Recent advances in understanding non-celiac gluten sensitivity

Food Intolerances, Food Allergies and IBS: Lights and Shadows

This narrative review delves into the intricate relationship between irritable bowel syndrome (IBS) and food intolerances. IBS, a chronic functional gastrointestinal disorder, is characterized by symptoms like abdominal pain and altered bowel habits. The prevalence of IBS has increased globally, especially among young adults. Food and dietary habits play a crucial role in IBS management. About 85-90% of IBS patients report symptom exacerbation linked to specific food consumption, highlighting the strong connection between food intolerances and IBS. Food intolerances often exhibit a dose-dependent pattern, posing a challenge in identifying trigger foods. This issue is further complicated by the complex nature of gastrointestinal physiology and varying food compositions. This review discusses various dietary patterns and their impact on IBS, including the low-FODMAP diet, gluten-free diet, and Mediterranean diet. It highlights the importance of a personalized approach in dietary management, considering individual symptom variability and dietary history. In conclusion, this review emphasizes the need for accurate diagnosis and holistic management of IBS, considering the complex interplay between dietary factors and gastrointestinal pathophysiology. It underlines the importance of patient education and adherence to treatment plans, acknowledging the challenges posed by the variability in dietary triggers and the psychological impact of dietary restrictions.

Gluten Sensitivity Underlying Resistant "Laryngopharyngeal Reflux" Symptoms and Signs

INTRODUCTION

Laryngopharyngeal reflux (LPR) is one of the most common conditions encountered in otolaryngology. Gluten sensitivity may mimic the signs and symptoms of LPR or act as an aggravating cofactor with LPR. Gluten sensitivity and food intolerance also have been implicated as conditions that may be associated specifically with LPR symptoms and signs resistant to traditional medical treatment. Medical management of LPR may be insufficient to control symptoms and laryngeal signs of reflux, constituting resistant LPR. Eliminating gluten from the diet could provide symptomatic relief to patients with gluten sensitivity and LPR that is not controlled adequately by current regimens. The purpose of our study was to investigate the relationship between gluten sensitivity and LPR. We aimed to evaluate reflux finding score (RFS) improvement following elimination of gluten from the diet in patients with resistant LPR who had positive blood tests associated with gluten sensitivity. Symptom improvement was also assessed following dietary gluten elimination. Lastly, we aimed to identify predictors for a positive response to a gluten-free diet.

METHODS

Adult patients who underwent gluten sensitivity testing for treatment-resistant LPR symptoms and/or signs were included. Patients with ≥1 positive test were advised to begin a therapeutic trial of a gluten-free diet. Subjects who chose not to trial a gluten-free diet or tested negative for gluten sensitivity markers served as controls. RFS was the primary outcome measure.

RESULTS

One hundred ninety-seven patients were included; 81 trialed a gluten-free diet. Subjects who trialed the gluten-free diet were significantly more likely to demonstrate objective improvement in RFS (77.14% vs 43.88%), and report subjective improvement (55.41% vs 25.77%) than those who did not. RFS had decreased significantly from baseline at 1-3, 3-6, 6-12, and >12-month interval follow-up examinations in subjects who trialed a gluten-free diet. Comparison between subjects who trialed the gluten-free diet, tested positive for a gluten sensitivity marker but did not trial the gluten-free diet, and subjects who were negative for all gluten sensitivity markers revealed that a gluten-free diet was associated with a significantly greater percent improvement in RFS compared to controls at 1-3, 6-12, and >12-months.

CONCLUSION

Gluten sensitivity can mimic or aggravate LPR. A gluten-free diet should be considered for patients with resistant LPR, especially if blood test abnormalities that suggest gluten sensitivity are identified. The diet should be maintained for a minimum of three months to demonstrate objective improvement using RFS.

