Therapeutic options for coeliac disease: What else beyond gluten-free diet?

Coeliac disease is a chronic and systemic autoimmune condition triggered by gluten ingestion in genetically predisposed subjects. Currently, the only effective treatment available is a strict, lifelong gluten-free diet. However, patients perceive gluten withdrawal as an unsustainable burden in their life and some of them can exhibit persistent symptoms despite a strict diet. Thus, gluten-free diet represents a challenge, leading scientists to look for alternative or complementary treatments. This review will focus on non-dietary therapies for coeliac disease highlighting six therapeutic strategies: (1) decreasing gluten immunogenic content before it reaches the intestine; (2) sequestering gluten in the gut lumen before absorption; (3) blocking the passage of gluten through a leaky intestinal barrier; (4) preventing the enhancement of immune response against gliadin; (5) dampening the downstream immune activation; (6) inducing immune tolerance to gluten. Most developing therapies are only in the pre-clinical phase with only a few being tested in phase 2b or 3 trials. Although new approaches raise the hope for coeliacs giving them a chance to come back to gluten, for the time being a cautionary appraisal of new therapies suggests that they may have a complementary role to gluten withdrawal, mainly to prevent inadvertent gluten contamination.

Irritable Bowel Syndrome-Like Disorders in Endometriosis: Prevalence of Nickel Sensitivity and Effects of a Low-Nickel Diet. An Open-Label Pilot Study

Alimentary nickel (Ni) may result in allergic contact mucositis (ACM), whose prevalence is >30% and may present with IBS-like and extra-intestinal symptoms. These symptoms are also frequent in endometriosis, and Ni allergic contact dermatitis has already been observed in endometriosis. Therefore, intestinal and extra-intestinal symptoms in endometriosis may depend on a Ni ACM, and a low-Ni diet could improve symptoms. We studied the prevalence of Ni ACM in endometriosis and focused on the effects of a low-Ni diet on gastrointestinal, extra-intestinal, and gynecological symptoms. We recruited 84 women with endometriosis, symptomatic for gastrointestinal disorders. Thirty-one out of 84 patients completed the study. They underwent Ni oral mucosa patch test (omPT), questionnaire for intestinal/extra-intestinal/gynecological symptoms, and a low-Ni diet. Clinical evaluation was performed at baseline (T0) and after three months (T1). Twenty-eight out 31 (90.3%) patients showed Ni omPT positive results, with Ni ACM diagnosis, whereas three out of 31 (9.7%) patients showed negative Ni omPT. After three months of low-Ni diet, all gastrointestinal, extra-intestinal and gynecological symptoms showed a statistically significant reduction. Ni ACM has a high prevalence in endometriosis and a low-Ni diet may be recommended in this condition to reduce gastrointestinal, extra-intestinal and gynecological symptoms.

Microbial transglutaminase: A biotechnological tool to manage gluten intolerance

Celiac disease (CD) is a chronic immune-mediated disease in which gluten ingestion leads to damage of the small intestinal mucosa in genetically susceptible individuals. The enteropathy is mainly induced by the production of IFN-γ from intestinal CD4⁺T cells that recognise gliadin peptides following deamidation by tissue transglutaminase. The only available therapy is a strict, lifelong gluten-free diet (GFD). This diet is strongly demanding for patients, which justifies the search for alternative strategies. The enzyme approach is one promising strategy to address this issue. In particular, transamidation of wheat gliadin by microbial transglutaminase (mTG) was fully effective at inhibiting gliadin-specific IFN-γ secretion in intestinal T cells from CD patients. Furthermore, transamidated gliadin induced higher levels of the anti-inflammatory IL-10 than native gliadin in different in vitro models. These data suggest that a more balanced immune response could be induced by mTG-treated gliadin in the small intestine of celiac patients. Furthermore, the highlighted biological property of mTG-treated gliadin could be exploited to induce tolerance to native gliadin in at-risk individuals.

Incidence and prevalence of self-reported non-coeliac wheat sensitivity and gluten avoidance in Australia

OBJECTIVES

To determine the incidence of self-reported non-coeliac wheat sensitivity (SR-NCWS) and factors associated with its onset and resolution; to describe the prevalence of factors associated with gluten avoidance.

DESIGN

Longitudinal cohort study; analysis of responses to self-administered validated questionnaires (Digestive Health and Wellbeing surveys, 2015 and 2018).

SETTING, PARTICIPANTS

Subset of an adult population sample randomly selected in 2015 from the electoral rolls for the Newcastle and Gosford regions of New South Wales.

MAIN OUTCOME MEASURES

Prevalence of SR-NCWS (2015, 2018) and incidence and resolution of SR-NCWS, each by demographic and medical factors; prevalence of gluten avoidance and reasons for gluten avoidance (2018).

RESULTS

1322 of 2185 eligible participants completed the 2018 survey (response rate, 60.5%). The prevalence of SR-NCWS was similar in 2015 (13.8%; 95% CI, 12.0-15.8%) and 2018 (13.9%; 95% CI, 12.1-15.9%); 69 of 1301 respondents (5.3%) reported developing new onset (incident) SR-NCWS between 2015 and 2018 (incidence, 1.8% per year). Incident SR-NCWS was significantly associated with a diagnosis of functional dyspepsia, and negatively associated with being male or older. Gluten avoidance was reported in 2018 by 24.2% of respondents (20.5% partial, 3.8% complete avoidance); general health was the most frequent reason for avoidance (168 of 316 avoiders, 53%). All 13 participants with coeliac disease, 56 of 138 with irritable bowel syndrome (41%), and 69 of 237 with functional dyspepsia (29%) avoided dietary gluten.

CONCLUSIONS

The prevalence of SR-NCWS was similar in 2015 and 2018. Baseline (2015) and incident SR-NCWS (2018) were each associated with functional gastrointestinal disorders. The number of people avoiding dietary gluten exceeds that of people with coeliac disease or SR-NCWS, and general health considerations and abdominal symptoms are the most frequently reported reasons for avoidance.

Improving Nutritional and Functional Quality by Genome Editing of Crops: Status and Perspectives

Genome-editing tools including meganucleases, zinc finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats (CRISPR) system have been applied to improve the quality of staple, oilseed, and horticultural crops with great accuracy and efficiency compared to conventional breeding. In particular, the CRISPR method has proven to be a feasible, cost-effective and versatile tool allowing precise and efficient editing of plant genomes in recent years, showing great potential in crop improvement. Until now, various genome-edited crops with enhanced commercial value have been developed by not only global companies but also small laboratories in universities, suggesting low entry barriers with respect to manpower and capital. In this study, we review the current applications of genome editing technologies to improve the nutritional and functional quality and preferred traits of various crops. Combining this rapidly advancing genome-editing technology and conventional breeding will greatly extend the potential of genome-edited crops and their commercialization.

IBD: Role of intestinal compartments in the mucosal immune response

BACKGROUND AND AIMS

Laser capture microdissection (LCM) is a powerful tool for the isolation of specific tissue compartments. We aimed to investigate the mucosal immune response that takes place in different intestinal compartments of IBD patients, dissected by LCM, analyzing cytokines expression profile and endoplasmic reticulum (ER) stress markers.

