Efficacy of Different Dietary Patterns in the Treatment of Functional Gastrointestinal Disorders in Children and Adolescents: A Systematic Review of Intervention Studies

Functional gastrointestinal disorders (FGIDs) are common in children and adolescents. In recent years, interest in the role of diet in the treatment of FGIDs has increased. Currently, interest focuses on the low-FODMAP diet (LFD), the fructose- or lactose-restricted diet (FRD or LRD), the gluten-free diet (GFD), and the Mediterranean diet (MD). In this review, we focus on the role of these dietary patterns in the FGIDs most commonly diagnosed in clinical practice, namely irritable bowel syndrome (IBS), functional abdominal pain (FAP), functional dyspepsia (FD), and functional constipation (FC). Fifteen clinical trials were systematically reviewed (both RCTs and single-arm clinical trials). We demonstrated the lack of high-quality intervention trials. Based on current evidence, low-FODMAP diet, LRD, FRD, and GFD have no place in daily clinical practice for the management of children and adolescents with FGIDs. Nevertheless, some patients with IBS or RAP may experience some benefit from the use of a low-FODMAP diet or FRD/LRD. Limited data suggest that MD may be promising in the management of FGIDs, especially in IBS patients, but more data are required to investigate the mechanisms of its protective effects.

Celiac Disease and the Risk of Cardiovascular Diseases

Celiac disease (CD) is a chronic autoimmune disorder that affects the small intestine in genetically predisposed individuals. Previous studies have investigated the potential link between CD and cardiovascular disease (CVD); however, the findings have been inconsistent. We aimed to provide an updated review of the literature on the association between CD and CVD. PubMed was searched from inception to January 2023 using keywords including CD, cardiovascular disease, coronary artery disease, cardiac arrhythmia, heart failure, cardiomyopathy, and myocarditis. We summarized the results of the studies, including meta-analyses and original investigations, and presented them according to the different forms of CVD. Meta-analyses published in 2015 provided mixed results regarding the relationship between CD and CVD. However, subsequent original investigations have shed new light on this association. Recent studies indicate that individuals with CD are at a higher risk of developing overall CVD, including an increased risk of myocardial infarction and atrial fibrillation. However, the link between CD and stroke is less established. Further research is needed to determine the link between CD and other cardiac arrhythmias, such as ventricular arrhythmia. Moreover, the relationship between CD and cardiomyopathy or heart failure, as well as myopericarditis, remains ambiguous. CD patients have a lower prevalence of traditional cardiac risk factors, such as smoking, hypertension, hyperlipidemia, and obesity. Therefore, it is important to discover strategies to identify patients at risk and reduce the risk of CVD in CD populations. Lastly, it is unclear whether adherence to a gluten-free diet can diminish or increase the risk of CVD among individuals with CD, necessitating further research in this area. To fully comprehend the correlation between CD and CVD and to determine the optimal prevention strategies for CVD in individuals with CD, additional research is necessary.

Autoimmune Cerebellar Ataxia: Etiology and Clinical Characteristics of a Case Series from China

Autoimmune cerebellar ataxia (ACA) is an important and potentially treatable cause of sporadic cerebellar syndrome, but studies with large sample size are limited. This study reported a large ACA series in China and described its etiology and clinical characteristics. We reviewed all ACA patients from our hospital (2013-2021) and analyzed their clinical and paraclinical features, treatment, and outcome. ACA subtypes investigated included paraneoplastic cerebellar degeneration (PCD), primary autoimmune cerebellar ataxia (PACA), anti-glutamate decarboxylase (GAD)-associated cerebellar ataxia, opsoclonus-myoclonus syndrome (OMS), Miller Fisher syndrome (MFS), and ACA-associated with autoimmune encephalitis. A total of 127 patients were identified and 40.9% were male. The median onset age was 47.0 years. Gait ataxia was the most prevalent feature followed by limb ataxia, dizziness, and dysarthria/dysphagia. Extracerebellar manifestations included pyramidal signs (28.3%) and peripheral neuropathy/radiculopathy (15.0%). ACA subtypes were PCD (30.7%), PACA (37.8%), ACA associated with autoimmune encephalitis (12.6%), anti-GAD-associated ACA (8.7%), MFS (7.1%), and OMS (3.1%). Neuronal antibodies were positive in 67.7% of patients. Brain magnetic resonance imaging was unremarkable (55.7%) or showed atrophy (18.3%) or abnormal signal intensity (26.1%, most of which was extracerebellar). Although most patients received immunotherapy, the modified Rankin scale at last follow-up was ≤ 2 in only 47.3% patients. Thirteen patients died and 24 relapsed. Compared with PACA, PCD patients were older and had poorer outcome. This study illustrates the heterogeneity in the clinical features of ACA and suggests the importance of neuronal antibody testing in ACA diagnosis. PCD and PACA are the dominant ACA subtypes, and the former has a less favorable prognosis.

Anemia in non-celiac wheat sensitivity: Prevalence and associated clinical and laboratory features

BACKGROUND

Patients suffering from non-celiac wheat sensitivity (NCWS) frequently report extra-intestinal symptoms, such as anemia.

AIMS

We investigated the prevalence and associated clinical features of anemia in NCWS patients.

METHODS

Data from 244 NCWS patients, diagnosed by double-blind placebo-controlled wheat challenge, were retrospectively reviewed and compared with 2 control groups (celiac disease (CD) and irritable bowel syndrome (IBS)). Furthermore, 31 NCWS anemic patients were prospectively re-evaluated after at least 12 months on the "strict" wheat-free diet (WFD).

RESULTS

Anemia prevalence in NCWS patients was 34.8% (mean hemoglobin 10.4 ± 1.4 g/dl), significantly higher than in IBS (17.4%, P = 0.03), but not in CD ones. The NCWS group, on the whole, had sideropenic-like features with low serum iron and altered iron deposits. Both anemia prevalence and sideropenic-like features were more evident in CD than in NCWS patients, whereas only a few IBS subjects showed such features. Significant differences were found in anemic vs non-anemic NCWS patients as regards to female sex, diagnostic delay, poly/hypermenorrhea, iron deficiency, and higher TSH values. A long-term WFD significantly reduced anemia and improved iron metabolism.

CONCLUSION

Microcytic/hypochromic anemia and altered iron metabolism occur frequently in NCWS and can be treated with a long-term strict WFD. NCWS should be included in differential diagnosis of anemic patients with "functional gastrointestinal troubles".

Gluten-free diet in postural orthostatic tachycardia syndrome (POTS)

OBJECTIVES

Postural orthostatic tachycardia syndrome (POTS) is a chronic disorder of the autonomic nervous system that is associated with orthostatic intolerance (OI) and gastrointestinal (GI) symptoms. We aimed to determine if a gluten-free diet (GFD) may be an effective treatment in patients with POTS.

METHODS

Patients with confirmed POTS and without celiac disease who followed GFD for  4 weeks retrospectively completed pre- and post- GFD COMPASS-31 questionnaires. Paired-samples t-tests were conducted to compare COMPASS-31 scores before and after adopting GFD.

RESULTS

All 20 patients (all females, age 16-62 years (mean age 33)), had POTS symptoms for 1-30 years (mean 10.8, SD  =  10.23 years). Eleven patients had co-morbid mast cell activation syndrome, and 8 had hypermobile Ehlers-Danlos syndrome. Pre-GFD COMPASS-31 scores (mean 57.8) were significantly higher than post-GFD scores (mean 38.2, t(19) = -8.92, p < 0.00001), with the largest improvement noted in the OI (p < 0.00001), vasomotor, (p  =  0.0034), and GI (p  =  0.0004) domains and with a mean reduction in total COMPASS-31 score by 33.9% after implementing GFD. All patients reported improved symptoms on GFD with mean self-assessed improvement of 50.5% (range 10-99%).

DISCUSSION

GFD may be effective in reducing the symptom burden in patients with POTS, particularly in the OI, vasomotor, and GI symptom domains. Large prospective studies are necessary to confirm whether GFD is an effective long-term treatment option for patients.

