Food-specific IgGs Are Highly Increased in the Sera of Patients with Inflammatory Bowel Disease and Are Clinically Relevant to the Pathogenesis

Pro and anti-inflammatory diets as strong epigenetic factors in inflammatory bowel disease

Inflammatory bowel disease (IBD) is the consequence of a complex interplay between environmental factors, like dietary habits, that alter intestinal microbiota in response to luminal antigens in genetically susceptible individuals. Epigenetics represents an auspicious area for the discovery of how environmental factors influence the pathogenesis of inflammation, prognosis, and response to therapy. Consequently, it relates to gene expression control in response to environmental influences. The increasing number of patients with IBD globally is indicative of the negative effects of a food supply rich in trans and saturated fats, refined sugars, starches and additives, as well as other environmental factors like sedentarism and excess bodyweight, influencing the promotion of gene expression and increasing DNA hypomethylation in IBD. As many genetic variants are now associated with Crohn's disease (CD), new therapeutic strategies targeting modifiable environmental triggers, such as the implementation of an anti-inflammatory diet that involves the removal of potential food antigens, are of growing interest in the current literature. Diet, as a strong epigenetic factor in the pathogenesis of inflammatory disorders like IBD, provides novel insights into the pathophysiology of intestinal and extraintestinal inflammatory disorders.

IBD functions as a double-edged sword for food allergy in BALB/c mice model

Inflammatory bowel disease (IBD) and food allergy (FA) increase in tandem, but the potential impact of IBD on FA remains unclear. We sought to determine the role of IBD on FA. We first assessed the changes of FA-related risk factors in dextran sulphate sodium salt (DSS) induced colitis mice model. Then, we evaluated the role of IBD on FA in mice. FA responses were determined using a clinical allergy score, body temperature change, serum antibody levels, cytokines level and mouse mast cell protease 1 (MMCP-1) concentration. Accumulation of regulatory T cells was tested using flow cytometry. Intestinal changes were identified by histology, immunohistochemistry, gene expression and gut microbial community structure. In DSS-induced colitis mice model, we found the intestinal damage, colonic neutrophil infiltration, and downregulation of splenic Th2 cytokines and Tregs in mesenteric lymph nodes (MLN). Moreover, we also found that IBD can alleviate the FA symptoms and lead to the significant downregulation of Th2 cytokines, serum IgE and MMCP-1. However, IBD exacerbates intestinal injury and promotes the gene expression levels of IL-33 and IL-5 in the small intestine, damages the intestinal tissue structure and aggravates intestinal dysbiosis in FA. IBD functions as a double-edged sword in FA. From the perspective of clinical symptoms and humoral immune responses, IBD can reduce FA response by downregulating Th2 cytokines. But from the perspective of the intestinal immune system, IBD potentially disrupts intestinal tolerance to food antigens by damaging intestinal tissue structure and causing intestinal dysbiosis.

Inflammatory Bowel Disease: A Comprehensive Analysis of Molecular Bases, Predictive Biomarkers, Diagnostic Methods, and Therapeutic Options

In inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), the immune system relentlessly attacks intestinal cells, causing recurrent tissue damage over the lifetime of patients. The etiology of IBD is complex and multifactorial, involving environmental, microbiota, genetic, and immunological factors that alter the molecular basis of the organism. Among these, the microbiota and immune cells play pivotal roles; the microbiota generates antigens recognized by immune cells and antibodies, while autoantibodies target and attack the intestinal membrane, exacerbating inflammation and tissue damage. Given the altered molecular framework, the analysis of multiple molecular biomarkers in patients proves exceedingly valuable for diagnosing and prognosing IBD, including markers like C reactive protein and fecal calprotectin. Upon detection and classification of patients, specific treatments are administered, ranging from conventional drugs to new biological therapies, such as antibodies to neutralize inflammatory molecules like tumor necrosis factor (TNF) and integrin. This review delves into the molecular basis and targets, biomarkers, treatment options, monitoring techniques, and, ultimately, current challenges in IBD management.

