Prevalence of Self-Reported Gluten Sensitivity and Adherence to a Gluten-Free Diet in Argentinian Adult Population

Gluten and Wheat in Women's Health: Beyond the Gut

Since the rise of awareness of gluten/wheat-related disorders in the academic and clinical field in the last few decades, misinformation regarding the gluten-free diet (GFD) and its impact on health has been spreading among the general population. Despite the established link between gluten and celiac disease (CD), where a GFD is mandatory to reach clinical and histological remission, things are more complicated when it comes to non-celiac gluten/wheat sensitivity (NCGWS) and other autoimmune/dysimmune disorders. In the last conditions, a beneficial effect of gluten withdrawal has not been properly assessed, but still is often suggested without strong supporting evidence. In this context, women have always been exposed, more than men, to higher social pressure related to nutritional behaviors and greater engagement in controlling body weight. With this narrative review, we aim to summarize current evidence on the adherence to a GFD, with particular attention to the impact on women's health.

Identification of RNAi hypoallergic bread wheat lines for wheat-dependent exercise-induced anaphylaxis patients

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is one of the most severe forms of wheat allergy. It occurs in patients when they exercise after ingesting wheat-containing foods. Nowadays, the only possible alternative for WDEIA patients is to avoid such foods. This study investigated the potential of six RNA of interference (RNAi) wheat lines with low-prolamin content as alternatives for WDEIA patients. For that purpose, a high performance-liquid chromatography (HPLC) analysis was performed to evaluate differences in gluten protein fractions among these lines. Next, western blots were conducted to measure the immunoglobulin E (IgE) reactivity to wheat proteins in sera from five WDEIA patients. Additionally, monoclonal antibodies (moAb) recognition sites and the IgE binding sites were searched in all peptides identified by LC-MS/MS after protein digestion. The results showed a 61.4%-81.2% reduction in the gliadin content of the RNAi lines, accompanied by an increase in their high-molecular weight (HMW) glutenin content compared to the wild type bread wheat line (WT). In all cases, the reduction in gliadin content correlated with a decrease in IgE reactivity observed in the sera of WDEIA patients, highlighting the E82 and H320 lines. These two RNAi lines exhibited a ≤90% reduction in IgE reactivity. This reduction could be attributed to an absence of IgE binding sites associated with α- and ω5-gliadins, which were present in the WT. Overall, these lines offer a potential alternative for foodstuff for individuals with WDEIA.

Self-reported food intolerances in an Indian population: Need for individualization rather than a universal low-FODMAP diet

Background and Aim

Low-fermentable oligo-, di-, and monosaccharides and polyol (FODMAP) diets have been recommended for individuals with food intolerance and irritable bowel syndrome (IBS). Individual food intolerances may, however, not correspond to the FODMAP content alone.

Methods

We conducted a survey on self-reported intolerance to articles of food commonly identified as high FODMAP in 400 healthy Indian subjects (median age 40 years; 69% men) and 204 consecutive consenting patients with IBS (median age 36 years; 58% men).

Results

One-hundred seventy-nine (44.8%) healthy subjects and 147 (72.1%) patients with IBS reported some food intolerance (P < 0.00001); the latter reported intolerance to all items (except nuts) more frequently than healthy subjects. The prevalence, however, varied from 2.5 to 32%. Milk intolerance was reported equally commonly by healthy subjects and patients (23% vs 29.9%). Twenty-three (11.3%) patients and no healthy subjects reported wheat sensitivity. The IBS diarrhea subgroup reported intolerance to milk, pulses, capsicum, cauliflower, leafy vegetables, and dry fruits more frequently than the constipation subgroup.

Conclusion

From among a list of high-FODMAP items, individuals' intolerance varied widely, suggesting that individuals should be the final judge in deciding their elimination diets rather than devise them based on the FODMAP content alone. As in the West, food intolerance was reported more commonly by patients with IBS, especially those with diarrhea, than by healthy individuals. Also noteworthy is the low prevalence of milk intolerance in a subcontinent labeled as high in lactose intolerance. Unlike in the West, wheat intolerance was not reported by any healthy individual.

Adherence to a gluten-free diet in celiac disease patients from Paraguay

INTRODUCTION AND AIM

The treatment for celiac disease is a gluten-free diet that should be strictly and permanently carried out. Our aims were to determine adherence to the gluten-free diet and the risk factors for non-adherence.

MATERIALS AND METHODS

An observational, cross-sectional, comparative study was conducted. It included individuals of both sexes and of any age that presented with celiac disease, lived in Paraguay from January to April 2021, and agreed to participate in the survey. Incomplete questionnaires were excluded. Non-probabilistic convenience sampling was utilized. Adherence was measured using the Leffler questionnaire. The study was approved by the Ethics Committee of the Universidad Privada del Este.

RESULTS

The sample consisted of 371 respondents, 322 (87%) of whom were adults, with a mean age of 38 ± 12 years, and 49 (13%) of whom were children and adolescents, with a mean age of 10 ± 5 years. Female sex was predominant (85%). Adherence to the gluten-free diet was detected in 59% of the adults and 73% of the children and adolescents. The factors significantly associated with adherence included belonging to the child and adolescent age group and having had the diagnosis for a longer time: 9 ± 8 years for the adherence group and 7 ± 8 years for the non-adherence group.

CONCLUSIONS

The present study demonstrated the frequency of adherence to the gluten-free diet in celiac patients in Paraguay. Psychologic and nutritional support is recommended for individuals with celiac disease that do not adhere to their treatment.

Combination of Gut Microbial Features and the Proteomic Pattern Revealed Changes in Specific Intestinal Luminal Factors and Mechanisms of Their Regulation of Gluten Allergy

Recent research consensus has highlighted the role of intestinal luminal factors in the association between intestinal microenvironment homeostasis and food allergy. However, the association between intestinal immune homeostasis and food allergy-related proteomic features remains elusive. In this study, we aimed to investigate the changes in gluten allergy (GA)-defined phenotypes and endotypes and intestinal microenvironment factors in BALB/c mice and linked GA to colonic proteomic signatures. Combined with increased allergy and diarrhea scores, intense antibody responses and abnormalities in T-cell cytokine production were induced in mice. GA-associated disruption of intestinal microenvironment homeostasis was underlined by the increased colonic pH, decreased intestinal antioxidant capacity, impaired intestinal barrier function, and decreased production and imbalanced proportions of short-chain fatty acids. 16S rRNA amplicon sequencing showed that the gut microbiota dysbiosis in mice was characterized by significant enrichment of six bacterial taxonomic units, including Prevotellaceae, Escherichia Shigella, Alloprevotella, Escherichia coli, Bacteroides vulgatus, and Lachnospiraceae bacterium DW59, which was correlated with immune end points. Using a label-free proteomics quantitative approach, 24 differentially expressed proteins linking GA-induced gut dysbiosis were identified, with four of them enriched in the serine endopeptidase inhibitor activity pathway. The development of GA in mice was associated with changes in specific intestinal luminal factors and may be mediated by serine protease activity-associated metabolic routes.

