Non-Celiac Gluten Sensitivity: A Review

Food Hypersensitivity: Distinguishing Allergy from Intolerance, Main Characteristics, and Symptoms-A Narrative Review

Background/Objectives: Food hypersensitivity remains an understudied and overlooked subject globally. It is characterized by adverse reactions to dietary substances, potentially triggered by various mechanisms. Food allergy, a subset of food hypersensitivity, denotes an immune response to food proteins categorized into immunoglobulin IgE-mediated or non-IgE-mediated reactions. Conversely, food intolerance, another facet of food hypersensitivity, refers to non-immunological reactions, in which the human body cannot properly digest certain foods or components, leading to gastrointestinal discomfort and other non-immune-related symptoms. The main objective of this study was to determine and differentiate the differences, characteristics, and types of food hypersensitivity. Methods: This study involved a comprehensive review of key research from 1990 onward, including review articles, prospective studies, nested case-control studies, and meta-analyses. Results: Recognizing these differences is essential for healthcare professionals to ensure accurate diagnosis, effective management, and improved patient outcomes, while also aiding dietitians in providing optimal nutritional and dietary guidance. Conclusions: there are big differences between the main characteristics, such as symptoms, complications, and treatments between allergies, and food intolerances. Commonly reported trigger foods include cow milk, gluten, eggs, nuts, and seafood.

The Role of Killer Ig-like Receptors in Diseases from A to Z

Killer Ig-like Receptors (KIRs) regulate immune responses, maintaining the balance between activation and inhibition of the immune system. KIRs are expressed on natural killer cells and some CD8 T cells and interact with HLA class I molecules, influencing various physiological and pathological processes. KIRs' polymorphism creates a variability in immune responses among individuals. KIRs are involved in autoimmune disorders, cancer, infections, neurological diseases, and other diseases. Specific combinations of KIRs and HLA are linked to several diseases' susceptibility, progression, and outcomes. In particular, the balance between inhibitory and activating KIRs can determine how the immune system responds to pathogens and tumors. An imbalance can lead to an excessive response, contributing to autoimmune diseases, or an inadequate response, allowing immune evasion by pathogens or cancer cells. The increasing number of studies on KIRs highlights their essential role as diagnostic and prognostic biomarkers and potential therapeutic targets. This review provides a comprehensive overview of the role of KIRs in all clinical conditions and diseases, listed alphabetically, where they are analyzed.

Gluten-Free Diet for Fashion or Necessity? Review with New Speculations on Irritable Bowel Syndrome-like Disorders

Nowadays, the gluten-free diet (GFD) has become much more than the dietary treatment for celiac disease. Due to its presumed beneficial effects even in non-celiac subjects, it has become a new fashion statement and it is promoted by some healthcare professionals, social media and marketing strategists. On the other hand, regardless of a proper medical indication, a GFD may present side effects, such as poor palatability, high costs and socio-psychological adversities. Moreover, it can be an obstacle to correct clinical practice and may induce nutritional deficiency due to a low-quality diet. In addition, a GFD can trigger or exacerbate many irritable bowel syndrome (IBS)-like disorders in predisposed subjects: reactivity to dietary nickel, the increased consumption of FODMAP-rich foods and histamine intolerance seem to frequently play a relevant role. The possible intersections between high-risk foods in these categories of patients, as well as the possible overlaps among IBS-like disorders during GFD, are described. In conclusion, it is advisable to undergo a careful clinical evaluation by a gastroenterologist and a nutritionist (in some cases, also a psychotherapist) before starting and during a GFD, because both benefits and risks are possible. It is also important to take into account IBS-like disorders that can be exacerbated by a GFD and that are still underestimated today.

Recurrent reproductive failure and celiac genetic susceptibility, a leading role of gluten

Introduction

The prevalence of gluten-related disorders, mainly celiac disease (CD) and non-celiac gluten sensitivity (NCGS), varies between 0.6% and 13% in the general population. There is controversial evidence regarding the association of both CD and NCGS with extra-digestive manifestations, including recurrent reproductive failure (RRF), which may have clinical implications.

Objective

To study the prevalence of HLA susceptibility alleles for CD/NCGS in a cohort of female patients with RRF from a single reference center and to evaluate the effect of a gluten-free diet on reproductive success.

Material and methods

A retrospective study was conducted on 173 patients with RRF, consecutively attended at the Reproductive Immunology Unit of San Carlos University Clinical Hospital in Madrid. We collected and analyzed the clinical, analytical, and immunological profiles of RRF patients who presented HLA alleles associated with CD and NCGS (HLA DQ2.2, DQ2.5, DQ8, and DQ7.5).

Results

We observed a significantly higher prevalence of HLA alleles associated with CD and NCGS in our RRF cohort compared to the prevalence in the general population (69% vs. 35%-40%, p<0.0001). Only 2.3% of patients met the criteria for a CD diagnosis. In our RRF cohort, HLA-genetic susceptibility for CD/NCGS (HLA-risk group) was associated with a significantly higher rate of hypothyroidism compared to patients without these alleles (HLA-negative group) (48.7% vs. 26.92%, p=0.03). Patients with HLA-genetic susceptibility for CD/NCGS and thyroid disease had a significantly higher success rate in the subsequent pregnancy after management (55% vs. 30%, p=0.002). Two factors were found to be significant in this group: a gluten-free diet (p=0.019) and the use of levothyroxine (p=0.042).

Conclusions

In our cohort of RRF patients, we observed a significantly higher prevalence of HLA susceptibility genes for CD/NCGS compared to the general population, also associated with a higher incidence of thyroid alterations. A gluten-free diet and the use of levothyroxine in cases of thyroid pathology had significant beneficial effects on pregnancy outcomes. We suggest that HLA typing for CD/NCGS and a gluten-free diet, in the presence of risk alleles, can improve pregnancy outcomes in RRF patients.

Self-Reported Nonceliac Gluten Sensitivity in Italian Young Adults: A Cross-Sectional Study. A Dietary Fad?

