Increased intestinal permeability in bronchial asthma

Intestinal barrier function in the naked mole-rat: an emergent model for gastrointestinal insights

The intestinal barrier plays a crucial role in homeostasis by both facilitating the absorption of nutrients and fluids and providing a tight shield to prevent the invasion by either pathogen or commensal microorganisms. Intestinal barrier malfunction is associated with systemic inflammation, oxidative stress, and decreased insulin sensitivity, which may lead to the dysregulation of other tissues. Therefore, a deeper understanding of physiological aspects related to an enhanced barrier function is of significant scientific and clinical relevance. The naked mole-rat has many unusual biological features, including attenuated colonic neuron sensitivity to acid and bradykinin and resistance to chemical-induced intestinal damage. However, insight into their intestinal barrier physiology is scarce. Here, we observed notable macroscopic and microscopic differences in intestinal tissue structure between naked mole-rats and mice. Moreover, naked mole-rats showed increased number of larger goblet cells and elevated mucus content. In measuring gut permeability, naked mole-rats showed reduced permeability compared with mice, measured as transepithelial electrical resistance, especially in ileum. Furthermore, intestinal ion secretion induced by serotonin, bradykinin, histamine, and capsaicin was significantly reduced in naked mole-rats compared with mice, despite the expression of receptors for all these agonists. In addition, naked mole-rats exhibited reduced prosecretory responses to the nonselective adenylate cyclase activator forskolin. Collectively, these findings indicate that naked mole-rats possess a robust and hard-to-penetrate gastrointestinal barrier that is resistant to environmental and endogenous irritants. Naked mole-rats may therefore provide valuable insights into the physiology of the intestinal barrier and set the stage for the development of innovative and effective therapies.NEW & NOTEWORTHY This is the first study to characterize the intestinal function of naked mole-rats. We found that these animals show a robust gut tissue structure, displaying thicker intestinal layers, longer villi, and larger crypts. Naked mole-rats showed more and larger goblet cells, with increased mucus content. Intestinal permeability, especially in the ileum, was substantially lower than that of mice. Finally, naked mole-rats showed reduced intestinal anion secretion in response to serotonin, bradykinin, histamine, capsaicin, and forskolin.

Exploring the Role of Lactoferrin in Managing Allergic Airway Diseases among Children: Unrevealing a Potential Breakthrough

The prevalence of allergic diseases has dramatically increased among children in recent decades. These conditions significantly impact the quality of life of allergic children and their families. Lactoferrin, a multifunctional glycoprotein found in various biological fluids, is emerging as a promising immunomodulatory agent that can potentially alleviate allergic diseases in children. Lactoferrin's multifaceted properties make it a compelling candidate for managing these conditions. Firstly, lactoferrin exhibits potent anti-inflammatory and antioxidant activities, which can mitigate the chronic inflammation characteristic of allergic diseases. Secondly, its iron-binding capabilities may help regulate the iron balance in allergic children, potentially influencing the severity of their symptoms. Lactoferrin also demonstrates antimicrobial properties, making it beneficial in preventing secondary infections often associated with respiratory allergies. Furthermore, its ability to modulate the immune response and regulate inflammatory pathways suggests its potential as an immune-balancing agent. This review of the current literature emphasises the need for further research to elucidate the precise roles of lactoferrin in allergic diseases. Harnessing the immunomodulatory potential of lactoferrin could provide a novel add-on approach to managing allergic diseases in children, offering hope for improved outcomes and an enhanced quality of life for paediatric patients and their families. As lactoferrin continues to capture the attention of researchers, its properties and diverse applications make it an intriguing subject of study with a rich history and a promising future.

Christensenella minuta, a new candidate next-generation probiotic: current evidence and future trajectories

Background

As the field of probiotic research continues to expand, new beneficial strains are being discovered. The Christensenellaceae family and its newly described member, Christensenella minuta, have been shown to offer great health benefits. We aimed to extensively review the existing literature on these microorganisms to highlight the advantages of their use as probiotics and address some of the most challenging aspects of their commercial production and potential solutions.

Methods

We applied a simple search algorithm using the key words "Christensenellaceae" and "Christensenella minuta" to find all articles reporting the biotherapeutic effects of these microorganisms. Only articles reporting evidence-based results were reviewed.

Results

The review showed that Christensenella minuta has demonstrated numerous beneficial properties and a wider range of uses than previously thought. Moreover, it has been shown to be oxygen-tolerant, which is an immense advantage in the manufacturing and production of Christensenella minuta-based biotherapeutics. The results suggest that Christensenellaceae and Christensenella munita specifically can play a crucial role in maintaining a healthy gut microbiome. Furthermore, Christensenellaceae have been associated with weight management. Preliminary studies suggest that this probiotic strain could have a positive impact on metabolic disorders like diabetes and obesity, as well as inflammatory bowel disease.

Conclusion

Christensenellaceae and Christensenella munita specifically offer immense health benefits and could be used in the management and therapy of a wide range of health conditions. In addition to the impressive biotherapeutic effect, Christensenella munita is oxygen-tolerant, which facilitates commercial production and storage.

Allergic Airway Inflammation Emerges from Gut Inflammation and Leakage in Mouse Model of Asthma

Asthma is an allergic airway inflammatory disease characterized by type 2 immune responses. Growing evidence suggests an association between allergic airways and intestinal diseases. However, the primary site of disease origin and initial mechanisms involved in the development of allergic airway inflammation (AAI) is not yet understood. Therefore, the initial contributing organs and mechanisms involved in the development of AAI are investigated using a mouse model of asthma. This study, without a local allergen challenge into the lungs, demonstrates a significant increase in intestinal inflammation with signature type-2 mediators including IL-4, IL-13, STAT6, eosinophils, and Th2 cells. In addition, gut leakage and mRNA expressions of gut leakage markers significantly increase in the intestine. Moreover, reduced mRNA expressions of tight junction proteins are observed in gut and interestingly, in lung tissues. Furthermore, in lung tissues, an increased pulmonary barrier permeability and IL-4 and IL-13 levels associated with significant increase of lipopolysaccharide-binding protein (LBP-gut leakage marker) and eosinophils are observed. However, with local allergen challenges into the lungs, these mechanisms are further enhanced in both gut and lungs. In conclusion, the primary gut originated inflammatory responses translocates into the lungs to orchestrate AAI in a mouse model of asthma.

Microbial signature of intestine in children with allergic rhinitis

INTRODUCTION

Previous studies have found that unique patterns of gut microbial colonization in infancy associated with the development of allergic diseases. However, there is no research on the gut microbiota characteristics of AR children in Chinese Mainland.

OBJECTIVE

To investigate the changes of gut microbial of AR children in Chinese Mainland and evaluate the correlation between gut microbial and clinical indexes.

METHODS

In this clinical study, fecal samples from 24 AR children and 25 healthy control children (HCs) were comparative via next generation sequencing of the V3-V4 regions of the 16S rRNA gene. Analyzed the relationship between clinical features and gut microbial using Spearman correlation.

RESULTS

Compared to HCs, AR children showed significant decreases in Shannon index and significant increases in Simpson index at both the family and genera levels (all p < 0.05). In terms of bacterial composition, at the phylum level, AR children had higher abundance of Bacteroidetes than that in the HCs group (p < 0.05) and were significantly positively correlated with TNSS (p < 0.05). At the family level, AR children had higher abundance of Prevotellaceae and Enterobacteriaceae higher than that in the HCs group (all p < 0.05) and had a significantly positive correlation with TNSS, eosinophils (EOS) and total immunoglobulin E (tIgE) (all p < 0.05). At the genus level, reduced abundance of Agathobacter, Parasutterella, Roseburia and Subdoligranulum were also observed in the AR cohorts compared to HCs (all p < 0.05) and significantly negatively associated with TNSS, EOS, tIgE, QOL, and FeNO (all p < 0.05).

CONCLUSION

AR children in Chinese Mainland were characterized by reduced microbial diversity and distinguished microbial characteristics in comparison with HCs. The observations of this study offer proof that distinctive gut microbiota profiles were present in AR children and necessitate further investigation in the form of mechanistic studies.