Fighting Celiac Disease: Improvement of pH Stability of Cathepsin L In Vitro by Computational Design

Roughly 1% of the global population is susceptible to celiac disease (CD)-inheritable autoimmune inflammation of the small intestine caused by intolerance to gliadin proteins present in wheat, rye, and barley grains, and called gluten in wheat. Classical treatment is a life-long gluten-free diet, which is constraining and costly. An alternative approach is based upon the development and oral reception of effective peptidases that degrade in the stomach immunogenic proline- and glutamine-rich gliadin peptides, which are the cause of the severe reaction in the intestine. In previous research, we have established that the major digestive peptidase of an insect Tribolium castaneum-cathepsin L-hydrolyzes immunogenic prolamins after Gln residues but is unstable in the extremely acidic environment (pH 2-4) of the human stomach and cannot be used as a digestive aid. In this work, using molecular dynamics simulations, we discover the probable cause of the pH instability of cathepsin L-loss of the catalytically competent rotameric state of one of the active site residues, His 275. To "fix" the correct orientation of this residue, we designed a V277A mutant variant, which extends the range of stability of the peptidase in the acidic environment while retaining most of its activity. We suggest this protein as a lead glutenase for the development of oral medical preparation that fights CD and gluten intolerance in susceptible people.

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.

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

BACKGROUND AND AIMS

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic Dilemma, Possible Non-celiac Gluten Sensitivity: Consideration in Approach and Management

Non-celiac gluten sensitivity (NCGS) is clinically identified as a condition where a percentage of the population reports intestinal and/or extraintestinal symptoms caused by gluten and/or wheat ingestion, and they are tested negative for celiac disease (CD) on the basis of specific serology and histopathology. NCGS should be labelled after the exclusion of CD and wheat allergy. This population reports improved symptoms on a gluten-free diet. Despite great interest and work on NCGS, much remains unknown about its pathogenesis. A positive and improved response to a gluten-free diet for a limited period of time (e.g., six to eight weeks), followed by retrieval of symptoms in case of gluten intake, is presently considered to be the best strategy for confirmation of diagnosis.

A middle-aged lady came for medical attention with concerns of weight loss, lethargy and abdominal discomfort. On investigations, her serum transglutaminase IgA was found to be largely raised. The patient was switched to a gluten-free diet with suspicion of CD. Upper GI endoscopy was done one week after being on a gluten-free diet. Both endoscopy with histopathology was negative for villous atrophy and increased intraepithelial lymphocytes. Later human leukocyte antigen (HLA) testing was found to be negative for CD, leading to a diagnostic conundrum. On the basis of remarkable symptom improvement on a gluten-free diet, drop in transglutaminase levels, negative biopsy and HLA testing, the diagnosis was made as possible NCGS. Considering gluten-related disorders are rising and not much is known about NCGS, we aimed to present this case to create awareness and raise questions regarding diagnosis, need for specific monitoring and implications on the management.

Plasma IL-2 and Symptoms Response after Acute Gluten Exposure in Subjects With Celiac Disease or Nonceliac Gluten Sensitivity

INTRODUCTION

Treated patients with celiac disease (CeD) and nonceliac gluten sensitivity (NCGS) report acute, transient, incompletely understood symptoms after suspected gluten exposure. To determine whether (i) blinded gluten exposure induces symptoms, (ii) subjects accurately identify gluten exposure, and (iii) serum interleukin-2 (IL-2) levels distinguish CeD from NCGS subjects after gluten exposure.

METHODS

Sixty subjects (n = 20 treated, healed CeD; n = 20 treated NCGS; n = 20 controls) were block randomized to a single, double-blind sham (rice flour) or 3-g gluten challenge with 72-hours follow-up. Twelve serial questionnaires (100 mm visual analog scale; pain, bloating, nausea, and fatigue) and 10 serial plasma samples were collected. Mucosal permeability was assessed using both urinary lactulose-13C mannitol ratios and endoscopic mucosal impedance.