Skin gluten-related disorders: new and old cutaneous manifestations to be considered

The term gluten-related disorders (GRD) refer to a spectrum of different clinical manifestations triggered by the ingestion of gluten in genetically susceptible individuals, including coeliac disease (CD), wheat allergy and non-celiac gluten sensitivity (NCGS). GRD are characterized by a large variety of clinical presentations with both intestinal and extra-intestinal manifestations. The latter may affect almost every organ of the body, including the skin. Besides the well-known association between CD and dermatitis herpetiformis, considered as the cutaneous specific manifestation of CD, many other muco-cutaneous disorders have been associated to GRD. In this review, we analyzed the main features of dermatological diseases with a proven association with GRD and those that improve after a gluten-free diet, focusing on the newly described cutaneous manifestations associated with NCGS. Our main hypothesis is that a "cutaneous-gluten sensitivity," as specific cutaneous manifestation of NCGS, may exist and could represent a diagnostic marker of NCGS.

Recurrent Psychosis in Non-celiac Gluten Sensitivity

Neuropsychological manifestations following food exposures in patients with food sensitivities are increasingly being identified in the literature, as understanding of the gut-brain axis is further improved. Non-celiac gluten sensitivity (NCGS) has been shown to occur in individuals without serological or biopsied evidence of celiac disease (CD), who manifest psychotic ormood disorders that resolve following elimination of gluten. In this case history, we discuss a similar manifestation in a 31-year-old woman without serological evidence of CD, whose psychiatric symptoms improve with gluten elimination.

Gene Expression Profiling in Coeliac Disease Confirmed the Key Role of the Immune System and Revealed a Molecular Overlap with Non-Celiac Gluten Sensitivity

Coeliac disease (CeD) is an immune-mediated disorder triggered by the ingestion of gluten and an as yet unidentified environmental factor in genetically predisposed individuals. The disease involves a major autoimmune component that primarily damages the intestinal mucosa; although, it also has systemic involvement. The Th1 inflammatory response is one of the main events leading to mucosal damage; although, enterocytes and the innate immune response also participate in the pathological mechanism. In this study, we performed an analysis of the gene expression profile of the intestinal mucosa of patients with active disease and compared it with that of patients who do not suffer from gluten-related disorders but report dyspeptic symptoms. This analysis identified 1781 differentially expressed (DE) genes, of which 872 were downregulated and 909 upregulated. Gene Ontology and pathway analysis indicated that the innate and adaptive immune response, in particular the Th1 pathway, are important pathogenetic mechanisms of CeD, while the key cytokines are IL27, IL21, IL2, IL1b, TNF, CSF2 and IL7, as well as type I (IFNA1, IFNA2) and type II (IFNG) interferons. Finally, the comparison between the DE genes identified in this study and those identified in our previous study in the intestinal mucosa of patients with non-celiac gluten sensitivity (NCGS) revealed a high degree of molecular overlap. About 30% of the genes dysregulated in NCGS, most of which are long non-coding RNAs, are also altered in CeD suggesting that these diseases may have a common root (dysregulated long non-coding RNAs) from which they develop towards an inflammatory phenotype of variable degree in the case of CeD and NCGS respectively.

Combined RNAscope and immunohistochemistry staining on duodenal paraffin sections as a new tool to reveal cytolytic potential of intraepithelial lymphocytes

Immunohistochemistry (IHC) is a consolidated technique for the identification of surface and cytoplasmic antigens in cells or tissue sections using specific antibodies, yet simultaneous detection of two markers on the same cell may be difficult to achieve. Here we develop a protocol to perform a double staining using RNAscope, a new in-situ hybridization (ISH) technology, to visualize perforin transcripts, and classical IHC to visualize either CD8 or TcRγδ positive intraepithelial lymphocytes (IELs) in small intestinal paraffin sections of celiac disease (CD) patients. This double assay will allow to investigate the cytotoxic properties of two subsets of IELs in different stages of CD, thus contributing to understand the events leading to tissue destruction and healing.

Nutritional Considerations in Celiac Disease and Non-Celiac Gluten/Wheat Sensitivity

A gluten-free diet (GFD) is the only available treatment for celiac disease (CeD), and it may also improve symptoms in non-celiac gluten/wheat sensitivity (NCGWS). In CeD, gluten triggers an immune reaction leading to enteropathy, malabsorption, and symptoms; in NCGWS, the mechanism leading to symptoms is unknown, and neither wheat nor gluten triggers enteropathy or malabsorption. A strict GFD is, therefore, necessary for CeD, but a gluten-restricted diet (GRD) may suffice to achieve symptom control for NCGWS. Regardless of this distinction, the risk of malnutrition and macro- and micronutrient deficiencies is increased by the adoption of a GFD or GRD. Thus, patients with CeD or NCGWS should undergo nutritional assessment and subsequent monitoring, based on evidence-based tools, under the care of a multidisciplinary team involving physicians and dietitians, for the long-term management of their nutrition. This review gives an overview of available nutrition assessment tools and considerations for the nutritional management of CeD and NCGWS populations.

Prevalence of non-coeliac gluten sensitivity and assessment of the response to gluten-free diet in a cohort of patients with fibromyalgia

OBJECTIVES

To establish the prevalence of non-coeliac gluten sensitivity (NCGS) in a cohort of fibromyalgia patients and to evaluate their clinical response to a six-week gluten-free diet (GFD), the improvement in their symptoms, the percentage of diet responders who did not fulfil the diagnostic criteria for NCGS and the baseline characteristics that were associated with diet response and diagnostic criteria fulfilment.

METHODS

Uncontrolled prospective experimental study in a cohort of patients with fibromyalgia from a specialized hospital unit. The percentage of patients that fulfilled the Salerno Experts' Criteria, that responded to GFD, that improved their symptomatology and baseline characteristics associated with GFD response and diagnostic criteria fulfilment was analysed.

RESULTS

In total, 142 patients were selected and a NCGS prevalence of 5.6% was observed. A total of 21.8% responded to GFD due to their improvement in intestinal symptoms. In total, 74.2% of the responders did not fulfil the Salerno Experts' Criteria. The presence of diarrhoea and intraepithelial lymphocytosis and lower levels of anxiety were predictive factors of GFD response. No predictive factors of NCGS criteria fulfilment were found due to the low number of discriminators between gluten and placebo.

CONCLUSIONS

A NCGS prevalence similar to that estimated in the general population was found. A GFD cannot be systematically recommended to all patients with fibromyalgia, although it could be evaluated in those with diarrhoea or intraepithelial lymphocytosis to evaluate if there are improvements in their intestinal symptoms.

Nonceliac gluten sensitivity

PURPOSE OF REVIEW

To describe recent advances on nonceliac gluten sensitivity (NCGS), a recently described disorder characterized by variable symptoms and frequent irritable bowel syndrome (IBS)-like manifestations.

RECENT FINDINGS

The recent description of disease-triggering wheat components other than gluten, such as fructans and amylase-trypsin inhibitors (ATIs), definitely suggests that nonceliac wheat sensitivity (NCWS) is a better 'umbrella' terminology than NCGS. Self-reported NCWS is very common worldwide, particularly in patients seen at the gastroenterology clinic, but many of these diagnoses are not confirmed by standard clinical criteria. A biomarker of NCWS is still lacking, however, subtle histological features at the small intestinal biopsy may facilitate diagnosis. Treatment of NCWS is based on the gluten-free diet (GFD). The GFD has proven to be an effective treatment of a significant proportion of NCWS-related IBS patients. Dietary therapies for IBS, including the GFD, should be offered by dietitians who first assess dietary triggers and then tailor the intervention according to patient choice. Pioneer studies are under way to test the therapeutic efficacy of supplemental gluten-digesting enzyme preparations in patients with NCWS.

SUMMARY

Recent studies highlight interesting pathophysiological and clinical features of NCWS. Many questions remain, however, unanswered, such as the epidemiology, a biomarker(s), and the natural history of this clinical entity.