METHODS

Frozen sections of gut were obtained from patients with Crohn's disease (CD), ulcerative colitis (UC) and from controls. Using LCM, surface epithelium (SE) and lamina propria (LP) compartments were isolated and total RNA extracted. The relative expression of Th1, Th17 and Treg cytokines was evaluated by quantitative reverse transcriptase real-time PCR (qRT-PCR), in addition to the assessment of mRNA splicing of the transcription factor X-box binding protein-1 (XBP1). Human neutrophil elastase (HNE) and the transcription factor forkhead box P3 (Foxp3) were also analyzed by immunohistochemistry.

RESULTS

The increased expression of IL-17 was observed in both intestinal compartments of IBD patients when compared to controls. IFN- γ, TNF-α , IL-10, HNE and Foxp3 were overexpressed in the LP compartment of both IBD patients as compared to controls. An upregulation of IFN-γ and an infiltration of HNE+ cells was found in the SE of patients with UC. Splicing of XBP1 mRNA was recognized in both intestinal compartments of IBD patients when compared to controls.

CONCLUSIONS

In IBD patients, both intestinal compartments are involved in Th17 response, whereas, LP compartment plays a prominent role in Th1 and Treg immune responses. Nevertheless, high level of IFN- γ was found in the SE of UC patients, suggesting that this compartment is involved in the Th1 immune response. Our data also suggested that ER stress signalling is active in both LP and SE compartment of IBD patients, thus advocating that ER stress and immunity are intertwined.

The Role of Diet in Functional Dyspepsia Management

Functional dyspepsia is a common functional gastrointestinal disease that is characterized by postprandial fullness, early satiation, epigastric pain, and/or epigastric burning. Eating a meal is a key factor in the occurrence of symptoms during functional dyspepsia, and patients frequently request dietary advice that could relieve these symptoms. Eating behaviors, irregular meal patterns, and moderate-to-fast eating rates are significantly associated with functional dyspepsia. The role of diet is complex; fat ingestion increases the occurrence of symptoms in dyspeptic patients, which might be affected by cognitive factors and palatability. Data concerning the role of carbohydrates are conflicting. Wheat may induce symptoms in patients with nonceliac gluten/wheat sensitivity, and gluten-free diets might be beneficial. Data concerning the role of FODMAPs (Fructo, Oligo, Di-, Monosaccharides, And Polyols) in functional dyspepsia are lacking; however, as there is a frequent overlap between functional dyspepsia and irritable bowel syndrome, a diet that is low in FODMAPs might be useful in relieving some symptoms. Data concerning alcohol are also conflicting. Adherence to a Mediterranean diet seems to be associated with a decrease in dyspepsia symptoms. Finally, data concerning diet modifications are conflicting, and the impact of diet modifications on symptom intensity or frequency has never been reported in randomized prospective studies. Common sense dietary recommendations, such as eating slowly and regularly, as well as decreasing the fat content of meals, can be provided in daily clinical practice.

Pharmacological activation of ERβ by arctigenin maintains the integrity of intestinal epithelial barrier in inflammatory bowel diseases

Intestinal epithelial barrier dysfunction is deeply involved in the pathogenesis of inflammatory bowel diseases (IBD). Arctigenin, the main active constituent in Fructus Arctii (a traditional Chinese medicine), has previously been found to attenuate colitis induced by dextran sulfate sodium (DSS) in mice. The present study investigated whether and how arctigenin protects against the disruption of the intestinal epithelial barrier in IBD. Arctigenin maintained the intestinal epithelial barrier function of mice with DSS- and TNBS-induced colitis. In Caco-2 and HT-29 cells, arctigenin lowered the monolayer permeability, increased TEER, reversed the abnormal expression of tight junction proteins, and restored the altered localization of F-actin induced by TNF-α and IL-1β. The specific antagonist PHTPP or shRNA of ERβ largely weakened the protective effect of arctigenin on the epithelial barrier function of Caco-2 and HT-29 cells. Molecular docking demonstrated that arctigenin had high affinity for ERβ mainly through hydrogen bonds as well as hydrophobic effects, and the protective effect of arctigenin on the intestinal barrier function was largely diminished in ERβ-mutated (ARG346 and/or GLU305) Caco-2 cells. Moreover, arctigenin-blocked TNF-α induced increase of the monolayer permeability in Caco-2 and HT-29 cells and the activation of myosin light chain kinase (MLCK)/myosin light chain (MLC) pathway in an ERβ-dependent manner. ERβ deletion in colons of mice with DSS-induced colitis resulted in a significant attenuation of the protective effect of arctigenin on the barrier integrity and colon inflammation. Arctigenin maintained the integrity of the intestinal epithelial barrier under IBD by upregulating the expression of tight junction proteins through the ERβ-MLCK/MLC pathway.

A Comparative Study of Modern and Heirloom Wheat on Indicators of Gastrointestinal Health

Wheat consumption has declined amid growing concerns about gluten-sensitivity. To determine if genetic manipulation of wheat contributes to systemic and localized gut inflammation, we compared the effects of the modern variety Gallagher and a blend of two heirloom varieties, Turkey and Kharkof, on measures of gut inflammation, structural characteristics, and barrier integrity under normal and Western diet (WD) conditions in C57BL/6 mice. Indicators of gut inflammation, including lymphocyte infiltration and cytokine expression, were largely unaffected by WD or wheat, although WD elevated interferon-γ (Ifng) and heirloom varieties modestly reduced interleukin-17 (Il17) in the context of WD. WD negatively affected jejunal villi structure, while the modern variety improved villi structure in the ileum. Relative mRNA and tight junction proteins and serum lipopolysaccharide binding protein were unaltered by WD or wheat. These findings indicate that the modern variety did not compromise barrier function or contribute to gut inflammation compared to its heirloom predecessor.

An explorative study identifies miRNA signatures for the diagnosis of non-celiac wheat sensitivity

Non-celiac wheat sensitivity (NCWS), also referred to as non-celiac gluten sensitivity, is a recently described disorder triggered by wheat/gluten ingestion. NCWS elicits a wide range of symptoms including diarrhoea, intestinal discomfort, and fatigue in analogy with other wheat/gluten-related disorders and celiac disease in particular. From the pathological standpoint, NCWS patients only have a slight increase of intraepithelial lymphocytes, while antibodies to tissue transglutaminase (tTG) and villous atrophy, otherwise diagnostic features of celiac disease, are absent. To date, the diagnosis of NCWS relies on symptoms and exclusion of confounding diseases, since biomarkers are not yet available. Here, the expression levels of selected miRNAs were examined in duodenal biopsies and peripheral blood leukocytes collected from newly diagnosed patients with NCWS and, as controls, from patients with celiac disease and gluten-independent gastrointestinal problems. We identified a few miRNAs whose expression is higher in the intestinal mucosa of patients affected by NCWS in comparison to control patients affect by gluten-independent dyspeptic symptoms (Helicobacter pylori-negative) and celiac disease. The present study provided the first evidence that NCWS patients have a characteristic miRNA expression patterns, such peculiarity could be exploited as a biomarker to the diagnosis of this disease.