Adverse Food Reactions in Inflammatory Bowel Disease: State of the Art and Future Perspectives

Limited knowledge is available about the relationship between food allergies or intolerances and inflammatory bowel disease (IBD). Clinicians frequently encounter patients who report food allergies or intolerances, and gastroenterologists struggle distinguishing between patients with organic disorders and those with functional disorders, which the patients themselves may associate with specific dietary components. This task becomes even more arduous when managing patients with significant underlying organic conditions, like IBD. The aim of this review is to summarize and emphasize any actual associations between food allergies and intolerances and inflammatory diseases, such as ulcerative colitis and Crohn's disease. Through a narrative disceptation of the current literature, we highlight the increased prevalence of various food intolerances, including lactose, fructose, histamine, nickel, and non-celiac gluten sensitivity, in individuals with IBD. Additionally, we explore the association between increased epithelial barrier permeability in IBD and the development of food sensitization. By doing so, we aim to enhance clinicians' awareness of the nutritional management of patients with IBD when facing complaints or evidence of food allergies or intolerances.

Serum food specific IgG antibodies are associated with small bowel inflammation in patients with Crohn's disease

BACKGROUND/AIMS

Food antigens are thought to play a vital role in the initiation and perpetuation of Crohn's disease (CD). The main purpose of this study was to evaluate the potential association of serum food specific IgG antibodies and small bowel (SB) inflammation in CD patients.

METHODS

We conducted a prospective observational study with 96 CD patients. Demographic, disease-related data and inflammatory parameters were collected. Serum food IgG antibodies were measured using enzyme-linked immunosorbent assay (ELISA). Capsule endoscopy was performed to detect SB inflammation quantified by the Lewis Score.

RESULTS

Seventy-eight of (81.3%) CD patients were detected positive for at least one food-specific antibody. The five most prevalent food antibodies in CD patients were tomato, egg, corn, rice, and soybean. Patients with SB inflammation had a higher positive rate of food IgG antibodies (P = 0.010) and more IgG-positive food items (P = 0.010) than those without. Specifically, patients with SB inflammation were more likely to have positive food-specific IgG against egg (P = 0.014), corn (P = 0.014), and wheat (P = 0.048). Additionally, the number of positive food IgGs ≥ 3 and elevated ESR were independently associated with concurrent SB inflammation (P = 0.015 and P = 0.013, respectively).

CONCLUSION

Our study confirmed that CD patients with SB inflammation had a higher positive rate of food IgG antibodies and more IgG-positive food items. The number of food positive IgGs ≥ 3 and elevated ESR were independently associated with concurrent SB inflammation.

IgE-Dependent Food Sensitisation and Its Role in Clinical and Laboratory Presentation of Paediatric Inflammatory Bowel Disease

The rising prevalence of inflammatory bowel disease (IBD) and food allergies and their partially overlapping mechanisms such as microbiome diversity reduction raise questions about the role of allergies in IBD. While data on their comorbidity are available, analysis of IgE-sensitization's influence on the clinical presentation of IBD is lacking and is the aim of this study. Histories of 292 children with newly diagnosed IBD (173 cases of ulcerative colitis, 119 cases of Crohn's disease) were analyzed. Disease age of onset, activity, location, behaviour, and anthropometric and laboratory parameters were tested for its dependence on the presence of chosen IgE sensitization markers. A.o. Chi2, OR and phi coefficient were assessed. In Crohn's disease (CD), elevated total IgE (tIgE) correlated with weight loss, rectal bleeding, ASCA IgG positivity (φ = 0.19 for all) and negatively correlated with complicated disease behaviour (φ = -0.19). TIgE > 5 × reference range correlated with being underweight (φ = 0.2), ASCA IgG positivity (φ = 0.3), ASCA double (IgA and IgG) positivity (φ = 0.25) and elevated total IgG (φ = 0.18). The presence of specific IgEs (sIgE) correlated with extraintestinal manifestations of IBD (φ = 0.19): Egg white sIgE correlated with upper GI involvement (L4b) (φ = 0.26), severe growth impairment (φ = 0.23) and colonic mucosal eosinophilia (φ = 0.19). In ulcerative colitis, decreased IgA correlated with egg white sIgE (φ = 0.3), as well as the presence of any (φ = 0.25) or multiple sIgEs (φ = 0.2); the latter correlated also with elevated IgG (φ = 0.22), fever (φ = 0.18), abdominal pain (φ = 0.16) and being underweight (φ = 0.15). Cow's milk sIgE correlated positively with growth impairment (φ = 0.15) and elevated IgG (φ = 0.17) and negatively with extensive colitis (φ = -0.15). Pancolitis correlated negatively with sIgE presence (φ = -0.15). In summary, single moderate and numerous weak but interesting relationships were observed.

