Inequality leads to the evolution of intolerance in reputation-based populations.

This work studies the impact of economic inequality on the evolution of intolerance through a reputation-based model of indirect reciprocity. Results show that economic inequality is a powerful enhancer of intolerance, inducing the escalation of out-group discrimination even without the presence of new intolerant mutants. It also generates behavior modifications within tolerant disfavored minorities: their members either relax punishments against the uncooperative or prioritize helping the wealthy, even suffering discrimination in return. On the other hand, the redistribution of wealth is proven as a viable solution to avoid the spread of intolerance as long as it increases equality and is implemented before intolerance permeates part of the population.

Tritordeum breads are well tolerated with preference over gluten-free breads in non-celiac wheat-sensitive patients and its consumption induce changes in gut bacteria.

BACKGROUND: The ingestion of wheat and other cereals are related to several gut disorders. The specific components responsible for non-celiac wheat-sensitivity (NCWS) may include gluten and other compounds. Tritordeum is a new cereal derived from crossing durum wheat with a wild barley species, which differs from bread wheat in its gluten composition. In the present work, we examined the response of NCWS patients to tritordeum bread Gastrointestinal symptoms as well as tritordeum acceptability, gluten immunogenic peptides excretion, and the composition and structure of the intestinal microbiota were evaluated. RESULTS: Gastrointestinal symptoms of the subjects showed no significant change between the gluten-free bread and the tritordeum bread. Participating subjects rated tritordeum bread higher than the gluten-free bread. Analysis of the bacterial gut microbiota indicated that tritordeum consumption does not alter the global structure and composition of the intestinal microbiota, and only a few changes in some butyrate-producing bacteria were observed. CONCLUSIONS: All the results derived from acceptability, biochemical and microbiological tests suggest that tritordeum may be tolerated by a sub-set of NCWS sufferers who do not require strict exclusion of gluten from their diet. © 2020 Society of Chemical Industry.

Memory-n strategies of direct reciprocity.

Humans routinely use conditionally cooperative strategies when interacting in repeated social dilemmas. They are more likely to cooperate if others cooperated before, and are ready to retaliate if others defected. To capture the emergence of reciprocity, most previous models consider subjects who can only choose from a restricted set of representative strategies, or who react to the outcome of the very last round only. As players memorize more rounds, the dimension of the strategy space increases exponentially. This increasing computational complexity renders simulations for individuals with higher cognitive abilities infeasible, especially if multiplayer interactions are taken into account. Here, we take an axiomatic approach instead. We propose several properties that a robust cooperative strategy for a repeated multiplayer dilemma should have. These properties naturally lead to a unique class of cooperative strategies, which contains the classical Win-Stay Lose-Shift rule as a special case. A comprehensive numerical analysis for the prisoner's dilemma and for the public goods game suggests that strategies of this class readily evolve across various memory-n spaces. Our results reveal that successful strategies depend not only on how cooperative others were in the past but also on the respective context of cooperation.

The Human Digestive Tract Is Capable of Degrading Gluten from Birth.

The human gastrointestinal system has the capacity to metabolize dietary gluten. The capacity to degrade gliadin-derived peptide is present in humans from birth and increases during the first stages of life (up to 6-12 months of age). Fecal samples from 151 new-born and adult non-celiac disease (NCD) volunteers were collected, and glutenase and glianidase activities were evaluated. The capacity of total fecal proteins to metabolize 33-mer, 19-mer, and 13-mer gliadin peptides was also evaluated by high-performance liquid chromatography (HPLC). Feces from new-borns (meconium) showed glutenase and gliadinase activities, and peptidase activity against all three gliadin peptides. Maximal gluten degradative activity was observed in fecal samples from the youngest volunteers (0-12 months old). After the age of nine months, the gluten digestive capacity of gastrointestinal tract decreases and, from ±8 years old, individuals lose the ability to completely degrade toxic peptides. The gastrointestinal proteases involved in gluten digestion: elastase 2A, elastase 3B, and carboxipeptidase A1 are present from earlier stages of life. The human digestive tract contains the proteins capable of metabolizing gluten from birth, even before starting gluten intake. Humans are born with the ability to digest gluten and to completely degrade the potentially toxic gliadin-derived peptides (33-, 19-, and 13-mer).