To Be or Not to Be a Pathogen: Candida albicans and Celiac Disease

Celiac disease (CD) is an immune-mediated disorder triggered by the ingestion of gluten and characterized by reversible small-bowel mucosal atrophy in genetically predisposed subjects. Although the prevalence of CD has increased, many aspects of this pathology are still unrecognized. Candida albicans, a commensal of the human gastrointestinal tract, has been linked to CD for a long time based, among others, upon the observation of similarity between the fungal wall component, hyphal wall protein 1, and CD-related gliadin T-cell epitopes. We have recently demonstrated that Candida may switch from commensal to pathogen contingent upon several players, including mast cells, key sentinels of the immune system at the interface between the environment and the host, and the pleiotropic cytokine IL-9. However, other factors are likely to play a role by altering the balance between inflammation and tolerance. In this regard, tryptophan and its metabolites are increasingly being recognized in promoting mucosal homeostasis by balancing the immune response to external cues. Based on these premises, we will discuss how the output of Candida colonization in the gut is highly contextual, being determined at the intersection of many immunological (IL-9/mast cells) and metabolic (tryptophan) pathways that ultimately dictate the Candida commensalism vs. pathogenicity in CD, thus paving the way for novel therapeutic opportunities in CD.

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.

Impact of Heavy Metals on Host Cells: Special Focus on Nickel-Mediated Pathologies and Novel Interventional Approaches

BACKGROUND

Heavy metals [arsenic, aluminium, cadmium, chromium, cobalt, lead, nickel (Ni), palladium and titanium] are environmental contaminants able to impact with host human cells, thus, leading to severe damage.

OBJECTIVE

In this review, the detrimental effects of several heavy metals on human organs will be discussed and special emphasis will be placed on Ni. In particular, Ni is able to interact with Toll-like receptor-4 on immune and non-immune cells, thus, triggering the cascade of pro-inflammatory cytokines. Then, inflammatory and allergic reactions mediated by Ni will be illustrated within different organs, even including the central nervous system, airways and the gastrointestinal system.

DISCUSSION

Different therapeutic strategies have been adopted to mitigate Ni-induced inflammatoryallergic reactions. In this context, the ability of polyphenols to counteract the inflammatory pathway induced by Ni on peripheral blood leukocytes from Ni-sensitized patients will be outlined. In particular, polyphenols are able to decrease serum levels of interleukin (IL)-17, while increasing levels of IL- 10. These data suggest that the equilibrium between T regulatory cells and T helper 17 cells is recovered with IL-10 acting as an anti-inflammatory cytokine. In the same context, polyphenols reduced elevated serum levels of nitric oxide, thus, expressing their anti-oxidant potential. Finally, the carcinogenic potential of heavy metals, even including Ni, will be highlighted.

CONCLUSION

Heavy metals, particularly Ni, are spread in the environment. Nutritional approaches seem to represent a novel option in the treatment of Ni-induced damage and, among them, polyphenols should be taken into consideration for their anti-oxidant and anti-inflammatory activities.

Differential Physiological Responses Elicited by Ancient and Heritage Wheat Cultivars Compared to Modern Ones

Although ancient, heritage, and modern wheat varieties appear rather similar from a nutritional point of view, having a similar gluten content and a comparable toxicity linked to their undigested gluten peptide, whenever the role of ancient end heritage wheat grains has been investigated in animal studies or in clinical trials, more anti-inflammatory effects have been associated with the older wheat varieties. This review provides a critical overview of existing data on the differential physiological responses that could be elicited in the human body by ancient and heritage grains compared to modern ones. The methodology used was that of analyzing the results of relevant studies conducted from 2010 through PubMed search, by using as keywords “ancient or heritage wheat”, “immune wheat” (protein or peptides), and immune gluten (protein or peptides). Our conclusion is that, even if we do not know exactly which molecular mechanisms are involved, ancient and heritage wheat varieties have different anti-inflammatory and antioxidant proprieties with respect to modern cultivars. It is, therefore, reasonable to assume that the health proprieties attributed to older cultivars could be related to wheat components which have positive roles in the modulation of intestinal inflammation and/or permeability.

Diet Associated with Inflammation and Alzheimer's Disease

Neurocognitive disorders, such as Alzheimer's disease (AD), affect millions of people worldwide and are characterized by cognitive decline. Human and animal studies have shown that chronic immune response and inflammation are important factors in the pathogenesis of AD. Chronic inflammation can accelerate the aggregation of amyloid-β peptides and later hyperphosphorylation of tau proteins. The exact etiology of AD is not clear, but genetics and environmental factors, such as age, family history, and lifestyle are linked to neurodegenerative diseases. Lifestyle habits, such as poor diet, are associated with inflammation and could accelerate or slow down the progression of neurodegenerative diseases. Here we provide a review of the potential conditions and factors that stimulate the inflammatory processes in AD. An understanding of inflammatory mechanisms influencing the development of AD may help to protect against dementia and AD.

Precision medicine, agriculture, and genome editing: science and ethics

The era of precision medicine has generated advances in various fields of science and medicine with the potential for a paradigm shift in healthcare delivery that will ultimately lead to an individualized approach to medicine. Such timely topics were explored in 2018 at a workshop held at the Third International Conference on One Medicine One Science (iCOMOS), in Minneapolis, Minnesota. A broad range of scientists and regulatory experts provided detailed insights into the challenges and opportunities associated with precision medicine and gene editing. There was a general consensus that advances in studying the genomic traits driving differential pharmacogenomics will undoubtedly enhance individualized treatments for a wide variety of diseases. Ethical considerations, societal implications, approaches for prioritizing safe and secure use of treatment modalities, and the advent of high-throughput computing and analysis of large, complex datasets were discussed. Large biobanks, such as the All of Us Research Program and the Veterans Affairs Million Veterans Program, can aid studies of various conditions in massive cohorts of patients. As the applications of precision medicine continue to mature, the full potential and promise of these individualized approaches will continue to yield important advances in transplant medicine, oncology, public health, agriculture, pharmacology, and bioinformatics.

Qualitative proteomic comparison of metabolic and CM-like protein fractions in old and modern wheat Italian genotypes by a shotgun approach

The close relationship between diet and health is generally recognized and the growing wellness and consciousness, especially in developed countries, have led to increasing interest for old wheat genotypes, based on perceived health benefits. Although nutritional comparison between old and modern wheat varieties is still controversial, it is generally accepted that old wheat genotypes remained unchanged over the last hundred years. By contrast, modern wheat genotypes are derived by modification of old wheats during the so-called "Green-Revolution" in the second half of the 20th century focusing on obtaining properties in terms of higher grain yield. The present work reports the first comprehensive proteomic profiling and qualitative comparison at the molecular level of metabolic and Chloroform-Methanol (CM)-like protein fractions extracted from mature kernels of two old Sicilian durum wheat landraces, Russello and Timilia Reste Bianche, and Simeto, an improved durum wheat variety widespread in Italy and other Mediterranean countries and chosen as representative of the most widely commercial cultivars. The results obtained reveal that metabolic and CM-like protein fractions of old and modern genotypes present remarkably high similarity with only minor differences. This leads to the conclusion that from a food and nutritional perspective there is a substantial equivalence of the protein composition of the old and modern cultivars. Data are available via ProteomeXchange with identifier PXD014449. BIOLOGICAL SIGNIFICANCE: In recent years consumers have shown growing interest in the old wheat genotypes, which are generally perceived more "natural" and healthier than modern ones. However, comparison of nutritional value for modern and old wheat varieties is still controversial suggesting further studies. In particular proteome analysis of old and modern wheat genotypes is currently ongoing with particular focus on gluten proteins, whereas the metabolic protein fraction has not yet been investigated. In the present study, we conducted a comprehensive proteomic profile and qualitative comparison at the molecular level of metabolic and Chloroform-Methanol (CM)-like protein fractions of the old Sicilian landraces Russello and Timilia Reste Bianche and the modern cultivar Simeto by applying a shotgun approach. The results reveal that the metabolic and CM-like protein fractions of old and modern genotypes are remarkably similar with only minor differences, leading to the conclusion that from a food and nutritional perspective there is a substantial equivalence of these cultivars. These results may contribute to improved understanding of the relationship between protein profiles of old wheat genotypes and their potential benefits for human consumption.