How does carrageenan cause colitis? A review

Carrageenan is a common additive, but mounting studies have reported that it may cause or aggravate inflammation in the intestines. The safety of carrageenan remains controversial and its inflammatory mechanisms are unclear. In this review, the pathogenesis of colitis by carrageenans was discussed. We analyzed the pathogenesis of inflammatory bowel disease, followed that line of thought, the existing evidence of carrageenans causing colitis in cellular and animal models was summarized to draw its colitis pathogenesis. Two pathways were described including: 1) carrageenan changed the composition of intestinal microbiota, especially Akkermansia muciniphila, which destroyed the mucosal barrier and triggered the inflammatory immune response; and 2) carrageenan directly contacted with receptors on epithelial cells and activated the NF-κB inflammatory pathway. This review aim to provide guidance for exploring the treatment of colitis caused by carrageenan, and safe processing and utilization of carrageenan in food industry, which is worthy of study in the future.

Influence of letermovir treatment on gut inflammation in people living with HIV on antiretroviral therapy: protocol of the open-label controlled randomised CIAO study

INTRODUCTION

Chronic cytomegalovirus (CMV) infection is very frequent in people living with HIV (PLWH). High anti-CMV IgG titres, which may be linked to transient CMV replication, have been associated with earlier mortality, CD8 T-cell expansion, lower CD4/CD8 ratio and increased T-cell senescence. We previously showed that anti-CMV IgG titres correlated with gut permeability in PLWH on antiretroviral therapy (ART), which was associated with microbial translocation, systemic inflammation and non-infectious/non-AIDS comorbidities. Letermovir, a novel anti-CMV drug with a good safety profile, was recently approved for anti-CMV prophylaxis in allogeneic haematopoietic stem cell transplant recipients. A drastic and selective reduction of both low-grade replication and clinically significant CMV infections, combined with an improved immune reconstitution have been reported. In vitro, letermovir prevented CMV-induced epithelial disruption in intestinal tissues. Based on these findings, we aim to assess whether letermovir could inhibit CMV subclinical replication in CMV-seropositive PLWH receiving ART and, in turn, decrease CMV-associated gut damage and inflammation.

METHOD AND ANALYSIS

We will conduct a multi-centre, open-label, randomised, controlled clinical trial, including a total of 60 CMV-seropositive ART-treated PLWH for at least 3 years, with a viral load <50 copies/mL and CD4+ count >400 cells/µL. Forty participants will be randomised to receive letermovir for 14 weeks and 20 participants will receive standard of care (ART) alone. Plasma, pheripheral blood mononuclear cells (PBMCs), and stool samples will be collected. Colon biopsies will be collected in an optional substudy. We will assess the effect of letermovir on gut damage, microbial translocation, inflammation and HIV reservoir size.

ETHICS AND DISSEMINATION

The study was approved by Health Canada and the Research Ethics Boards of the McGill University Health Centre (MUHC-REB, protocol number: MP37-2022-8295). Results will be made available through publications in open access peer-reviewed journals and through the CIHR/CTN website.

TRIAL REGISTRATION NUMBER

NCT05362916.

Evaluation of gut microbiota of iranian patients with celiac disease, non-celiac wheat sensitivity, and irritable bowel syndrome: are there any similarities?

BACKGROUND AND AIMS

Individuals with celiac disease (CD), non-celiac wheat sensitivity (NCWS), and irritable bowel syndrome (IBS), show overlapping clinical symptoms and experience gut dysbiosis. A limited number of studies so far compared the gut microbiota among these intestinal conditions. This study aimed to investigate the similarities in the gut microbiota among patients with CD, NCWS, and IBS in comparison to healthy controls (HC).

MATERIALS AND METHODS

In this prospective study, in total 72 adult subjects, including CD (n = 15), NCWS (n = 12), IBS (n = 30), and HC (n = 15) were recruited. Fecal samples were collected from each individual. A quantitative real-time PCR (qPCR) test using 16S ribosomal RNA was conducted on stool samples to assess the relative abundance of Firmicutes, Bacteroidetes, Bifidobacterium spp., and Lactobacillus spp.

RESULTS

In all groups, Firmicutes and Lactobacillus spp. had the highest and lowest relative abundance respectively. The phylum Firmicutes had a higher relative abundance in CD patients than other groups. On the other hand, the phylum Bacteroidetes had the highest relative abundance among healthy subjects but the lowest in patients with NCWS. The relative abundance of Bifidobacterium spp. was lower in subjects with CD (P = 0.035) and IBS (P = 0.001) compared to the HCs. Also, the alteration of Firmicutes to Bacteroidetes ratio (F/B ratio) was statistically significant in NCWS and CD patients compared to the HCs (P = 0.05).

CONCLUSION

The principal coordinate analysis (PCoA), as a powerful multivariate analysis, suggested that the investigated gut microbial profile of patients with IBS and NCWS share more similarities to the HCs. In contrast, patients with CD had the most dissimilarity compared to the other groups in the context of the studied gut microbiota.

Type 2 and type 17 effector cells are increased in the duodenal mucosa but not peripheral blood of patients with functional dyspepsia

Background

Functional dyspepsia is characterised by chronic symptoms of post-prandial distress or epigastric pain not associated with defined structural pathology. Increased peripheral gut-homing T cells have been previously identified in patients. To date, it is unknown if these T cells were antigen-experienced, or if a specific phenotype was associated with FD.

Objective

This study aimed to characterise T cell populations in the blood and duodenal mucosa of FD patients that may be implicated in disease pathophysiology.

Methods

We identified duodenal T cell populations from 23 controls and 49 Rome III FD patients by flow cytometry using a surface marker antibody panel. We also analysed T cell populations in peripheral blood from 37 controls and 61 patients. Where available, we examined the number of duodenal eosinophils in patients and controls.

Results

There was a shift in the duodenal T helper cell balance in FD patients compared to controls. For example, patients had increased duodenal mucosal Th2 populations in the effector (13.03 ± 16.11, 19.84 ± 15.51, p=0.038), central memory (23.75 ± 18.97, 37.52 ± 17.51, p=0.007) and effector memory (9.80±10.50 vs 20.53±14.15, p=0.001) populations. Th17 populations were also increased in the effector (31.74±24.73 vs 45.57±23.75, p=0.03) and effector memory (11.95±8.42 vs 18.44±15.63, p=0.027) subsets. Peripheral T cell populations were unchanged between FD and control.

Conclusion

Our findings identify an association between lymphocyte populations and FD, specifically a Th2 and Th17 signature in the duodenal mucosa. The presence of effector and memory cells suggest that the microinflammation in FD is antigen driven.

Is Irritable Bowel Syndrome out of date and misleading as a diagnosis?

Aim

This study aimed at assessing the efficacy of targeted interventions addressing common food sensitivities and lifestyle factors that commonly contribute to the presentation of gastrointestinal problems identified as Irritable bowel syndrome (IBS).

Background

IBS has served to cover the expression of multifactorial disorders with variable aetiology and pathophysiology. Food antigens implicated in the modern lifestyle, acting as strong epigenetic factors is strongly implicated in pathophysiology of conditions under IBS. Identifying and addressing food sensitivities in patients presenting with IBS like symptoms are currently underemphasised in clinical guidelines yet have the potential to provide major benefits for patients.

Methods

Information was collected from the medical records of patients that were referred to the Gastroenterology Unit of Palmerston North DHB with unexplained gastrointestinal (GI) symptoms with or without other GI comorbidities between September 2018 and November 2021.

Results

The main management option offered to the 121 patients included in this study, was lifestyle adjustment and/or a trial of 6 weeks, eliminating gluten and lactose from the diet. The most prevalent symptoms were abdominal pain 96/121 (79%), diarrhoea 83/121 (69%), followed by bloating and constipation. Seventy-eight patients had the outcomes of their improvement available. A total of 42 out of 78 patients (54%) were treated exclusively with gluten and lactose-free diet, in this group of patients 86% (36/42) reported a significant improvement in their symptoms with a score in the range of 40-100%.