RESULTS

Thirty-five of 40 (83%) subjects with CeD and NCGS reported symptoms with gluten (8 CeD, 9 NCGS) and sham (9 CeD, 9 NCGS) compared with 9 of 20 (45%) controls after gluten (n = 6) and sham (n = 3). There was no significant difference in symptoms among groups. Only 2 of 10 subjects with CeD and 4 of 10 NCGS identified gluten, whereas 8 of 10 subjects with CeD and 5 of 10 NCGS identified sham. A significant plasma IL-2 increase occurred only in subjects with CeD after gluten, peaking at 3 hours and normalizing within 24 hours postchallenge despite no significant intestinal permeability change from baseline.

DISCUSSION

Symptoms do not reliably indicate gluten exposure in either subjects with CeD or NCGS. IL-2 production indicates a rapid-onset gluten-induced T-cell activation in CeD despite long-standing treatment. The effector site is unknown, given no increased intestinal permeability after gluten.

Nutrition in Patients with Lactose Malabsorption, Celiac Disease, and Related Disorders

Lactose malabsorption (LM), celiac disease (CD), non-celiac gluten sensitivity (NCGS), and irritable bowel syndrome (IBS) are conditions associated with food triggers, improvement after withdrawal, treatment with dietary restriction, and subsequent nutritional detriments. LM occurs when there is incomplete hydrolysis of lactose due to lactase deficiency and frequently produces abdominal symptoms; therefore, it can cause lactose intolerance (LI). A lactose-restricted diet is frequently recommended, although it can potentially lead to nutrient deficiencies. Furthermore, lactose is an essential component of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) and is subsequently associated with intolerance to these compounds, especially in IBS. LM commonly presents in CD. Nutritional deficits are common in CD and can continue even on a gluten-free diet (GFD). Conditions triggered by gluten are known as gluten-related disorders (GRDs), including CD, wheat allergy, and NCGS. IBS can also be associated with a gluten sensitivity. A GFD is the treatment for CD, GRDs, and gluten sensitive IBS, although compliance with this restricted diet can be difficult. Strict dietary therapies can have a negative effect on quality of life. This review aims to provide an overview of the difficult nutritional elements of these disorders, which are critical for medical providers to recognize when managing these patients.

Study on the Introduction of Solid Fat with a High Content of Unsaturated Fatty Acids to Gluten-Free Muffins as a Basis for Designing Food with Higher Health Value

BACKGROUND

Shortenings are high in undesirable nutritionally saturated fatty acids. The aim of the study was to produce gluten-free muffins (GFM) of increased health quality and available to people intolerant to gluten, in which the shortenings were replaced with solid oleogels, consisting of 95% rapeseed oil.

METHODS

The dough and baked products were subjected to physical, textural, and structural analyses. Moreover, the fatty acids composition, chemical quality of fats extracted from muffins, and color of the products were determined. The dough was also observed at 600× magnification in bright field and polarized light microscopy, and microtomographic analysis of the structure of GTM was performed.

RESULTS

There was no effect of the type of lipids on physical properties, including water content in gluten-free muffins. However, the baked products differed in total porosity and brightness, as well as intensity of red and yellow colors. The use of rapeseed oil oleogels, instead of shortening in the muffin recipe, resulted in a decrease in the dietary undesirable SFA in lipid fractions (by approximately 40%), an increase in the content of MUFA (by approximately 30%), and an increase in the content of PUFA (by approximately 15%), with acceptable chemical quality.

CONCLUSIONS

Research confirms the possibility of obtaining products with increased nutritional value available to consumers on a gluten-free diet.

High Protein Substitutes for Gluten in Gluten-Free Bread

Gluten-free products have come into the market in order to alleviate health problems such as celiac disease. In this review, recent advances in gluten-free bread are described along with plant-based gluten-free proteins. A comparison with animal-based gluten-free proteins is made reporting on different high protein sources of animal origin. Sea microorganisms- and insect-based proteins are also mentioned, and the optimization of the structure of gluten-free bread with added high protein sources is highlighted along with protein digestibility issues. The latter is an issue for consideration that can be manipulated by a careful design of the mixture in terms of phenolic compounds, soluble carbohydrates and fibres, but also the baking process itself. Additionally, the presence of enzymes and different hydrocolloids are key factors controlling quality features of the final product.

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.