INTRODUCTION

In different countries, the exact prevalence of people that refer symptoms after gluten ingestion is increasing and the unavailability of reliable laboratory tests to diagnose the condition known as nonceliac gluten sensitivity (NCGS) has opened the door to the spread of survey-based studies to hypothesize a prevalence of this condition with highly discordant results. We aim to describe the attitude toward gluten consumption in a large population of young adults in Italy.

METHODS

A questionnaire-based cross-sectional study was conducted in 13 Italian cities to investigate the dietary attitudes of more than 9,400 people distributed throughout the country about gluten consumption. Only those referring to gluten-related symptoms with a frequency equal to "always" or "most of the time" were considered self-reported NCGS (SR-NCGS) patients.

RESULTS

Five thousand two hundred thirty-four of 9,432 eligible participants (55.5%) fully completed the questionnaire. Excluding those with previous gastrointestinal diagnoses of celiac disease and wheat allergy, we have finally analyzed 4,987 questionnaires. Four hundred eighty-seven participants indicated gluten-related symptoms always or most of the time (SR-NCGS subjects), while 121 already had a medical diagnosis of NCGS. The minimum prevalence figure of SR-NCGS is 6.4% (95% confidence interval 6.0-6.9), with a higher prevalence in women (79.9%). The most frequent gluten-related symptoms were bloating, abdominal pain, and tiredness.

DISCUSSION

The high prevalence of people reporting symptoms after gluten ingestion requires that the diagnosis of NCGS should be ascertained with a double-blind controlled study to limit the number of people who improperly approach a gluten-free diet.

The role of Killer immunoglobulin-like receptors (KIRs) in the genetic susceptibility to non-celiac wheat sensitivity (NCWS)

OBJECTIVES

Non-celiac wheat sensitivity (NCWS) is an emerging clinical condition characterized by gastrointestinal and extraintestinal symptoms following the ingestion of gluten-containing foods in patients without celiac disease (CD) or wheat allergy. Despite the great interest for NCWS, the genetic risk factors still need to be fully clarified. In this study, we first assessed the possible contribution of KIR genes and KIR haplotypes on the genetic predisposition to NCWS.

METHODS

Fifty patients with NCWS, 50 patients with CD, and 50 healthy controls (HC) were included in this study. KIR genes and KIR genotyping were investigated in all subjects by polymerase chain reaction with the sequence oligonucleotide probe (PCR-SSOP) method using Luminex technology.

RESULTS

We found a statistically different distribution of some KIR genes among NCWS, CD, and HC. Specifically, NCWS showed a decreased frequency of KIR2DL1, -2DL3, -2DL5, -2DS2, -2DS3, -2DS4, -2DS5, and -3DS1 genes, and an increased frequency of -3DL1 gene respect to both CD and HC. No difference was detected in the KIR haplotype expression. At the multivariate analysis, KIR2DL5, -2DS4, and -2DS5 were independent predictors of NCWS.

CONCLUSIONS

Our findings suggest a role of KIR genes in NCWS susceptibility, with KIR2DL5, -2DS4, and -2DS5 having a protective effect. Further large-scale multicentric studies are required to validate these preliminary findings.

Food-Intolerance Genetic Testing: A Useful Tool for the Dietary Management of Chronic Gastrointestinal Disorders

The rise in food intolerances and celiac disease, along with advanced diagnostic techniques, has prompted health professionals to seek effective and economical testing methods. This study evaluates combining genetic tests with routine carbohydrate-absorption breath tests to classify patients with chronic gastrointestinal disorders into therapeutic groups, enhancing dietary management and improving gut health and quality of life. Forty-nine patients with suspected carbohydrate intolerance underwent genetic testing for lactase non-persistence, hereditary fructose intolerance, and celiac disease risk. Simultaneously, breath tests assessed lactose and fructose absorption. The lactase non-persistence genotype appeared in 36.7% of cases, with one hereditary fructose-intolerance case in a heterozygous condition. Celiac disease risk markers (HLA-DQ2/8 haplotypes) were found in 49.0% of the population. Secondary lactose and/or fructose malabsorption was present in 67.3% of patients, with 66.1% of lactase non-persistence individuals showing secondary lactose malabsorption. Fructose malabsorption was prevalent in 45.8% of patients at risk for celiac disease. Two main treatment groups were defined based on genetic results, indicating primary and irreversible gastrointestinal disorder causes, followed by a sub-classification using breath test results. Genetic testing is a valuable tool for designing dietary management plans, avoiding unnecessary diet restrictions, and reducing recovery times.

Employee Dietary Initiative Improved Chronic Symptoms

With the awareness that the Standard American Diet is a critical contributor to chronic diseases, this initiative aimed to assess the effects of a 28-day dietary challenge health care improvement project on health system employee energy level, sleep quality, gastrointestinal function, ability to concentrate, and aches/pains, including the impact of adherence level, during a period of restricted intake of gluten, dairy, and sugar offered annually from 2021 to 2023. A total of 754 employees completed the pre-challenge survey; analyses included 354 employees who completed both pre-challenge and post-challenge surveys in at least 1 year of this project. Wilcoxon signed rank tests compared presurvey and postsurvey responses to self-reported energy level, sleep quality, gastrointestinal function, ability to concentrate, and aches/pains. Analysis of variance with Tukey's honestly significant difference tests compared self-reported adherence level with change scores, with η2 representing effect size. In each challenge year, the mean rank levels of energy, sleep quality, gastrointestinal function, concentration, and aches/pains improved significantly between pre-surveys and post-surveys (all P<.001). Although an association between significant positive change and diet adherence level was found for all items in at least 1 challenge year, those who mostly or completely adhered to the challenge diet restrictions reported significantly greater positive change in energy levels and gastrointestinal symptoms than those who did not or minimally adhered in all challenge years, with small to medium effect sizes. In conclusion, Essentia Health's employee challenge appeared to improve self-reported outcomes in 5 symptom domains, with energy levels and gastrointestinal symptoms correlating most favorably to adherence to the challenge. These findings have health and cost implications, which could be confirmed by formal research in employee and other populations.