Conclusion

Our study illustrates the importance of focusing on triggering factors when assessing patients with IBS. We suggest that careful identifying and eliminating the triggering food antigens as monotherapy or in addition to the lifestyle adjustment where appropriate should be the main objective in symptomatic patients fulfilling the IBS diagnostic criteria. These combinations and holistic approach in treating IBS' patients' symptoms are less expensive, non-toxic, and highly effective in achieving optimal outcomes and improving these patient's quality of life.

Mendelian randomization study of the genetic interaction between psoriasis and celiac disease

Epidemiological studies have observed some relationship between psoriasis and celiac disease (CD), while the causal link between these 2 autoimmune diseases was unclear. In the current study, we aimed to explore the causal link between psoriasis and celiac disease with bidirectional 2-sample Mendelian Randomization (MR) study. Eligible instrument variables (IVs) with genome-wide significance (p < 5E-08) were extracted from the summary-level datasets from the published genome-wide association studies (GWAS), which were conducted in the European population. The inverse variance weighted (IVW) method was performed as the main analysis, sensitivity analyses and post-MR analyses were also performed. Our MR analyses found that genetically doubling the odds of CD would increase the risk for psoriasis (p = 1.58e-03, OR [95% CI] 1.232 [1.061-1.432]). And the results were supported by sensitivity analyses. While we found that genetically determined psoriasis was not associated with the risk for CD (IVW: p = 0.985, OR [95% CI] 1.000 [0.965-1.037]). Our study provided novel genetic evidence that patients with CD were at an increased risk of developing psoriasis, while psoriasis was not associated with the risk for CD. Clinicians should be aware of the associations and pay attention to skin manifestations in patients with CD.

Management of Adult Patients with Gastrointestinal Symptoms from Food Hypersensitivity-Narrative Review

The incidence of food hypersensitivity has increased dramatically over the years not only among children but also in adults. Adult patients are usually less suspected of food hypersensitivity symptoms since food allergies are more typical for small children, with a tendency to outgrow the condition. The aim of this article is to increase awareness of hypersensitivity to food symptoms and their diagnosis and treatment possibilities among gastroenterologists and other health care professionals dealing with this type of patient. Symptoms of many gastrointestinal disorders, especially functional, may be driven by different types of mechanisms, and food intolerance or allergy should be considered as a potential cause. This article presents the current understanding of the epidemiology, diagnosis and treatment of immune- and non-immune-mediated food-induced diseases. Diagnosis of food hypersensitivity is based mainly on medical history, different types of sensitivity tests, e.g., hydrogen breath test, specific IgE (sIgE) serum concentration, tissue eosinophil count, skin tests and oral food challenges considered as a "gold standard" for food allergy. Elimination diet and pharmacologic treatment for allergy symptoms are first-line therapies. Eosinophilic gastrointestinal diseases are often caused by non-IgE-mediated food allergies, require endoscopic biopsy samples to confirm diagnosis and proper elimination diet often combined with steroids or proton pump inhibitor agents for treatment. Mast cell activation syndrome (MCAS) derives from pathologic reaction of mast cells with increased tryptase serum level as a marker. Symptoms may occur in the digestive, respiratory, skin, neurologic and cardiovascular system. Treatment is based on histamine type 1, type 2 (H1, H2) receptor antagonists and other mast cell stabilizing agents. Carbohydrate intolerances are the most common type of food hypersensitivity in adult patients, and an elimination diet is effective for reducing symptoms. Food additives hypersensitivity remains difficult to diagnose, but use of a diet low in chemical substances alleviates symptoms and helps to diagnose the triggering factors.

Replacing the Burden of the Gluten Free Diet: Then, Now, and the Future

Without a doubt, a majority of diseases are food-pattern-related. However, one disease stands out as an increasingly more common autoimmune-mediated enteropathy triggered by the ingestion of gluten. Celiac disease (CD) is an old disease, with changing clinical patterns, affecting any age, including infancy and adolescence, and becoming more frequent among the elderly. The gluten-free diet (GFD) has been the sole provider of clinical, serological, and histological improvement for patients with CD for more than seven decades. Nowadays, complete avoidance of dietary gluten is rarely possible because of the wide availability of wheat and other processed foods that contain even more gluten, to the detriment of gluten-free products. Undeniably, there is a definite need for replacing the burdensome GFD. An add-on therapy that could control the dietary transgressions and inadvertent gluten consumption that can possibly lead to overt CD should be considered while on GFD. Nevertheless, future drugs should be able to provide patients some freedom to self-manage CD and increase food independence, while actively reducing exposure and mucosal damage and alleviating GI symptoms. Numerous clinical trials assessing different molecules have already been performed with favorable outcomes, and hopefully they will soon be available for patient use.

Is it time to rethink the burden of non-coeliac gluten sensitivity? A systematic review

INTRODUCTION

Non-coeliac gluten sensitivity (NCGS) is still a poorly defined clinical condition. This review aims to describe the clinical features of subjects with a symptomatic response to gluten intake, and to estimate the prevalence of NCGS.

EVIDENCE ACQUISITION

Literature search was conducted in accordance with PRISMA recommendations. The PubMed database was searched for original articles until 1^st June 2020.

EVIDENCE SYNTHESIS

We identified 30 relevant articles, including 14 studies that investigated NCGS through a double-blind, placebo-controlled crossover trial (DBPCC), and 16 that examined the role of gluten in causing symptoms without a DBPCC. We found that regardless of the diagnostic work up, gluten-sensitive patients were predominately middle-aged females complaining of abdominal pain, bloating and diarrhea. The pooled prevalence of NCGS after DBPCC was 24% (5-34%). Subjects with irritable bowel syndrome or self-reporting gluten intolerance accounted for the vast majority of the patients who did not start a DBPCC. A symptomatic response to a gluten-free diet (GFD) occurred in between 7% and 93% of patients. No data on long-term outcomes of NCGS individuals were reported.

CONCLUSIONS

Clinical features of NCGS patients did not differ among all the included studies, whereas prevalence figures are rather heterogeneous. Long-term benefit of a GFD on these patients still needs to be ascertained.

Cerebellar Symptoms in Gluten Sensitivity: a Systematic Review of the Effect of a Gluten-Free Diet on Brain Imaging

Cerebellar manifestations have been described in patients with gluten sensitivity (GS)-related disorders. A better understanding of the neurological manifestations of GS requires the use of neuroimaging techniques. We performed a systematic review on neuroimaging findings in GS patients with cerebellar symptoms. We also included a specific search on neuroimaging findings in GS patients with cerebellar manifestations on a gluten-free diet (GFD). PubMed, Embase, and Bireme were systematically searched to identify studies assessing neuroimaging features of adults with cerebellar manifestations and GS with or without enteropathy on a GFD. Ten studies with a total of 222 adult-GS patients were included. Magnetic resonance imaging was used in 100% of the studies. Cerebellar atrophy was evaluated in 7 studies and observed in 63% of the patients. White matter abnormalities were described in 2 studies. Single-photon emission computed tomography was used in 2 studies, and decreased cerebellar perfusion was detected in 92% of the included patients. No study employed nuclear medicine after the start of GFD. Magnetic resonance spectroscopy (MRS) was performed in 2 studies before and after GFD. An increase in the Naa/Cr ratio in cerebellar vermis was seen in 98% of the cases on a strict GFD. Cerebellar atrophy was found to be a prevalent condition in GS patients. MRS demonstrated to be useful in the follow-up of GS patients with cerebellar manifestations on a GFD. Prospective studies using nuclear medicine imaging are needed to study brain changes in GS patients on a GFD.