Intestinal Barrier Function in Gluten-Related Disorders

Gluten-related disorders include distinct disease entities, namely celiac disease, wheat-associated allergy and non-celiac gluten/wheat sensitivity. Despite having in common the contact of the gastrointestinal mucosa with components of wheat and other cereals as a causative factor, these clinical entities have distinct pathophysiological pathways. In celiac disease, a T-cell mediate immune reaction triggered by gluten ingestion is central in the pathogenesis of the enteropathy, while wheat allergy develops as a rapid immunoglobulin E- or non-immunoglobulin E-mediated immune response. In non-celiac wheat sensitivity, classical adaptive immune responses are not involved. Instead, recent research has revealed that an innate immune response to a yet-to-be-defined antigen, as well as the gut microbiota, are pivotal in the development in this disorder. Although impairment of the epithelial barrier has been described in all three clinical conditions, its role as a potential pathogenetic co-factor, specifically in celiac disease and non-celiac wheat sensitivity, is still a matter of investigation. This article gives a short overview of the mucosal barrier of the small intestine, summarizes the aspects of barrier dysfunction observed in all three gluten-related disorders and reviews literature data in favor of a primary involvement of the epithelial barrier in the development of celiac disease and non-celiac wheat sensitivity.

Immune Activation in Functional Gastrointestinal Disorders

There is growing appreciation that functional gastrointestinal disorders (FGIDs) such as functional dyspepsia and irritable bowel syndrome are heterogeneous conditions linked by subtle inflammation within the gastrointestinal (GI) tract. The literature suggests that while the symptoms of these diseases may manifest with similar clinical presentations, there are significant differences in triggers and disease severity among patients classified into the same subtype. It is hypothesized that the subtle inflammation observed in these patients is related to an imbalance in GI homeostasis. Disruption of the delicate homeostatic balance within the GI tract can result from any number or combination of factors, including dysbiosis, loss of barrier integrity, genetic predisposition, or immune responses to dietary or luminal antigens. This article discusses the interplay between the immune system, microbiota, and luminal environment in FGIDs. In addition, the article proposes emerging immune pathways, including those involving T-helper type 17 response and innate lymphoid cells, as potential regulators of the subtle inflammation characteristic of FGIDs that warrant investigation in future studies.

The 5 Ws of a gluten challenge for gluten-related disorders

Gluten-related disorders (GRDs) are gradually emerging as epidemiologically relevant diseases, with a global prevalence estimated to be approximately 5% in the population. Conditions related to gluten ingestion include celiac disease (CD), wheat allergy (WA), and nonceliac gluten sensitivity (NCGS). Although mediated by different pathogenic pathways, these 3 conditions share similar clinical manifestations and can present a difficult differential diagnosis. The gluten challenge (GC) is an important diagnostic tool for GRDs, but there is great variability in regards to deciding which patients should be challenged, what amount of gluten should be used, what the GC duration should be, when and where the GC should occur, and, sometimes, why to conduct a GC. This review summarizes the current knowledge about the desirable characteristics of GCs in the 3 main GRDs following a 5 Ws approach-that is, the 5 main journalistic questions: who, what, when, where, why. The answers will help to determine the correct use of the GC in diagnosing GRDs.

The Dietary Management of Patients with Irritable Bowel Syndrome: A Narrative Review of the Existing and Emerging Evidence

Even though irritable bowel syndrome (IBS) has been known for more than 150 years, it still remains one of the research challenges of the 21st century. According to the current diagnostic Rome IV criteria, IBS is characterized by abdominal pain associated with defecation and/or a change in bowel habit, in the absence of detectable organic causes. Symptoms interfere with the daily life of patients, reduce health-related quality of life and lower the work productivity. Despite the high prevalence of approximately 10%, its pathophysiology is only partly understood and seems multifactorial. However, many patients report symptoms to be meal-related and certain ingested foods may generate an exaggerated gastrointestinal response. Patients tend to avoid and even exclude certain food products to relieve their symptoms, which could affect nutritional quality. We performed a narrative paper review of the existing and emerging evidence regarding dietary management of IBS patients, with the aim to enhance our understanding of how to move towards an individualized dietary approach for IBS patients in the near future.

Gluten and FODMAPS-Sense of a Restriction/When Is Restriction Necessary?

Gluten-free diet (GFD) is enjoying increasingly popularity, although gluten-free products are considerably more expensive. GFD is absolutely necessary for patients with celiac disease, as in this case even minor amounts of gluten can lead to the destruction of the intestinal mucosa. In addition, GFD is currently the best therapy to improve clinical symptoms of patients with non-celiac gluten sensitivity (NCGS), although the diet may not be as strict as that for patients with celiac disease. Beside gluten, other wheat components such as oligosaccharides and amylase trypsin inhibitors are discussed as triggers of NCGS in this review. An overlap between gastrointestinal symptoms in NCGS and irritable bowel syndrome (IBS) is described. Patients with NCGS attribute their symptoms to the consumption of gluten, while patients with IBS rarely describe gluten as a trigger. Recently, several studies have demonstrated that the introduction of a low FODMAP (fermentable oligo-, di-, monosaccharides, and polyols) diet reduced gastrointestinal symptoms in patients with IBS and this diet is suggested as the first choice of therapy in IBS. However, a low FODMAP diet also eliminates prebiotica and may negatively influence the gut microbiota. For this reason, the diet should be liberalized after symptom improvement. There is no evidence that a GFD is healthier than the standard diet. In contrast, GFD often is accompanied by nutritional deficiencies, mainly minerals and vitamins. Therefore, GFD and low FODMAP diets are not recommended for healthy subjects. Since wheat contains fructans belonging to FODMAPs), a GFD is not only gluten-free but also has less FODMAPs. Thus, symptom improvement cannot be correctly correlated with the reduction of either one or the other.