New celiac disease biomarkers.

Advances in the knowledge regarding celiac disease have enabled the development of diagnostic markers, such as anti-tissue transglutaminase and anti-deaminated gliadin antibodies. The wide availability of these antibodies, genetic studies of HLA-DQ and duodenal biopsies constitute the pillars necessary for a definitive diagnosis. However, difficulties sometimes arise in both the diagnosis and follow-up of celiac patients, which cannot be resolved using these tools. This article reviews the scientific evidence and possible clinical utility of different biomarkers. This review is structured according to biomarkers that have been evaluated pathophysiologically in relation to intestinal damage or immune response and their potential clinical utility in the diagnosis and follow-up of celiac disease patients.

Tritordeum: a novel cereal for food processing with good acceptability and significant reduction in gluten immunogenic peptides in comparison with wheat.

BACKGROUND: Tritordeum is a novel cereal obtained from the hybridization between durum wheat and a wild barley. This study evaluates acceptance, digestibility and immunotoxic properties of tritordeum, a novel cereal for food processing. Nineteen healthy volunteers participated in a study with different diets to compare tritordeum bread with wheat and gluten-free breads. RESULTS: Tritordeum breads had a similar acceptance to the wheat bread usually consumed, and the acceptance was significantly higher than the gluten-free bread and standardized wheat bread supplied in the study. There was no evidence for gastrointestinal symptoms among volunteers during the study. The reductions in the numbers of immunogenic epitopes in tritordeum in comparison with wheat were 78% for α-gliadins, 57% for γ-gliadins and 93% for ω-gliadins. The analysis of gluten immunogenic peptides (GIP) in stool samples showed a significantly lower excretion in the tritordeum ingestion phase than in the wheat ingestion phase. CONCLUSIONS: These results suggest that tritordeum may be an option of interest for general food processing, and especially for those who want to reduce their intake of gluten. However, it is not suitable for celiac disease sufferers as it contains gluten. © 2017 Society of Chemical Industry.

New coeliac disease treatments and their complications. / Nuevas terapias en la enfermedad celiaca y sus complicaciones.

The only accepted treatment for coeliac disease is strict adherence to a gluten-free diet. This type of diet may give rise to reduced patient quality of life with economic and social repercussions. For this reason, dietary transgressions are common and may elicit intestinal damage. Several treatments aimed at different pathogenic targets of coeliac disease have been developed in recent years: modification of gluten to produce non-immunogenic gluten, endoluminal therapies to degrade gluten in the intestinal lumen, increased gluten tolerance, modulation of intestinal permeability and regulation of the adaptive immune response. This review evaluates these coeliac disease treatment lines that are being researched and the treatments that aim to control disease complications like refractory coeliac disease.

Corrigendum: Fecal Gluten Peptides Reveal Limitations of Serological Tests and Food Questionnaires for Monitoring Gluten-Free Diet in Celiac Disease Patients.

This corrects the article DOI: 10.1038/ajg.2016.439.

Coeliac disease and gastrointestinal symptom screening in adult first-degree relatives.