Idiopathic Slow Transit Constipation: Pathophysiology, Diagnosis, and Management

Slow transit constipation (STC) has an estimated prevalence of 2-4% of the general population, and although it is the least prevalent of the chronic constipation phenotypes, it more commonly causes refractory symptoms and is associated with significant psychosocial stress, poor quality of life, and high healthcare costs. This review provides an overview of the pathophysiology, diagnosis, and management options in STC. STC occurs due to colonic dysmotility and is thought to be a neuromuscular disorder of the colon. Several pathophysiologic features have been observed in STC, including reduced contractions on manometry, delayed emptying on transit studies, reduced numbers of interstitial cells of Cajal on histology, and reduced amounts of excitatory neurotransmitters within myenteric plexuses. The underlying aetiology is uncertain, but autoimmune and hormonal mechanisms have been hypothesised. Diagnosing STC may be challenging, and there is substantial overlap with the other clinical constipation phenotypes. Prior to making a diagnosis of STC, other primary constipation phenotypes and secondary causes of constipation need to be ruled out. An assessment of colonic transit time is required for the diagnosis and can be performed by a number of different methods. There are several different management options for constipation, including lifestyle, dietary, pharmacologic, interventional, and surgical. The effectiveness of the available therapies in STC differs from that of the other constipation phenotypes, and prokinetics often make up the mainstay for those who fail standard laxatives. There are few available management options for patients with medically refractory STC, but patients may respond well to surgical intervention. STC is a common condition associated with a significant burden of disease. It can present a clinical challenge, but a structured approach to the diagnosis and management can be of great value to the clinician. There are many therapeutic options available, with some having more benefits than others.

Diet and Lifestyle Modifications for Fibromyalgia

Fibromyalgia (FM) is a complex, widespread pain disorder characterized by symptoms such as fatigue, sleep deprivation, mental fog, mood swings, and headaches. Currently, there are only three FDA-approved medications for FM patients: duloxetine, milnacipran, and pregabalin, with outcomes frequently being inadequate. This research team aims to investigate the effects of diet and lifestyle modifications on FM, with emphasis on anti-inflammatory diet, antioxidants, and gluten-free diets, as well as supplementation with Magnesium, CQ10, and Vitamin D, microbiome, sleep, exercise, and cognitive behavioral therapy. We reviewed the pathophysiology of certain foods that can be proinflammatory with the release of cytokines leading to activation of pain, fatigue and aggravation of the majority of Fibromyalgia symptoms. A literature review was performed by identifying FM articles published between 1994 and 2022 via PubMed and EMBASE databases, with particular emphasis on randomized controlled trials, meta-analysis, and evidence-based treatment guidelines. This review article was completed by a comprehensive narrative review process, in which our team systematically examined relevant scientific literature to provide a comprehensive overview of the significant role that diet and other lifestyle modifications play in mediating symptoms of Fibromyalgia. We propose that diet modifications and lifestyle changes, such as sleep, exercise, and weight loss, can be important steps in managing FM.

Myths and Facts about Food Intolerance: A Narrative Review

Most adverse reactions to food are patient self-reported and not based on validated tests but nevertheless lead to dietary restrictions, with patients believing that these restrictions will improve their symptoms and quality of life. We aimed to clarify the myths and reality of common food intolerances, giving clinicians a guide on diagnosing and treating these cases. We performed a narrative review of the latest evidence on the widespread food intolerances reported by our patients, giving indications on the clinical presentations, possible tests, and dietary suggestions, and underlining the myths and reality. While lactose intolerance and hereditary fructose intolerance are based on well-defined mechanisms and have validated diagnostic tests, non-coeliac gluten sensitivity and fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) intolerance are mainly based on patients' reports. Others, like non-hereditary fructose, sorbitol, and histamine intolerance, still need more evidence and often cause unnecessary dietary restrictions. Finally, the main outcome of the present review is that the medical community should work to reduce the spread of unvalidated tests, the leading cause of the problematic management of our patients.

Can open label placebos improve pain and gluten tolerance via open label placebos in fibromyalgia patients? A study protocol for a randomised clinical trial in an outpatient centre

INTRODUCTION

Fibromyalgia syndrome (FMS) is defined as a medical condition with chronic widespread musculoskeletal pain accompanied by mood disorders, fatigue and sleep disturbances. Treatment of this condition can often be challenging. As nutrition in general and nutritional interventions in the context of illness management become more and more important, current research also focuses on the relevance of diets for FMS, including gluten as field of interest. To date, there is no clear evidence that a gluten-free diet or other nutritional interventions are significantly important for the reduction of pain in the context of FMS. Only a very few studies show that FMS patients respond to a gluten-free diet and that cytokine production (also in FMS) can be reduced through the change. However, these studies have not investigated whether and to what extent cognitive factors, such as the expectation of symptom reduction triggered by diet, play a role. Recent research shows that treatment expectation plays an important role in the course of the disease and in the effectiveness of treatment approaches. For example, there are promising pain treatment options using open-label placebos (OLPs), which show that expectation alone, rather than the pharmacological substance of medication, can reduce pain experience. In our study protocol, we hypothesise that treatment expectation can be positively influenced by the given information regarding the placebos, resulting in improved treatment outcomes for pain and indigestions.

METHODS AND ANALYSIS

In this trial, patients with FMS will undergo a food challenge and take an OLP (patients will be informed about the placebo), followed by a 3-week OLP treatment. The subjects will be randomised into four groups: (a) gluten-free porridge+neutral OLP instructions; (b) gluten-free porridge+positive OLP instructions; (c) gluten-containing porridge+neutral OLP instructions and (d) gluten-containing porridge+positive OLP instructions. Patients will be recruited via different institutions and support groups in Hamburg. The inclusion criteria are (a) diagnosed FMS, (b) absence of wheat allergy, coeliac disease or pain-related red flags and (c) being a minimum age of 18 years. The study requires 100 subjects to assess the primary outcomes: pain intensity and occurence of indigestion. Secondary outcomes are functional capacity, treatment expectation, and different pain-related and inflammation-related blood parameters. The measure time points will be before and after the food challenge and before and after the 3-week OLP treatment.