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.

Safety Assessment of Foods and Drinks Consumed by People on a Gluten-Free Diet

Naturally gluten-free foods and processed foods that do not contain information about the potential presence of gluten in them pose a hypothetical threat to people with food allergies and celiac disease. Patients who should follow a strict gluten-free diet do not always do so. Therefore, the aim of this research was to analyze certified “gluten-free” and naturally gluten-free products without labeled “may contain gluten” information in terms of their content of gluten proteins. The enzyme immunoassay AgraQuant Gluten G12 ELISA test kit was used for the analysis. Of all the products used in the research, only 5.8% were found to contain gluten above 20 ppm. Only one product labeled “gluten-free” was contaminated with gluten at 79.3 ppm (cider cake). In addition, our research also examined the gluten content of commercial beers containing barley malt not labeled as “gluten-free”. Research has shown that 60% of samples are not safe for those on a strict gluten-free diet. Our research clearly shows that many manufacturers, although they do not monitor their products for the presence of gluten in them, offer safe products, although they cannot be recommended in a gluten-free diet. Therefore, there is a strong need to increase the frequency of testing by food manufacturers for the presence of gluten in their products, so that the number of products approved for people on a gluten-free diet continues to increase.

The effect of gluten in adolescents and young adults with gastrointestinal symptoms: a blinded randomised cross-over trial

BACKGROUND

The popularity of the gluten-free diet and sales of gluten-free products have increased immensely.

AIMS

To investigate whether gluten induces gastrointestinal symptoms, measured by self-reported questionnaires, as well as mental health symptoms in adolescents from a population-based cohort.

METHODS

The eligible participants (n = 273) were recruited from a population-based cohort of 1266 adolescents and had at least four different gastrointestinal symptoms. Phase one (n = 54) was a run-in phase where the participants lived gluten-free for 2 weeks. If they improved they continued to phase 2 (n = 33), a blinded randomised cross-over trial. Participants were blindly randomised either to start with 7 days of gluten, eating two granola bars containing 10 g of gluten or to 7 days on placebo, eating two granola bars without gluten, followed by the reverse and separated by a 7-day washout period. The effects of the intervention on gastrointestinal symptoms and mental health symptoms were assessed.

RESULTS

In total, 54/273 participants entered the run-in phase and 35 were eligible for randomization. A total of 33 were randomised and 32 completed the trial. The median age was 20.3 (IQR 19.2-20.9) and 32/33 participants were females. Compared with a placebo, gluten did not induce gastrointestinal symptoms. The difference in the average VAS was -0.01 (95% confidence interval -2.07 to 2.05). Nor did we find a difference in the outcomes measuring mental health.

CONCLUSION

Compared with placebo, adding gluten to the diet did not induce gastrointestinal symptoms or worsened mental health in adolescents recruited from a population-based cohort. The trial registration number is NCT04639921.

Self-reported nonceliac wheat sensitivity in an outpatient digestive endoscopy center: high frequency but insufficient medical approach

OBJECTIVE

'Self-reported wheat sensitivity' (SRWS) is a self-reported condition caused by wheat ingestion in the absence of celiac disease or wheat allergy. The aim of the study was to investigate the frequency and characteristics of SRWS in outpatients referred for digestive endoscopy.

METHODS

The study, performed at the University of Palermo, enrolled 496 outpatients.

RESULTS

Seven individuals (1.4%) had an already established diagnosis of celiac disease. The questionnaire was administered to the other 489 individuals: 98 subjects (20%) were SRWS, the remaining 391 served as controls (i.e. not-SRWS). SRWS patients were younger (P < 0.001), with a higher percentage of females (P = 0.002) than not-SRWS. 'gastroesophageal reflux disease and ulcer-like dyspepsia' and 'chronic unexplained diarrhea' were more frequently the reasons for the endoscopy study in SRWS than in not-SRWS (P = 0.002, and P = 0.05, respectively). Food allergies/intolerances (P = 0.04), milk allergy/intolerance (P = 0.0001), GERD (P = 0.0001), IBS (0.0001), anxiety (P = 0.005) and depression (P = 0.04) were the previous medical diagnoses reported more frequently in SRWS patients than in not-SRWS. In the SRWS group, 38% of the patients had already undergone previous upper endoscopy and 24% colonoscopy. After these investigations, 58% of SRWS patients received no diagnosis, and the other 42% were informed that they 'were not suffering from celiac disease or wheat allergy'. Finally, 28.6% SRWS patients had followed a gluten-free diet (GFD), and 71.4% of them referred being asymptomatic on GFD.

CONCLUSIONS

Our data showed a high frequency of SRWS in outpatients referred to a digestive endoscopy center and a lack of medical accuracy in identifying a possible gluten-related disease.

REGISTRATION

The study was registered on Clinicaltrials.gov (registration number: NCT04154137), accessible at: https://clinicaltrials.gov/ct2/show/NCT04154137?term=non+celiac+wheat&draw=2&rank=1.

Proteome Analysis and Epitope Mapping in a Commercial Reduced-Gluten Wheat Product

Gluten related disorders, such as coeliac disease, wheat allergy and baker's asthma are triggered by proteins present in food products made from wheat and related cereal species. The only treatment of these medical illnesses is a strict gluten-free diet; however, gluten-free products that are currently available in the market can have lower nutritional quality and are more expensive than traditional gluten containing cereal products. These constraints have led to the development of gluten-free or gluten-reduced ingredients. In this vein, a non-GMO wheat flour that purports to contain "65% less allergenic gluten" was recently brought to market. The present study aims to understand the alteration of the proteome profile of this wheat flour material. Liquid chromatography-mass spectrometry was used to investigate the proteome profile of the novel wheat flour, which was contrasted to a wheat flour control. Using both trypsin and chymotrypsin digests and a combined database search, 564 unique proteins were identified with 99% confidence. These proteins and the specific peptides used to identify them were mapped to the wheat genome to reveal the associated chromosomal regions in the novel wheat flour and the mixed wheat control. Of note, several ω- and γ-gliadins, and low-molecular weight glutenins mapping to the short arm of chromosome 1, as well as α-gliadins from the chromosome 6 short arm were absent or expressed at lower levels in the novel wheat variety. In contrast, the high-molecular weight glutenins and α-amylase/trypsin inhibitors were notably more abundant in this variety. A targeted quantitation experiment was developed using multiple reaction monitoring assays to quantify 359 tryptic and chymotryptic peptides from gluten and related allergenic proteins revealing a 33% decrease of gluten protein content in the novel wheat flour sample in comparison to mixed wheat control. However, additional mapping of known allergenic epitopes showed the presence of 53% higher allergenic peptides. Overall, the current study highlights the importance of proteomic analyses especially when complemented by sequence analysis and epitope mapping for monitoring immunostimulatory proteins.