Serum Zonulin Is a Biomarker for Severe Asthma

Zonulin is a regulator of epithelial and endothelial barrier function. It regulates intestinal permeability through disrupting tight junctions. Defective epithelial barrier function is a hallmark of airway inflammation in asthma. This study aimed to investigate the role of zonulin in the pathogenesis of severe asthma. We enrolled 56 adult patients with asthma (29 severe asthma and 27 mild-to-moderate asthma) and 33 normal controls. The clinical data, sera, and lung tissues of the patients were provided by the Cohort for Reality and Evolution of adult Asthma in Korea (COREA) and the Biobank of Soonchunhyang University Bucheon Hospital, South Korea. Serum zonulin levels were estimated using an enzyme-linked immunosorbent assay, and zonulin expression in the bronchial tissue was evaluated by immunohistochemical staining. The serum zonulin levels were significantly higher in patients with severe asthma (51.98 ± 19.66 ng/mL) than in those with mild-to-moderate asthma and normal controls (26.35 ± 13.70 vs. 17.26 ± 10.29 ng/mL, P < 0.001). They significantly correlated with percent predicted forced expiratory volume in one second (%FEV1) (r = -0.35, P = 0.009). The zonulin expression in the bronchial epithelium was greater in patients with severe asthma. A serum zonulin cutoff value to distinguish between severe and mild-to-moderate asthmatics was 38.83 ng/mL. Zonulin may play an important role in the pathogenesis of severe asthma, and serum zonulin could be a potential biomarker for severe asthma.

Butyrate Protects Barrier Integrity and Suppresses Immune Activation in a Caco-2/PBMC Co-Culture Model While HDAC Inhibition Mimics Butyrate in Restoring Cytokine-Induced Barrier Disruption

Low-grade inflammation and barrier disruption are increasingly acknowledged for their association with non-communicable diseases (NCDs). Short chain fatty acids (SCFAs), especially butyrate, could be a potential treatment because of their combined anti-inflammatory and barrier- protective capacities, but more insight into their mechanism of action is needed. In the present study, non-activated, lipopolysaccharide-activated and αCD3/CD28-activated peripheral blood mononuclear cells (PBMCs) with and without intestinal epithelial cells (IEC) Caco-2 were used to study the effect of butyrate on barrier function, cytokine release and immune cell phenotype. A Caco-2 model was used to compare the capacities of butyrate, propionate and acetate and study their mechanism of action, while investigating the contribution of lipoxygenase (LOX), cyclooxygenase (COX) and histone deacetylase (HDAC) inhibition. Butyrate protected against inflammatory-induced barrier disruption while modulating inflammatory cytokine release by activated PBMCs (interleukin-1 beta↑, tumor necrosis factor alpha↓, interleukin-17a↓, interferon gamma↓, interleukin-10↓) and immune cell phenotype (regulatory T-cells↓, T helper 17 cells↓, T helper 1 cells↓) in the PBMC/Caco-2 co-culture model. Similar suppression of immune activation was shown in absence of IEC. Butyrate, propionate and acetate reduced inflammatory cytokine-induced IEC activation and, in particular, butyrate was capable of fully protecting against cytokine-induced epithelial permeability for a prolonged period. Different HDAC inhibitors could mimic this barrier-protective effect, showing HDAC might be involved in the mechanism of action of butyrate, whereas LOX and COX did not show involvement. These results show the importance of sufficient butyrate levels to maintain intestinal homeostasis.

Granzymes, IL-16, and poly(ADP-ribose) polymerase 1 increase during wildfire smoke exposure

Background

Given the increasing prevalence of wildfires worldwide, understanding the effects of wildfire air pollutants on human health-particularly in specific immunologic pathways-is crucial. Exposure to air pollutants is associated with cardiorespiratory disease; however, immune and epithelial barrier alterations require further investigation.

Objective

We sought to determine the impact of wildfire smoke exposure on the immune system and epithelial barriers by using proteomics and immune cell phenotyping.

Methods

A San Francisco Bay area cohort (n = 15; age 30 ± 10 years) provided blood samples before (October 2019 to March 2020; air quality index = 37) and during (August 2020; air quality index = 80) a major wildfire. Exposure samples were collected 11 days (range, 10-12 days) after continuous exposure to wildfire smoke. We determined alterations in 506 proteins, including zonulin family peptide (ZFP); immune cell phenotypes by cytometry by time of flight (CyTOF); and their interrelationship using a correlation matrix.

Results

Targeted proteomic analyses (n = 15) revealed a decrease of spondin-2 and an increase of granzymes A, B, and H, killer cell immunoglobulin-like receptor 3DL1, IL-16, nibrin, poly(ADP-ribose) polymerase 1, C1q TNF-related protein, fibroblast growth factor 19, and von Willebrand factor after 11 days' average continuous exposure to smoke from a large wildfire (P < .05). We also observed a large correlation cluster between immune regulation pathways (IL-16, granzymes A, B, and H, and killer cell immunoglobulin-like receptor 3DL1), DNA repair [poly(ADP-ribose) 1, nibrin], and natural killer cells. We did not observe changes in ZFP levels suggesting a change in epithelial barriers. However, ZFP was associated with immune cell phenotypes (naive CD4+, TH2 cells).

Conclusion

We observed functional changes in critical immune cells and their proteins during wildfire smoke exposure. Future studies in larger cohorts or in firefighters exposed to wildfire smoke should further assess immune changes and intervention targets.

Intestinal permeability and its significance in psychiatric disorders - a narrative review and future perspectives

The topic of increased intestinal permeability and its impact on the human body is. increasingly being addressed by researchers. It is associated with disruption of the. intestinal barrier, leading to the "leaky gut" syndrome. This can be assessed by. classical methods, determining the concentration of orally administered tracer. molecules in urine or by using biomarkers such as LPS, LBP or zonulin in blood. plasma. The presence of bacterial endotoxins in the body causes inflammation. In this. article, we review research on increased intestinal permeability in psychiatric illness. mood disorders, schizophrenia, alcohol dependence, anxiety disorders,. neurodegenerative and neurodevelopmental disorders. The results of the studies used. to assess intestinal permeability in different disease entities are presented. Possible. mechanisms for these interactions are the effects of chronic, low-grade inflammation. on the human brain, causing interruption of the brain blood barrier and dysfunction of. astrocytes and microglia. This affects brain function by reducing the number of. dopaminergic neurons, disrupting tryptophan metabolism and altering the amount of. GABA and glutamate. The links and mechanisms found may, in the future, allow earlier. detection of diseases and their targeted treatment.

The gut microbiota of people with asthma influences lung inflammation in gnotobiotic mice

The gut microbiota in early childhood is linked to asthma risk, but may continue to affect older patients with asthma. Here, we profile the gut microbiota of 38 children (19 asthma, median age 8) and 57 adults (17 asthma, median age 28) by 16S rRNA sequencing and find individuals with asthma harbored compositional differences from healthy controls in both adults and children. We develop a model to aid the design of mechanistic experiments in gnotobiotic mice and show enterotoxigenic Bacteroides fragilis (ETBF) is more prevalent in the gut microbiota of patients with asthma compared to healthy controls. In mice, ETBF, modulated by community context, can increase oxidative stress in the lungs during allergic airway inflammation (AAI). Our results provide evidence that ETBF affects the phenotype of airway inflammation in a subset of patients with asthma which suggests that therapies targeting the gut microbiota may be helpful tools for asthma control.

Gastrointestinal consequences of lipopolysaccharide-induced lung inflammation

BACKGROUND

Respiratory inflammation is the body's response to lung infection, trauma or hypersensitivity and is often accompanied by comorbidities, including gastrointestinal (GI) symptoms. Why respiratory inflammation is accompanied by GI dysfunction remains unclear. Here, we investigate the effect of lipopolysaccharide (LPS)-induced lung inflammation on intestinal barrier integrity, tight-junctions, enteric neurons and inflammatory marker expression.

METHODS

Female C57bl/6 mice (6-8 weeks) were intratracheally administered LPS (5 µg) or sterile saline, and assessed after either 24 or 72 h. Total and differential cell counts in bronchoalveolar lavage fluid (BALF) were used to evaluate lung inflammation. Intestinal barrier integrity was assessed via cross sectional immunohistochemistry of tight junction markers claudin-1, claudin-4 and EpCAM. Changes in the enteric nervous system (ENS) and inflammation in the intestine were quantified immunohistochemically using neuronal markers Hu + and nNOS, glial markers GFAP and S100β and pan leukocyte marker CD45.