[Dermatitis herpetiformis and other forms of wheat sensitivity]

BACKGROUND

Wheat sensitivity is a collective term for several, especially gastrointestinal, diseases that occur as part of a hypersensitivity reaction after wheat consumption. The symptoms, which are mostly similar to those of irritable bowel syndrome, are often accompanied by skin lesions. In addition to celiac disease and dermatitis herpetiformis, the cutaneous manifestation of celiac disease, wheat sensitivity also includes nonceliac gluten sensitivity (NCGS), allergic nickel contact mucositis, wheat allergy, amylase-trypsin inhibitor intolerance, and fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) intolerance.

OBJECTIVES

This review article aims to provide an overview of the clinical, especially dermatological and gastrointestinal features of the different forms of wheat sensitivity. Diagnosis and therapeutic management are also discussed.

MATERIALS AND METHODS

A selective literature search was carried out with evaluation of our own clinical data.

RESULTS

The skin lesions in dermatitis herpetiformis are very disease-specific. In contrast, wheat allergy often shares signs and symptoms with many other diseases. Other forms of wheat sensitivity cause primarily gastrointestinal abnormalities, but extra-intestinal manifestations can also occur. Their diagnosis is often complex and requires cross-disciplinary collaboration with experts in gastroenterology. The therapy consists of a wheat- or gluten-free diet.

CONCLUSIONS

Knowledge of the different and frequently occurring dermatological signs of wheat sensitivity is of great importance, because dermatological manifestations associated with gastrointestinal pathology, intolerance reactions, and allergies appear more and more frequently.

The low-FODMAP diet and the gluten-free diet in the management of functional abdominal bloating and distension

This review summarizes current knowledge on the role of low-FODMAP diet and gluten-free diet in functional abdominal bloating and distension, an emerging disorder of gut-brain interaction characterized by remarkable costs for healthcare systems and a significant impact on the patient's quality of life. Ingested food plays a key role in the pathophysiology of disorders of gut-brain interaction as up to 84% of patients with irritable bowel syndrome (IBS) report food-triggered symptoms. Potential pathogenetic mechanisms of food-related symptoms in these patients are discussed, focusing on bloating and abdominal distension. These mechanisms provide the rationale for dietary treatment in patients with functional abdominal bloating and distension. The role of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) and gluten in functional abdominal bloating and distension is examined. Current literature evaluating the efficacy of the low-FODMAP diet and the gluten-free diet in abdominal bloating and distension is analyzed. Available evidence originates mainly from studies on patients with IBS, since clinical studies on selected cohorts of patients with only functional abdominal bloating and distension have been missing to date. Promising evidence on the potential efficacy of the low-FODMAP diet in functional abdominal bloating and distension is provided by the reduction of the bloating observed in patients with IBS. Regarding the gluten-free diet, there is insufficient evidence to recommend it to reduce bloating and abdominal distension. In conclusion, this review asserts the need for a close collaboration with experts in nutrition to optimize the management of these patients and reduce the risks associated with elimination diets.

Effectiveness of the low-FODMAP diet in improving non-celiac gluten sensitivity: a systematic review

Non-celiac gluten sensitivity is characterised by the presence of gastrointestinal and extraintestinal symptoms following gluten ingestion. Recent studies suggested an association between non-celiac gluten sensitivity and the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP). This systematic review aimed to examine literature evidence on the relationship between non-celiac gluten sensitivity and FODMAP intake. A comprehensive search was carried out for randomised clinical trials addressing gastrointestinal symptoms as the primary outcome, published between 2010 and 2020 in Portuguese, English or Spanish, and indexed in Scopus, PubMed, SciELO, Cochrane Library, CINAHL, Embase or VHL (LILACS) databases. The systematic review was performed using the population, intervention, comparison and outcome (PICO) framework. A total of 1133 articles were retrieved for further assessment. Three articles were selected for systematic review, one of which included two interventions with different periods and assessments. Quality of evidence was assessed according to the GRADE protocol. The selected articles used different instruments to measure gastrointestinal symptoms and quality of life, hindering comparison of data. Clinical trials identified an association between decreased gastrointestinal symptoms and FODMAP restriction. There are few studies on the topic, and those available used different instruments to assess gastrointestinal symptoms and quality of life. Nevertheless, current evidence supports the gluten-free diet still represents first-line therapy. However, a FODMAP restriction can decrease gastrointestinal symptoms in individuals with non-celiac gluten sensitivity. Further research is needed to confirm this finding.

The duodenal mucosa associated microbiome, visceral sensory function, immune activation and psychological comorbidities in functional gastrointestinal disorders with and without self-reported non-celiac wheat sensitivity

Frequently, patients with functional gastrointestinal disorders (FGIDs) report intolerance of wheat products. We compared gastrointestinal symptoms, sensory function, psychiatric comorbidities, gut-homing immune cells, and duodenal mucosa-associated microbiome (d-MAM) in FGID patients and controls with and without self-reported wheat sensitivity (SR-NCWS). We recruited 40 FGID patients and 20 controls referred by GPs for treatment. Gastrointestinal/extraintestinal symptoms, visceral sensory function, psychological comorbidities, and SR-NCWS were assessed in a standardized approach. Peripheral gut homing T-cells (CD4⁺α4⁺β7⁺CCR9⁺/CD8⁺α4⁺β7⁺CCR9⁺) were quantified, and the d-MAM was assessed by DNA sequencing for 46 subjects. Factors of bacterial genera were extracted utilizing factor analysis with varimax rotation and factors univariately associated with FGID or SR-NCWS included in a subsequent multivariate analysis of variance to identify statistically independent discriminators. Anxiety scores (p < .05) and increased symptom responses to a nutrient challenge (p < .05) were univariately associated with FGID. Gut homing T-cells were increased in FGID patients with SR-NCWS compared to other groups (p all <0.05). MANOVA revealed that anxiety (p = .03), visceral sensory function (p = 0.007), and a d-MAM factor comprise members of the Alloprevotella, Prevotella, Peptostreptococcus, Leptotrichia, and Veillonella lineages were significantly (p = .001) associated with FGID, while gut homing CD4⁺α4⁺ β7⁺CCR9⁺ T-cells were associated (p = .002) with SR-NCWS. Compared to controls, patients with and without SR-NCWS show that there are shifts in the amplicon sequence variants within specific bacterial genera between the FGID subgroups (particularly Prevotella and Streptococcus) as well as distinct bacterial taxa discriminatory for the two different FGID subtypes. Compared to controls, both FGID patients with and without SR-NCWS have an increased symptom response to a standardized nutrient challenge and increased anxiety scores. The FGID patients with SR-NCWS - as compared to FGID without SR-NCWS (and controls without SR-NCWS) - have increased gut homing T-cells. The d-MAM profiles suggest species and strain-based variations between the two FGID subtypes and in comparison to controls.

Proteins from Modern and Ancient Wheat Cultivars: Impact on Immune Cells of Healthy Individuals and Patients with NCGS

In non-celiac gluten sensitivity (NCGS), the elimination of wheat results in a clear symptom improvement, but gluten has still not been proven as (the sole) trigger. Due to the increase in the prevalence of gluten-related diseases, the breeding of high-performance wheat cultivars is discussed as a trigger. To analyze the immune stimulation and signal pathways, the immune cells of healthy subjects and patients with NCGS were stimulated with gliadins from wheat, and the expression and secretion of interleukin 1ß (IL1ß) and interleukin 6 (IL6) were studied. To determine the impact of wheat breeding, the monocyte cell line THP1 and human immune cells were stimulated with gliadin, glutenin, and albumin/globulin fractions of ancient and modern cereals, and expression of inflammatory molecules was checked. Immune cells of patients with NCGS showed an increased expression of IL1ß and IL6 after stimulation with gliadins compared to immune cells of healthy controls. Gliadins caused a strong activation of P-STAT3 in immune cells of healthy controls, and inhibitors of JAK and NFκB pathways considerably reduced this response. In addition to gliadins, we further showed that glutenins and albumin/globulins from all wheat cultivars from the last century, and especially from einkorn and spelt, also markedly induced the expression of inflammatory genes in THP1 and human immune cells. There was no correlation between enhanced immune stimulation and ancient or modern cultivars. This does not support the hypothesis that modern wheat breeding is responsible for the increase in gluten-related diseases. An altered immune situation is suggested in patients with NCGS.