Genome-wide association study reveals an association between the HLA-DPB1∗02:01:02 allele and wheat-dependent exercise-induced anaphylaxis

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a life-threatening food allergy triggered by wheat in combination with the second factor such as exercise. The identification of potential genetic risk factors for this allergy might help high-risk individuals before consuming wheat-containing food. We aimed to identify genetic variants associated with WDEIA. A genome-wide association study was conducted in a discovery set of 77 individuals with WDEIA and 924 control subjects via three genetic models. The associations were confirmed in a replication set of 91 affected individuals and 435 control individuals. Summary statistics from the combined set were analyzed by meta-analysis with a random-effect model. In the discovery set, a locus on chromosome 6, rs9277630, was associated with WDEIA in the dominant model (OR = 3.95 [95% CI, 2.31-6.73], p = 7.87 × 10-8). The HLA-DPB1∗02:01:02 allele displayed the most significant association with WDEIA (OR = 4.51 [95% CI, 2.66-7.63], p = 2.28 × 10-9), as determined via HLA imputation following targeted sequencing. The association of the allele with WDEIA was confirmed in replication samples (OR = 3.82 [95% CI, 2.33-6.26], p = 3.03 × 10-8). A meta-analysis performed in the combined set revealed that the HLA-DPB1∗02:01:02 allele was significantly associated with an increased risk of WDEIA (OR = 4.13 [95% CI, 2.89-5.93], p = 1.06 × 10-14). Individuals carrying the HLA-DPB1∗02:01:02 allele have a significantly increased risk of WDEIA. Further validation of these findings in independent multiethnic cohorts is needed.

Wheat/Gluten-Related Disorders and Gluten-Free Diet Misconceptions: A Review

In the last 10,000 years, wheat has become one of the most important cereals in the human diet and today, it is widely consumed in many processed food products. Mostly considered a source of energy, wheat also contains other essential nutrients, including fiber, proteins, and minor components, such as phytochemicals, vitamins, lipids, and minerals, that together promote a healthy diet. Apart from its nutritional properties, wheat has a set of proteins, the gluten, which confer key technical properties, but also trigger severe immune-mediated diseases, such as celiac disease. We are currently witnessing a rise in the number of people adhering to gluten-free diets unwarranted by any medical need. In this dynamic context, this review aims to critically discuss the nutritional components of wheat, highlighting both the health benefits and wheat/gluten-related disorders, in order to address common misconceptions associated with wheat consumption.

A Modified Brewing Procedure Informed by the Enzymatic Profiles of Gluten-Free Malts Significantly Improves Fermentable Sugar Generation in Gluten-Free Brewing

The mashing step underpins the brewing process, during which the endogenous amylolytic enzymes in the malt, chiefly β-amylase, α-amylase, and limit dextrinase, act concurrently to rapidly hydrolyze malt starch to fermentable sugars. With barley malts, the mashing step is relatively straightforward, due in part to malted barley’s high enzyme activity, enzyme thermostabilities, and gelatinization properties. However, barley beers also contain gluten and individuals with celiac disease or other gluten intolerances should avoid consuming these beers. Producing gluten-free beer from gluten-free malts is difficult, generally because gluten-free malts have lower enzyme activities. Strategies to produce gluten-free beers commonly rely on exogenous enzymes to perform the hydrolysis. In this study, it was determined that the pH optima of the enzymes from gluten-free malts correspond to regions already typically targeted for barley mashes, but that a lower mashing temperature was required as the enzymes exhibited low thermostability at common mashing temperatures. The ExGM decoction mashing procedure was developed to retain enzyme activity, but ensure starch gelatinization, and demonstrates a modified brewing procedure using gluten-free malts, or a combination of malts with sub-optimal enzyme profiles, that produces high fermentable sugar concentrations. This study demonstrates that gluten-free malts can produce high fermentable sugar concentrations without requiring enzyme supplementation.

Frequency and Clinical Aspects of Neurological and Psychiatric Symptoms in Patients with Non-Celiac Wheat Sensitivity

Background: Non-Celiac Wheat Sensitivity (NCWS) is characterized by both intestinal and extra-intestinal symptoms. The study aims to investigate the frequency of neuropsychiatric manifestations in NCWS patients and identify their clinical and demographic characteristics. Methods: 278 clinical records of NCWS patients, diagnosed by a double-blind placebo-controlled wheat challenge between 2006 and 2020, were retrospectively revised. Fifty-two patients with Celiac Disease (CD) and 54 patients with Irritable Bowel Syndrome (IBS) served as controls. Results: 87% of the NCWS patients had an IBS-like clinical presentation. The NCWS group showed a longer duration of symptoms, a higher frequency of positive serum anti-nuclear antibodies than CD and IBS patients, and a higher frequency of DQ2/DQ8 haplotypes and duodenal mucosa lymphocytosis than IBS controls. In addition, 50% of NCWS patients showed neuropsychiatric manifestations, while lower percentages were observed in CD (25%) and IBS (28%) controls. Neuropsychiatric symptoms in NCWS were more frequently associated with the male sex, longer duration of symptoms, and IBS-diarrhea-like clinical presentation. Conclusions: Our data suggest that in patients with IBS-like symptoms and neuropsychiatric manifestations of unknown cause, it could be useful to investigate a correlation of these symptoms with wheat ingestion to identify NCWS patients with this ‘atypical’ manifestation.

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.

Organic food consumption and gluten-free diet, is there a link? Results in French adults without coeliac disease

The rising popular belief that gluten is unhealthy has led to growth in gluten avoidance in people without coeliac disease. Little information is available on their dietary profiles and their dietary behaviours. Our aim was to compare the consumption of organic foods between gluten avoiders and non-avoiders, and their places of food purchase. We described their sociodemographic and dietary profiles. The study population included participants of the NutriNet-Santé cohort who completed both a food exclusion questionnaire and an organic semi-quantitative FFQ (n 23 468). Food intake and organic food consumption ratios were compared using multivariable adjusted ANCOVA models. Associations between gluten avoidance and organic food consumption as well as places of food purchase were investigated with multivariable logistic regression. Participants avoiding gluten were more likely to be women and had a healthier dietary profile. Organic food consumption was higher among gluten avoiders (48·50 % of total diet for total avoiders, 17·38 % for non-avoiders). After adjustments for confounders, organic food consumption and purchase in organic stores were positively associated with gluten avoidance: adjusted OR (aOR)Q5 v.Q1 organic food = 4·95; 95 % CI 3·70, 6·63 and aORorganic stores v.supermarkets = 1·82; 95 % CI 1·42, 2·33 for total avoiders. Our study highlights that individuals avoiding gluten are high organic consumers and frequently purchase their foods in organic stores which propose an extended offer of gluten-free food. Further research is needed to determine the underlying common motivations and the temporality of the dietary behaviours of healthy people avoiding gluten.