RESULTS

Intratracheal LPS significantly increased the number of neutrophils in BALF at 24 and 72 h. These changes were associated with an increase in CD45 + cells in the ileal mucosa at 24 and 72 h, increased goblet cell expression at 24 h, and increased expression of EpCAM at 72 h. LPS had no effect on the expression of GFAP, S100β, nor the number of Hu + neurons or proportion of nNOS neurons in the myenteric plexus.

CONCLUSIONS

Intratracheal LPS administration induces inflammation in the ileum that is associated with enhanced expression of EpCAM, decreased claudin-4 expression and increased goblet cell density, these changes may contribute to systemic inflammation that is known to accompany many inflammatory diseases of the lung.

Alteration of Gut Immunity and Microbiome in Mixed Granulocytic Asthma

Growing evidence suggests that there is an essential link between the gut and lungs. Asthma is a common chronic inflammatory disease and is considered a heterogeneous disease. While it has been documented that eosinophilic asthma affects gut immunity and the microbiome, the effect of other types of asthma on the gut environment has not been examined. In this study, we utilized an OVA/poly I:C-induced mixed granulocytic asthma model and found increased Tregs without significant changes in other inflammatory cells in the colon. Interestingly, an altered gut microbiome has been observed in a mixed granulocytic asthma model. We observed an increase in the relative abundance of the Faecalibaculum genus and Erysipelotrichaceae family, with a concomitant decrease in the relative abundance of the genera Candidatus arthromitus and Streptococcus. The altered gut microbiome leads to changes in the abundance of genes associated with microbial metabolism, such as glycolysis. We found that mixed granulocytic asthma mainly affects the gut microbial composition and metabolism, which may have important implications in the severity and development of asthma and gut immune homeostasis. This suggests that altered gut microbial metabolism may be a potential therapeutic target for patients with mixed granulocytic asthma.

Intestinal Barrier Permeability in Allergic Diseases

The role of intestinal permeability (IP) markers among children and adults with food allergies is not fully understood, and the identification of biological indicators/markers that predict growth retardation in children with allergic diseases and atopy has not been well explained. Studies have shown that patients with atopic diseases respond abnormally to food allergens. Accordingly, differences in the types of immune complexes formed in response to antigen challenges are significant, which seems to underlie the systemic signs of the food allergy. Increased intestinal permeability over the course of a food allergy allows allergens to penetrate through the intestinal barrier and stimulate the submucosal immune system. Additionally, the release of cytokines and inflammatory mediators enhances the degradation of the epithelial barrier and leads to an improper cycle, resulting in increased intestinal permeability. Several studies have also demonstrated increased permeability of the epithelial cells in those afflicted with atopic eczema and bronchial asthma. Ongoing research is aimed at finding various indicators to assess IP in patients with atopic diseases.

Phytogenic Compounds for Enhancing Intestinal Barrier Function in Poultry-A Review

After the European Union ban of antibiotic growth promoters, works on different methods of improving gut health have intensified. The poultry industry is struggling with problems that were previously controlled by antibiotic growth promoters, therefore the search for optimal solutions continues. Simultaneously, there is also increasing social pressure to minimize the use of antibiotics and replace them with alternative feed additives. A variety of available alternatives is considered safe by consumers, among which phytogenics play a significant role. However, there are still some limitations that need to be considered. The most questionable are the issues related to bioavailability, metabolism of plant derivatives in birds, and the difficulty of standardizing commercial products. There is still a need for more evidence-based recommendations for the use of phytogenics in livestock. On the other hand, a positive influence of phytogenic compounds on the health of poultry has been previously described by many researchers and practical application of these compounds has auspicious perspectives in poultry production. Supplementation with phytogenic feed additives has been shown to protect birds from various environmental threats leading to impaired intestinal barrier function. Phytogenic feed additives have the potential to improve the overall structure of intestinal mucosa as well as gut barrier function on a molecular level. Recognition of the phytogenics' effect on the components of the intestinal barrier may enable the selection of the most suitable ones to alleviate negative effects of different agents. This review aims to summarize current knowledge of the influence of various phytogenic constituents on the intestinal barrier and health of poultry.

Asthma and obesity: endotoxin another insult to add to injury?

Low-grade inflammation is often an underlying cause of several chronic diseases such as asthma, obesity, cardiovascular disease, and type 2 diabetes mellitus (T2DM). Defining the mediators of such chronic low-grade inflammation often appears dependent on which disease is being investigated. However, downstream systemic inflammatory cytokine responses in these diseases often overlap, noting there is no doubt more than one factor at play to heighten the inflammatory response. Furthermore, it is increasingly believed that diet and an altered gut microbiota may play an important role in the pathology of such diverse diseases. More specifically, the inflammatory mediator endotoxin, which is a complex lipopolysaccharide (LPS) derived from the outer membrane cell wall of Gram-negative bacteria and is abundant within the gut microbiota, and may play a direct role alongside inhaled allergens in eliciting an inflammatory response in asthma. Endotoxin has immunogenic effects and is sufficiently microscopic to traverse the gut mucosa and enter the systemic circulation to act as a mediator of chronic low-grade inflammation in disease. Whilst the role of endotoxin has been considered in conditions of obesity, cardiovascular disease and T2DM, endotoxin as an inflammatory trigger in asthma is less well understood. This review has sought to examine the current evidence for the role of endotoxin in asthma, and whether the gut microbiota could be a dietary target to improve disease management. This may expand our understanding of endotoxin as a mediator of further low-grade inflammatory diseases, and how endotoxin may represent yet another insult to add to injury.

The rich pharmacological activities of Magnolia officinalis and secondary effects based on significant intestinal contributions

ETHNOPHARMACOLOGICAL RELEVANCE

Magnolia officinalis Cortex (M. officinalis) is a traditional herbal drug widely used in Asian countries. Depending on its multiple biological activities, M. officinalis is used to regulate gastrointestinal (GI) motility, relieve cough and asthma, prevent cardiovascular and cerebrovascular diseases, and treat depression and anxiety.

AIM OF THE REVIEW

We aimed to review the abundant form of pharmacodynamics activity and potential mechanisms of action of M. officinalis and the characteristics of the internal processes of the main components. The potential mechanisms of local and distance actions of M. officinalis based on GI tract was provided, and it was used to reveal the interconnections between traditional use, phytochemistry, and pharmacology.

MATERIALS AND METHODS

Published literatures about M. officinalis and its main components were collected from several scientific databases, including PubMed, Elsevier, ScienceDirect, Google Scholar and Web of Science etc. RESULTS: M. officinalis was shown multiple effects including effects on digestive system, respiratory system, central system, which is consistent with traditional applications, as well as some other activities such as cardiovascular system, anticancer, anti-inflammatory and antioxidant effects and so on. The mechanisms of these activities are abundant. Its chief ingredients such as magnolol and honokiol can be metabolized into active metabolites in vivo, which can increase water solubility and bioavailability and exert pharmacological activity in the whole body. In the GI tract, M. officinalis and its main ingredient can regulate GI hormones and substance metabolism, protect the intestinal barrier and affect the gut microbiota (GM). These actions are effective to improve local discomfort and some distal symptoms such as depression, asthma, or metabolic disorders.

CONCLUSIONS

Although M. officinalis has rich pharmacological effects, the GI tract makes great contributions to it. The GI tract is not only an important place for absorption and metabolism but also a key site to help M. officinalis exert local and distal efficacy. Pharmacodynamical studies on the efficacies of distal tissues based on the contributions of the GI tract hold great potential for understanding the benefits of M. officinalis and providing new ideas for the treatment of important diseases.

Dietary Fibers: Effects, Underlying Mechanisms and Possible Role in Allergic Asthma Management

The prevalence of asthma is increasing, but the cause remains under debate. Research currently focuses on environmental and dietary factors that may impact the gut-lung axis. Dietary fibers are considered to play a crucial role in supporting diversity and activity of the microbiome, as well as immune homeostasis in the gut and lung. This review discusses the current state of knowledge on how dietary fibers and their bacterial fermentation products may affect the pathophysiology of allergic asthma. Moreover, the impact of dietary fibers on early type 2 asthma management, as shown in both pre-clinical and clinical studies, is described. Short-chain fatty acids, fiber metabolites, modulate host immunity and might reduce the risk of allergic asthma development. Underlying mechanisms include G protein-coupled receptor activation and histone deacetylase inhibition. These results are supported by studies in mice, children and adults with allergic asthma. Fibers might also exert direct effects on the immune system via yet to be elucidated mechanisms. However, the effects of specific types of fiber, dosages, duration of treatment, and combination with probiotics, need to be explored. There is an urgent need to further valorize the potential of specific dietary fibers in prevention and treatment of allergic asthma by conducting more large-scale dietary intervention trials.