ETHICS AND DISSEMINATION

Ethical approval was obtained in October 2021 from the Hamburg Medical Ethics Council. The results of the study will be disseminated through publications, presentations and conference meetings.

TRIAL REGISTRATION NUMBER

German Clinical Trials Register (DRKS; DRKS00027130).

Metabolic Disorders and Psoriasis: Exploring the Role of Nutritional Interventions

(1) Background: Psoriasis is a chronic autoimmune disease with a close relationship with metabolic diseases such as obesity, diabetes, and dyslipidemia. The aim of this review was to identify the relationship between psoriasis, metabolic diseases, and dietetic therapies. According to recent findings, there is a strong association between psoriasis and obesity as well as vitamin D and micronutrient deficiencies. (2) Methods: This review was conducted via PubMed, aiming to search for studies involving psoriasis linked with metabolic disorders or with nutritional treatments. (3) Results: Our review shows that a healthy lifestyle can positively influence the course of the disease. The maintaining of a proper body weight together with physical activity and good nutritional choices are associated with an improvement in psoriasis severity. A Mediterranean diet rich in fiber, vitamins, and polyphenols may indeed be a strategy for controlling psoriasis symptoms. The effectiveness of this diet lies not only in its anti-inflammatory power, but also in its ability to favorably influence the intestinal microbiota and counteract dysbiosis, which is a risk factor for many autoimmune diseases. (4) Conclusions: In synergy with standard therapy, the adoption of an appropriate diet can be recommended to improve the clinical expression of psoriasis and reduce the incidence of comorbidities.

Celiac disease, non-celiac gluten sensitivity and irritable bowel syndrome: diagnostic difficulties

The article is devoted to the difficulties of differential diagnosis of irritable bowel syndrome (IBS) and gluten-associated diseases. A clinical example illustrating the features of the diagnosis of these conditions is given

Allergenicity of wheat protein in diet: Mechanisms, modifications and challenges

Wheat is widely available in people's daily diets. However, some people are currently experiencing IgE-mediated allergic reactions to wheat-based foods, which seriously impact their quality of life. Thus, it is imperative to provide comprehensive knowledge and effective methods to reduce the risk of wheat allergy (WA) in food. In the present review, recent advances in WA symptoms, the major allergens, detection methods, opportunities and challenges in establishing animal models of WA are summarized and discussed. Furthermore, an updated overview of the different modification methods that are currently being applied to wheat-based foods is provided. This study concludes that future approaches to food allergen detection will focus on combining multiple tools to rapidly and accurately quantify individual allergens in complex food matrices. Besides, biological modification has many advantages over physical or chemical modification methods in the development of hypoallergenic wheat products, such as enzymatic hydrolysis and fermentation. It is worth noting that using biotechnology to edit wheat allergen genes to produce allergen-free food may be a promising method in the future which could improve the safety of wheat foods and the health of allergy sufferers.

The Gliadin Hydrolysis Capacity of B. longum, L. acidophilus, and L. plantarum and Their Protective Effects on Caco-2 Cells against Gliadin-Induced Inflammatory Responses

BACKGROUND

Non-celiac wheat sensitivity (NCWS) is a poorly understood gluten-related disorder (GRD) and its prominent symptoms can be ameliorated by gluten avoidance. This study aimed to determine the effectiveness of a probiotic mixture in hydrolyzing gliadin peptides (toxic components of gluten) and suppressing gliadin-induced inflammatory responses in Caco-2 cells.

METHODS

Wheat dough was fermented with a probiotic mix for 0, 2, 4, and 6 h. The effect of the probiotic mix on gliadin degradation was monitored by SDS-PAGE. The expression levels of IL-6, IL-17A, INF-γ, IL-10, and TGF-β were evaluated using ELISA and qRT-PCR methods.

RESULTS

According to our findings, fermenting wheat dough with a mix of B. longum, L. acidophilus, and L. plantarum for 6 h was effective in gliadin degradation. This process also reduced levels of IL-6 (p = 0.004), IL-17A (p = 0.004), and IFN-γ (p = 0.01) mRNA, as well as decreased IL-6 (p = 0.006) and IFN-γ (p = 0.0009) protein secretion. 4 h fermentation led to a significant decrease in IL-17A (p = 0.001) and IFN-γ (p = 0.003) mRNA, as well as reduced levels of IL-6 (p = 0.002) and IFN-γ (p < 0.0001) protein secretion. This process was also observed to increase the expression levels of IL-10 (p < 0.0001) and TGF-β (p < 0.0001) mRNA.

CONCLUSIONS

4 h fermentation of wheat flour with the proposed probiotic mix might be a good strategy to develop an affordable gluten-free wheat dough for NCWS and probably other GRD 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.

New Insights and Evidence on "Food Intolerances": Non-Celiac Gluten Sensitivity and Nickel Allergic Contact Mucositis

The clinical examination of patients often includes the observation of the existence of a close relationship between the ingestion of certain foods and the appearance of various symptoms. Until now, the occurrence of these events has been loosely defined as food intolerance. Instead, these conditions should be more properly defined as adverse food reactions (AFRs), which can consist of the presentation of a wide variety of symptoms which are commonly identified as irritable bowel syndrome (IBS). In addition, systemic manifestations such as neurological, dermatological, joint, and respiratory disorders may also occur in affected patients. Although the etiology and pathogenesis of some of them are already known, others, such as non-celiac gluten sensitivity and adverse reactions to nickel-containing foods, are not yet fully defined. The study aimed to evaluate the relationship between the ingestion of some foods and the appearance of some symptoms and clinical improvements and detectable immunohistochemical alterations after a specific exclusion diet. One hundred and six consecutive patients suffering from meteorism, dyspepsia, and nausea following the ingestion of foods containing gluten or nickel were subjected to the GSRS questionnaire which was modified according to the "Salerno experts' criteria". All patients underwent detection of IgA antibodies to tissue transglutaminase, oral mucosal patch tests with gluten and nickel (OMPT), and EGDS, including biopsies. Our data show that GSRS and OMPT, the use of APERIO CS2 software, and the endothelial marker CD34 could be suggested as useful tools in the diagnostic procedure of these new pathologies. Larger, multi-center clinical trials could be helpful in defining these emerging clinical problems.