Probiotics Supplements Reduce ER Stress and Gut Inflammation Associated with Gliadin Intake in a Mouse Model of Gluten Sensitivity

Exposure to gluten, a protein present in wheat rye and barley, is the major inducer for human Celiac Disease (CD), a chronic autoimmune enteropathy. CD occurs in about 1% worldwide population, in genetically predisposed individuals bearing human leukocyte antigen (HLA) DQ2/DQ8. Gut epithelial cell stress and the innate immune activation are responsible for the breaking oral tolerance to gliadin, a gluten component. To date, the only treatment available for CD is a long-term gluten-free diet. Several studies have shown that an altered composition of the intestinal microbiota (dysbiosis) could play a key role in the pathogenesis of CD through the modulation of intestinal permeability and the regulation of the immune system. Here, we show that gliadin induces a chronic endoplasmic reticulum (ER) stress condition in the small intestine of a gluten-sensitive mouse model and that the coadministration of probiotics efficiently attenuates both the unfolded protein response (UPR) and gut inflammation. Moreover, the composition of probiotics formulations might differ in their activity at molecular level, especially toward the three axes of the UPR. Therefore, probiotics administration might potentially represent a new valuable strategy to treat gluten-sensitive patients, such as those affected by CD.

A systematic review of psychological, clinical and psychosocial correlates of perceived food intolerance

OBJECTIVE

Perceived food intolerance (PFI) is a distressing condition reported by 3% - 35% of individuals, whereas prevalence of food allergy is 0.9%-3%. The present paper aims to systematically review the evidence for psychological, clinical and psychosocial factors associated with PFI in order to advance the current understanding.

METHODS

Articles published from 1970 until October 2020 were identified. Case-control, prospective cohort, cross-sectional and retrospective studies published in English that a) included a subject population of adults over 18 with PFI and b) examined psychological, clinical and/or psychosocial factors of PFI were reviewed against inclusion criteria. Methodological quality was assessed, data extracted, and a narrative synthesis conducted.

RESULTS

Of 2864 abstracts identified, thirty-six articles met inclusion criteria. Evidence consistently found PFI is associated with female sex, and individuals with PFI often report physical health complaints including gastrointestinal and extraintestinal symptoms, and gastrointestinal and atopic conditions. Evidence for an association between psychological factors and PFI was inconsistent, although some suggested increased levels of common mental disorders and distress. Findings regarding psychosocial factors were mixed and sociodemographic data were infrequently collected.

CONCLUSIONS

PFI is associated with female sex and gastrointestinal and extraintestinal complaints. Limited high-quality evidence supports the role of psychological factors associated with PFI. High-quality research using prospective and longitudinal designs with multivariate analyses is needed. Future research should explore modifiable psychological factors as potential targets for intervention and identify clinical and psychosocial risk factors of PFI to aid in formulating a biopsychosocial model of PFI.

Prevalence of Wheat/Gluten-Related Disorders and Gluten-Free Diet in Paraguay: An Online Survey-Based Study

Gluten-related disorders (GRDs) are increasing around the world, but their magnitude and relevance remain unknown in most Latin American countries. Thus, an online survey was conducted to estimate the prevalence of GRDs as well as adherence to a gluten-free diet (GFD) in Paraguayan adult population. There were 1058 individuals surveyed using a validated questionnaire (response rate of 93.9%). The self-reported prevalence rates were as follows (95% CI): gluten sensitivity (GS), 10.30% (8.53-12.29); non-celiac GS (NCGS), 5.19% (3.94-6.71); physician-diagnosed celiac disease (PD-CD), 3.11% (2.15-4.35); wheat allergy (WA), 2.07% (1.30-3.13); and adherence to GFD, 15.69% (13.55-18.02). Excluding CD, more women than men met the criteria for GRDs, adverse food reactions, and GFD (p < 0.05). Eight respondents reported the coexistence of NCGS with PD-CD and/or WA. Most cases on a GFD indicated medical/dietitian advice for following the diet (68.07%). Non-self-reported GS individuals indicated weight control (46.4%) and the notion that the GFD is healthier (20.2%) as the main motivations for following the diet. GRDs are not uncommon in Paraguayan adult population. It seems that there is awareness about GRDs and the GFD, but training about the diagnosis of GRDs is desirable because of the informed overlapping diagnoses of CD or WA with NCGS. Future studies involving face-to-face interviews are necessary.

Non-celiac wheat sensitivity: rationality and irrationality of a gluten-free diet in individuals affected with non-celiac disease: a review

Non-celiac gluten or wheat sensitivity (NCWS) is a “clinical entity induced by the ingestion of wheat leading to intestinal and/or extraintestinal symptoms that improve once the wheat-containing foodstuff is removed from the diet, and celiac disease and wheat allergy have been excluded”. This mostly accepted definition raises several points that remain controversial on this condition. In the present review, the authors summarize the most recent advances in the clinic and research on NCWS through an accurate analysis of different studies. We screened PubMed, Medline, Embase, and Scopus using the keywords “non-celiac gluten sensitivity”, “non-celiac wheat sensitivity”, and “diagnosis”. We would like to emphasize two main points, including (A) the controversial clinical and etiological aspects in different trials and experiences with particular attention to the Salerno criteria for the diagnosis of NCWS and (B) the histological aspects. The etiology of NCWS remains controversial, and the relationship with irritable bowel syndrome is obscure. Histologically, the duodenal mucosa may show a variable pattern from unremarkable to a slight increase in the number of T lymphocytes in the superficial epithelium of villi. The endorsement of this disease is based on a positive response to a gluten-free diet for a limited period, followed by the reappearance of symptoms after gluten challenge. The Salerno expert criteria may help to diagnose NCWS accurately. Social media and inaccurate interpretation of websites may jeopardize the diagnostic process if individuals self-label as gluten intolerant.

Non-celiac gluten sensitivity as a rare cause of growth retardation in children: a case series study

AIM

Herein, we present five children and adolescents with a final diagnosis of non-celiac gluten sensitivity (NCGS).

BACKGROUND

Non-celiac gluten sensitivity (NCGS) is a condition characterized by gastrointestinal and extra-intestinal symptoms triggered by ingestion of gluten-containing compounds, e.g., wheat, rye, and barley, in subjects without celiac disease or wheat allergy.

METHODS

Demographic characteristics, clinical manifestations, serum biomarkers and skin prick test were evaluated. Patient data was also recorded after they followed a gluten-free diet (GFD). Height and weight were measured, and all patients were examined 6 months after following the suggested GFD.

RESULTS

All patients had failure to thrive and abdominal pain. Clinical symptoms were reduced, and significant weight and height gains were detected after 1 month of following a gluten-free diet.