Association between serum zonulin level and severity of house dust mite allergic asthma

BACKGROUND

Increased intestinal permeability, either due to the exposure to antigens in asthmatic patients or due to a barrier defect, plays a critical role in susceptibility to environmental allergens. House dust mite allergy occurs more commonly than any other type of allergy among Egyptian asthmatic patients.

AIM

To assess the relation between serum zonulin level as a marker of increased intestinal permeability and the severity of house dust mite allergic asthma.

METHODS

A case-control study which included 48 patients with house dust mite allergic asthma and 48 healthy control subjects attending the Allergy and Immunology Unit, Microbiology and Immunology Department, Faculty of Medicine, Zagazig University.

RESULTS

A statistically significant difference was detected between the two studied groups with respect to serum IgE and serum zonulin levels (p ˂ 0.001 and ˂ 0.001, respectively). The mean serum zonulin was equal to 258.3 ± 153.01 ng/ml in the asthmatic group and 80 ± 13 ng/ml in the control group. Serum zonulin level significantly increased with the increase of asthma severity (p ˂ 0.001). The cut off value of serum zonulin was ≥ 198 ng/ml, and the area under the curve was 0.76. It displayed sensitivity equal to 80% and specificity equal to 71.4%. Its negative predictive value was equal to 83.3%.

CONCLUSION

Intestinal barrier dysfunction contributes to the pathogenesis of allergic asthma. Serum zonulin level reflects an increase in intestinal permeability. Zonulin acts as prognostic factor of severity in asthma. Correction of the gut barrier defect may have a potential positive prognostic effect in asthma.

Expression profiling of ileal mucosa in asthma reveals upregulation of innate immunity and genes characteristic of Paneth and goblet cells

Background

The expression profiles of the intestinal mucosa have not been comprehensively investigated in asthma. We aimed to explore this in the Correlated Expression and Disease Association Research (CEDAR) patient cohort.

Methods

Differential expression analysis of ileal, transverse colon, and rectal biopsies were supplemented by a comparison of transcriptomes from platelets and leukocytes subsets, including CD4+, CD8+, CD14+, CD15+, and CD19+ cells. Asthma patients (n = 15) and controls (n = 15) had similar age (p = 0.967), body mass index (p = 0.870), similar numbers of females (80%) and smoking rates (13.3%).

Results

Significant differential expression was found in the ileum alone, and not in any other cell/tissue types. More genes were found to be overexpressed (1,150) than under-expressed (380). The most overexpressed genes included Fc Fragment of IgG Binding Protein (FCGBP, logFC = 3.01, pFDR = 0.015), Mucin 2 (MUC2, logFC = 2.78, pFDR = 0.015), and Alpha 1B Defensin (DEFA1B, logFC = 2.73, pFDR = 0.024). Gene ontology implicated the immune system, including interleukins 4 and 13, as well as antimicrobial peptides in this overexpression. There was concordance of gene over- (STAT1, XBP1) and underexpression (NELF, RARA) in asthma and Crohn’s disease ileum when our results were compared to another dataset (p = 3.66 × 10^–7).

Conclusion

Ileal mucosa in asthma exhibits a specific transcriptomic profile, which includes the overexpression of innate immune genes, mostly characteristic of Paneth and goblet cells, in addition to other changes that may resemble Crohn’s disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-021-00584-9.

Allergy-related diseases and early gut fungal and bacterial microbiota abundances in children

BACKGROUND

The early gut microbiota has been proposed as an important link between environmental exposures and development of allergy-related diseases. Beyond the widely investigated associations between the gut bacterial microbiota, we investigated the involvement of early gut mycobiota and gut permeability in the pathogenesis of asthma, allergic rhinoconjunctivitis (AR) and eczema.

METHODS

In the Probiotics in the Prevention of Allergy among Children in Trondheim trial with maternal probiotic supplementation, we collected faecal samples at four timepoints between 0 and 2 years from a cohort of 278 children. Clinical information on allergy-related diseases was collected in a paediatric examination at 2 years and questionnaires at 6 weeks and 1, 2 and 6 years. By quantitative PCR and 16S/ITS1 MiSeq rRNA gene sequencing, we analysed the gut bacterial and fungal microbiota abundance and bacterial diversity and explored associations with allergy-related diseases. We also measured gut permeability markers (lipopolysaccharide-binding protein [LBP] and fatty acid-binding protein 2 [FABP2]).

RESULTS

Children with higher fungal abundance at 2 years were more likely to develop asthma and AR by 6 years, odds ratios 1.70 (95% CI: 1.06-2.75) and 1.41 (1.03-1.93), respectively. We explored causal connections, and children with eczema at 1-2 years appeared to have more mature bacterial microbiota, as well as being depleted of Enterococcus genus. Although LBP and FABP2 did not correlate with eczema, increased bacterial abundance was associated with increased serum FABP2.

CONCLUSIONS

We observed positive associations between gut fungal abundance and allergy-related disease, but increased gut permeability does not appear to be involved in the underlying mechanisms for this association. Our findings should be confirmed in future microbiota studies.

Population Pharmacokinetic Analysis of Fevipiprant in Healthy Subjects and Asthma Patients using a Tukey’s g-and-h Distribution

Aim The objective of this analysis was to characterize the population pharmacokinetics (PK) of fevipiprant in asthma patients and to evaluate the effect of baseline covariates on the PK of fevipiprant.

Methods PK data from 1281 healthy subjects or asthma patients were available after single or once daily dosing of fevipiprant. Population PK analysis was conducted to describe fevipiprant plasma concentration data using a non-linear mixed effect modeling approach.

Results Fevipiprant PK was described by a two-compartment model with first-order absorption and first-order elimination. Exploration of fevipiprant PK in the population from the phase III studies revealed an over-dispersed and skewed distribution. This unusual distribution was described using Tukey’s g-and-h distribution (TGH) on the between-subject variability of apparent clearance (CL/F). The model identified a significant impact of disease status on CL/F, with the value in healthy subjects being 62% higher than that in asthma patients. Bodyweight, age and renal function showed statistically significant impact on fevipiprant clearance; however, compared with a typical asthma patient, the simulated difference in steady-state exposure was at most 16%.

Conclusion Fevipiprant PK was described by a two-compartment model with first-order absorption and first-order elimination. The TGH distribution was appropriate to describe the over-dispersed and skewed PK data as observed in the current studies. Asthma patients had approximately 37% higher exposure than healthy subjects did. Other covariates changed exposure by at most 16%.

The Gut Microbiome of Adults with Allergic Rhinitis Is Characterised by Reduced Diversity and an Altered Abundance of Key Microbial Taxa Compared to Controls

INTRODUCTION

Unique gut microbial colonisation patterns are associated with the onset of allergic disease in infants; however, there is insufficient evidence to determine if aberrant microbial composition patterns persist in adult allergic rhinitis (AR) sufferers.

OBJECTIVE

To compare the gut microbiome composition between adult AR sufferers and controls.

METHODS

Gut microbial composition in stool samples was compared between 57 adult AR sufferers (39.06 ± 13.29 years) and 23 controls (CG; 36.55 ± 10.51 years) via next-generation sequencing of the V3-V4 hypervariable regions of the 16S rRNA gene. Taxonomic classification and identity assignment was performed using a reference-based approach with the NCBI database of 16S rRNA gene sequences.

RESULTS

Species richness determined via the Shannon index was significantly reduced in the AR cohort compared to the CG (4.35 ± 0.59 in AR vs. 4.65 ± 0.55 in CG, p = 0.037); trends for reductions in operational taxonomic unit (OTU) counts, inverse Simpson, and CHAO1 diversity indices were also noted. Bacteroidetes (p = 0.014) was significantly more abundant in the AR group than in the CG. In contrast, the Firmicutes phylum was significantly less abundant in the AR group than in the CG (p = 0.006). An increased abundance of Parabacteroides (p = 0.008) and a reduced abundance of Oxalobacter (p = 0.001) and Clostridiales (p = 0.005) were also observed in the AR cohort compared to the CG.

CONCLUSION

Adult AR sufferers have a distinct gut microbiome profile, marked by a reduced microbial diversity and altered abundance of certain microbes compared to controls. The results of this study provide evidence that unique gut microbial patterns occur in AR sufferers in adulthood and warrant further examination in the form of mechanistic studies.