Diagnostic management of patients reporting symptoms after wheat ingestion

Many patients report symptoms after wheat ingestion experiencing a wide spectrum of clinical manifestations. Three possible diagnoses have been recognized: celiac disease (CD), wheat allergy (WA), and non-celiac (gluten) wheat sensitivity (NCGS/NCWS). CD is a chronic immune-mediated disease of the small bowel caused by exposure to dietary gluten in genetically predisposed individuals, with a prevalence of approximately 1%. It is characterized by mucosal inflammation and atrophy following exposure to gluten and improvement after gluten withdrawal. Food allergies are immunological responses to a food antigen. WA is the expression of an immunologically mediated process that can be immunoglobulin E (IgE) or non-IgE mediated; its many symptoms include urticaria/angioedema, asthma, rhinitis, and anaphylaxis. NCGS/NCWS is characterized by gastrointestinal and/or extra-intestinal symptoms after ingestion of gluten-containing food in subjects not affected by CD or WA. The aim of this review is to help physicians and nutritionists diagnose the cause of symptoms reported after wheat ingestion, thus avoiding patient frustration, inappropriate testing, and incorrect or missed diagnoses. An algorithm for the diagnostic approach in these patients is provided, to help to diagnose CD, WA, NCGS/NCWS or to identify possible functional disorders as the wheat-sensitive irritable bowel syndrome. A personalized approach, regular follow-up, and the help of a skilled healthcare professional are mandatory for patients with symptoms following wheat ingestion is provided. A gluten-free-diet is often recommended for patients with self-reported gluten/wheat-dependent symptoms; for patients with symptoms similar to those of functional diseases while there is evidence that a low-FODMAP diet could be the first option.

Potential tolerability of ancient grains in non-celiac wheat sensitivity patients: A preliminary evaluation

Background and aims

A wheat-free diet (WFD) represents the elective treatment for Non-celiac Wheat Sensitivity (NCWS) patients. Preliminary reports have shown a possible better tolerability of ancient grains in these subjects. The aim of this observational study was to evaluate the frequency of consumption of ancient grains and its correlation with clinical manifestations in NCWS patients.

Methods

223 NCWS patients were recruited, and their consumption of ancient grains was monitored. Participants were first administered a modified version of the Pavia/Biagi questionnaire to investigate their adherence to “modern WFD.” The appearance/exacerbation of symptoms after ingestion of ancient grains was then assessed with WHO toxicity grading scale.

Results

50.2% of the recruited patients reported consuming ancient grains before NCWS diagnosis; the diagnostic delay in this group was significantly higher than in non-consumers [median (range) 72 (6–612) vs. 60 months (3–684), P = 0.03] and these patients reported lower frequency of constipation (P = 0.04). Of the 107 patients with optimal adherence to modern WFD, 14 reported eating ancient wheat after NCWS diagnosis. Among them, 5 reported milder symptoms than those caused by modern wheat intake and 3 had an excellent tolerability without symptoms. Timilia/Tumminia variety was the most frequently used ancient grain.

Conclusions

NCWS patients who consume ancient grains may receive a late diagnosis due to the possible clinical benefit (tolerability) obtained with these grains. Even after diagnosis, 10% of the patients still consumed ancient grains and had mild or no symptoms. Further studies are required to define the pathophysiological mechanism behind their putative greater tolerability.

Elevated interleukin-17A levels despite reduced microRNA-326 gene expression in celiac disease patients under gluten-free diet

Introduction: The microRNA-326 (miR-326) gene, by targeting ETS Proto-Oncogene 1 (ETS1), regulates the differentiation and interleukin-17A production of T helper 17 (Th17) cells. Celiac disease (CD) is an intestinal autoimmune disorder, in which the cascade of Th17 cells plays an important role in its pathogenicity. The aim of this study was to evaluate the expression changes of miR-326 and its two target genes ETS1 and IL-17A in celiac disease patients under a gluten-free diet (GFD). We expected the expression of miR-326 and IL-17A gene to decrease, and the expression of the ETS1 gene to increase, following the adherence to GFD.

Methods: Peripheral blood samples of 40 CD patients under GFD (for more than 1 year) and 40 healthy individuals were collected. RNA was extracted, cDNA was synthesized and the miR-326, ETS1 and IL-17A gene expressions were evaluated by the quantitative polymerase real-time qPCR method. P-value ˂ 0.05 was considered statistically significant.

Results: Although miR-326 mRNA expression was significantly lower in CD patients (P = 0.001), no significant difference was observed in ETS1 mRNA level between the two groups (P = 0.54), but IL-17A was significantly overexpressed in CD patients (P=0.002). No significant correlation was observed between the expression of the studied genes and the patientsʼ symptoms and Marsh classification.

Conclusion:Adherence to the GFD for one to two years did not have the expected effect on the expression of genes in this panel. The most important finding that contradicted our hypothesis was the observation of high IL-17A levels in CD patients despite dieting, which may be related to the protective effect of this cytokine on intestinal tight junctions, which needs to be confirmed in further studies.

Consumption of Yeast-Fermented Wheat and Rye Breads Increases Colitis and Mortality in a Mouse Model of Colitis

BACKGROUND

Cereals are known to trigger for wheat allergy, celiac disease and non-celiac wheat sensitivity (NCWS). Inflammatory processes and intestinal barrier impairment are suspected to be involved in NCWS, although the molecular triggers are unclear.

AIMS

We were interested if different bread types influence inflammatory processes and intestinal barrier function in a mouse model of inflammatory bowel disease.

METHODS

Epithelial caspase-8 gene knockout (Casp8ΔIEC) and control (Casp8fl) mice were randomized to eight groups, respectively. The groups received different diets for 28 days (gluten-free diet, gluten-rich diet 5 g%, or different types of bread at 50 g%). Breads varied regarding grain, milling and fermentation. All diets were isocaloric.

RESULTS

Regardless of the diet, Casp8ΔIEC mice showed pronounced inflammation in colon compared to ileum, whereas Casp8fl mice were hardly inflamed. Casp8fl mice could tolerate all bread types. Especially yeast fermented rye and wheat bread from superfine flour but not pure gluten challenge increased colitis and mortality in Casp8ΔIEC mice. Hepatic expression of lipopolysaccharide-binding protein and colonic expression of tumor necrosis factor-α genes were inversely related to survival. The bread diets, but not the gluten-rich diet, also decreased colonic tight junction expression to variable degrees, without clear association to survival and inflammation.

CONCLUSIONS

Bread components, especially those from yeast-fermented breads from wheat and rye, increase colitis and mortality in Casp8ΔIEC mice highly susceptible to intestinal inflammation, whereas control mice can tolerate all types of bread without inflammation. Yet unidentified bread components other than gluten seem to play the major role.

Transamidated wheat gliadin induces differential antigen recognition in the small intestine of HLA/DQ8 transgenic mice

A lifelong gluten-free diet (GFD) is currently the only available therapy for coeliac disease (CD). However, GFD compliance is difficult and alternative strategies are envisaged in the near future. We previously found that wheat gliadin following transamidation by microbial transglutaminase (mTG) does not induce IFN-γ secretion by intestinal T cells from CD patients. Fully transamidated gliadin with lysine ethyl ester can be recovered in a soluble protein fraction (spf) generated by the enzymatic treatment of wheat flour. Herein, we analysed the performance of transamidation by mTG on a pilot-scale (1L) by evaluating the reaction kinetics and its biological effect on the intestinal immune response in HLA/DQ8 transgenic mice, a model of gluten sensitivity. At 1 h, all gliadin fractions showed a faster electrophoretic mobility by acid-polyacrylamide gel electrophoresis (A-PAGE) following transamidation in comparison with their native counterparts. In parallel, the yield of residual native gliadin dropped (30% at 180 min), confirming our previous findings on a lab scale. Mucosal sensitisation of mice with gliadin via the intranasal route induced a Th1 phenotype in mesenteric lymph nodes (MLNs). Importantly, IFN-γ secretion was significantly reduced when gliadin-specific MLN cells were challenged in vitro with spf (P < 0.001). Multiplex analysis revealed that the adaptive immune response evoked by spf involved a distinct cell population characterised by secretion of IL-2, IL-3 and IL-5. Notably, spf stimulated in vitro a reduced or null secretion of all of the examined pro-inflammatory markers mainly associated to innate immunity. In conclusion, our data revealed the ability of transamidated gliadin to modulate both innate and adaptive mechanisms involved in the inflammatory response induced by wheat gliadin in the small intestine of DQ8 mice.