BACKGROUND AND AIM: The first-degree relatives (FDRs) of patients with coeliac disease are the main risk group for disease development. The study aims to evaluate the screening strategy in FDRs with negative coeliac serology based on human leukocyte antigen (HLA) genotyping, followed by duodenal biopsy, and to analyze the prevalence of gastrointestinal symptoms and the influence of gluten intake. METHODS: Adult FDRs with negative coeliac serology were invited to participate (n = 205), and a total of 139 completed the study protocol. HLA genotyping, transglutaminase antibody assessment, and duodenal biopsy were performed. Symptomatology was assessed using questionnaires during the various phases of dietary modification (baseline diet, gluten-free diet, and gluten overload). RESULTS: The study included 139 participants (mean age, 42 years; 53.2% women). HLA-DQ2/8 was positive in 78.4% of the participants (homozygous, 15.1%; heterozygous, 63.3%). Histopathological alterations were noted in 37.1% of participants who underwent duodenal biopsy (Marsh I, 32.7%; Marsh IIIa, 4.4%). At baseline, symptoms were observed in 45.7% of the participants, and the proportion decreased to 24.5% after the gluten-free diet (P < 0.001). Symptoms were not associated with the presence of histological alterations or genetic risk. However, younger age (odds ratio [OR] = 0.91), female sex (OR = 2.9), and the presence of autoimmune disorders (OR = 2.8) were independently associated with a significant symptom response to the gluten-free diet. CONCLUSIONS: Duodenal lymphocytosis and atrophy are frequently noted in FDRs, despite negative serological markers. In addition, gastrointestinal symptoms are commonly present and associated with gluten intake regardless of the histological pathology.

Fecal Gluten Peptides Reveal Limitations of Serological Tests and Food Questionnaires for Monitoring Gluten-Free Diet in Celiac Disease Patients.

OBJECTIVES: Treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). Patients should be followed-up with dietary interviews and serology as CD markers to ensure adherence to the diet. However, none of these methods offer an accurate measure of dietary compliance. Our aim was to evaluate the measurement of gluten immunogenic peptides (GIP) in stools as a marker of GFD adherence in CD patients and compare it with traditional methods of GFD monitoring. METHODS: We performed a prospective, nonrandomized, multicenter study including 188 CD patients on GFD and 84 healthy controls. Subjects were given a dietary questionnaire and fecal GIP quantified by enzyme-linked immunosorbent assay (ELISA). Serological anti-tissue transglutaminase (anti-tTG) IgA and anti-deamidated gliadin peptide (anti-DGP) IgA antibodies were measured simultaneously. RESULTS: Of the 188 celiac patients, 56 (29.8%) had detectable GIP levels in stools. There was significant association between age and GIP in stools that revealed increasing dietary transgressions with advancing age (39.2% in subjects ≥13 years old) and with gender in certain age groups (60% in men ≥13 years old). No association was found between fecal GIP and dietary questionnaire or anti-tTG antibodies. However, association was detected between GIP and anti-DGP antibodies, although 46 of the 53 GIP stool-positive patients were negative for anti-DGP. CONCLUSIONS: Detection of gluten peptides in stools reveals limitations of traditional methods for monitoring GFD in celiac patients. The GIP ELISA enables direct and quantitative assessment of gluten exposure early after ingestion and could aid in the diagnosis and clinical management of nonresponsive CD and refractory CD. Trial registration number NCT02711397.

GRAvity- versus Wall suction-drIven large volume Thoracentesis: a rAndomized controlled Study (GRAWITAS study).

BACKGROUND: Prior studies found no differences in procedural chest discomfort for patients undergoing manual syringe aspiration or drainage with gravity after thoracentesis. However, whether gravity drainage could protect against chest pain due to the larger negative pressure gradient generated by wall suction has not been investigated. RESEARCH QUESTION: Does wall suction drainage result in more chest discomfort compared to gravity drainage in patients undergoing large volume thoracentesis? STUDY DESIGN AND METHODS: In this multicenter, single-blinded, randomized controlled trial, patients with large free-flowing effusions of ≥500 mL were assigned to wall suction or gravity drainage in a 1:1 ratio. Wall suction was performed with suction system attached to the suction tubing and with vacuum pressure adjusted to full vacuum. Gravity drainage was performed with a drainage bag placed 100 cm below the catheter insertion site and connected via straight tubing. Patients rated chest discomfort on a 100-mm visual analog scale before, during, and after drainage. The primary outcome was postprocedural chest discomfort at 5 minutes. Secondary outcomes included measures of post procedure chest discomfort, breathlessness, procedure time, volume of fluid drained and complication rates. RESULTS: Of the 228 patients initially randomized, 221 were included in the final analysis. The primary outcome of procedural chest discomfort did not differ significantly between the groups (p = 0.08), nor did the secondary outcomes of postprocedural discomfort and dyspnea. Similar volumes were drained in both groups, but the procedure duration was longer in the gravity arm by approximately 3 minutes. No differences in rate of pneumothorax or re-expansion pulmonary edema were noted between the two groups. INTERPRETATION: Thoracentesis via wall suction and gravity drainage results in similar levels of procedural discomfort and dyspnea improvement.