Serum zonulin measured by enzyme-linked immunosorbent assay may not be a reliable marker of small intestinal permeability in healthy adults

The association between intestinal permeability (IP) and body composition remains unclear. The gold standard differential sugar-absorption test is arduous to complete, with zonulin being increasingly used as an independent biomarker of IP. This pilot study aimed to explore the association between small IP, zonulin concentrations, and body composition in healthy adults. The urinary lactulose-rhamnose ratio was used to measure small IP. Serum zonulin, lipopolysaccharide (LPS) and high-sensitivity C-reactive protein (hs-CRP) were analyzed in serum. Body composition was measured using dual-energy X-ray absorptiometry and anthropometric measurements were collected. In total, 34 participants were included (12 males, median age 28 years, body mass index 24 kg/m², waist circumference 77cm). No correlation was observed between the lactulose-rhamnose ratio and zonulin (r = -.016, P = .929). The lactulose-rhamnose ratio displayed a strong positive correlation with LPS (n 20, r = .536, P = .018) but did not correlate with body composition measures. Conversely, zonulin displayed a moderate positive correlation with waist circumference (r = .437, P = .042) in female participants and hs-CRP (r = .485, P = .004) in all participants. These findings raise important considerations for the measurement of small IP, warranting exploration in larger powered studies that address the limitations of the present study.

Maternal Allergy and the Presence of Nonhuman Proteinaceous Molecules in Human Milk

Human milk contains proteins and/or protein fragments that originate from nonhuman organisms. These proteinaceous molecules, of which the secretion might be related to the mother's allergy status, could be involved in the development of the immune system of the infant. This may lead, for example, to sensitization or the induction of allergen-specific tolerance. The aim of this study was to investigate the relation between maternal allergy and the levels of nonhuman proteinaceous molecules in their milk. In this study, we analysed trypsin-digested human milk serum proteins of 10 allergic mothers and 10 nonallergic mothers. A search was carried out to identify peptide sequences originating from bovine or other allergenic proteins. Several methods were applied to confirm the identification of these sequences, and the differences between both groups were investigated. Out of the 78 identified nonhuman peptide sequences, 62 sequences matched Bos taurus proteins. Eight peptide sequences of bovine β -lactoglobulin had significantly higher levels in milk from allergic mothers than in milk from nonallergic mothers. Dietary bovine β -lactoglobulin may be absorbed through the intestinal barrier and secreted into human milk. This seems to be significantly higher in allergic mothers and might have consequences for the development of the immune system of their breastfed infant.

Evaluation of Invasive Intra-abdominal Candidiasis in Crohn Disease at the Time of Surgery

Purpose

The aim of this study was to determine whether a connection exists between Crohn disease and fungi, specifically Candida albicans, because one possible cause of disease is thought to be the presence of fungi in the intra-abdominal cavity. The diagnosis of invasive candidiasis is difficult due to the lack of specific clinical manifestations of the disease. A retrospective evaluation of the presence of invasive candidiasis was done in a group of 54 patients with Crohn disease and in a group of 31 patients who received surgery primarily for right-sided cancer of the colon.

Methods

Culture samples were obtained from the wall of the extraluminal portion of the terminal ileum and the adjacent mesenterium, and then sent to the microbiology laboratory for further investigation. Sabouraud agar (SGC2) and chromID Candida agar (CAN2) were used for both short-term (48 hours) and long-term (10 days) cultivation.

Results

Pearson chi-square test revealed a statistically significant difference in the prevalence of fungi and yeast between the 2 groups of patients (χ² = 4.3873, P < 0.05).

Conclusion

Patients with Crohn disease had a significantly higher prevalence of fungi and yeasts in the intra-abdominal cavity compared with cancer patients.

Association between irritable bowel syndrome and asthma: a meta-analysis and systematic review

Background:

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder often seen in outpatient clinics. Diagnosing IBS is often challenging, as it frequently presents with other complicated rheumatological and psychiatric conditions. Asthma has often been associated with gastrointestinal conditions such as gastroesophageal reflux disease and eosinophilic esophagitis. This review and meta-analysis aimed at a better understanding of the association between the conditions.

Methods:

A comprehensive literature review was completed using MEDLINE and EMBASE databases through January 2019. Case-control, cross-sectional and cohort studies that evaluated the association between asthma and IBS were divided into 2 groups: the first included studies that identified patients with asthma first and then looked for the presence of IBS. The second group included studies that identified IBS patients first and then looked for the presence of asthma. Random effects meta-analysis was conducted using STATA 15.

Results:

The search strategy generated a total of 634 studies and 10 eligible studies (8 case-control and 2 cross-sectional) were selected for meta-analysis. Analysis showed that asthmatics have twice the risk of having IBS (pooled odds ratio [OR] 2.0, 95% confidence interval [CI] 1.5-2.8), and patients with IBS have twice the risk of having asthma (pooled OR 2.2, 95%CI 1.3-3.9).

Conclusions:

This study highlights that the risk of asthma is considerably higher in IBS patients and vice versa. Physicians should look out for pulmonary symptoms in IBS patients and consider evaluation with spirometry when necessary. Likewise, asthmatics presenting with gastrointestinal symptoms may need consultation and evaluation for IBS.

Non-IgE-mediated gastrointestinal allergies-Do they have a place in a new model of the Allergic March

The rise in food allergy has been described as the "second wave" of the allergy epidemic, with some developed countries reporting a prevalence of 10% of challenge-proven food allergies. Recognition of the Allergic March has played a crucial role in identifying causality in allergic conditions, linking atopic dermatitis to food allergy and food allergy to other atopic disorders, thereby highlighting opportunities in prevention and the importance of early intervention. This publication will establish the value of weaving the less well-understood, non-IgE-mediated food allergy into the Allergic March and mapping its progression through childhood and its associated co-morbidities. The proposed non-IgE-mediated Allergic March highlights the concomitant presentation of gastrointestinal symptoms and atopic dermatitis as early presenting symptoms in confirmed non-IgE-mediated allergies and the later development of atopic co-morbidities, including asthma and allergic rhinitis, similar to the IgE-mediated Allergic March. This publication highlights recent observations of a link between non-IgE-mediated food allergy in early childhood and functional gastrointestinal disorders in later life and also the reported occurrence of extra-intestinal manifestations at later ages. Although significant limitations exist in regard to the proposed evolution of the Allergic March model, the authors hope that this publication will influence the management of non-IgE-mediated gastrointestinal allergies and inform future research and interventions.

Change in gut microbiota for eczema: Implications for novel therapeutic strategies

Eczema is one of the most common inflammatory diseases, often constituting a lifelong burden for afflicted individuals. The complex interaction of host genetic and multiple environmental factors contribute to its pathogenesis. A relationship between maladjustment of gut microbiota and eczema has been brought into the light of day in most previous studies. In eczema preclinical models, specific intestinal microbial species have been demonstrated to prohibit or dwindle immune responsiveness, indicating that these strains among commensal gut bacteria may exert either a morbific or phylactic function in eczema progression. As such, oral probiotics can serve as a medicinal approach for eczema therapy. Given that relative scientific work is still at the early stage, only limited data are available in the field. New sequencing techniques have been fortunately performed to gain access to an extended research on the relationship between gut bacterial flora and human diseases. In the current review, we identified the role of intestinal microbiota in the development of eczema and how specific bacterial strains adjust the immune responsiveness in the midst of disease progression. Probiotics as an applicable treatment for eczema were evaluated in other threads as well.

β-eudesmol suppresses allergic reactions via inhibiting mast cell degranulation

The regulatory effect of β-eudesmol, which is an active constituent of Pyeongwee-San (KMP6), is evaluated for allergic reactions induced by mast cell degranulation. Phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated human mast cell line, HMC-1 cells, and compound 48/80-stimulated rat peritoneal mast cells (RPMCs) are used as the in vitro models; mice models of systemic anaphylaxis, ear swelling, and IgE-dependent passive cutaneous anaphylaxis (PCA) are used as the in vivo allergic models. The results demonstrate that β-eudesmol suppressed the histamine and tryptase releases from the PMA plus calcium ionophore A23187-stimulated HMC-1 cells. β-eudesmol inhibits the expression and activity of histidine decarboxylase in the activated HMC-1 cells. In addition, β-eudesmol inhibits the levels of histamine and tryptase released from the compound 48/80-stimulated RPMCs. Furthermore, β-eudesmol decreases the intracellular calcium level in the activated RPMCs. β-eudesmol also decreases the compound 48/80-induced mortality and ear swelling response. β-eudesmol suppresses the serum levels of histamine, IgE, interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-13, and vascular endothelial growth factor (VEGF) under PCA mice as well as PCA reactions. Therefore, the results from this study indicate the potential of β-eudesmol as an anti-allergic drug with respect to its pharmacological properties against mast cell-mediated allergic reactions.