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.

Meta-Analysis and Systematic Review of HLA DQ2/DQ8 in Adults with Celiac Disease

Although people with human leukocyte antigens (HLA) DQ2 and/or DQ8 are more likely to develop celiac disease (CD), the condition cannot be fully explained by this genetic predisposition alone. Multiple, as yet unidentified, factors contribute to the genesis of CD, including genetics, the environment, and the immune system. In order to provide insight into a prospective possibility and an expanded screening technique, we aim to undertake a comprehensive and meta-analytical study of the assessment and distribution of HLA class II (HLA-DQ2/DQ8) in adult CD patients. A systematic review was conducted using an electronic search of databases (PubMed, Google Scholar, Embase, and Direct Science) from January 2004 to February 2022. DQ2/DQ2 homozygotes have the highest risk of developing CD. DQ2/DQ8 typing is an effective test to exclude CD from the differential diagnosis of a patient with CD symptoms. Although other non-HLA genes have been associated with CD, they are rarely considered at diagnosis because they account for only a small proportion of the heritability of CD. This finding, together with the information gathered previously, may be useful in considering widely available and economically feasible screening options for celiac disease in young people.

Diets for inflammatory bowel disease: What do we know so far?

In recent years, the role of diet in the pathogenesis of inflammatory bowel disease (IBD) has gained great interest within the scientific community. Eating habits from industrialised countries (the so-called western diet or WD) have been associated with a higher incidence of IBD in observational studies, although the dietary factors responsible for the development of the disease are still to be elucidated. Some components of the diet with proinflammatory potential may cause changes in immunity and intestinal microbiota, leading to the inflammatory reaction that causes IBD-related lesions. The quality of available evidence is low, due to methodological issues, such as the lack of intervention studies, small sample size and heterogeneity of studies. For this reason, scientific societies have offered their recommendations using clinical practice guidelines and consensus documents, in order to establish a common criterion in the nutritional treatment of patients with IBD. The objective of this review was to summarise the data published regarding diet in IBD and review the recommendations given by scientific societies.

Genetically modified rodent models and celiac, non-celiac gluten sensitivity: a minireview

Celiac disease (CD) is a disorder that affects both children and adults. Over the few last decades, several new atypical cases have been identified through improved diagnostic tools. On the other hand, the onset of CD at a later age, including atypical CD forms whose clinical picture overlaps with other autoimmune diseases, shows that currently there are several unknown gene mutations, which could be responsible for the disease development. Non-celiac gluten sensitivity (NCGS) is entity included by the ingestion of gluten leading to intestinal, or extraintestinal symptoms that improve once the gluten is removed from the nutrition. In this article relationships between genetically modified rodent animals with previously unknown multiple organ changes and CD, respectively NCGS are reviewed. Relationships between the small bowel histological changes and other organs pathology are discussed. Results of research document that changes have similar genetic background and can develop to serious autoimmune systematic diseases, including small bowel inflammation resembling atypical CD or NCGS. These may have extra-intestinal symptomatology but without a clear explanation of causes and differences in their manifestations. Research on animal models helps to discover links between several disorders associated with gastrointestinal damage. New methods based on individual gene mutations can help in atypical adult CD and NCGS recognitions in the future.

Patterning Large-Scale Nanostructured Microarrays on Coverslip for Sensitive Plasmonic Detection of Aqueous Gliadin Traces

User-friendly devices for detecting low gliadin content in commercial foods are of extreme importance for people with gluten diseases. With this concern, the present work proposes a rapid and sensitive optical nanostructured microarrays platform for the detection of gliadin using specific anti-gliadin IgG antibodies immobilized on annealed gold nanostructures (AuNPs) obtained after the high annealing process (550 °C) of gold thin films evaporated on commercial glass coverslips. Localized Surface Plasmon Resonance (LSPR) immunosensing of gliadin in the range of 0.1 ppm to 1000 ppm is successfully achieved. In addition, the biofunctionalization protocol was used for gluten screening in five food complex products.

Histopathology of non-coeliac gluten sensitivity

Diagnosis of non-coeliac gluten sensitivity (NCGS) remains still problematic due to the subjectiveness and lack of a specific biomarker. We aimed to compare NCGS duodenal mucosae with healthy individuals and Marsh type 1 coeliac disease (CD), to determine whether NCGS has characteristic histological features. A total of 44 healthy controls, 42 NCGS, and 44 type 1 CD patients were selected according to clinical, serological, and laboratory data. Duodenal biopsies were evaluated on H&E, CD, and CD117 for villus/crypt ratio, IEL counts/100 enterocytes, uneven distribution pattern with clusters of IELs in the villous epithelium, linear distribution of T lymphocytes in the basal lamina propria, and eosinophils and mast cells in the lamina propria. IEL counts were within normal range in controls (13 ± 7.65), normal or mildly increased in NCGS (24.7 ± 10.46), and increased in CD (58.79 ± 14.97) on CD3. The presence of uneven distribution pattern of IELs in the villous epithelium was significantly higher in NCGS (90.5%), in contrast to controls (27.3%) and CD (34.1%). The presence of linear distribution of T lymphocytes in the basal lamina propria (68.2%, 76.2%, 78.1%), eosinophil counts (6.85 ± 3.42, 6.21 ± 2.8, 7.62 ± 3.89), and mast cell counts (25.1 ± 5.1, 26 ± 2.9, 30.3 ± 4.4) was similar in controls, NCGS, and CD, respectively. In conclusion, duodenal mucosae in NCGS are characterized by preserved villous architecture, normal or mildly increased IELs with clusters, and eosinophils and mast cells within normal limits. We believe uneven distribution of IELs with clusters in the villous epithelium can be used as a supportive histopathological tool for NCGS in the right clinical setting.

