AUC of 81.8%,indicating stronger predictive power in the diagnosis of CeD.In mucosal samples,AUCs for bacterial,viral,and fungal microbiota were 81.2%,58.6%,and 35%,respectively,indicating that mucosal bacteria alone had the highest predictive power.Two bacteria,Bacteroides intestinalis and Burkholderiales bacterium 1-1-47,in fecal samples and one virus,Human_endogenous_retrovirus_K,in mucosal samples are predicted to be“important”biomarkers,differentiating celiac from nonceliac disease groups.Bacteroides intestinalis is known to degrade complex arabinoxylans and xylan which have a protective role in the intestinal mucosa.Similarly,several Burkholderiales species have been reported to produce peptidases that hydrolyze gluten peptides,with the potential to reduce the gluten content of food.Finally,a role for Human_endogenous_retrovirus_K in immune-mediated disease such as CeD has been reported.CONCLUSION The excellent predictive power of the combination of the fecal bacterial and viral microbiota with mucosal bacteria alone indicates a potential role in the diagnosis of difficult cases of CeD.Bacteroides intestinalis and Burkholderiales bacterium 1-1-47,which were found to be deficient in CeD,have a potential protective role in the development of prophylactic modalities.Further studies on the role of the microbiota in general and Human_endogenous_retrovirus_K in particular are needed.

Efficacy of probiotics supplementation in amelioration of celiac disease symptoms and enhancement of immune system

Patients with celiac disease(CD)have a mucosal layer that is unable to regulate the gut microbiota,leaving the host vulnerable to dangerous infections and antigens.When compared to healthy people,this dysbiosis is marked by a decrease in intra-and intergeneric biodiversity,which demonstrates an imbalance between helpful bacteria and possibly harmful or proinflammatory species.The early gut microbiota is influenced by the genotype of newborns with the HLADQ2 haplotypes,and this may modify how gluten is handled in the intestinal lumen,polarize innate or adaptive immune responses,and result in glutensensitive enteropathy.The outcome of gluten digestion can vary depending on the composition of the intestinal gut bacteria and the partial conversion of gluten into peptides larger than ten amino acids in the small intestines,which can be immunogenic.In the small intestine,114 different bacterial strains belonging to 32 different species have 27 of them exhibiting peptidolytic activity.Thus,the individual risk of developing a gluten-related illness is further influenced by microbial composition and gluten degrading capacity.The conclusion that lactobacilli and Bifidobacterium spp.may be used as a probiotic supplement in CD patients is based on their shared possession of the most extensive peptidolytic and proteolytic activity thought to be engaged in the breakdown of gluten among all potential bacterial genera present in the gut microbiota.In children with CD autoimmunity,daily oral dose of Lactobacillus.plantarum HEAL9 and Lactobacillus.paracasei 8700:2 was found to modify the peripheral immune response.Bifidobacterium.breve strains have demonstrated a beneficial effect on reducing pro-inflammatory cytokine TNF-production in CD children on gluten-free diets.

Capsule endoscopy in celiac disease

Video capsule endoscopy is an attractive and patient- friendly tool that provides high quality images of the small bowel. Obscure gastrointestinal bleeding is the primary and most evaluated indication to capsule endoscopy;however,indications are expanding and a small number of preliminary reports have been presented concerning the role of video capsule endoscopy in the diagnosis of celiac disease. The purpose of this review is to update the current knowledge and to hypothesize on future perspectives of the use of video capsule endoscopy in patients with celiac disease.

Refractory celiac disease and sprue-like intestinal disease

Celiac disease is a gluten-dependent small intestinal mucosal disorder that causes malabsorption, often with diarrhea and weight loss. Diagnosis is based on detection of typical biopsy changes in the proximal small bowel, followed by evidence for an unequivocal response to a gluten-free diet. Refractoriness in celiac disease may be due to poor diet compliance, sometimes intentional, or consumption of ubiquitious sources of gluten. Alternatively, the original diagnosis may not be correct (eg., duodenal Crohn's disease), or a second cause for symptoms may be present (eg., collagenous colitis, functional bowel disorder). In some with recurrent symptoms, a complication may be present (eg., collagenous sprue, small bowel carcinoma, lymphoma). In some, a response to a gluten-free diet can not be unequivocally defined, and more precise historical terms have been used including "sprue-like intestinal disease" or "unclassified sprue". Although a "wastebasket diagnosis", these likely represent a heterogeneous group, and some, but not all, may develop lymphoma. Precise definition will be critical in the future as an array of new treatments, including biological agents, may emerge.