Clinical Characteristics, Comorbidities and Hospital Outcomes in Hospitalizations with Cyclic Vomiting Syndrome: A Nationwide Analysis

BACKGROUND

Data on cyclic vomiting syndrome (CVS) are limited to studies from tertiary care centers. There is a paucity of information about CVS on a national scale.

AIM

To study the clinical characteristics, comorbidities, and hospital outcomes in patients hospitalized with CVS using a nationwide database.

METHODS

We identified all hospitalizations associated with a primary diagnosis of CVS in 2010 and 2011 using the Nationwide Inpatient Sample with an age category of 18-55 years. A 1:2 random sample of non-CVS hospitalizations with the same age category was obtained, and comparisons between groups were made. Multivariate logistic regression analysis was used to determine comorbidities independently associated with CVS.

RESULTS

Our study included 20,952 CVS and 44,262 non-CVS patients. CVS patients tended to be younger, male, and white compared to non-CVS patients. On multivariate analysis, CVS was significantly associated with comorbidities including dysautonomia, migraine, anxiety, marijuana use, irritable bowel syndrome, gastroparesis, gastroesophageal reflux disease, asthma, cigarette smoking, and hypertension. CVS patients underwent esophagogastroduodenoscopy, colonoscopy, and gastric emptying tests more frequently. They had more favorable hospital outcomes like more routine discharges (discharge to home/self-care), lower mortality, and shorter length of stay but tended to leave against medical advice more frequently. CVS patients incurred total hospital charges of about $400 million over the 2 years.

CONCLUSIONS

Our study showed that CVS is associated with several comorbidities and incurred substantial health care costs despite benign outcomes. Efforts to optimize therapy of CVS, manage comorbid conditions and reduce healthcare utilization are warranted.

Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases

Beside digesting nutrients and absorbing solutes and electrolytes, the intestinal epithelium with its barrier function is in charge of a tightly controlled antigen trafficking from the intestinal lumen to the submucosa. This trafficking dictates the delicate balance between tolerance and immune response causing inflammation. Loss of barrier function secondary to upregulation of zonulin, the only known physiological modulator of intercellular tight junctions, leads to uncontrolled influx of dietary and microbial antigens. Additional insights on zonulin mechanism of action and the recent appreciation of the role that altered intestinal permeability can play in the development and progression of chronic inflammatory disorders has increased interest of both basic scientists and clinicians on the potential role of zonulin in the pathogenesis of these diseases. This review focuses on the recent research implicating zonulin as a master regulator of intestinal permeability linked to the development of several chronic inflammatory disorders.

Increased C-reactive protein and fever in Japanese infants with food protein-induced enterocolitis syndrome

BACKGROUND

Increased C-reactive protein (CRP) and fever are observed in some infants with food protein-induced enterocolitis syndrome (FPIES) in Japan, but the reproducibility of these findings has not yet been confirmed on oral food challenge (OFC).

METHODS

Fourteen infants with FPIES induced by cow's milk (CM) formula were enrolled. OFC using CM formula was performed on each infant once or repeatedly (total 18 tests), with a stepwise incremental protocol in an infection-controlled setting. CRP was measured 24 h after the last ingestion of the CM formula.

RESULTS

Increased CRP was observed in 11 of the 18 OFC conducted (median, 2.60 mg/dL; range, 0.22-4.84 mg/dL). Fever was induced in six occasions during OFC. Serum CRP in the patients with fever increased to median 3.76 mg/dL (range, <0.7-4.84 mg/dL), which was significantly higher than that of the patients without fever (median <0.1 mg/dL; range, <0.1-2.6 mg/dL; P < 0.001). CRP during OFC significantly correlated with that at disease onset (rs = 0.62, P < 0.02). Three of the four patients with fever at disease onset also had fever during OFC.

CONCLUSIONS

Increased CRP and fever are reproducible during OFC in some infants with FPIES, suggesting that these are not accidental phenomena, but instead are associated with FPIES itself in Japanese patients.

Intestinal permeability in children with recurrent respiratory and gastrointestinal symptoms

AIM

Increased intestinal permeability has been reported in asthmatic subjects as well as in patients with gastrointestinal disease, thus suggesting the involvement of all the mucosal immune system. We aimed to assess intestinal permeability according to recurrent respiratory and gastrointestinal symptoms in children with asthma and children with functional gastrointestinal disorders (FGIDs).

METHODS

In 108 outpatients aged 3-14 years (45 asthmatic, 63 with FGIDs), we measured the urinary lactulose/mannitol (L/M) ratio, performed allergy skin prick tests and administered questionnaires for recurrent respiratory and gastrointestinal symptoms starting from at least 2 months which persisted over the previous 4 weeks. L/M ratios were compared with previously reported normal values yielded by our chromatographic method (liquid chromatography-mass spectrometry).

RESULTS

High L/M ratios (>0.030) were less frequent in asthmatic children than in children with FGIDs (9/45: 20% vs. 41/63: 65%, P < 0.001). High L/M ratios were associated with gastrointestinal symptoms in 8/9 asthmatic (P < 0.05) and 39/41 subjects with FGIDs (P < 0.005). L/M ratios were not associated with respiratory symptoms or atopy. In a regression model, a high L/M was predicted by low height, absence of asthma and presence of gastrointestinal symptoms (r = 0.72, P < 0.001).

CONCLUSIONS

Increased intestinal permeability is associated with recurrent gastrointestinal symptoms rather than with recurrent respiratory symptoms in both asthmatic children and those with FGIDs. Our findings do not support the hypothesis of mucosal intestinal damage following an inflammatory stimulus in the respiratory mucosa.

Self-reported adverse reactions and IgE sensitization to common foods in adults with asthma

Background

There is very few data available on the prevalence of food hypersensitivity among adults with asthma. The aim of this study was to explore the prevalence of self-reported adverse reactions and IgE sensitization to the different foods and to determine the spectrum and the prevalence of food-related gastrointestinal symptoms in adults with and with no asthma.

Methods

A cross sectional study based on interviews and questionnaire responses from 1527 subjects, aged 18–75 years of age, from Västra Götaland in Sweden, as part of the larger West Sweden Asthma Study. IgE analyses were performed in sera from all subjects.

Results

Fifty three percent of adults with asthma reported adverse reactions to foods compared to 30 % of non-asthmatics. Most asthmatics reported symptoms from eating hazelnut, followed by other nuts, birch-related foods, milk, peanut and shellfish. Furthermore, adults with asthma experienced significantly more often gastrointestinal symptoms from hazelnut, apple and milk and were found to significantly more often be sensitized to the most common foods compared to the non-asthmatic subjects. The asthmatics showed a significant correlation between IgE to both hazelnut and birch and self-reported symptoms after ingestion of hazelnut and to a lesser extent to almonds.

Conclusions

The prevalence of self-reported adverse reactions and sensitization to the most common foods was much higher among the asthmatic subjects. Hazelnut was the food that asthmatics most frequently experienced adverse reactions from, and the strong correlation between IgE to hazelnut and birch indicate that the observed adverse reactions are partly due to sensitization to allergens from the PR-10 family.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-015-0067-6) contains supplementary material, which is available to authorized users.

Small intestinal permeability in patients with eosinophilic oesophagitis during active phase and remission

BACKGROUND

Eosinophilic oesophagitis (EoE) is presumed to be an isolated oesophageal disease; yet other allergic diseases associated with eosinophilic infiltration of target tissues, such as asthma and eczema, show perturbed functions of other sites that may be involved in the diathesis of allergy modulation.

AIM

To analyse small intestinal permeability in patients with active EoE and in a separate group of patients in remission.

METHODS

Small bowel permeability was determined using a dual sugar method by calculating lactulose:mannitol (L:M) ratio in 17 patients who met consensus criteria for active EoE (>15 eos/HPF) and 8 patients in remission (<5 eos/HPF). Data from 28 healthy controls was used for comparison.