Artificial Intelligence Analysis of Celiac Disease Using an Autoimmune Discovery Transcriptomic Panel Highlighted Pathogenic Genes including BTLA

Celiac disease is a common immune-related inflammatory disease of the small intestine caused by gluten in genetically predisposed individuals. This research is a proof-of-concept exercise focused on using Artificial Intelligence (AI) and an autoimmune discovery gene panel to predict and model celiac disease. Conventional bioinformatics, gene set enrichment analysis (GSEA), and several machine learning and neural network techniques were used on a publicly available dataset (GSE164883). Machine learning and deep learning included C5, logistic regression, Bayesian network, discriminant analysis, KNN algorithm, LSVM, random trees, SVM, Tree-AS, XGBoost linear, XGBoost tree, CHAID, Quest, C&R tree, random forest, and neural network (multilayer perceptron). As a result, the gene panel predicted celiac disease with high accuracy (95–100%). Several pathogenic genes were identified, some of the immune checkpoint and immuno-oncology pathways. They included CASP3, CD86, CTLA4, FASLG, GZMB, IFNG, IL15RA, ITGAX, LAG3, MMP3, MUC1, MYD88, PRDM1, RGS1, etc. Among them, B and T lymphocyte associated (BTLA, CD272) was highlighted and validated at the protein level by immunohistochemistry in an independent series of cases. Celiac disease was characterized by high BTLA, expressed by inflammatory cells of the lamina propria. In conclusion, artificial intelligence predicted celiac disease using an autoimmune discovery gene panel.

Diploid Wheats: Are They Less Immunogenic for Non-Celiac Wheat Sensitive Consumers?

Non-celiac wheat sensitivity (NCWS) is a clinical entity induced by the ingestion of gluten that leads to intestinal and/or extraintestinal symptoms, and is diagnosed when celiac disease and wheat allergy have been ruled out. In addition to gluten, other grains’ components, including amylase trypsin inhibitors (ATIs) and fermentable short-chain carbohydrates (FODMAPs), may trigger symptoms in NCWS subjects. Several studies suggest that, compared with tetraploid and hexaploid modern wheats, ancient diploid wheats species could possess a lower immunogenicity for subjects suffering from NCWS. This review aims to discuss available evidence related to the immunological features of diploid wheats compared to common wheats, and at outlining new dietary opportunities for NCWS subjects.

Prospective, double-blind diagnostic multicentre study of confocal laser endomicroscopy for wheat sensitivity in patients with irritable bowel syndrome

OBJECTIVE

A considerable proportion of patients with irritable bowel syndrome (IBS) may be wheat-sensitive and respond to a gluten-free diet (GFD) although they do not have coeliac disease. However, a diagnostic test for wheat sensitivity (WS) is missing. Our study evaluated the diagnostic accuracy (sensitivity and specificity) of confocal laser endomicroscopy (CLE) for the identification of WS as primary outcome.

DESIGN

In this prospective, double-blind diagnostic study 147 non-coeliac patients fulfilling the Rome III criteria for IBS were tested by CLE for duodenal changes after wheat (index test), soy, yeast or milk exposure. Patients with IBS responding to 2 months of GFD were classified as having WS (reference test) using response criteria recommended by regulatory bodies for pharmaceutical trials of patients with IBS. After 2 months, CLE results were unblinded and patients were advised to exclude those food components that had led to a positive CLE reaction. The clinical response was assessed at follow-up after 6 and 12 months.

RESULTS

Of 130 patients who completed the study per protocol, 74 (56.9%) responded to GFD and were classified as WS after 2 months, and 38 of these 74 patients were correctly identified by CLE (sensitivity 51.4%; 97.5% CI: 38.7% to 63.9%). A total of 38 of 56 patients without WS were correctly identified by CLE (specificity 67.9%; 97.5% CI: 52.9% to 79.9%). At 6 months follow-up, CLE correctly identified 49 of 59 food-sensitive patients (sensitivity 83.1%; 97.5% CI: 69.9% to 91.3%) but specificity was only 32% (97.5% CI: 15.7% to 54.3%).

CONCLUSION

In light of the high proportion of patients with IBS responding to GFD, the diagnostic accuracy of CLE is too low to recommend widespread use of this invasive procedure.

TRAIL REGISTRATION NUMBER

This study was registered as clinical trial in the German Registry for Clinical Studies (DRKS00010123).

No Difference in Tolerance between Wheat and Spelt Bread in Patients with Suspected Non-Celiac Wheat Sensitivity

Individuals with suspected non-celiac wheat sensitivity (NCWS) often report better tolerance of spelt (Triticum aestivum ssp. spelta) compared to wheat (Triticum aestivum ssp. aestivum) bakery products. This experience has neither been validated nor explained on a molecular level. Therefore, we performed blinded wheat and spelt bread challenge in this patient group. Twenty-four adults with a history of NCWS but suspected spelt tolerance were challenged in a single-blinded crossover design over six weeks with six different study breads each at 300 g per day for 4 days followed by a washout phase of 3 days. Study breads comprised spelt and wheat breads made either after a traditional (T) or a current (C) recipe, resulting in four bread types plus a gluten-free bread with 1.5% added oligosaccharides (+FODMAP) and a gluten-free bread with 5% added wheat gluten (+Gluten). The main outcome parameter was the Irritable Bowel Syndrome—Severity Scoring System, which was higher than self-estimated by the participants after spelt bread consumption (p = 0.002 for T; p = 0.028 for C) and lower for wheat bread (p = 0.052 for T; p = 0.007 for C), resulting in no difference between wheat and spelt bread tolerance. The +FODMAP bread was better tolerated than both T breads (p = 0.003 for spelt; p = 0.068 for wheat) and equally well tolerated as both C breads and +Gluten breads after normalization to the washout scores. Neither signs of inflammation nor markers for intestinal barrier integrity were influenced. Our data do not confirm, on an objective basis, the differences in expected symptoms resulting from wheat and spelt products, suggesting a strong nocebo effect for wheat and a placebo effect for spelt.

Non-Celiac Gluten Sensitivity and Protective Role of Dietary Polyphenols

Pathogenetically characterized by the absence of celiac disease and wheat allergy, non-celiac gluten sensitivity (NCGS) is a clinical entity triggered by the consumption of gluten-containing foods that relieved by a gluten-free diet. Since it is very difficult to maintain a complete gluten-free diet, there is a high interest in discovering alternative strategies aimed at reducing gluten concentration or mitigating its toxic effects. Plant-based dietary models are usually rich in bioactive compounds, such as polyphenols, recognized to prevent, delay, or even reverse chronic diseases, including intestinal disorders. However, research on the role of polyphenols in mitigating the toxicity of gluten-containing foods is currently limited. We address the metabolic fate of dietary polyphenols, both as free and bound macromolecule-linked forms, with particular reference to the gastrointestinal compartment, where the concentration of polyphenols can reach high levels. We analyze the potential targets of polyphenols including the gluten peptide bioavailability, the dysfunction of the intestinal epithelial barrier, intestinal immune response, oxidative stress and inflammation, and dysbiosis. Overall, this review provides an updated overview of the effects of polyphenols as possible dietary strategies to counteract the toxic effects of gluten, potentially resulting in the improved quality of life of patients with gluten-related disorders.