The Gluten-Free Diet for Celiac Disease and Beyond

The gluten-free diet (GFD) has gained popularity beyond its main medical indication as the treatment for gluten-induced immune-mediated disorders such as celiac disease (CD), dermatitis herpetiformis, gluten ataxia, wheat allergy, and non-celiac gluten sensitivity. However, the diet carries some disadvantages such as elevated costs, nutritional deficiencies, and social and psychological barriers. The present work aims to review indications, proven benefits, and adverse events of a gluten-free diet. Close follow-up with patients following the diet is recommended. More data is needed to assess the effectiveness of the diet in managing mental and cognitive disorders and to establish a connection between the brain and gluten.

Fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), but not gluten, elicit modest symptoms of irritable bowel syndrome: a double-blind, placebo-controlled, randomized three-way crossover trial

BACKGROUND

Irritable bowel syndrome (IBS) has been associated with diets rich in fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), and gluten. Most previous studies have been single-blind and have focused on the elimination of FODMAPs or provocation with single FODMAPs. The effect of gluten is unclear, large trials isolating the effect of gluten from that of FODMAPs are needed.

OBJECTIVES

The aims of this study were to ensure high intakes of a wide range of FODMAPs, gluten, or placebo, and to evaluate the effects on IBS symptoms using the IBS-severity scoring system (IBS-SSS).

METHODS

The study was carried out with a double-blind, placebo-controlled, randomized 3-way crossover design in a clinical facility in Uppsala from September 2018 to June 2019. In all, 110 participants fulfilling the IBS Rome IV criteria, with moderate to severe IBS, were randomly assigned; 103 (90 female, 13 male) completed the trial. Throughout, IBS participants maintained a diet with minimal FODMAP content and no gluten. Participants were block-randomly assigned to 1-wk interventions with FODMAPs (50 g/d), gluten (17.3 g/d), or placebo, separated by 1-wk washout. All participants who completed ≥1 intervention were included in the intention-to-treat analysis.

RESULTS

In participants with IBS (n = 103), FODMAPs caused higher IBS-SSS scores (mean 240 [95% CI: 222, 257]) than placebo (198 [180, 215]; P = 0.00056) or gluten (208 [190, 226]; P = 0.013); no differences were found between the placebo and gluten groups (P = 1.0). There were large interindividual differences in IBS-SSS scores associated with treatment. No adverse events were reported.

CONCLUSION

In participants with IBS, FODMAPs had a modest effect on typical IBS symptoms, whereas gluten had no effect. The large interindividual differences in responses to the interventions warrant further detailed studies to identify possible underlying causes and enable individual prediction of responses. This trial was registered at www.clinicaltrials.gov as NCT03653689.

Pandemic Effects and Gluten-Free Diet: An Adherence and Mental Health Problem

The COVID-19 pandemic has been present for many months, influencing diets such as the gluten-free diet (GFD), which implies daily challenges even in non-pandemic conditions. Persons following the GFD were invited to answer online ad hoc and validated questionnaires characterizing self-perceptions of the pandemic, current clinical condition, dietary characteristics, adherence to GFD, anxiety, and depression. Of 331 participants, 87% experienced shortage and higher cost of food and 14.8% lost their jobs. Symptoms increased in 29% and 36.6% failed to obtain medical help. Although 52.3% increased food preparation at home and purchased alternative foodstuffs, 53.8% had consumed gluten-containing foods. The Health Eating Index was intermediate/"needs improvement" (mean 65.6 ± 13.3 points); in 49.9% (perception) and 44.4% (questionnaire), adherence was "bad". Anxiety and depression scores were above the cutoff in 28% and 40.4%, respectively. Adherence and mental health were strongly related. The likelihood of poor adherence was 2.3 times higher (p < 0.004) in participants declaring that pandemic altered GFD. Those suffering depressive symptoms were 1.3 times more likely to have poor adherence (p < 0.000). Depression and faulty GFD (mandatory for treatment) appear, affecting a high proportion of participants, suggesting that support measures aimed at these aspects would help improve the health condition of people that maintain GFD. Comparisons of data currently appearing in the literature available should be cautious because not only cultural aspects but conditions and timing of data collection are most variable.

Non-Celiac Gluten Sensitivity: An Update

Non-celiac gluten sensitivity (NCGS) is a clinical entity characterized by the absence of celiac disease and wheat allergy in patients that trigger reproducible symptomatic responses to gluten-containing foods consumption. Due to the lack of sensitive and reproducible biomarkers for NCGS diagnosis, placebo-controlled gluten challenges must be carried out for its diagnosis. The gluten challenges can be either double- or single-blind, for research or clinical practice purposes, respectively. For improving our understanding about the magnitude and relevance of NCGS in different populations, epidemiological studies based on self-report have been carried out. However, the gluten challenge-based prevalence of NCGS remains to be estimated. Since NCGS was recently recognized as a clinical entity, more studies are needed to delve into NCGS pathogenesis, for instance, the molecular interactions between the suspected cereal grain components that trigger NCGS, such as fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) and amylase and trypsin inhibitors, and the immune system remains to be elucidated. Although still under debate, NCGS patients can be susceptible to only one or more than one of the NCGS triggers. The treatment of NCGS involves the dietary restriction of the suspected triggers of the disease, but there is controversial data about the effectiveness of different dietary interventions such as the gluten-free diet and low-FODMAP diet. Certainly, our understanding of NCGS is improving quickly due to the constant availability of new scientific information on this topic. Thus, the aim of the present narrative review is to present an up-to-date overview on NCGS from epidemiology to current therapy.