Effects of Lactobacillus plantarum and Lactobacillus paracasei on the Peripheral Immune Response in Children with Celiac Disease Autoimmunity: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Two Lactobacillus strains have proven anti-inflammatory properties by reducing pro-inflammatory responses to antigens. This randomized double-blind placebo-controlled trial tested the hypothesis that L. plantarum HEAL9 and L. paracasei 8700:2 suppress ongoing celiac disease autoimmunity in genetically at risk children on a gluten-containing diet in a longitudinally screening study for celiac disease. Seventy-eight children with celiac disease autoimmunity participated of whom 40 received 10¹⁰ CFU/day of L. plantarum HEAL9 and L. paracasei 8700:2 (probiotic group) and 38 children maltodextrin (placebo group) for six months. Blood samples were drawn at zero, three and six months and phenotyping of peripheral blood lymphocytes and IgA and IgG autoantibodies against tissue transglutaminase (tTG) were measured. In the placebo group, naïve CD45RA+ Th cells decreased (p = 0.002) whereas effector and memory CD45RO+ Th cells increased (p = 0.003). In contrast, populations of cells expressing CD4+CD25^highCD45RO+CCR4+ increased in the placebo group (p = 0.001). Changes between the groups were observed for NK cells (p = 0.038) and NKT cells (p = 0.008). Median levels of IgA-tTG decreased more significantly over time in the probiotic (p = 0.013) than in the placebo (p = 0.043) group whereas the opposite was true for IgG-tTG (p = 0.062 respective p = 0.008). In conclusion, daily oral administration of L. plantarum HEAL9 and L. paracasei 8700:2 modulate the peripheral immune response in children with celiac disease autoimmunity.

Effects of Lactobacillus plantarum and Lactobacillus paracasei on the Peripheral Immune Response in Children with Celiac Disease Autoimmunity: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Two Lactobacillus strains have proven anti-inflammatory properties by reducing pro-inflammatory responses to antigens. This randomized double-blind placebo-controlled trial tested the hypothesis that L. plantarum HEAL9 and L. paracasei 8700:2 suppress ongoing celiac disease autoimmunity in genetically at risk children on a gluten-containing diet in a longitudinally screening study for celiac disease. Seventy-eight children with celiac disease autoimmunity participated of whom 40 received 10¹⁰ CFU/day of L. plantarum HEAL9 and L. paracasei 8700:2 (probiotic group) and 38 children maltodextrin (placebo group) for six months. Blood samples were drawn at zero, three and six months and phenotyping of peripheral blood lymphocytes and IgA and IgG autoantibodies against tissue transglutaminase (tTG) were measured. In the placebo group, naïve CD45RA+ Th cells decreased (p = 0.002) whereas effector and memory CD45RO+ Th cells increased (p = 0.003). In contrast, populations of cells expressing CD4+CD25^highCD45RO+CCR4+ increased in the placebo group (p = 0.001). Changes between the groups were observed for NK cells (p = 0.038) and NKT cells (p = 0.008). Median levels of IgA-tTG decreased more significantly over time in the probiotic (p = 0.013) than in the placebo (p = 0.043) group whereas the opposite was true for IgG-tTG (p = 0.062 respective p = 0.008). In conclusion, daily oral administration of L. plantarum HEAL9 and L. paracasei 8700:2 modulate the peripheral immune response in children with celiac disease autoimmunity.

Tangible pathologies in functional dyspepsia

Functional dyspepsia (FD) is a common, costly and complex disease, currently defined by symptoms, directed by the Rome consensus on functional bowel disorders, which has evolved over the past two decades. Symptoms include abdominal pain, are often meal related and there are two major subtypes, postprandial distress syndrome and epigastric pain syndrome, not attributed to pathology. Increasingly it is recognised that tangible pathologies occur in FD, for example Helicobacter pylori and other pathophysiological changes, most notably duodenal pathology, namely duodenal eosinophilia, permeability alterations, structural neuronal changes and microbial duodenal dysbiosis. This has led to the idea that FD is a true disease entity and triggers of this condition based on epidemiology studies point towards allergy, immune disorders and infection. Anxiety and depression may precede or follow FD, (brain-gut/gut-brain disorders). Currently most therapies for FD are inadequate but underlying pathology may lead to targeted treatment success as an attainable goal.

Gluten-related disorders: Celiac disease, wheat allergy, and nonceliac gluten sensitivity

The consumption of gluten-free products is becoming an increased alimentary habit in the general population. The scientific unfounded perception suggesting that the avoidance of gluten would improve health or that gluten could be toxic for humans are fostering medically unjustified adherences to a gluten-free diet. Currently, only patients diagnosed with celiac disease are advised to follow a strict lifelong gluten-free diet. In the same way, patients diagnosed with IgE-mediated wheat allergy must avoid exposure to wheat in any form. In that context, a third disorder, called nonceliac gluten sensitivity, characterized by distress after gluten consumption and in which neither celiac disease nor IgE-mediated allergy plays a role, has gained increased attention in the last years. Although important scientific advances have been made in the understanding of the pathologic mechanisms behind nonceliac gluten sensitivity, this disorder is still a matter of active debate in the scientific community. In the present review, the most recent advances in the immunopathology, diagnostic biomarkers and susceptibility determinants of gluten-related diseases are summarized and discussed. Furthermore, an updated overview of the new potential therapies that are currently underway for the treatment of gluten-related disorders is also provided.

Pediatric Nonceliac Gluten Sensitivity: A Gluten-related Disorder Treatment Center Experience

OBJECTIVE

The aim of the study was to identify the prevalence and clinical characteristics of children with nonceliac gluten sensitivity (NCGS) presenting to a tertiary care center specialized for evaluation of gluten-related disorders.

METHODS

The medical records of all patients aged 0 to 18 years who presented to our center over a 4-year period (July 2013-June 2018) and consented to participate in our research registry were reviewed. Patients meeting the clinical criteria for NCGS were reviewed in detail.

RESULTS

Among 500 pediatric patients who volunteered to participate in the registry during the study period, we identified 26 (5.2%) with NCGS. Both gastrointestinal and extraintestinal symptoms associated with gluten ingestion were common with abdominal pain (57.7%), bloating (53.9%), rash (53.9%), diarrhea/loose stool (42.3%), and emotional/behavioral issues (42.3%) emerging as the predominant complaints. In addition, children with NCGS demonstrated a high personal history (61.5%) and family history (61.5%) of concomitant allergic/atopic disease.

CONCLUSIONS

Even within our highly specialized population of patients with a suspected gluten-related disorder, pediatric NCGS is relatively uncommon. The estimated prevalence and clinical features mirror those previously reported in a similarly highly selective population of adults. In the absence of celiac disease, clinical suspicion for NCGS should arise in a child with gastrointestinal and/or extraintestinal complaints alleviated with gluten removal and considered in symptomatic patients with associated allergic/atopic disease. Proper and adequate exclusion of celiac disease and other potential causes of the clinical complaints is essential to justify adoption of the gluten-free diet according to an appropriate stringency and with dietitian supervision to avoid nutritional deficiencies.

Food Intolerances

Food intolerances are estimated to affect up to 20% of the population but complete understanding of diagnosis and management is complicated, given presentation and non-immunological mechanisms associated vary greatly. This review aims to provide a scientific update on common food intolerances resulting in gastrointestinal and/or extra-intestinal symptoms. FODMAP sensitivity has strong evidence supporting its mechanisms of increased osmotic activity and fermentation with the resulting distention leading to symptoms in those with visceral hypersensitivity. For many of the other food intolerances reviewed including non-coeliac gluten/wheat sensitivity, food additives and bioactive food chemicals, the findings show that there is a shortage of reproducible well-designed double-blind, placebo-controlled studies, making understanding of the mechanisms, diagnosis and management difficult. Enzyme deficiencies have been proposed to result in other food sensitivities including low amine oxidase activity resulting in histamine intolerance and sucrase-isomaltase deficiency resulting in reduced tolerance to sugars and starch. Lack of reliable diagnostic biomarkers for all food intolerances result in an inability to target specific foods in the individual. As such, a trial-and-error approach is used, whereby suspected food constituents are reduced for a short-period and then re-challenged to assess response. Future studies should aim to identify biomarkers to predict response to dietary therapies.