Measures of gluten-related reactivity in children with autism spectrum disorders in the absence of overt gastrointestinal symptoms: a pilot study from the United Arab Emirates

Objectives

The aetiology of autism spectrum disorder (ASD) is multifactorial, sometimes genetic, and may be associated with abnormal immunological responses to peptides from proteins such as gluten. These peptides may cross the blood-brain barrier and affect neurotransmission, resulting in behavioural symptoms consistent with ASD. The aim of this study was to screen for markers of gluten-related immune reactivity in the absence of overt gastrointestinal symptoms in patients with ASD in the United Arab Emirates, a country associated with a high prevalence of ASD but lacking this type of research.

Methods

Patients diagnosed with ASD (using Diagnostic and Statistical Manual of Mental Disorders-IV-based criteria and Autism Diagnostic Observational Schedules) were compared with controls, regarding anti-tissue transglutaminase (tTG) immunoglobulin (Ig) A and anti-deamidated gliadin peptide (DGP) IgA levels.

Results

Sixty-six patients with ASD and 101 controls were included. Patients with ASD showed statistically significant lower anti-DGP IgA levels, but no significant difference in anti-tTG IgA levels, versus healthy controls. Correlations between immunological data and clinical symptoms were synergistic, but not statistically significant.

Conclusion

ASD may be associated with reduced levels of anti-DGP IgA.

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.

The Gluten Gene: Unlocking the Understanding of Gluten Sensitivity and Intolerance

Wheat flour is one of the most important food ingredients containing several essential nutrients including proteins. Gluten is one of the major protein components of wheat consisted of glutenin (encoded on chromosome 1) and gliadin (encoded on chromosome 1 and 6) and there are around hundred genes encoding it in wheat. Gluten proteins have the ability of eliciting the pathogenic immune responses and hypersensitivity reactions in susceptible individuals called “gluten-related disorders (GRDs)”, which include celiac disease (CD), wheat allergy (WA), and non-celiac gluten sensitivity (NCGS). Currently removing gluten from the diet is the only effective treatment for mentioned GRDs and studies for the appropriate and alternative therapeutic approaches are ongoing. Accordingly, several genetic studies have focused on breeding wheat with low immunological properties through gene editing methods. The present review considers genetic characteristics of gluten protein components, focusing on their role in the incidence of gluten-related diseases, and genetic modifications conducted to produce wheat with less immunological properties.

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.

Insights into the Potential of Sourdough-Related Lactic Acid Bacteria to Degrade Proteins in Wheat

Sourdough processing contributes to better digestible wheat-based bakery products, especially due to the proteolytic activity of lactic acid bacteria (LAB). Therefore, sourdough-related LAB were screened for their capacity to degrade immunogenic proteins like gluten and alpha-amylase-trypsin inhibitors (ATIs). Firstly, the growth of 87 isolates was evaluated on a gluten-based medium. Further, the breakdown capacity of selected isolates was determined for gluten with a focus on gliadins by measuring acidification parameters and MALDI-TOF MS protein profiles. ATI degradation after 72 h of incubation within an ATI-based medium was investigated by means of acidification, HPLC, and competitive ELISA. All isolates exhibited the potential to degrade ATIs to a high degree, whereas the gliadin degradation capacity varied more greatly among tested LAB, with Lacticaseibacillus paracasei Lpa4 exhibiting the strongest alterations of the gliadin pattern, followed by Lactiplantibacillus plantarum Lpl5. ATI degradation capacities ranged from 52.3% to 85.0% by HPLC and 22.2% to 70.2% by ELISA, with Lacticaseibacillus paracasei Lpa4 showing superior breakdown properties. Hence, a selection of specific starter cultures can be used in sourdough processing for wheat-based bakery products with reduced gluten and ATI content and, further, better tolerated products for patients suffering from non-celiac wheat sensitivity (NCWS).

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.