Celiac disease:Management of persistent symptoms in patients on a gluten-free diet

AIM:To investigate all patients referred to our center with non-responsive celiac disease (NRCD),to establish a cause for their continued symptoms.METHODS:We assessed all patients referred to our center with non-responsive celiac disease over an 18-mo period.These individuals were investigated to establish the eitiology of their continued symptoms.The patients were first seen in clinic where a thorough history and examination were performed with routine blood work including tissue transglutaminase antibody measurement.They were also referred to a specialist gastroenterology dietician to try to identift any lapses in the diet and sources of hidden gluten ingestion.A repeat small intestinal biopsy was also performed and compared to biopsies from the referring hospital where possible.Colonoscopy,lactulose hydrogen breath testing,pancreolauryl testing and computed tomography scan of the abdomen were undertaken if the symptoms persisted.Their clinical progress was followed over a minimum of 2 years.RESULTS:One hundred and twelve consecutive patients were referred with NRCD.Twelve were found not to have celiac disease (CD).Of the remaining 100 patients,45% were not adequately adhering to a strict gluten-free diet,with 24 (53%) found to be inadvertently ingesting gluten,and 21 (47%) admitting noncompliance.Microscopic colitis was diagnosed in 12% and small bowel bacterial overgrowth in 9%.Refractory CD was diagnosed in 9%.Three of these were diagnosed with intestinal lymphoma.After 2 years,78 patients remained well,eight had continuing symptoms,and four had died.CONCLUSION:In individuals with NRCD,a remediable cause can be found in 90%:with continued gluten ingestion as the leading cause.We propose an algorithm for investigation.

Adult celiac disease in the elderly

There is an increased awareness that celiac disease may occur in the elderly although presentations with either diarrhea, weight loss or both may be less common causing delays in diagnosis for prolonged periods. Higher detection rates also seem evident owing to active case screening, largely through serodiagnostic measures. In some elderly patients who are genetically predisposed, it has been hypothesized that celiac disease might be precipitated late in life by an antigen, possibly from an infectious agent. As a result, peptide mimicry or other poorly-defined mechanisms may precipitate an autoimmune gluten-dependent clinical state. Although diarrhea and weight loss occur, only isolated iron deficiency anemia may be present at the time of initial diagnosis. In addition, the risk of other autoimmune disorders, particularly autoimmune thyroiditis, and bone disease, are increased. Osteopenia may also be associated with an increased risk of fractures. Finally, elderly celiacs have an increased risk of malignant intestinal disease, especially lymphoma.

Non-responsive celiac disease in children on a gluten free diet

BACKGROUND Non-responsive celiac disease(NRCD) is defined as the persistence of symptoms in individuals with celiac disease(CeD) despite being on a gluten-free diet(GFD). There is scant literature about NRCD in the pediatric population.AIM To determine the incidence, clinical characteristics and underlying causes of NRCD in children.METHODS Retrospective cohort study performed at Boston Children’s Hospital(BCH). Children < 18 years diagnosed with CeD by positive serology and duodenal biopsies compatible with Marsh Ⅲ histology between 2008 and 2012 were identified in the BCH’s Celiac Disease Program database. Medical records were longitudinally reviewed from the time of diagnosis through September 2015. NRCD was defined as persistent symptoms at 6 mo after the initiation of a GFD and causes of NRCD as well as symptom evolution were detailed. The children without symptoms at 6 mo(responders) were compared with the NRCD group. Additionally, presenting signs and symptoms at the time of diagnosis of CeD among the responders and NRCD patients were collected and compared to identify any potential predictors for NRCD at 6 mo of GFD therapy.RESULTS Six hundred and sixteen children were included. Ninety-one(15%) met criteria for NRCD. Most were female(77%). Abdominal pain [odds ratio(OR) 1.8 95% confidence interval(CI) 1.1-2.9], constipation(OR 3.1 95%CI 1.9-4.9) and absence of abdominal distension(OR for abdominal distension 0.4 95%CI 0.1-0.98) at diagnosis were associated with NRCD. NRCD was attributed to a wide variety of diagnoses with gluten exposure(30%) and constipation(20%) being the most common causes. Other causes for NRCD included lactose intolerance(9%), gastroesophageal reflux(8%), functional abdominal pain(7%), irritable bowel syndrome(3%), depression/anxiety(3%), eosinophilic esophagitis(2%), food allergy(1%), eating disorder(1%), gastric ulcer with Helicobacter pylori(1%), lymphocytic colitis(1%), aerophagia(1%) and undetermined(13%). 64% of children with NRCD improved on follow-up.CONCLUSION NRCD after ≥ 6 mo GFD is frequent among children, especially females, and is associated with initial presenting symptoms of constipation and/or abdominal pain. Gluten exposure is the most frequent cause.

Classical and Non-Classical Celiac Disease Comparison: Ten Years of Study

Objective: Celiac disease (CD) is an immune-mediated systemic disorder triggered by gluten. It has a variable combination of clinical manifestations and changes that have been occurring in recent decades however they are not known in detail. The purpose of the article is to compare Classical and Non-Classical CD cases in terms of demographic characteristics, duodenal biopsy, extraintestinal manifestations, and associated comorbidities. Materials and Methods: A comparative retrospective cohort study from January 2008 to December 2018. Results: A total of 128 cases were included: 84 Classical (66%) and 44 Non-Classical CD (34%). The family history of CD was identified in 14% of cases without differences between groups. The age at diagnosis was distinct for Classical and Non-Classical CD (4.9 ± 4 and 8.3 ± 4 years old;p 0.001), respectively. Important changes were found within the classical presentation, including mono symptoms and a significantly higher rate of intestinal atrophy;p = 0.04. The main Non-Classical CD symptom was recurrent abdominal pain. The extraintestinal manifestations (EIM) were identified in 42% and occurred in both groups. The comparison between groups showed differences in rates of migraine and vitamin D deficiency and was higher for Non-Classical CD (p 0.05). Associated diseases occurred in 10.9%, and type 1 diabetes was significant for the Non-Classical CD group (p = 0.04). Conclusion: The classical CD was the most prevalent profile and presented a decrease in the severity of symptoms however remain a higher rate of intestinal atrophy. Recurrent abdominal pain was the main symptom of Non-Classical CD. Extraintestinal manifestations and associated diseases presented an increasing trend of occurrence among cases of Non-Classical CD.