Does Irritable Bowel Syndrome Exist? Identifiable and Treatable Causes of Associated Symptoms Suggest It May Not

Significant shortcomings in irritable bowel syndrome (IBS) diagnosis and treatment may arise from IBS being an “umbrella” diagnosis that clusters several underlying identifiable and treatable causes for the same symptom presentation into one classification. This view is compatible with the emerging understanding that the pathophysiology of IBS is heterogeneous with varied disease mechanisms responsible for the central pathological features. Collectively, these converging views of the pathophysiology, assessment and management of IBS render the traditional diagnosis and treatment of IBS less relevant; in fact, they suggest that IBS is not a disease entity per se and posit the question “does IBS exist?” The aim of this narrative review is to explore identifiable and treatable causes of digestive symptoms, including lifestyle, environmental and nutritional factors, as well as underlying functional imbalances, that may be misinterpreted as being IBS.

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.

A Gluten-Free Diet, Not an Appropriate Choice without a Medical Diagnosis

In the past, only people diagnosed with celiac disease, approximately 1% of the population, avoided gluten consumption through all their meals. However, popular media often now mistakenly present gluten-free foods as being a healthier choice, and more people have now concluded that gluten is a harmful part of the diet. A review of literature on gluten-free diets, gluten sensitivity, celiac disease, and attitudes toward gluten consumption was undertaken to examine the prevalence and consequences of adopting a gluten-free diet and to provide guidance to healthcare practitioners whose patients are now often adopting this diet without medical input. Aside from celiac disease, nonceliac gluten sensitivity (NCGS) occurs in those persons in which gluten ingestion leads to symptomatic manifestations in the absence of celiac disease or wheat allergy but who report a remission of certain symptoms after removing gluten from their diet. However, it was been shown that a large percentage of people who claim NCGS do not feel those manifestations under a double-blind challenge to gluten. Moreover, some parents, believing that ingesting gluten is detrimental for their health, adopt gluten-free diets for their children. A review of existing data shows that there are detrimental effects to going gluten free, including loss of the dietary fiber, deficiencies in dietary minerals and vitamins, and potential heavy metal exposure. Healthcare practitioners should query patients about their dietary choices, and in cases of questionable adoption of gluten-free diet, patients and parents are educated about the detriments of a gluten-free diet, and in cases where patients continue to insist on gluten-free foods, referrals to nutritional counseling are warranted in order to minimize potential harm.

Going Against the Grains: Gluten-Free Diets in Patients Without Celiac Disease-Worthwhile or Not?

While the gluten-free diet (GFD) is the only known effective therapy for celiac disease, in recent years it has become increasingly popular in the USA and worldwide, with many believing it to be more "healthful" and others claiming that it has beneficial effects for health conditions, many extraintestinal, other than celiac disease. This review examines the evidence for use of the GFD in patients without celiac disease who self-report intestinal and/or extraintestinal symptoms (non-celiac gluten sensitivity), as well as for enhancement of athletic performance and treatment of autism, rheumatoid arthritis, and psychiatric disorders. Overall, the evidence for use of GFDs in conditions other than celiac disease is poor. Though non-celiac gluten sensitivity may ultimately emerge as a biomarker-defined condition, a large proportion of patients with apparent non-celiac gluten sensitivity have, after careful investigation, an alternative diagnosis. In light of this, and coupled with the potential physical and psychological harms associated with the avoidance of gluten, initiating a GFD should not be encouraged for people who have these other conditions or are seeking physical/athletic enhancement.

Large-scale determination and characterization of cell type-specific regulatory elements in the human genome

Histone modifications have been widely elucidated to play vital roles in gene regulation and cell identity. The Roadmap Epigenomics Consortium generated a reference catalog of several key histone modifications across >100s of human cell types and tissues. Decoding these epigenomes into functional regulatory elements is a challenging task in computational biology. To this end, we adopted a differential chromatin modification analysis framework to comprehensively determine and characterize cell type-specific regulatory elements (CSREs) and their histone modification codes in the human epigenomes of five histone modifications across 127 tissues or cell types. The CSREs show significant relevance with cell type-specific biological functions and diseases and cell identity. Clustering of CSREs with their specificity signals reveals distinct histone codes, demonstrating the diversity of functional roles of CSREs within the same cell or tissue. Last but not least, dynamics of CSREs from close cell types or tissues can give a detailed view of developmental processes such as normal tissue development and cancer occurrence.

How Patients with IBS Use Low FODMAP Dietary Information Provided by General Practitioners and Gastroenterologists: A Qualitative Study

There is a lack of dietitians trained to deliver the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet (LFD) for irritable bowel syndrome (IBS). Many patients receive nutritional information from general practitioners (GPs) or gastroenterologists (GEs). Since the LFD is dietitian-led, the aim of this research was to qualitatively explore the effects of GP- and GE-delivered LFD information, in IBS self-management. Semi-structured interviews were conducted in a purposive sample of 8 people with IBS (6 female), who used the LFD as their primary treatment. Interpretive Phenomenological Analysis (IPA) was used to develop themes on the lived experience of the participant’s use of LFD information from GPs and GEs. This information was perceived as trustworthy but simplistic; often just ”food lists” with little personalisation to meet individual needs and difficult to apply in ”real life”. The information required substantial interpretation and the familial and social effects of implementation were not addressed in the materials provided. Supplementary digital resources were regarded as more practical but the participants expressed concern in relation to the validity of these materials. The findings in this study support current clinical guidelines proposed by both the National Institute for Health and Care Excellence and the British Dietetic Association that the LFD should be considered a dietitian-led only intervention.

Dermatitis Herpetiformis: Novel Perspectives

Dermatitis herpetiformis (DH) is an inflammatory disease of the skin, considered the specific cutaneous manifestation of celiac disease (CD). Both DH and CD occur in gluten-sensitive individuals, share the same Human Leukocyte Antigen (HLA) haplotypes (DQ2 and DQ8), and improve following the administration of a gluten-free diet. Moreover, almost all DH patients show typical CD alterations at the small bowel biopsy, ranging from villous atrophy to augmented presence of intraepithelial lymphocytes, as well as the generation of circulating autoantibodies against tissue transglutaminase (tTG). Clinically, DH presents with polymorphic lesions, including papules, vesicles, and small blisters, symmetrically distributed in typical anatomical sites including the extensor aspects of the limbs, the elbows, the sacral regions, and the buttocks. Intense pruritus is almost the rule. However, many atypical presentations of DH have also been reported. Moreover, recent evidence suggested that DH is changing. Firstly, some studies reported a reduced incidence of DH, probably due to early recognition of CD, so that there is not enough time for DH to develop. Moreover, data from Japanese literature highlighted the absence of intestinal involvement as well as of the typical serological markers of CD (i.e., anti-tTG antibodies) in Japanese patients with DH. Similar cases may also occur in Caucasian patients, complicating DH diagnosis. The latter relies on the combination of clinical, histopathologic, and immunopathologic findings. Detecting granular IgA deposits at the dermal-epidermal junction by direct immunofluorescence (DIF) from perilesional skin represents the most specific diagnostic tool. Further, assessing serum titers of autoantibodies against epidermal transglutaminase (eTG), the supposed autoantigen of DH, may also serve as a clue for the diagnosis. However, a study from our group has recently demonstrated that granular IgA deposits may also occur in celiac patients with non-DH inflammatory skin diseases, raising questions about the effective role of eTG IgA autoantibodies in DH and suggesting the need of revising diagnostic criteria, conceivably emphasizing clinical aspects of the disease along with DIF. DH usually responds to the gluten-free diet. Topical clobetasol ointment or dapsone may be also applied to favor rapid disease control. Our review will focus on novel pathogenic insights, controversies, and management aspects of DH.