RESULTS

Patients with active EoE had significantly higher L:M ratios when compared to controls (0.045 vs. 0.033, p<0.001) and to EoE in remission (0.041 vs. 0.027, p<.001). There was no significant difference in L:M between the group with EoEin remission and healthy controls. The current data show that L:M ratio of 0.033 also provides a reasonable cut-off that defined the active EoE group compared to patients in remission. The main component explaining the change in L:M ratio was increased absorption (and excretion) of lactulose ((1601 ± 106 ug) when compared to the EoE remission (969 ± 91 ug) and control (1043 ± 92 ug, p<.001) groups.

CONCLUSIONS

Small bowel permeability is overall increased in patients with active EoE, and is normal in patients with EoE in remission when compared to healthy controls. The role of the small bowel in active EoE deserves further investigation.

Intestinal and gastric permeability in children with eosinophilic esophagitis and reflux esophagitis

OBJECTIVES

Eosinophilic esophagitis (EoE) is an allergic and immune-mediated entity that leads to a characteristic inflammation of esophageal mucosa. Patients complain of dysphagia and reflux-like symptoms. As many as 80% of patients with EoE may also have a history of atopy, and patients with asthma and eczema have previously been shown to have increased intestinal permeability. This study was designed to assess small intestinal and gastric permeability in patients with EoE and to see whether it differed from healthy individuals and patients with reflux esophagitis (RE).

METHODS

Gastric and small intestinal permeability was measured using sugar probe tests containing lactulose, mannitol, and sucrose. Lactulose-to-mannitol (L/M) ratios in the patient's urine were a measure for intestinal permeability, and total sucrose was a measure for gastric permeability.

RESULTS

We analyzed samples from 23 patients with EoE, 20 RE, 14 normal upper endoscopy with gastrointestinal symptoms, and 26 healthy controls. All of the 4 groups had L/M ratios less than the upper limit of normal (<0.025). There was no statistically significant difference in gastric permeability between the 4 groups (L/M P = 0.26, sucrose P = 0.46).

CONCLUSIONS

Our data suggest that an alteration in gastric and intestinal permeability does not play a role in EoE or RE pathogenesis.

Increased incidence of inflammatory bowel disease in Québec residents with airway diseases

The objective of the study was to assess whether the incidences of Crohn's disease and ulcerative colitis are increased in patients with asthma and chronic obstructive pulmonary disease (COPD) compared to the general population. A population-based retrospective cohort study was conducted using the administrative health databases of Québec, Canada. Incidences of Crohn's disease and ulcerative colitis among patients with asthma and COPD were assessed for the 2001-2006 period. In total, 136 178 subjects with asthma and 143 904 subjects with COPD were identified. The average incidence of Crohn's disease and ulcerative colitis was 23.1 and 8.8 per 100 000 person-years among asthmatic patients; in the COPD cohort there were 26.2 Crohn's disease cases and 17 ulcerative colitis cases per 100 000 person-years. The incidence of Crohn's disease in asthma and COPD patients was 27% and 55% higher than in the general population of Québec; the incidence of ulcerative colitis was 30% higher among COPD patients compared to the general population. Incidence of inflammatory bowel disease was significantly increased in asthma and COPD patients compared to the general population of Québec. Incidence rates were particularly high in patients with COPD. Awareness of an association between airway diseases and inflammatory bowel disease in older age groups may play an important role in earlier detection of bowel disease and in the therapeutic management of such patients.

Toll-like receptor 2 activation by β2→1-fructans protects barrier function of T84 human intestinal epithelial cells in a chain length-dependent manner

Dietary fiber intake is associated with lower incidence and mortality from disease, but the underlying mechanisms of these protective effects are unclear. We hypothesized that β2→1-fructan dietary fibers confer protection on intestinal epithelial cell barrier function via Toll-like receptor 2 (TLR2), and we studied whether β2→1-fructan chain-length differences affect this process. T84 human intestinal epithelial cell monolayers were incubated with 4 β2→1-fructan formulations of different chain-length compositions and were stimulated with the proinflammatory phorbol 12-myristate 13-acetate (PMA). Transepithelial electrical resistance (TEER) was analyzed by electric cell substrate impedance sensing (ECIS) as a measure for tight junction-mediated barrier function. To confirm TLR2 involvement in barrier modulation by β2→1-fructans, ECIS experiments were repeated using TLR2 blocking antibody. After preincubation of T84 cells with short-chain β2→1-fructans, the decrease in TEER as induced by PMA (62.3 ± 5.2%, P < 0.001) was strongly attenuated (15.2 ± 8.8%, P < 0.01). However, when PMA was applied first, no effect on recovery was observed during addition of the fructans. By blocking TLR2 on the T84 cells, the protective effect of short-chain β2→1-fructans was substantially inhibited. Stimulation of human embryonic kidney human TLR2 reporter cells with β2→1-fructans induced activation of nuclear factor kappa-light-chain-enhancer of activated B cells, confirming that β2→1-fructans are specific ligands for TLR2. To conclude, β2→1-fructans exert time-dependent and chain length-dependent protective effects on the T84 intestinal epithelial cell barrier mediated via TLR2. These results suggest that TLR2 located on intestinal epithelial cells could be a target of β2→1-fructan-mediated health effects.

Intestinal allergic inflammation in birch pollen allergic patients in relation to pollen season, IgE sensitization profile and gastrointestinal symptoms

BACKGROUND

Birch pollen allergic patients frequently experience gastrointestinal upset accompanied by a local allergic inflammation in the small intestine especially during the pollen season. However, it is not known if the GI pathology is connected to the subjective symptoms of the patient. The objective of this study was to evaluate the immune pathology of the duodenal mucosa and the serum IgE antibody profiles in birch pollen allergic patients in relation to their gastrointestinal symptoms, during and outside the birch pollen season.

METHODS

Thirty-two patients with birch pollen allergy and sixteen healthy controls were enrolled in the study. Twenty allergic patients had gastrointestinal symptoms and twelve did not. All participants underwent an allergy investigation and gastroscopy with duodenal biopsy. The duodenal biopsies were retrieved during the pollen season (May-June) and off-season (November-March). The biopsies were immunostained for mast cells (IgE and tryptase), eosinophils, T cells (CD3), and dendritic cells (CD11c). Pollen-specific IgE antibodies were determined by ImmunoCAP and component microarray (ISAC).

RESULTS

Patients in both pollen allergic groups showed similar degree of intestinal allergic inflammation during the pollen season regardless of gastrointestinal symptoms. The eosinophils, mast cells and dendritic cells were increased in the mucosa. Patients with gastrointestinal symptoms had significantly elevated IgE antibodies to birch (rBet v 1), hazelnut (rCor a 1), and apple (rMal d1) during the pollen season.

CONCLUSIONS

Patients allergic to birch pollen have clear signs of an ongoing allergic inflammation in their intestinal mucosa, which is aggravated during the pollen season. The magnitude of the allergic intestinal inflammation is not associated with subjective gastrointestinal symptoms of the individual patient.

Maternally acquired genotoxic Escherichia coli alters offspring's intestinal homeostasis

The neonatal gut is rapidly colonized by a newly dominant group of commensal Escherichia coli strains among which a large proportion produces a genotoxin called colibactin. In order to analyze the short- and long-term effects resulting from such evolution, we developed a rat model mimicking the natural transmission of E. coli from mothers to neonates. Genotoxic and non-genotoxic E. coli strains were equally transmitted to the offspring and stably colonized the gut across generations. DNA damage was only detected in neonates colonized with genotoxic E. coli strains. Signs of genotoxic stress such as anaphase bridges, higher occurrence of crypt fission and accelerated renewal of the mature epithelium were detected at adulthood. In addition, we observed alterations of secretory cell populations and gut epithelial barrier. Our findings illustrate how critical is the genotype of E. coli strains acquired at birth for gut homeostasis at adulthood.