A Japanese infant presenting with hypocalcemic seizures resulting from hypovitaminosis D induced by non-celiac gluten sensitivity

Vitamin D deficiency is a major cause of hypocalcemic seizures in infants. Chronic enteropathy can cause both malnutrition and vitamin deficiency disorders, such as celiac disease, in Western Caucasians. However, gluten-related disorders are considered uncommon in most Asian countries, and there have been no reports of any infant being diagnosed with a gluten-related disorder in Japan. Here, we describe a case where a Japanese infant, with non-celiac gluten sensitivity, presented with hypocalcemic seizures resulting from a vitamin D deficiency. In this case, an eight-month-old boy had an afebrile seizure, and blood tests revealed both hypocalcemia and prolonged prothrombin time resulting in his transfer to our hospital. The presence of fatty stools and evidence of multiple vitamin deficiencies indicated some form of fat malabsorption. His laboratory and histological findings showed enteropathy, and he was thus diagnosed with non-celiac gluten sensitivity. Therefore, he was treated with a gluten-free diet supplemented with vitamins. This case suggests that infants with a vitamin D deficiency caused by celiac disease or non-celiac gluten sensitivity should be carefully monitored when they are given oral supplements of vitamin D, to prevent any adverse side-effects associated with the varied roles of vitamin D in the immune response.

Gluten-degrading bacteria: availability and applications

Gluten is a mixture of storage proteins in wheat and occurs in smaller amounts in other cereal grains. It provides favorable structure to bakery products but unfortunately causes disease conditions with increasing prevalence. In the human gastrointestinal tract, gluten is cleaved into proline and gluten rich peptides that are not degraded further. These peptides trigger immune responses that might lead to celiac disease, wheat allergy, and non-celiac gluten sensitivity. The main treatment option is a gluten-free diet. Alternatively, using enzymes or microorganisms with gluten-degrading properties might alleviate the disease. These components can be used during food production or could be introduced into the digestive tract as food supplements. In addition, natural food from the environment is known to enrich the microbial communities in gut and natural environmental microbial communities have high potential to degrade gluten. It remains to be investigated if food and environment-induced changes in the gut microbiome could contribute to the triggering of gluten-related diseases. KEY POINTS: • Wheat proteins, gluten, are incompletely digested in human digestive tract leading to gluten intolerance. • The only efficient treatment of gluten intolerance is life-long gluten-free diet. • Environmental bacteria acquired together with food could be source of gluten-degrading bacteria detoxifying undigested gluten peptides.

Gluten-related disorders

Gluten-related disorders are a heterogeneous group of clinical entities caused by intolerance of wheat, rye, and barley flour components. They occur in 3-5% of genetically predisposed persons and based on pathogenic and clinical features are classified into celiac disease, non-celiac gluten sensitivity, and wheat allergy. There are also specific entities such as dermatitis herpetiformis or gluten ataxia, which can occur either within the celiac disease or independently. This article based on the current knowledge shows the basic details of the pathogenesis, clinical expression, diagnosis, and treatment of these disorders.

From Polyclonal Sera to Recombinant Antibodies: A Review of Immunological Detection of Gluten in Foodstuff

Gluten is the ethanol-soluble protein fraction of cereal endosperms like wheat, rye, and barley. It is widely used in the food industry because of the physical-chemical properties it gives to dough. Nevertheless, there are some gluten-related diseases that are presenting increasing prevalences, e.g., celiac disease, for which a strict gluten-free diet is the best treatment. Due to this situation, gluten labeling legislation has been developed in several countries around the world. This article reviews the gluten immune detection systems that have been applied to comply with such regulations. These systems have followed the development of antibody biotechnology, which comprise three major methodologies: polyclonal antibodies, monoclonal antibodies (mAbs) derived from hybridoma cells (some examples are 401.21, R5, G12, and α-20 antibodies), and the most recent methodology of recombinant antibodies. Initially, the main objective was the consecution of new high-affinity antibodies, resulting in low detection and quantification limits that are mainly achieved with the R5 mAb (the gold standard for gluten detection). Increasing knowledge about the causes of gluten-related diseases has increased the complexity of research in this field, with current efforts not only focusing on the development of more specific and sensitive systems for gluten but also the detection of protein motifs related to pathogenicity. New tools based on recombinant antibodies will provide adequate safety and traceability methodologies to meet the increasing market demand for gluten-free products.

Determinants of gluten-free diet adoption among individuals without celiac disease or non-celiac gluten sensitivity

OBJECTIVES

Gluten-free (GF) foods are typically less nutritious and more expensive than their gluten-containing variants, yet people without a diagnosed gluten sensitivity continue to adopt this diet. There is a lack of research about what factors drive people without Celiac disease or non-Celiac gluten sensitivity to follow the GF diet.

METHODS

A nationally representative sample of 2982 US residents without a diagnosed gluten sensitivity were surveyed about their attitudes, perceptions, and experiences with the GF diet. Logistic regression was used to compare respondents who were currently avoiding or had avoided gluten previously (GF consumer) to respondents who had never tried a GF diet (non-GF consumer).

RESULTS

Over one-fifth of respondents were GF consumers. Beliefs that a gluten-reduced diet is healthier (OR 1.69; 95% CI [1.30,2.18]), that GF products are more nutritious (OR 1.46, 95% CI [1.11,1.90), and that a GF diet can help clear acne (OR 1.46; 95% CI [1.13,1.88]) were all positively associated with trying a GF diet. Personal research was the most influential source of information associated with trying a GF diet (OR 2.92; 95% CI [1.91,4.52]). This was followed by "healthcare center or health professional" (OR 2.57; 95% CI [1.71,3.90]. Respondents who were never encouraged to try the GF diet were less likely to try the diet (OR 0.33, 95% CI [0.23,0.46]).

CONCLUSIONS

Positive, but scientifically unsubstantiated, beliefs about the benefits of the GF diet were strongly associated with trying a GF diet, and the source of recommendation to try a GF diet was important.