Establishment of Food Allergy Model in Dextran Sulfate Sodium Induced Colitis Mice

Food allergy (FA) has become a global food safety issue. Evidence suggests that inflammatory bowel disease (IBD) can increase the incidence of FA, but it is mostly based on epidemiological studies. An animal model is pivotal for unraveling the mechanisms involved. However, dextran sulfate sodium (DSS)-induced IBD models may cause substantial animal losses. To better investigate the effect of IBD on FA, this study aimed to establish a murine model to fit both IBD and FA symptoms. Firstly, we compared three DSS-induced colitis models by monitoring survival rate, disease activity index, colon length, and spleen index, and then eliminated the colitis model with a 7-day administration of 4% due to high mortality. Moreover, we evaluated the modeling effects on FA and intestinal histopathology of the two models selected and found the modeling effects were similar in both the colitis model with a 7-day administration of 3% DSS and the colitis model with long-term administration of DSS. However, for animal survival reasons, we recommend the colitis model with long-term administration of DSS.

Advances in the Study of Probiotics for Immunomodulation and Intervention in Food Allergy

Food allergies are a serious food safety and public health issue. Soybean, dairy, aquatic, poultry, and nut products are common allergens inducing allergic reactions and adverse symptoms such as atopic dermatitis, allergic eczema, allergic asthma, and allergic rhinitis. Probiotics are assumed as an essential ingredient in maintaining intestinal microorganisms' composition. They have unique physiological roles and therapeutic effects in maintaining the mucosal barrier, immune function, and gastrointestinal tract, inhibiting the invasion of pathogenic bacteria, and preventing diarrhea and food allergies. Multiple pieces of evidence reveal a significant disruptive effect of probiotics on food allergy pathology and progression mechanisms. Thus, this review describes the allergenic proteins as an entry point and briefly describes the application of probiotics in allergenic foods. Then, the role of probiotics in preventing and curing allergic diseases by regulating human immunity through intestinal flora and intestinal barrier, modulating host immune active cells, and improving host amino acid metabolism are described in detail. The anti-allergic role of probiotics in the function and metabolism of the gastrointestinal tract has been comprehensively explored to furnish insights for relieving food allergy symptoms and preventing food allergy.

Regulatory T cells and immunoglobulin E: A new therapeutic link for autoimmunity?