Probiotics in the management of lung diseases

The physiology and pathology of the respiratory and gastrointestinal tracts are closely related. This similarity between the two organs may underlie why dysfunction in one organ may induce illness in the other. For example, smoking is a major risk factor for COPD and IBD and increases the risk of developing Crohn's disease. Probiotics have been defined as "live microorganisms which, when administered in adequate amounts, confer health benefits on the host." In model systems probiotics regulate innate and inflammatory immune responses. Commonly used probiotics include lactic acid bacteria, particularly Lactobacillus, Bifidobacterium, and Saccharomyces, and these are often used as dietary supplements to provide a health benefit in gastrointestinal diseases including infections, inflammatory bowel disease, and colon cancer. In this respect, probiotics probably act as immunomodulatory agents and activators of host defence pathways which suggest that they could influence disease severity and incidence at sites distal to the gut. There is increasing evidence that orally delivered probiotics are able to regulate immune responses in the respiratory system. This review provides an overview of the possible role of probiotics and their mechanisms of action in the prevention and treatment of respiratory diseases.

Study on traditional Chinese medicine theory of lung being connected with large intestine

OBJECTIVE

The theory of lung being connected with large intestine, which is a major topic in Traditional Chinese Medicine (TCM), has guided clinical practice for thousands of years in China.

METHODS

In this study, we analyzed the history, main contents, clinical application, and material basis of the theory, to attempt to improve the potential clinical significance of "lung being connected with large intestine" in China.

RESULTS

The lung being connected with large intestine was first described in "Huang Di Nei Jing", and formed one of the basic theories of TCM. For thousands of years, the majority of TCM practitioners explored this theory continuously, leading to its development and use as an important theory in the guidance of TCM clinics In the last decade, researchers in the field of integrated TCM and Western medicine have studied clinical applications and biomedical mechanisms with experimental methods to explore the implications of the theory.

CONCLUSION

With the further development of science and technology, research concerning the theory of lung being connected with large intestine will be greatly stimulated and contribute to the modernization of TCM.

Oral administration of fermented red ginseng suppressed ovalbumin-induced allergic responses in female BALB/c mice

Anti-allergic efficacy of red ginseng (RG) and fermented red ginseng (FRG) was evaluated. RG or FRG were administered to ovalbumin (OVA)-sensitized mice for 8 weeks. Immunoglobulins (Igs), Th1/Th2 type cytokines, and β-lactoglobulin (BLG) in serum, and intestinal barrier-related molecules in jejunum were measured using enzyme-linked immunosorbent assay or reverse transcription-polymerase chain reaction. Mice sensitized with OVA increased serum IgG₁, IgE, OVA-IgG₁, and OVA-IgE. Both RG and FRG decreased serum IgE, OVA-IgE, and pro-inflammatory cytokines. Serum BLG, a marker of gut permeability, was significantly higher in sensitized animals and was decreased in mice fed RG or FRG. In addition, intestinal barrier-related markers such as MMCP-1, IL-4, TNF-α, COX-2, and iNOS mRNA expressions were decreased by RG or FRG. Our results suggest in vivo anti-allergic activities of RG or FRG, which are associated with the regulation of Th1/Th2 balance, intestinal inflammation and subsequent the suppression of IgE.

Gut matters: microbe-host interactions in allergic diseases

The human body can be considered a metaorganism made up of its own eukaryotic cells and trillions of microbes that colonize superficial body sites, such as the skin, airways, and gastrointestinal tract. The coevolution of host and microbes brought about a variety of molecular mechanisms, which ensure a peaceful relationship. The mammalian barrier and immune functions warrant simultaneous protection of the host against deleterious infections, as well as tolerance toward harmless commensals. Because these pivotal host functions evolved under high microbial pressure, they obviously depend on a complex network of microbe-host interactions. The rapid spread of immune-mediated disorders, such as autoimmune diseases, inflammatory bowel diseases, and allergies, in westernized countries is thus thought to be due to environmentally mediated disturbances of this microbe-host interaction network. The aim of the present review is to highlight the importance of the intestinal microbiota in shaping host immune mechanisms, with particular emphasis on allergic diseases and possible intervention strategies.

Pulmonary-intestinal cross-talk in mucosal inflammatory disease

Chronic obstructive pulmonary disease (COPD) and inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of mucosal tissues that affect the respiratory and gastrointestinal tracts, respectively. They share many similarities in epidemiological and clinical characteristics, as well as in inflammatory pathologies. Importantly, both conditions are accompanied by systemic comorbidities that are largely overlooked in both basic and clinical research. Therefore, consideration of these complications may maximize the efficacy of prevention and treatment approaches. Here, we examine both the intestinal involvement in COPD and the pulmonary manifestations of IBD. We also review the evidence for inflammatory organ cross-talk that may drive these associations, and discuss the current frontiers of research into these issues.

Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer

The primary functions of the gastrointestinal tract have traditionally been perceived to be limited to the digestion and absorption of nutrients and to electrolytes and water homeostasis. A more attentive analysis of the anatomic and functional arrangement of the gastrointestinal tract, however, suggests that another extremely important function of this organ is its ability to regulate the trafficking of macromolecules between the environment and the host through a barrier mechanism. Together with the gut-associated lymphoid tissue and the neuroendocrine network, the intestinal epithelial barrier, with its intercellular tight junctions, controls the equilibrium between tolerance and immunity to non-self antigens. Zonulin is the only physiological modulator of intercellular tight junctions described so far that is involved in trafficking of macromolecules and, therefore, in tolerance/immune response balance. When the finely tuned zonulin pathway is deregulated in genetically susceptible individuals, both intestinal and extraintestinal autoimmune, inflammatory, and neoplastic disorders can occur. This new paradigm subverts traditional theories underlying the development of these diseases and suggests that these processes can be arrested if the interplay between genes and environmental triggers is prevented by reestablishing the zonulin-dependent intestinal barrier function. This review is timely given the increased interest in the role of a "leaky gut" in the pathogenesis of several pathological conditions targeting both the intestine and extraintestinal organs.

The impact of asthma on the gastrointestinal tract (GIT)

The gastrointestinal tract (GIT) of vertebrates is composed of several distinct compartments and glands as well as an extensive mucosal surface. Its primary function is that of chemical and physical digestion of food and the absorption of nutrients; however, due to its continual antigen exposure, the GIT also has an important defensive immunological function. The GIT's immunological participation is facilitated by the mucosa-associated lymphoid tissues, thought to share the mucosal immunological system with the respiratory mucosa-associated lymphoid tissues. As a result of this shared mucosal immunity, it has been hypothesized that bronchial asthma may be able to affect the body's GIT in the same pathophysiological manner as the airways and lungs. Here we discuss the link between bronchial asthma and pathophysiological features in the GIT - including leukocyte influx, goblet cell alterations, fibrosis, and epithelial and villous atrophy.

Asthma and autoimmunity: a complex but intriguing relation

Asthma and autoimmune diseases apparently have little to share except for the involvement of the immune system in both types of disorder. However, epidemiological studies have shown that asthma and Type 1 diabetes, a typical autoimmune disease, are associated at the population level, and some experimental findings have suggested that autoimmune mechanisms might be operating in asthma as well. Female preponderance, increased incidence of antinuclear autoantibodies and detection of autoantibodies against either bronchial epithelial antigens or endothelial antigens in patients with nonallergic asthma suggest that the disease may have an autoimmune basis. Approximately 50% of patients with nonallergic asthma react to intradermal injection of autologous serum, indicating the presence of circulating vasoactive factors and suggesting an autoreactive mechanism. Recent findings in experimental animals support the involvement of an autoreactive mechanism in allergic asthma as well, indicating that human alpha-nascent polypeptide-associated complex, identified as an IgE-reactive autoantigen, has the potential to sensitize and induce immediate skin reactions and airway inflammation. In summary, asthma is a heterogeneous disorder characterized by chronic inflammation of the respiratory airways that can be triggered by allergen exposure or by other mechanisms, possibly autoreactive/autoimmune. The autoimmune hypothesis is further, indirectly, supported by the response to immunosuppressive drugs.

Gastrointestinal eosinophils in health, disease and functional disorders

Eosinophils are potent innate immune cells that home to the gastrointestinal tract where they participate in host immunity to luminal pathogens, and help to maintain intestinal epithelial homeostasis. However, these cells are now recognized to have key functions in the pathogenesis of numerous other disorders of the gastrointestinal tract, including primary eosinophilic gastrointestinal disease, common functional conditions, such as dyspepsia, and also in gastrointestinal disorders in patients with allergic disease. We are just beginning to understand the potential pathological role of eosinophils in gastrointestinal disease, and it is increasingly likely that gastroenterologists and histopathologists will need to account for the presence of gastrointestinal eosinophils and relate their presence to gastrointestinal symptoms. This Review discusses the role of gastrointestinal eosinophils in health and disease, including their associations with functional and allergic disorders.