Noncoeliac wheat sensitivity and diet

PURPOSE OF REVIEW

Noncoeliac gluten sensitivity (NCGS) can be suspected after exclusion of coeliac disease and wheat allergy. However, poorly understood pathogenesis of the NCGS, lack of gold standard for diagnosis and agreement in the definition for the NCGS condition, open the space for future investigation. This review aims to give an overview on the diagnosis and effective diet composition in the treatment of NCGS symptoms.

RECENT FINDINGS

It appears that a diet low in fermentable oligo, di, and monosaccharides and polyols (FODMAPs) and gluten-free diet play a prominent role in the strategy of NCGS management. Considering available evidence with respect to diagnostic tools, it is challenging to prepare a standard guideline for NCGS diagnosis and treatment with clear cut-offs for symptom reduction/improvement that could directly be translated into test results. Nutritional support, including the use of pre/probiotics, has to be tailored to the individual situation of NCGS patients.

SUMMARY

The exclusion of such components of wheat as amylase/trypsin inhibitors, wheat-germ agglutinins, or free of FODMAPs diet can reduce clinical symptoms of NCGS. The further investigation on microbiota changes may strengthen the knowledge in this area, where the major challenge is to develop biomarkers for NCGS investigation.

An updated overview of spectrum of gluten-related disorders: clinical and diagnostic aspects

The incidence of gluten-related disorders (GRDs) continues to increase and its global prevalence is estimated at approximately 5% of the population. Celiac disease (CD), dermatitis herpetiformis (DH), gluten ataxia (GA), wheat allergy (WA), and non-celiac gluten sensitivity (NCGS) are the five major GRDs that present with a wide range of clinical manifestations. The diagnosis of GRDs can be challenging because the typical and atypical clinical manifestations of the GRDs overlap. In this review, the current definitions of gluten-related disorders, focusing on their clinical features, diagnostic and therapeutic approaches are presented. We concluded that GRDs are usually diagnosed using a combination of clinical features, serological tests, and histopathological findings. Treatment usually involves dietary modification.

Gluten hypersensitivities and their impact on the production of gluten-free beer

This article consists of a study of the literature and an assessment of available data on the production of gluten-free beer and its constituents. The article shows how the FAO/WHO Codex Alimentarius Commission for Nutrition and Foods for Special Dietary Uses defines celiac disease, gluten-free products, and gluten-free beer. It describes diet-dependent diseases, which require a gluten-free diet, and groups of potential consumers of gluten-free beer. This article describes the use of oats as a raw material for the production of brewing malt and its usefulness in the production of beer. It specifies how the technological process of standard beer production needs to be modified so that the product meets the requirements of patients with celiac disease. The article also provides an overview of literature data on the production of gluten-free beer from pseudocereal malts, such as sorghum malt, buckwheat malt, amaranth malt, and quinoa malt.

Global and local diet popularity rankings, their secular trends, and seasonal variation in Google Trends data

OBJECTIVES

The Internet has become the main source of health-related information including nutrition. The aim of this study was to rank the most popular diets among Google users globally and regionally in addition to secular and seasonal trends in the years 2004 to 2019.

METHODS

We used Google Trends (GT) to identify and analyze course over time and regional interest of 47 topics related to diets. We analyzed secular trends using the Seasonal Mann-Kendall test and seasonal variation using time-series decomposition. The topic "Mediterranean diet" (MedD) was used as a benchmark. We calculated the interest of all topics in proportion to the relative search volume (RSV) of MedD.

RESULTS

Globally, Google users were particularly interested in veganism (19.54 times higher than MedD), vegetarianism (15.09 times higher than MedD), and gluten-free diet (11.11 times higher than MedD). Veganism was the most frequently searched diet type in 23 countries followed by vegetarianism (14), ketogenic diet (7), and low-carbohydrate diet (7). Whereas an increase of RSV over time was observed for 23 diets, a decrease was noted for 20. The most dynamic increase was found for FODMAP (6.12 RSV/year), gluten-free diet (5.95 RSV/year), and raw veganism (5.72 RSV/year). Sharp declines concerned negative-calorie food (-4.34 RSV/year), macrobiotic diet (-3.89 RSV/year), and cabbage soup diet (-3.50 RSV/year). The interest in most diets falls in December but peaks in January.

CONCLUSION

Veganism, vegetarianism, and gluten-free diet attract the largest public interest globally. Both secular trends and seasonal variation shape the ever-changing landscape of diet popularity. GT holds promise as a valuable tool in local and international nutrition research.

Differentiating Psychosomatic, Somatopsychic, Multisystem Illnesses, and Medical Uncertainty

There is often difficulty differentiating between psychosomatic, somatopsychic, multisystem illness, and different degrees of medical uncertainty. Uncommon, complex, and multisystem diseases are commonly misdiagnosed. Two case histories are described, and relevant terms differentiating psychosomatic, somatopsychic, and multisystem illnesses are identified, reviewed, and discussed. Adequate differentiation requires an understanding of the mind/body connection, which includes knowledge of general medicine, psychiatry, and the systems linking the body and the brain. A psychiatric diagnosis cannot be given solely based upon the absence of physical, laboratory, or pathological findings. Medically unexplained symptoms, somatoform disorder, and compensation neurosis are outdated and/or inaccurate terms. The terms subjective, nonspecific, and vague can be used inaccurately. Conversion disorders, functional disorders, psychogenic illness, factitious disorder imposed upon another (Munchausen's syndrome by proxy), somatic symptom disorder, psychogenic seizures, psychogenic pain, psychogenic fatigue, and delusional parasitosis can be over-diagnosed. Bodily distress disorder and bodily distress syndrome are scientifically unsupported and inaccurate. Many "all in your head" conditions may be related to the microbiome and the immune system. Better education concerning the interface between medicine and psychiatry and the associated diagnostic nomenclature as well as utilizing clinical judgment and thorough assessment, exercising humility, and maintaining our roots in traditional medicine will help to improve diagnostic accuracy and patient trust.

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.