A Population Survey of Dietary Attitudes towards Gluten

It is unclear how the prevalence of people who believe the gluten-free diet (GFD) to be generally healthy (“Lifestylers”) is impacting the overall rates of self-reported gluten sensitivity (GS). We repeated a population survey from 2012 in order to examine how attitudes towards GS have changed over time. Our survey (N = 1004) was administered in Sheffield (UK) in 2015, replicating the 2012 experiment. The questionnaire included a food frequency survey and assessed self-reported GS as well as associated variables (prevalence, current diet, pre-existing conditions, etc.). The overall rates of key variables and chi-squared analysis in comparison to the previous survey were as follows: self-reported GS was 32.8% (previously 12.9%, p < 0.001), pre-existing coeliac disease (CD) was 1.2% (previously 0.8%, p = 0.370), following a GFD was 3.7% (previously 3.7%, p = 0.997). Self-reported GS was positively associated with some pre-existing conditions, including anxiety, depression, chronic fatigue, headaches, and other food allergies/intolerances (including irritable bowel syndrome (IBS); chi-squared analyses, all p < 0.001). Over a 3-year period, the fraction of people who self-reported GS increased by over 250%. Despite this, arguably more meaningful indications of underlying physiological GS remained comparable. This research suggests that the public perception of gluten is causing a marked increase in the number of people who erroneously believe they are sensitive to it.

Non-Celiac Gluten Sensitivity: A Review

Background and objectives: Grain food consumption is a trigger of gluten related disorders: celiac disease, non-celiac gluten sensitivity (NCGS) and wheat allergy. They demonstrate with non-specific symptoms: bloating, abdominal discomfort, diarrhea and flatulence. Aim: The aim of the review is to summarize data about pathogenesis, symptoms and criteria of NCGS, which can be helpful for physicians. Materials and Methods: The PubMed and Google Scholar databases were searched in January 2019 with phrases: 'non-celiac gluten sensitivity', non-celiac gluten sensitivity', non-celiac wheat gluten sensitivity', non-celiac wheat gluten sensitivity', and gluten sensitivity'. More than 1000 results were found. A total of 67 clinical trials published between 1989 and 2019 was scanned. After skimming abstracts, 66 articles were chosen for this review; including 26 clinical trials. Results: In 2015, Salerno Experts' Criteria of NCGS were published. The Salerno first step is assessing the clinical response to gluten free diet (GFD) and second is measuring the effect of reintroducing gluten after a period of treatment with GFD. Several clinical trials were based on the criteria. Conclusions: Symptoms of NCGS are similar to other gluten-related diseases, irritable bowel syndrome and Crohn's disease. With Salerno Experts' Criteria of NCGS, it is possible to diagnose patients properly and give them advice about nutritional treatment.

The Role of Dietary Energy and Macronutrients Intake in Prevalence of Irritable Bowel Syndromes

Background

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by abdominal pain and altered bowel habits in the absence of any detectable organic illnesses. Interest in the effect of dietary opponents to the IBS pathogenesis has been increased in recent years. This study aims to review previous studies to determine the relationship between IBS prevalence in community and dietary energy and macronutrients intakes according to the national nutrition surveys.

Methods

A literature search was conducted in PubMed and EMBASE to September, 2018, to identify population-based studies that reported the prevalence of IBS. Daily energy intake, daily carbohydrates, and protein and fat percent contribution to energy intake (%) were obtained from study population-based national nutrition survey. The correlations of prevalence of IBS and dietary intakes were obtained by Spearman coefficient or Pearson coefficient.

Results

Global prevalence of IBS was 11.7%. There was no correlation between overall prevalence of IBS of individual countries and national energy intake (P = 0.785), protein proportion (P = 0.063), carbohydrates proportion (P = 0.505), or fat proportion (P = 0.384) according to the years when the studies were conducted. No correlations were detected between dietary intake and male or female IBS prevalence. Interestingly, protein proportion was positively correlated with the prevalence of IBS in Rome III criteria (r = 0.569).

Conclusion

Our findings demonstrate that dietary energy and macronutrients intake do not play a direct role in prevalence of IBS. However, IBS diagnostic criteria seem to have a bias on the correlation between prevalence of IBS and dietary intake. Further studies are needed to confirm the correlation between prevalence of IBS and specific dietary intake.

Celiac-Related Autoantibodies and IL-17A in Bulgarian Patients with Dermatitis Herpetiformis: A Cross-Sectional Study

Background and objectives: Dermatitis herpetiformis (DH) is a blistering dermatosis, which shares common immunologic features with celiac disease (CD). The aim of the present study was to explore the performance of a panel of CD-related antibodies and IL-17A in Bulgarian patients with DH. Materials and Methods: Serum samples from 26 DH patients at mean age 53 ± 15 years and 20 healthy controls were assessed for anti-tissue transglutaminase (anti-tTG), anti-deamidated gliadin peptides (anti-DGP), anti-actin antibodies (AAA), and IL-17A by enzyme linked immuno-sorbent assay (ELISA), as well as anti-tTG, anti-gliadin (AGA), and anti-Saccharomyces cerevisiae antibodies (ASCA) using immunoblot. Results: The average serum levels of anti-tTG, anti-DGP, AGA, AAA, and the cytokine IL-17A were at significantly higher levels in patients with DH compared to the average levels in healthy persons which stayed below the cut-off value (p < 0.05). Anti-DGP and anti-tTG antibodies showed the highest diagnostic sensitivity and specificity, as well as acceptable positive and negative predictive value. None of the healthy individuals was found positive for the tested antibodies, as well as for ASCA within the DH group. All tests showed good to excellent correlations (r = 0.5 ÷ 0.9, p < 0.01). Conclusions: Although the diagnosis of DH relies on skin biopsy for histology and DIF, serologic testing of a panel of celiac-related antibodies could be employed with advantages in the diagnosing process of DH patients. Furthermore, DH patients who are positive for the investigated serologic parameters could have routine monitoring for gastrointestinal complications typical for the gluten-sensitive enteropathy.