CONCLUSION

The relationship between failure to thrive (FTT) and NCGS is still unknown; hence, NCGS may be one of the main causes of FTT which can be prevented by gluten-free diets.

Optimization of nutrient retention in whole flours extruded from cowpea biofortified grain

Abstract Whole flour of cowpea grains of the cultivar BRS Tumucumaque biofortified in iron and zinc were processed in a co-rotating twin-screw extruder Clextral HT 25. A central rotational composite design 23, combining temperature (from 86.4 to 153.6 °C), screw rotation speed (from 163.6 to 836.4 rpm) and moisture content (from 16.6% to 23.4%), was used to assess the effects on flour constituents. The three variables significantly affected (p < 0.05) the levels of protein and copper in the extrudates. The reactions of the extrusion process caused a decrease in the levels of proteins and an increase in the levels of copper, zinc and potassium, and these amounts were accentuated as the values of the process variables approached those of the central point region. Extreme conditions at high rotational screw speeds combined with low moisture content reduced the magnesium content, at the opposite end of the values for these two variables, the intensity of the reduction was lower. In the analysis of global desirability, it was found that the extrusion condition at 112.6 °C, 587.4 rpm and 23.4% moisture provided the highest nutrient retention. The levels of iron and zinc remained above 60 and 40 mg kg-1, respectively, in extruded products.

Non-Celiac Gluten Sensitivity in the Context of Functional Gastrointestinal Disorders

Gluten-free diets are increasingly chosen in the Western world, even in the absence of a diagnosis of celiac disease. Around 10% of people worldwide self-report gluten-related complaints, including intestinal and extra-intestinal symptoms. In most cases, these subjects would be labeled as patients suffering from irritable bowel syndrome (IBS) who place themselves on a gluten-free diet even in the absence of celiac disease. In some instances, patients report a clear benefit by avoiding gluten from their diet and/or symptom worsening upon gluten reintroduction. This clinical entity has been termed non-celiac gluten sensitivity (NCGS). The symptoms referred by these patients are both intestinal and extra-intestinal, suggesting that similarly to functional gastrointestinal disorders, NCGS is a disorder of gut-brain interaction. It remains unclear if gluten is the only wheat component involved in NCGS. The mechanisms underlying symptom generation in NCGS remain to be fully clarified, although in the past few years, the research has significantly moved forward with new data linking NCGS to changes in gut motility, permeability and innate immunity. The diagnosis is largely based on the self-reported reaction to gluten by the patient, as there are no available biomarkers, and confirmatory double-blind challenge protocols are unfeasible in daily clinical practice. Some studies suggest that a small proportion of patients with IBS have an intolerance to gluten. However, the benefits of gluten-free or low-gluten diets in non-celiac disease-related conditions are limited, and the long-term consequences of this practice may include nutritional and gut microbiota unbalance. Here, we summarize the role of gluten in the clinical features, pathophysiology, and management of NCGS and disorders of gut-brain interaction.

Complementary and Alternative Medicine Use in Pediatric Functional Abdominal Pain Disorders at a Large Academic Center

OBJECTIVE

To describe the use of complementary and alternative medicine (CAM) in pediatric functional abdominal pain disorders at a large Midwestern pediatric gastroenterology center.

STUDY DESIGN

A survey of patients attending a follow-up visit for functional abdominal pain disorders was completed. Data were collected on demographics, quality of life, use of conventional therapies, patient's opinions, and perception of provider's knowledge of CAM.

RESULTS

Of 100 respondents (mean age, 13.3 ± 3.5 years), 47 (60% female) had irritable bowel syndrome, 29 (83% female) had functional dyspepsia, 18 (67% female) had functional abdominal pain, and 6 (83% female) had abdominal migraine (Rome III criteria). Ninety-six percent reported using at least 1 CAM modality. Dietary changes were undertaken by 69%. Multivitamins and probiotics were the most common supplements used by 48% and 33% of respondents, respectively. One-quarter had seen a psychologist. Children with self-reported severe disease were more likely to use exercise (P < .05); those with active symptoms (P < .01) or in a high-income group (P < .05) were more likely to make dietary changes; and those without private insurance (P < .05), or who felt poorly informed regarding CAM (P < .05), were more likely to use vitamins and supplements. Seventy-seven percent of patients described their quality of life as very good or excellent.

CONCLUSIONS

The use of CAM in children with functional abdominal pain disorders is common, with a majority reporting a high quality of life. Our study underscores the importance of asking about CAM use and patient/family knowledge of these treatments.

Evaluation of Quality of Life of Adult Patients with Celiac Disease in Argentina: From Questionnaire Validation to Assessment

This cross-sectional study aimed to translate, culturally adapt, validate, and apply a Celiac Disease Quality of Life (CD-QoL) questionnaire to a representative sample of Argentina’s celiac population. A previously developed and validated questionnaire (Celiac Disease Questionnaire: CDQ) was chosen as a tool for assessing the health-related quality of Life (HRQoL) of adult celiac patients in Argentina. Therefore, the study was performed in four stages: (a) translation and re-translation of the CDQ to Argentinian-Spanish language; (b) cultural adaptation and semantic evaluation; based on the Delphi method (c) validation of the CDQ by applying it to a representative sample of Argentinian celiac patients; (d) statistical analysis of the data. The result of stages (a) and (b) was a translated and culturally adapted an Argentinian-Spanish version of the CDQ, which was generated after reaching consensus between the corresponding four (phase a) and 10 (phase b) professionals involved in the different phases of this process. Among them, we can cite bilingual healthcare professionals with extensive experience in research and celiac disease, celiac patients, gastroenterologists, general practitioners, dieticians, and psychologists. The resulting CDQ proved to be an appropriate measuring tool to assess the HRQoL of Argentinian celiac patients confirmed by a good fit in the confirmatory factor validity analysis (RMSEA < 0.001 and χ² = 267.325, df = 313, p = 0.971) and high values of internal consistency (Cronbach’s alpha > 0.7). A total of 191 participants accessed the questionnaire, and 171 individuals from 20 out of 23 Argentinian states completed the questionnaire. There was no correlation between higher educational level nor marital status with QoL. Individuals on a strict gluten-free diet (GFD) and those who do not take antidepressants showed higher QoL. Male gender also presented better HRQoL. There was no correlation between differences in HRQoL and age of the respondent, age at diagnosis, symptoms at diagnosis, or having other chronic diseases. However, a significantly higher score of HRQoL was reported among those individuals who disclosed having knowledge of CD related national regulations and benefits. This study highlights the importance of maintaining current public health regulations that support chronic disease patients, such as celiac patients.