Reduced frequency of circulating regulatory T cells and their related immunosuppressive mediators in treated celiac patients

BACKGROUND

Regulatory T cells (Tregs) have an important role in the control of the immune responses. This study aimed to compare the frequency of peripheral blood (PB) CD4+ CD25+ FoxP3+ Treg cells and PB and duodenal expression levels of pro- and anti-inflammatory mediators in treated celiac disease (CD) patients and healthy controls.

METHODS AND RESULTS

Duodenal biopsy specimens and PB samples were collected from 60 treated CD patients and 60 controls. Flow cytometry analysis was conducted on peripheral blood mononuclear cell (PBMC) specimens and relative PB and duodenal mRNA expression levels of CD25, forkhead box P3 (Foxp3), interleukin (IL)-10 and granzyme B (GrzB) were evaluated using quantitative real-time PCR. The levels of serum IL-10 and IL-6 were tested with sandwich enzyme-linked immunosorbent assay kits. p values < 0.05 were considered significant. Flow cytometry analysis showed a significant decrease in the number of Tregs in CD patients' PBMC specimens (p = 0.012). CD25 and Foxp3 PB mRNA expressions were also lower in CD patients without reaching the significance level (p > 0.05). IL-10 PB mRNA and protein expression did not differ between the groups (p > 0.05), and GrzB PB expression was significantly reduced in CD patients (p = 0.001). In duodenal specimens of CD patients, while significantly increased CD25, Foxp3 mRNA expression (p = 0.01 and 0.001, respectively) and decreased IL-10 mRNA expression (p = 0.02) were observed, GrzB mRNA expression did not differ between groups (p > 0.05). Moreover, a high serum level of IL-6 was observed in CD patients (p = 0.001).

CONCLUSIONS

Despite following the gluten free diet, there may still be residual inflammation in the intestine of CD patients. Accordingly, finding a therapeutic approach based on strengthening the function of Treg cells in CD might be helpful.

Genome edited wheat- current advances for the second green revolution

Common wheat is a major source of nutrition around the globe, but unlike maize and rice hybrids, no breakthrough has been made to enhance wheat yield since Green Revolution. With the availability of reference genome sequence of wheat and advancement of allied genomics technologies, understanding of genes involved in grain yield components and disease resistance/susceptibility has opened new avenues for crop improvement. Wheat has a huge hexaploidy genome of approximately 17 GB with 85% repetition, and it is a daunting task to induce any mutation across three homeologues that can be helpful for the enhancement of agronomic traits. The CRISPR-Cas9 system provides a promising platform for genome editing in a site-specific manner. In wheat, CRISPR-Cas9 is being used in the improvement of yield, grain quality, biofortification, resistance against diseases, and tolerance against abiotic factors. The promising outcomes of the CRISPR-based multiplexing approach circumvent the constraint of targeting merely one gene at a time. Deployment of clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) 9 endonuclease (CRISPR-Cas9) and Cas9 variant systems such as cytidine base editing, adenosine base editing, and prime editing in wheat has been used to induce point mutations more precisely. Scientists have acquired major events such as induction of male sterility, fertility restoration, and alteration of seed dormancy through Cas9 in wheat that can facilitate breeding programs for elite variety development. Furthermore, a recent discovery in tissue culturing enables scientists to significantly enhance regeneration efficiency in wheat by transforming the GRF4-GIF1 cassette. Rapid generation advancement by speed breeding technology provides the opportunity for the generation advancement of the desired plants to segregate out unwanted transgenes and allows rapid integration of gene-edited wheat into the breeding pipeline. The combination of these novel technologies addresses some of the most important limiting factors for sustainable and climate-smart wheat that should lead to the second "Green Revolution" for global food security.

Gluten Induces Subtle Histological Changes in Duodenal Mucosa of Patients with Non-Coeliac Gluten Sensitivity: A Multicentre Study

Background: Histological changes induced by gluten in the duodenal mucosa of patients with non-coeliac gluten sensitivity (NCGS) are poorly defined. Objectives: To evaluate the structural and inflammatory features of NCGS compared to controls and coeliac disease (CeD) with milder enteropathy (Marsh I-II). Methods: Well-oriented biopsies of 262 control cases with normal gastroscopy and histologic findings, 261 CeD, and 175 NCGS biopsies from 9 contributing countries were examined. Villus height (VH, in μm), crypt depth (CrD, in μm), villus-to-crypt ratios (VCR), IELs (intraepithelial lymphocytes/100 enterocytes), and other relevant histological, serologic, and demographic parameters were quantified. Results: The median VH in NCGS was significantly shorter (600, IQR: 400−705) than controls (900, IQR: 667−1112) (p < 0.001). NCGS patients with Marsh I-II had similar VH and VCR to CeD [465 µm (IQR: 390−620) vs. 427 µm (IQR: 348−569, p = 0·176)]. The VCR in NCGS with Marsh 0 was lower than controls (p < 0.001). The median IEL in NCGS with Marsh 0 was higher than controls (23.0 vs. 13.7, p < 0.001). To distinguish Marsh 0 NCGS from controls, an IEL cut-off of 14 showed 79% sensitivity and 55% specificity. IEL densities in Marsh I-II NCGS and CeD groups were similar. Conclusion: NCGS duodenal mucosa exhibits distinctive changes consistent with an intestinal response to luminal antigens, even at the Marsh 0 stage of villus architecture.

Diagnostic therapeutic care pathway for pediatric food allergies and intolerances in Italy: a joint position paper by the Italian Society for Pediatric Gastroenterology Hepatology and Nutrition (SIGENP) and the Italian Society for Pediatric Allergy and Immunology (SIAIP)

Epidemiologic data suggest an increased prevalence of pediatric food allergies and intolerances (FAIs) during the last decades. This changing scenario has led to an increase in the overall healthcare costs, due to a growing demand for diagnostic and treatment services. There is the need to establish Evidence-based practices for diagnostic and therapeutic intervention that could  be adopted in the context of public health policies for FAIs are needed.

This joint position paper has been prepared by a group of experts in pediatric gastroenterology, allergy and nutrition from the Italian Society for Pediatric Gastroenterology Hepatology and Nutrition (SIGENP) and the Italian Society for Pediatric Allergy and Immunology (SIAIP). The paper is focused on the Diagnostic Therapeutic Care Pathway (DTCP) for pediatric FAIs in Italy.

Evidence-Based and Emerging Diet Recommendations for Small Bowel Disorders

Diet plays a key role in the manifestation and severity of gastrointestinal symptoms, with increasing research interest on the role of diet in small bowel disorders. There are predominantly 3 small bowel conditions that have potential dietary interventions. Self-reported nonceliac gluten/wheat sensitivity is prevalent. Although gluten is believed to be a potential trigger for symptoms, other components of wheat may also be triggers, including fructans, alpha-amylase trypsin inhibitors, and wheat germ agglutinins. The diagnosis can be challenging, given the lack of validated biomarkers. A gluten-free diet that excludes the abovementioned triggers is the cornerstone of treatment; however, unlike celiac disease, there is uncertainty about the level of adherence or whether the gluten-free diet is a lifelong intervention. Several primary gastrointestinal disorders are associated with an increase in inflammatory cells including eosinophils. Diet seems to be an important driver of disease pathogenesis in eosinophilic gastroenteritis, with elimination and elemental diets showing promise in management, with further robust trials required. Small intestinal bacterial overgrowth is an example of microbial dysbiosis, with renewed interest in diet being postulated to cause an adaptive change of the microbes colonizing the small intestine. However, the diagnosis of small intestinal bacterial overgrowth is limited by a lack of sensitive and specific tests, with significant knowledge gaps in relation to therapeutic measures to manage and cure small intestinal bacterial overgrowth. Currently, antimicrobials are the established management option. There have been significant clinical advances in dietary interventions related to the small bowel, but this area is currently a novel and advancing field for both patients and clinicians.