[Enteropathy-associated intestinal t-cell lymphoma without celiac disease]. / Linfoma intestinal de células T asociado a enteropatía y sin relación con enfermedad celíaca.

Type II enteropathy-associated T-cell lymphoma (EATL) is an uncommon intestinal lymphoma. We report the case of a 73-year-old man with diarrhea and weight loss. Duodenal biopsy showed atrophy and infiltration of irregular lymphocytes. Immunohistochemistry was positive for CD3, CD8, and CD56 with monoclonal TCR rearrangement. The HLA-DQ genotype was DQ5/DQ9. The Epstein-Barr virus RNA test was negative. Before specific chemotherapy could be administered, the patient was admitted to hospital for a respiratory infection and died from a cause unrelated to his lymphoma. The differential diagnosis of CD56-positive lymphoproliferative processes include type II EATL, primary T-cell/natural killer-cell intestinal lymphoma and hepatosplenic T-cell lymphoma. The patient had CD8 y CD56+ markers that allowed type I EATL to be excluded. The HLA-DQ genotype did not correspond to celiac disease and the biopsy showed proliferation of lymphocytes with atypia. The primary intestinal T-cell/natural killer-cell lymphoma was characterized mainly by the absence of CD8 and monoclonal reassortment of the TCR present in this case.

Consumption of Tritordeum Bread Reduces Immunogenic Gluten Intake without Altering the Gut Microbiota.

Gluten proteins are responsible for the wheat breadmaking quality. However, gluten is also related to human pathologies for which the only treatment is a gluten-free diet (GFD). GFD has gained popularity among individuals who want to reduce their gluten intake. Tritordeum is a cereal species that originated after crossing durum wheat with wild barley and differs from bread wheat in its gluten composition. In this work, we have characterized the immunogenic epitopes of tritordeum bread and results from a four-phase study with healthy adults for preferences of bread and alterations in the gut microbiota after consuming wheat bread, gluten-free bread, and tritordeum bread are reported. Tritordeum presented fewer peptides related to gluten proteins, CD-epitopes, and IgE binding sites than bread wheat. Participants rated tritordeum bread higher than gluten-free bread. Gut microbiota analysis revealed that the adherence to a strict GFD involves some minor changes, especially altering the species producing short-chain fatty acids. However, the short-term consumption of tritordeum bread does not induce significant changes in the diversity or community composition of the intestinal microbiota in healthy individuals. Therefore, tritordeum bread could be an alternative for healthy individuals without wheat-related pathologies who want to reduce their gluten consumption without harming their gut health.

Oral Consumption of Bread from an RNAi Wheat Line with Strongly Silenced Gliadins Elicits No Immunogenic Response in a Pilot Study with Celiac Disease Patients.

Celiac disease (CD) is a genetically predisposed, T cell-mediated and autoimmune-like disorder caused by dietary exposure to the storage proteins of wheat and related cereals. A gluten-free diet (GFD) is the only treatment available for CD. The celiac immune response mediated by CD4+ T-cells can be assessed with a short-term oral gluten challenge. This study aimed to determine whether the consumption of bread made using flour from a low-gluten RNAi wheat line (named E82) can activate the immune response in DQ2.5-positive patients with CD after a blind crossover challenge. The experimental protocol included assessing IFN-γ production by peripheral blood mononuclear cells (PBMCs), evaluating gastrointestinal symptoms, and measuring gluten immunogenic peptides (GIP) in stool samples. The response of PBMCs was not significant to gliadin and the 33-mer peptide after E82 bread consumption. In contrast, PBMCs reacted significantly to Standard bread. This lack of immune response is correlated with the fact that, after E82 bread consumption, stool samples from patients with CD showed very low levels of GIP, and the symptoms were comparable to those of the GFD. This pilot study provides evidence that bread from RNAi E82 flour does not elicit an immune response after a short-term oral challenge and could help manage GFD in patients with CD.