Living with Gluten and Other Food Intolerances: Self-Reported Diagnoses and Management

People suffering from a food intolerance (FI) tend to initiate restrictive diets such as a gluten-free diet (GFD), to alleviate their symptoms. To learn about how people live with these problems in daily life (independent of their medical diagnoses), 1203 participants answered a previously validated questionnaire and were divided into: G1 (those self-reporting symptoms after gluten consumption) and G2 (those informing no discomfort after gluten consumption). Self-reported clinical characteristics, diagnoses and diets followed were registered. Twenty nine percent referred some FI (8.5% in G1). In G1, self-reported diagnoses were more frequent (p < 0.0001), including a high proportion of eating and mood disorders. Diagnoses were reported to be given by a physician, but GFD was indicated by professional and nonprofessional persons. In G2, despite declaring no symptoms after gluten consumption, 11.1% followed a GFD. The most frequent answer in both groups was that GFD was followed “to care for my health”, suggesting that some celiac patients do not acknowledge it as treatment. Conclusion: close to one third of the population report suffering from some FI. Those perceiving themselves as gluten intolerant report more diseases (p < 0.0001). A GFD is followed by ~11% of those declaring no symptoms after gluten ingestion. This diet is perceived as a healthy eating option.

Prevalence of Adverse Reactions to Gluten and People Going on a Gluten-Free Diet: A Survey Study Conducted in Brazil

Background: The prevalence of gluten-related disorders (GRD) and adherence to a gluten-free diet (GFD) remains unknown in Brazilian population and there is no published information on the scientific literature about the proportion of Brazilians that were diagnosed with a gluten-related disorder. Thus, the aim of this work was to estimate the prevalence of GRDs and adherence to a GFD by self-report in adult Brazilian population. Materials and Methods: A questionnaire-based cross-sectional study was conducted in two Brazilian cities. Results: The response rate was 93.2% (1630/1749). The self-reported prevalence rates were (95% CI): adverse reactions to gluten 10.06% (8.64–11.62); gluten sensitivity 2.33% (1.65–3.18); physician-diagnosed celiac disease 0.3% (0.09–0.71); non-celiac gluten sensitivity 1.71% (1.14–2.47); wheat allergy 0.79% (0.42–1.36); adherence to gluten-free diet 7.48% (6.25–8.87); gluten avoiders 15.21% (13.5–17.05). Among those who were following a GFD (n = 122), 65.6% (n = 80) of them reported that they did not develop symptoms after wheat/gluten ingestion and 50% (n = 61) were following the diet without medical/dietitian advice. The main motivation for following a GFD in the self-reported and non-self-reported gluten sensitivity groups were the symptoms triggered after wheat/gluten ingestion (86.8%) and weight control (57.1%), respectively. Conclusions: Implementation of programs to increase awareness about GRDs among healthcare professionals and giving scientifically sound information to the general population about the risks and benefits for following a GFD are desirable actions in Brazil. The results also add to the growing body of evidence for highlighting the under-diagnosis of GRD and the trend for following a GFD in Latin America.

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

OBJECTIVES

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

DESIGN

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

SETTING, PARTICIPANTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Translation, Cultural Adaptation, and Evaluation of a Brazilian Portuguese Questionnaire to Estimate the Self-Reported Prevalence of Gluten-Related Disorders and Adherence to Gluten-Free Diet

Background: A Spanish version of a questionnaire intended to estimate, at the population level, the prevalence rates of self-reported gluten-related disorders and adherence to gluten-free diets has been applied in four Latin American countries. However, idiom issues have hampered the questionnaire application in the Brazilian population. Thus, the aim of the present study was to carry out a translation, cultural adaptation, and evaluation of a Brazilian Portuguese questionnaire to estimate the self-reported prevalence of gluten-related disorders and adherence to gluten-free diets in a Brazilian population. Materials and Methods: Two bilingual Portuguese–Spanish health professionals carried out the translation of the original Spanish version of the questionnaire to Brazilian-Portuguese. Matching between the two translations was evaluated using the WCopyFind.4.1.5 software. Words in conflict were conciliated, and the conciliated version of the Brazilian Portuguese instrument was evaluated to determine its clarity, comprehension, and consistency. A pilot study was carried out using an online platform. Results: The two questionnaires translated into Brazilian Portuguese were highly matched (81.8%–84.1%). The questions of the conciliated questionnaire were clear and comprehensible with a high agreement among the evaluators (n = 64) (average Kendall’s W score was 0.875). The participants did not suggest re-wording of questions. The answers to the questions were consistent after two applications of the questionnaire (Cohen’s k = 0.869). The pilot online survey yielded low response rates (9.0%) highlighting the need for face-to-face interviews. Conclusions: The translation and evaluation of a Brazilian Portuguese questionnaire to estimate the self-reported prevalence rates of gluten-related disorders and adherence to gluten-free diets was carried out. The instrument is clear, comprehensible, and generates reproducible results in the target population. Further survey studies involving face-to-face interviews are warranted.

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

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

Gluten-free diet in French adults without coeliac disease: sociodemographic characteristics, motives and dietary profile

The number of people avoiding gluten is growing in many Western countries. However, little information is available on their sociodemographic and dietary profiles. We aimed to describe sociodemographic, behavioural and dietary profiles of participants avoiding gluten in the NutriNet-Santé cohort. Participants of the NutriNet-Santé cohort – excluding coeliac patients – who completed a questionnaire about food exclusions, with complete data on sociodemographic characteristics and dietary intake were included (n 20 456). Food group consumptions and nutrient intakes according to self-reported avoidance of gluten were estimated using ANCOVA adjusted for age, sex and daily energy intake. Based on principal component analysis, three dietary patterns (DP) were identified. Association between DP and avoidance of gluten was investigated using multivariate logistic regression. All data were weighted on the French census. A total of 10·31 (95 % CI 9·90, 10·73) % of the participants declared avoiding gluten, of which 1·65 % totally. They were more likely to be women, older persons, non-smokers, to have a lower educational level and declared more food intolerances. They had higher consumption of fruit, vegetables and lower consumption of dairy products, salty/sweet and fatty foods and alcohol. After adjustments on confounders, a healthy dietary pattern was positively associated with total gluten avoidance (ORQuintile5vsQuintile1 = 14·44, 95 % CI 8·62, 24·19). Our study highlighted that, in this population, individuals who avoid gluten from their diet tend to have a diet more favourable to health. These results can serve as a basis for future studies investigating the potential consequences of a gluten-free diet in non-coeliac population.

Non-Celiac Gluten Sensitivity: A Review

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

Gluten Vehicle and Placebo for Non-Celiac Gluten Sensitivity Assessment

Non-celiac gluten sensitivity (NCGS) is a syndrome characterized by gastrointestinal and extraintestinal manifestations triggered after gluten ingestion in the absence of celiac disease and wheat allergy. Because of the lack of biomarkers for NCGS diagnosis, the cornerstone for its assessment is a single- or double-blind placebo-controlled (DBPC) gluten challenge. However, there are some non-standardized points in the diagnostic approach proposed by the experts. This complicate comparisons among the results published by different research groups. The gluten vehicle and placebo must be indistinguishable from each other, which entails sensory and technological evaluations of the designed gluten vehicle and placebo products. At the moment, there is no standardized method for the preparation of the gluten vehicle and placebo for carrying out DBPC gluten challenges for NCGS assessment. This review focuses on the challenges that researchers have to face, either for the development of an accepted gluten vehicle and placebo or for identifying NCGS cases on the basis of DBPC gluten challenges.