Celiac Disease in Children, Particularly with Accompanying Type 1 Diabetes, Is Characterized by Substantial Changes in the Blood Cytokine Balance, Which May Reflect Inflammatory Processes in the Small Intestinal Mucosa

Cytokines play a pivotal role in the maintenance of intestinal homeostasis inducing pro- or anti-inflammatory response and mucosal barrier function in celiac disease (CD) and type 1 diabetes (T1D). We aimed to compare the levels of pro- and anti-inflammatory cytokines in CD patients without and with coexisting T1D, as well as to evaluate its association with the presence of enteroviruses (EV), regulatory T cells (Tregs), and dendritic cells (DCs) in small bowel mucosa. Altogether, 72 patients (median age 10.1 years) who had undergone small bowel biopsy were studied. The study group consisted of 24 patients with CD (median age 6.5 years), 9 patients with CD and concomitant T1D (median age 7.0 years), two patients with T1D (median age 8.5 years), and 37 patients (median age 14.0 years) with functional gastrointestinal disorders (FGD) and a normal small bowel mucosa as controls. The levels of 33 cytokines in serum were measured by multiple analysis using the Milliplex® MAP Magnetic Bead assay. The densities of FOXP3+ Tregs, CD11c+ DC, indoleamine 2,3-dioxygenase+ (IDO+) DC, langerin+ (CD207+) DCs, and EV were evaluated by immunohistochemistry as described in our previous studies. Circulating anti-EV IgA and IgG were evaluated using ELISA. The most important finding of the study is the significant increase of the serum levels of IL-5, IL-8, IL-13, IL-15, IL-17F, IL-22, IL-27, IP-10, MIP-1β, sIL-2Rα, sTNFRII, and TNFα in CD patients compared to controls and its correlation with the degree of small bowel mucosa damage graded according to the Marsh classification. The leptin level was higher in females in all study groups. The levels of IL-2, IL-6, IL-12 (P70), IL-15, IP-10, and IFNγ correlated significantly with the density of FOXP3+ Tregs in lamina propria of the small bowel mucosa, which supports the evidence about the signaling role of these cytokines in the peripheral maintenance of FOXP3+ Tregs. At the same time, a significant negative correlation occurred between the level of IL-4 and density of FOXP3+ Tregs in controls. Another important finding of our study was the correlation of IL-17F, IP-10, sTNFRII, MCP-1, and GM-CSF with the density of EV-positive cells in the lamina propria of the small bowel mucosa. Correlation of MIP-1 (CCL-4) with CD103+ DC and langerin+ DC densities may point to their significance in the recruitment of immune cells into the lamina propria and in driving the inflammatory response in CD patients. Our results suggest the predominance of Th1 and Th17 immune responses over EV VP1 protein in CD and T1D patients. The significant elevation of Th2 cytokines, like IL-5 and IL-13, but not IL-4, in CD patients and its correlation with the degree of small bowel mucosa damage could reflect the role of these cytokines in gut defense and inflammation.

A Scoring System for Identifying Patients Likely to Be Diagnosed with Low-Grade Coeliac Enteropathy

BACKGROUND & AIMS

Determining whether patients with lymphocytic enteritis (LE) have coeliac disease is a challenge. We analysed the variables associated with a low-grade coeliac enteropathy diagnosis in patients with suspected coeliac disease but without villous atrophy, and developed a scoring system to identify them.

METHODS

We collected data from 2010 through to 2016 on patients with lymphocytic enteritis and persistent symptoms compatible with the clinical spectrum of coeliac disease. One hundred and four patients starting on a gluten-free diet (GFD) were included. Duodenal biopsies were collected before the GFD and analysed for numbers of CD3⁺ T-cell receptor gamma delta+ (TCRγδ⁺), and CD3^- intraepithelial lymphocytes. We performed a logistic regression analysis to identify factors associated with a low-grade coeliac enteropathy diagnosis.

RESULTS

Sixty-two patients achieved clinical remission after the GFD. Fifty of these 62 patients were diagnosed with low-grade coeliac enteropathy. Multivariate analysis identified the presence of >25% intraepithelial lymphocytosis, HLA-DQ2.5, positive serology, and increased numbers of TCRγδ⁺ cells with a low-grade coeliac enteropathy diagnosis. We developed a scoring system that identified patients with an area under the ROC curve (AUC) of 0.91. Scores of >10 had 86% sensitivity and 85% specificity.

CONCLUSION

We developed a scoring system that identifies patients likely to be diagnosed with low-grade coeliac enteropathy with an AUC value of 0.91.

Human gut derived-organoids provide model to study gluten response and effects of microbiota-derived molecules in celiac disease

Celiac disease (CD) is an immune-mediated disorder triggered by gluten exposure. The contribution of the adaptive immune response to CD pathogenesis has been extensively studied, but the absence of valid experimental models has hampered our understanding of the early steps leading to loss of gluten tolerance. Using intestinal organoids developed from duodenal biopsies from both non-celiac (NC) and celiac (CD) patients, we explored the contribution of gut epithelium to CD pathogenesis and the role of microbiota-derived molecules in modulating the epithelium’s response to gluten. When compared to NC, RNA sequencing of CD organoids revealed significantly altered expression of genes associated with gut barrier, innate immune response, and stem cell functions. Monolayers derived from CD organoids exposed to gliadin showed increased intestinal permeability and enhanced secretion of pro-inflammatory cytokines compared to NC controls. Microbiota-derived bioproducts butyrate, lactate, and polysaccharide A improved barrier function and reduced gliadin-induced cytokine secretion. We concluded that: (1) patient-derived organoids faithfully express established and newly identified molecular signatures characteristic of CD. (2) microbiota-derived bioproducts can be used to modulate the epithelial response to gluten. Finally, we validated the use of patient-derived organoids monolayers as a novel tool for the study of CD.

The overlap of irritable bowel syndrome and noncoeliac gluten sensitivity

PURPOSE OF REVIEW

There has been significant interest in gluten over the last decade, with an increase in interest of gluten-related disorders outside coeliac disease. Particularly, there has been a focus on the role of gluten in noncoeliac gluten sensitivity (NCGS) and irritable bowel syndrome (IBS). There is significant overlap between both of these conditions, with the aim of this review to explore their complex relationship.

RECENT FINDINGS

Gluten has been demonstrated to generate symptoms in individuals with NCGS. However, there appears to be an increasing role for gluten in symptom generation in patients with IBS also. Other components of wheat, other than gluten, are now also thought to be contributing factors in symptom generation.

SUMMARY

There appears to be significant overlap between IBS and NCGS. It is likely that a subset of patients presenting with IBS actually have NCGS. In addition, it is likely that individuals with IBS may also have symptoms triggered by gluten. With the pathophysiology of both conditions not fully understood, as well as increasing knowledge of wheat components in symptom generation, further research is required to help distinguish between both.

Epithelial Claudin Proteins and Their Role in Gastrointestinal Diseases

Our bodies are protected from the external environment by mucosal barriers that are lined by epithelial cells. The epithelium plays a critical role as a highly dynamic, selective semipermeable barrier that separates luminal contents and pathogens from the rest of the body and controlling the absorption of nutrients, fluid and solutes. A series of protein complexes including the adherens junction, desmosomes, and tight junctions function as the principal barrier in paracellular diffusion and regulators of intracellular solute, protein, and lipid transport. Tight junctions are composed of a series of proteins called occludins, junctional adhesion molecules, and claudins that reside primarily as the most apical intercellular junction. Here we will review one of these protein families, claudins, and their relevance to gastrointestinal and liver diseases.