Celiac disease:Prevalence,diagnosis,pathogenesis and treatment

Celiac disease(CD) is one of the most common diseases,resulting from both environmental(gluten) and genetic factors [human leukocyte antigen(HLA) and nonHLA genes].The prevalence of CD has been estimated to approximate 0.5%-1% in different parts of the world.However,the population with diabetes,autoimmune disorder or relatives of CD individuals have even higher risk for the development of CD,at least in part,because of shared HLA typing.Gliadin gains access to the basal surface of the epithelium,and interact directly with the immune system,via both trans-and para-cellular routes.From a diagnostic perspective,symptoms may be viewed as either "typical" or "atypical".In both positive serological screening results suggestive of CD,should lead to small bowel biopsy followed by a favourable clinical and serological response to the gluten-free diet(GFD) to confirm the diagnosis.Positive anti-tissue transglutaminase antibody or antiendomysial antibody during the clinical course helps to confirm the diagnosis of CD because of their over 99% specificities when small bowel villous atrophy is present on biopsy.Currently,the only treatment available for CD individuals is a strict life-long GFD.A greater understanding of the pathogenesis of CD allows alternative future CD treatments to hydrolyse toxic gliadin peptide,prevent toxic gliadin peptide absorption,blockage of selective deamidation of specific glutamine residues by tissue,restore immune tolerance towards gluten,modulation of immune response to dietary gliadin,and restoration of intestinal architecture.

New aspects in celiac disease

Celiac disease (CD) is a common autoimmune disorder characterized by an immune response to ingested gluten and has a strong HLA association with HLA- DQ2 and HLA-DQ8 molecules, but human HLA-DQ risk factors do not explain the entire genetic susceptibility to gluten intolerance. CD is caused by the lack of immune tolerance (oral tolerance) to wheat gluten. In this sense, the expression of soluble HLA-G in CD is of special interest because the molecule plays an important role in the induction of immune tolerance. The enhanced expression of soluble HLA-G found in CD may be part of a mechanism to restore the gluten intolerance. In this editorial, we review recent progress in understanding CD in relation to its prevalence, diagnosis and possible mechanisms of pathogenesis.

Intestinal epithelium, intraepithelial lymphocytes and the gut microbiota-Key players in the pathogenesis of celiac disease

Celiac disease(CD) is a chronic immune-mediated disorder triggered by the ingestion of gluten in genetically predisposed individuals. Before activating the immune system, gluten peptides are transferred by the epithelial barrier to the mucosal lamina propria, where they are deamidated by intestinal tissue transglutaminase 2. As a result, they strongly bind to human leucocyte antigens(HLAs), especially HLA-DQ2 and HLA-DQ8, expressed on antigen-presenting cells. This induces an inflammatory response, which results in small bowel enteropathy. Although gluten is the main external trigger activating both innate and adaptive(specific) immunity, its presence in the intestinal lumen does not fully explain CD pathogenesis. It has been hypothesized that an early disruption of the gut barrier in genetically susceptible individuals, which would result in an increased intestinal permeability, could precede the onset of gluten-induced immune events. The intestinal barrier is a complex functional structure, whose functioning is dependent on intestinal microbiotahomeostasis, epithelial layer integrity, and the gutassociated lymphoid tissue with its intraepithelial lymphocytes(IELs). The aim of this paper was to review the current literature and summarize the role of the gut microbiota, epithelial cells and their intercellular junctions, and IELs in CD development.

Celiac disease in the developing countries: A new and challenging public health problem

In the past, celiac disease was believed to be a chronic enteropathy, almost exclusively affecting people of European origin. The availability of new, simple, very sensitive and specific serological tests （anti-gliadin, anti- endomysium and anti-transglutaminase antibody assays） have shown that celiac disease is common not only in Europe and in people of European ancestry but also in the developing countries where the major staple diet is wheat （Southern Asia, the Middle East, North West and East Africa, South America）, both in the general population and in the groups at risk. Gluten intolerance thus appears to be a widespread public health problem and an increased level of awareness and clinical suspicion are needed in the New World where physicians must learn to recognize the variable clinical presentations （classical, atypical and silent forms） of celiac disease. In the developing countries, both serological screening in the general population and serological testing in groups at risk are necessary for an early identification of celiac patients. The gluten-free diet poses a challenging public health problem in the developing countries, especially since commercial gluten-free products are not available.