Self-Reported Non-Celiac Gluten Sensitivity in Brazil: Translation, Cultural Adaptation, and Validation of Italian Questionnaire

This study aimed to translate, culturally adapt, validate, and apply a questionnaire to the Brazilian non-celiac gluten sensitive (NCGS) population. We also aimed to estimate the prevalence of symptoms which affect Brazilian NCGS. The Brazilian Portuguese version of the NCGS questionnaire was developed according to revised international guidelines. Five-hundred-and-fourty-three participants responded the NCGS questionnaire. We evaluated the reproducibility and validity of the questionnaire which presents valid measures of reproducibility. This is the first specific self-reported validated questionnaire for NCGS patients in Brazilian Portuguese, and the first nationwide characterization of self-reported NCGS in Brazilian adults. Most respondents were female (92.3%), and the main intestinal symptoms reported were bloating and abdominal pain. The most frequent extraintestinal symptoms were lack of wellbeing, tiredness, and depression. We expect that the present study will provide a picture of Brazilian individuals with suspected NCGS, which could help health professionals and governmental institutions in developing effective strategies to improve the treatment and diagnosis of Brazilian NCGS.

Gluten and Functional Abdominal Pain Disorders in Children

In children, functional gastrointestinal disorders (FGIDs) are common at all ages. Consumption of certain foods, particularly gluten, is frequently associated with the development and persistence of FGIDs and functional abdominal pain disorders (FAPDs) in adults and children. However, this association is not well defined. Even without a diagnosis of celiac disease (CD), some people avoid gluten or wheat in their diet since it has been shown to trigger mostly gastrointestinal symptoms in certain individuals, especially in children. The incidence of conditions such as non-celiac gluten sensitivity (NCGS) is increasing, particularly in children. On the other hand, CD is a chronic, autoimmune small intestinal enteropathy with symptoms that can sometimes be mimicked by FAPD. It is still unclear if pediatric patients with irritable bowel syndrome (IBS) are more likely to have CD. Abdominal, pain-associated FGID in children with CD does not seem to improve on a gluten-free diet. The threshold for gluten tolerance in patients with NCGS is unknown and varies among subjects. Thus, it is challenging to clearly distinguish between gluten exclusion and improvement of symptoms related solely to functional disorders.

Recent advances in understanding non-celiac gluten sensitivity

Non-celiac gluten sensitivity (NCGS) is a condition characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing foods in the absence of celiac disease and wheat allergy. The diagnosis is cumbersome and currently confirmed only by gluten withdrawal and double-blind placebo challenge protocols. There is great overlap in symptoms between NCGS and other functional gastrointestinal disorders, making a differential diagnosis difficult. The pathophysiology of NCGS is largely unclear, and there are contrasting data on the trigger of this condition. This review will highlight the state-of-the-art knowledge on NCGS and the key open questions.

Wheat Intolerance and Chronic Gastrointestinal Symptoms in an Australian Population-based Study: Association Between Wheat Sensitivity, Celiac Disease and Functional Gastrointestinal Disorders

OBJECTIVES

Wheat avoidance in the absence of celiac disease (CD) is common but occurrence of concurrent functional gastrointestinal disorders (FGIDs) in this group is uncertain. The aims of this study were to determine the prevalence of self-reported wheat or gluten sensitivity and doctor diagnosed CD in an Australian population, define the associated gastrointestinal (GI) symptoms and FGIDs, and determine the relationship between self-reported wheat sensitivity, demographic and medical factors.

METHODS

A total of 3542 people randomly selected from the Australian population returned a mail survey which contained questions on wheat avoidance, GI symptoms, demographic, medical, and lifestyle factors. We defined self-reported wheat sensitivity as people who reported gastrointestinal symptoms on ingestion of wheat based foods, but did not suffer from celiac disease, inflammatory bowel disease or colorectal cancer. Functional dyspepsia (FD) and irritable bowel syndrome (IBS) were diagnosed by Rome III criteria. CD status was self-reported.

RESULTS

The prevalence of self-reported wheat sensitivity in this cohort was 14.9% (95% CI 13.7-16.2). The prevalence of CD was 1.2% (95%CI 0.8-1.6). Doctor diagnosed CD was significantly associated with a diagnosis of FD (OR 3.35, 95%CI 1.72-6.52) and IBS (OR 2.28, 95%CI 1.08-4.81). Those with self-reported wheat sensitivity were more likely to report multiple abdominal symptoms (of the 18 assessed) than those without (3.9 symptoms with self-reported wheat sensitivity vs. 1.6 without, p = 0.0001). In a multivariate analysis, self-reported wheat sensitivity was independently associated with IBS (OR 3.55, 95%CI 2.71-4.65) and FD (1.48, 95%CI 1.13-1.94).

CONCLUSIONS

Self-reported wheat sensitivity is common, with a prevalence of 14.9% in this cohort. There is a strong association between both celiac disease and self-reported wheat sensitivity, and chronic gastrointestinal symptoms, as well as a diagnosis of FD and IBS.

Gluten sensitivities and the allergist: Threshing the grain from the husks

"Gluten sensitivity" has become commonplace among the public. Wheat allergy (WA) and celiac disease (CD) are well-defined entities, but are becoming a fraction of individuals following a gluten-free diet (GFD). Wheat allergy has a prevalence of <0.5%. Wheat, specifically its omega-5 gliadin fraction, is the most common allergen implicated in food-dependent, exercise-induced anaphylaxis. CD is a non-IgE hypersensitivity to certain cereal proteins: gluten in wheat, secalin in rye, hordein in barley, and to a lesser extent avenin in oat. It is a rare disease, with an estimated prevalence that varied widely geographically, being higher in Northern Europe and the African Saharawi region than in South-East Asia. In addition to suggestive symptoms, serologic testing has high diagnostic reliability and biopsy is a confirmatory procedure. Patients with CD have extra-intestinal autoimmune comorbid conditions more frequently than expected. A third entity is nonceliac gluten sensitivity, which has been created because of the increasing number of subjects who claim a better quality of life or improvement of their variety of symptoms on switching to a GFD. The phenomenon is being fueled by the media and exploited by the industry. The lack of a specific objective test has been raising substantial controversy about this entity. Allergists and gastroenterologists need to pay attention to the multitudes of individuals who elect to follow a GFD. Many such subjects might have WA, CD, or another illness. Providing them with appropriate evaluation and specific management would be of great advantages, medically and economically.