Autoimmune diseases have a prevalence of approximately 7 to 9% and are classified as either organ-specific diseases, including type I diabetes, multiple sclerosis, inflammatory bowel disease and myasthenia gravis, or systemic diseases, including systemic lupus erythematosus, rheumatoid arthritis and Sjögren's syndrome. While many advancements have been made in understanding of the mechanisms of autoimmune disease, including the nature of self-tolerance and its breakdown, there remain unmet needs in terms of effective and highly targeted treatments. T regulatory cells (Tregs) are key mediators of peripheral tolerance and are implicated in many autoimmune diseases, either as a result of reduced numbers or altered function. Tregs may be broadly divided into those generated in the thymus (tTregs) and those generated in the periphery (pTregs). Tregs target many different immune cell subsets and tissues to suppress excessive inflammation and to support tissue repair and homeostasis: there is a fine balance between Treg cell stability and the plasticity that is required to adjust Tregs' regulatory purposes to particular immune responses. The central role of immunoglobulin E (IgE) in allergic disease is well recognized, and it is becoming increasingly apparent that this immunoglobulin also has a wider role encompassing other diseases including autoimmune disease. Anti-IgE treatment restores the capacity of plasmacytoid dendritic cells (pDCs) impaired by IgE- high-affinity IgE receptor (FcεR1) cross-linking to induce Tregs in vitro in atopic patients. The finding that anti-IgE therapy restores Treg cell homeostasis, and that this mechanism is associated with clinical improvement in asthma and chronic spontaneous urticaria suggests that anti-IgE therapy may also have a potential role in the treatment of autoimmune diseases in which Tregs are involved.

Associations between food-specific IgG antibodies and intestinal permeability biomarkers

Increasing translational evidence suggests that intestinal permeability may be a contributing factor to systemic inflammatory events and numerous pathologies. While associations between IgE-mediated food allergies and increased intestinal permeability have been well-characterized, the relationship between IgG-mediated food sensitivities and intestinal permeability is not well-described in the literature. Thus, we tested for associations between intestinal permeability biomarkers and food-specific IgG antibodies in 111 adults, with and without gastrointestinal symptoms. All biomarkers and food-specific IgG antibodies were measured via ELISA. The intestinal permeability biomarkers anti-lipopolysaccharide (LPS) and anti-occludin IgG and IgA antibodies, but not anti-vinculin or anti-CdtB IgG antibodies, were significantly and positively associated with IgG-mediated food sensitivities. These significant relationships were attenuated by adjusting for the severity of wheat, dairy, and egg reactions. The results of this study support strong associations between titers of food-specific IgG antibodies and intestinal permeability biomarkers in adults, to the extent that the presence of multiple IgG antibodies to food, and increasing IgG food titers, can be considered indicative of increased antibodies to LPS and occludin. Notably, neither IgG titers to wheat, eggs, and dairy, nor permeability biomarkers, were increased in symptomatic participants compared to those without symptoms.

Small bowel stomas are associated with higher risk of circulating food-specific-IgG than patients with organic gastrointestinal conditions and colostomies

Objective

The effects of food sensitivity can easily be masked by other digestive symptoms in ostomates and are unknown. We investigated food-specific-IgG presence in ostomates relative to participants affected by other digestive diseases.

Design

Food-specific-IgG was evaluated for 198 participants with a panel of 109 foods. Immunocompetency status was also tested. Jejunostomates, ileostomates and colostomates were compared with individuals with digestive tract diseases with inflammatory components (periodontitis, eosinophilic esophagitis, duodenitis, ulcerative colitis, Crohn’s disease and appendicitis), as well as food malabsorption due to intolerance. A logistic regression model with covariates was used to estimate the effect of the experimental data and demographic characteristics on the likelihood of the immune response.

Results

Jejunostomates and ileostomates had a significant risk of presenting circulating food-specific-IgG in contrast to colostomates (OR 12.70 (p=0.002), 6.19 (p=0.011) and 2.69 (p=0.22), respectively). Crohn’s disease, eosinophilic esophagitis and food malabsorption groups also showed significantly elevated risks (OR 4.67 (p=0.048), 8.16 (p=0.016) and 18.00 (p=0.003), respectively), but not the ulcerative colitis group (OR 2.05 (p=0.36)). Individuals with profoundly or significantly reduced, and mild to moderately reduced, levels of total IgG were protected from the formation of food-specific IgG (OR 0.09 (p=<0.001) and 0.33 (p=0.005), respectively). Males were at higher risk than females.