[Gastrointestinal manifestations in patients with primary immunodeficiencies causing antibody deficiency]. / Manifestaciones gastrointestinales en pacientes con inmunodeficiencias primarias que cursan con déficit de anticuerpos.

INTRODUCTION: Primary immunodeficiencies can lead to gastrointestinal manifestations that are still not well defined. OBJECTIVE: To analyze gastrointestinal manifestations associated with primary immunodeficiencies. MATERIAL AND METHODS: We performed a retrospective study that included patients diagnosed with primary antibody deficiencies in a third-level hospital. The patients were divided into two groups: isolated IgA deficiency and common variable immunodeficiency syndrome (CVIS). The timing of presentation and type of gastrointestinal symptoms were analyzed. RESULTS: There were 57 patients: 20 with CVIS (35%) and 37 with isolated IgA deficiency (65%). Diagnosis was made in the pediatric age in 17 patients, of whom 13 had isolated IgA deficiency. In 84% of the patients, diagnosis of immunodeficiency was made before the development of gastrointestinal manifestations. Digestive symptoms were found in 74% of the patients, the most frequent being diarrhea. In 46% of the patients, digestive disease was confirmed, mainly through endoscopy. Celiac-like lesions, chronic atrophic gastritis, ulcerative colitis-like disease and Crohn's disease were more common in CVIS. In isolated IgA deficiency, Helicobacter pylori-positive chronic gastritis predominated. Mean age was significantly higher (36 vs. 24 years, p=0.02) and IgA titer significantly lower (17 vs. 34UI/ml; p=0.008) in patients with associated gastrointestinal disease. CONCLUSIONS: Gastrointestinal symptoms are frequent and lead to endoscopic diagnosis in half of patients with primary immunodeficiencies. Ulcerative colitis, and celiac- and Crohn's-like disease are atypical entities that occur in CVIS.

Signalling boosts the evolution of cooperation in repeated group interactions.

Many biological and social systems show significant levels of collective action. Several cooperation mechanisms have been proposed, yet they have been mostly studied independently. Among these, direct reciprocity supports cooperation on the basis of repeated interactions among individuals. Signals and quorum dynamics may also drive cooperation. Here, we resort to an evolutionary game-theoretical model to jointly analyse these two mechanisms and study the conditions in which evolution selects for direct reciprocity, signalling, or their combination. We show that signalling alone leads to higher levels of cooperation than when combined with reciprocity, while offering additional robustness against errors. Specifically, successful strategies in the realm of direct reciprocity are often not selected in the presence of signalling, and memory of past interactions is only exploited opportunistically in the case of earlier coordination failure. Differently, signalling always evolves, even when costly. In the light of these results, it may be easier to understand why direct reciprocity has been observed only in a limited number of cases among non-humans, whereas signalling is widespread at all levels of complexity.

Challenges to drug discovery for celiac disease and approaches to overcome them.

Introduction: The only available effective treatment for celiac disease (CD) is strict and long-term compliance with a gluten-free diet. Dietary gluten restriction must be strict and long term, but is difficult to achieve in many cases and alternative dietary strategies have been investigated in the past few years. Areas covered: This review highlights the progress that has been made in the development of new therapeutics for CD. Detailed information is provided on the targets of drugs for CD as their related mechanisms of action. The therapies are classified in five mechanisms: modification of gluten, intraluminal therapies, immunomodulation, intestinal permeability and modulation of adaptative response. The actual development phase and future approach are also described and discussed. Expert opinion: There are several limitations in each of the treatment targets related either through complications or the lack of complete response to a normal gluten containing diet. It is clear that the most desired therapy for celiac patients would induce gluten tolerance and progress has been made as per the treatments described herein. Therefore, it is shortly expected that curative or complimentary tools to a gluten free diet will be available that will improve the quality of life of CD sufferers.