The Global Phenomenon of Self-Reported Wheat Sensitivity

Celiac disease affects about 1% of the population and is treated with a gluten-free diet. However, the last decade has seen a huge rise in individuals self-reporting wheat sensitivity, and consuming a gluten-free diet, despite not having a doctor-diagnosis of celiac disease. A recent flurry of observational studies from across the globe suggests that approximately 10% of the population is self-reporting wheat sensitivity. They describe a constellation of intestinal and extra-intestinal symptoms attributed to ingestion of gluten-based products. This phenomenon poses a significant challenge to clinicians with regards to adequately excluding celiac disease, identifying the culprit agent, understanding the pathophysiology, and providing safe aftercare.

Prevalence of Self-Reported Gluten-Related Disorders and Adherence to a Gluten-Free Diet in Salvadoran Adult Population

Gluten-related disorders are not considered of relevance at public health level in Central America. The prevalence of gluten-related disorders, and adherence to a gluten-free diet, remain unknown in the Central American region. We conducted a cross-sectional survey of the Central American population from San Salvador, El Salvador, to estimate the prevalence rates of self-reported gluten-related disorders and adherence to a gluten-free diet. 1326 individuals were surveyed. Self-reported prevalence rates were (95% Confidence Interval): gluten sensitivity 3.1% (2.3–4.2); physician-diagnosed celiac disease 0.15% (0.04–0.5); wheat allergy 0.75% (0.4–1.3); non-celiac gluten sensitivity 0.98% (0.5–1.6). The prevalence rate of adherence to a gluten-free diet was 7.0% (5.7–8.5). Seven self-reported physician diagnosed gluten-sensitive cases informed the co-existence of non-celiac gluten sensitivity with celiac disease and/or wheat allergy. Among the non-self-reported gluten sensitivity individuals following a gluten-free diet, 50% reported that they were seeing a health professional for gluten-free dietary advice. Gluten sensitivity is commonly reported in Salvadoran population, but some health professionals acknowledge the coexistence of wheat allergy, celiac disease, and non-celiac gluten sensitivity. Among studies at population level, the prevalence of adherence to a gluten-free diet in Salvadoran population is the highest reported until now. However, just a few of the gluten-free diet followers were doing it for health-related benefits; the others reported weight control and the perception that the diet is healthier as the main motivation for adopting such a diet.

Effect of the gluten-free diet on cardiovascular risk factors in patients with coeliac disease: A systematic review

BACKGROUND AND AIMS

A gluten-free diet (GFD), the mainstay of treatment for celiac disease, is being increasingly adopted by people without this condition. The long-term health effects of this diet, apart from its beneficial effect on enteropathy in celiac disease, are unclear. Concerns exist that the GFD may result in micronutrient deficiencies, increased exposure to toxins such as arsenic, and an increased cardiovascular risk. This systematic review addresses the effect of the GFD on several modifiable cardiovascular risk factors.

METHODS

A systematic search of the literature addressing the GFD and blood pressure, glycaemia, body mass index, waist circumference, and serum lipids in patients before and after adoption of a GFD was conducted using the MEDLINE, EMBASE, PSYCInfo, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases. Two authors performed abstract and full text screening, and quality assessment.

RESULTS

A total of 5372 articles were identified, from which 27 were included. Lack of control groups in all but one study prevented meta-analysis of results. Overall study quality was low and restricted to patients with celiac disease. Consistent findings across studies included an increase in total cholesterol, high density lipoprotein, fasting glycaemia, and body mass index (while remaining within the healthy weight range). Significant changes in low density lipoprotein, triglycerides, and blood pressure were not consistently reported.

CONCLUSIONS

A GFD alters certain cardiovascular risk factors in patients with celiac disease, but the overall effect on cardiovascular risk is unclear. Further studies are warranted.

The effect of a controlled gluten challenge in a group of patients with suspected non-coeliac gluten sensitivity: A randomized, double-blind placebo-controlled challenge

BACKGROUND

Non-coeliac gluten-sensitivity (NCGS) has been proposed as a new entity with unknown prevalence and mechanisms, and there is a need for a standardized procedure to confirm the diagnosis. The objective of this study was to characterize the response to an oral gluten-challenge in patients with a symptom-relief when following a gluten free-diet (GFD).

METHODS

Twenty patients (14F/6M, age range: 21-62 years) with suspected NCGS, without coeliac disease and wheat-allergy, were included while on a gluten-free diet. All patients went through four periods of double-blinded provocation, two with gluten and two with placebo in randomized order. They consumed two muffins a day (11/0 g gluten) for 4 days, followed by a 3-day wash-out. Gastrointestinal symptoms were recorded with questionnaires at baseline and after each provocation. We also investigated whether patients were able to correctly identify periods with gluten-exposure.

KEY RESULTS

Collectively the whole group reported the most severe symptoms after placebo (P = .012). Four out of twenty patients correctly identified the two periods when they received gluten, hence were diagnosed with NCGS. The diagnosed-group tended to show higher symptom scores than the not-diagnosed group both at baseline, after gluten exposure and after placebo, but no clear difference was seen between provocation with gluten and placebo. The not-diagnosed group showed more severe symptoms with placebo than with gluten (P = .029).

CONCLUSIONS AND INFERENCES

The present study showed that the majority of patients with suspected NCGS are not able to identify when challenged with gluten in a double-blind placebo-controlled food challenge, indicating that gluten is not the cause of their symptoms.

Non-coeliac gluten or wheat sensitivity: emerging disease or misdiagnosis?

Non-coeliac gluten or wheat sensitivity (NCG/WS) is a condition characterised by adverse gastrointestinal and/or extra-intestinal symptoms associated with the ingestion of gluten- or wheat-containing foods, in the absence of coeliac disease or wheat allergy. Up to one in 100 people in Australia may have coeliac disease but many more report adverse gastrointestinal and/or extra-intestinal symptoms after eating wheat products. In the absence of validated biomarkers, a diagnosis of NCG/WS can only be made by a double-blind, placebo-controlled, dietary crossover challenge with gluten, which is difficult to apply in clinical practice. Of people self-reporting gluten or wheat sensitivity, only a small proportion (16%) will have reproducible symptoms after a blinded gluten challenge of gluten versus placebo in a crossover dietary trial and fulfil the current consensus criteria for a diagnosis of NCG/WS. A wide range of symptoms are associated with NCG/WS, including gastrointestinal, neurological, psychiatric, rheumatological and dermatological complaints. The pathogenesis of NCG/WS is not well understood, but the innate immune system has been implicated, and there is overlap with coeliac disease and the functional gastrointestinal disorders (irritable bowel syndrome and functional dyspepsia). Identification of NCG/WS is important as gluten-free diets carry risks, are socially restricting and are costlier than regular diets.