Conclusion

The strength of a subject’s immunocompetence plays a role in the intensity to which the humoral system responds via food-specific-IgG. An element of biogeography emerges in which the maintenance of a colonic space might influence the risk of having circulating food-specific-IgG in ostomates.

Associations between food-specific IgG and health outcomes in an asymptomatic physical examination cohort

Background

Although the association of food-specific IgG with the development and progression of specific diseases was shown by many studies, it is also present in the population without clinical symptoms. However, the association between food-specific IgG and physical examination outcomes in healthy people has not been studied yet.

Methods

An asymptomatic physical examination cohort (APEC) was selected according to the inclusion and exclusion criteria, the physical examination data were compared between IgG positive and IgG negative groups, and their odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable logistic regression.

Results

The data of 28,292 subjects were included in the analysis. The overall IgG positive rate was up to 52.30%, mostly with mild to moderate IgG positivity. The multivariable Logistic regression showed the prevalence of hypertriglyceridemia, abnormal fasting blood glucose and overweight was lower in the IgG (+) positive group (OR 0.87, 95% CI 0.83–0.92; OR 0.93, 95% CI 0.87–0.99; OR 0.92, 95% CI 0.87–0.96) but there was a higher prevalence of thyroid disease (OR 1.09, 95% CI 1.04–1.15).

Conclusion

Food-specific IgG positivity was widespread in the APEC and was associated with lower prevalence of hypertriglyceridemia, abnormal fasting blood glucose and overweight. The underlying physiological mechanism merits further study.

The Regulation of Intestinal Inflammation and Cancer Development by Type 2 Immune Responses

The gut is among the most complex organs of the human body. It has to exert several functions including food and water absorption while setting up an efficient barrier to the outside world. Dysfunction of the gut can be life-threatening. Diseases of the gastrointestinal tract such as inflammatory bowel disease, infections, or colorectal cancer, therefore, pose substantial challenges to clinical care. The intestinal epithelium plays an important role in intestinal disease development. It not only establishes an important barrier against the gut lumen but also constantly signals information about the gut lumen and its composition to immune cells in the bowel wall. Such signaling across the epithelial barrier also occurs in the other direction. Intestinal epithelial cells respond to cytokines and other mediators of immune cells in the lamina propria and shape the microbial community within the gut by producing various antimicrobial peptides. Thus, the epithelium can be considered as an interpreter between the microbiota and the mucosal immune system, safeguarding and moderating communication to the benefit of the host. Type 2 immune responses play important roles in immune-epithelial communication. They contribute to gut tissue homeostasis and protect the host against infections with helminths. However, they are also involved in pathogenic pathways in inflammatory bowel disease and colorectal cancer. The current review provides an overview of current concepts regarding type 2 immune responses in intestinal physiology and pathophysiology.

FcγRI plays a critical role in patients with ulcerative colitis relapse

Ulcerative colitis (UC) is a disease that frequently relapses and affects more than 0.1% general population; the underlying mechanism is poorly understood. Published data show that polymorphonuclear neutrophils (PMN) contribute to the pathogenesis of UC. This study aims to identify antigen (Ag)-specific PMNs and investigate their role in UC relapse. In this study, the correlation between PMN activities and UC relapse was assessed in a group of UC patients. A UC mouse model was developed to expand the findings of UC patient study. The results showed that a positive correlation was detected between the high PMN activities and the food Ag-specific IgG amounts in colon biopsies of UC patients. UC patient-derived Ag-specific PMNs could be activated upon exposure to food specific Ag. The Ag/FcγRI complexes were detected on the surface of PMNs in UC patients. Re-exposure of sensitized PMNs to specific Ag triggered PMN activation and induced UC-like inflammation in the mouse colon. We conclude that FcγRI plays a critical role in UC relapse. Inhibition of FcγRI can efficiently inhibits experimental UC.