Mast cell-nerve interactions correlate with bloating and abdominal pain severity in patients with non-celiac gluten / wheat sensitivity

BACKGROUND

Gastrointestinal (GI) and extra-GI symptoms/manifestations represent key clinical features of patients with non-celiac gluten/wheat sensitivity (NCG/WS). This study aimed to investigate neuro-immune (focusing on mast cells, MCs) interactions in the duodenal submucosa of patients with NCG/WS.

METHODS

Submucosal whole mounts from duodenal biopsies of 34 patients with self-reported NCG/WS, 28 with celiac disease (CD), 13 with functional dyspepsia (FD), and 24 healthy controls (HC) were analyzed by immunohistochemistry. Quantitative data on neuronal and MCs density and the percentage of MCs in close vicinity to nerves were obtained, and correlations among neurons, MC density and MC-nerve distance (D), and symptoms were assessed in the three groups.

KEY RESULTS

The number of submucosal neurons was not different among groups. In NCG/WS, MC density was not different from HC, while it was slightly increased vs. CD (P = .07) and significantly decreased vs. FD (P < .05). The percentage of MCs close to nerves (D < 15 µm) was similarly increased in all three pathological groups vs. HC (P < .001). In NCG/WS, MC infiltration correlated with bloating (P = .001) and abdominal pain severity (P = .03) and the percentage of MCs in proximity to neurons correlated with the number of GI symptoms (D < 5 µm; P = .05), bloating and abdominal pain severity (D < 15um; P = .01).

CONCLUSIONS AND INFERENCES

Submucosal MC infiltration and the close (within 15 µm) MC-to-nerve proximity in the duodenum of NCG/WS patients are features providing a histopathological basis to better understand GI symptoms in this condition.

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.

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.

A Dietary Intervention with Reduction of Starch and Sucrose Leads to Reduced Gastrointestinal and Extra-Intestinal Symptoms in IBS Patients

Patients with irritable bowel syndrome (IBS) exhibit low-grade inflammation and increased gut permeability. Dietary sugar has been shown to contribute to low-grade inflammation and increased gut permeability, and to correlate with gastrointestinal (GI) symptoms. The aim of the present study was to examine the effect of a starch- and sucrose-reduced diet (SSRD) on gastrointestinal (GI) and extra-intestinal symptoms in IBS. One hundred and five IBS patients (82 women, 46.06 ± 13.11 years), with irritable bowel syndrome-symptom severity scale (IBS-SSS) > 175, were randomized to SSRD for 4 weeks or continued ordinary eating habits. The visual analog scale for irritable bowel syndrome (VAS-IBS), IBS-SSS, and 4-day food diaries were collected at baseline and after 2 and 4 weeks. After the intervention, one-third of the patients did not fulfill the criteria for IBS/functional gastrointestinal disorder. Half of the participants changed from moderate/severe disease to no/mild disease according to IBS-SSS. Comparisons between the groups showed decreased weight and sweet cravings, and parallel decreases in total IBS-SSS and extra-intestinal IBS-SSS scores, in the intervention group compared to controls (p < 0.001 for all). When calculating separate extra-intestinal symptoms, belching (p = 0.001), muscle/joint pain (p = 0.029), urinary urgency (p = 0.017), and tiredness (p = 0.011) were decreased after introduction of SSRD compared to controls. In conclusion, SSRD improves both GI and extra-intestinal symptoms in IBS.

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.

Recent practical researches in the development of gluten-free breads

Wheat bread is consumed globally and has played a critical role in the story of civilization since the development of agriculture. While the aroma and flavor of this staple food continue to delight and satisfy most people, some individuals have a specific allergy to wheat or a genetic disposition to celiac disease. To improve the quality of life of these patients from a dietary standpoint, food-processing researchers have been seeking to develop high-quality gluten-free bread. As the quality of wheat breads depends largely on the viscoelastic properties of gluten, various ingredients have been employed to simulate its effects, such as hydrocolloids, transglutaminase, and proteases. Recent attempts have included the use of redox regulation as well as particle-stabilized foam. In this short review, we introduce the ongoing advancements in the development of gluten-free bread, by our laboratory as well as others, focusing mainly on rice-based breads. The social and scientific contexts of these efforts are also mentioned.