Increased prevalence of gastrointestinal symptoms in patients with allergic disease

A systematic review of the association between environmental risk factors and the development of irritable bowel syndrome

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with roots in genetic, immune, psychological, and dietary factors. Recently, the potential correlation between environmental exposures, such as air pollution, and IBS has gained attention. This review aimed to systematically examine existing studies on environmental factors associated with IBS, elucidating this interplay and guiding future research.

METHODS

A literature search was conducted in Medline, EMBASE, Scopus, and Cochrane databases from database inception to October 10, 2023, using the keywords "Irritable Bowel" or IBS or "Irritable Colon" or "Mucous Colitis" or "Spastic Colitis" or "Spastic Colon" AND "environment* exposure*". Studies were included if they were original, published in English, described defined environmental exposure(s), and had documented diagnosis of IBS. For the purposes of this review, articles reporting physical (e.g. radiation and climate change), biological (e.g. bacteria and viruses), and chemical (e.g. harmful gases) exposures were included while psychological and dietary factors, which have been reviewed in detail elsewhere, are outside of the scope.

RESULTS

A total of seven studies focusing on air quality, microbial exposure, and other environmental factors were reviewed. Studies highlighted a potential association between air pollutants and increased IBS incidence. Microbial exposure, post-natural disaster or due to poor sanitation, was linked to IBS development and gut dysbiosis. Other exposures, such as early pet ownership, were also associated with IBS risk.

CONCLUSION

Existing research demonstrates an epidemiologic relationship between environmental exposures and the development of IBS. Further research is needed to understand these associations.

Multimorbidity of Allergic Diseases Is Associated With Functional Gastrointestinal Disorders in a Young Japanese Population

Background/Aims

Although certain allergic diseases have been reported to be associated with the prevalence of functional dyspepsia (FD) and irritable bowel syndrome (IBS), it is unclear whether the presence of multiple allergic diseases further increases the prevalence of FD and IBS. The aim of this study is to determine this issue in young people.

Methods

A cohort of 8923 Japanese university students was enrolled and diagnoses of FD and IBS were confirmed using Rome III criteria. Allergic disorders diagnosed at medical institutions were obtained by means of a self-administered questionnaire.

Results

The prevalence of FD, IBS, and their overlap was found to be 1.9%, 6.5%, and 1.1%, respectively. Pollen allergy was independently positively correlated with FD, IBS, and overlap of FD and IBS. Allergic rhinitis was positively linked to IBS. Drug allergy was positively associated with FD. The presence of multiple allergic diseases was positively correlated with FD and IBS (FD: adjusted OR for 2 allergic diseases: 1.95 [95% CI, 1.24-2.98], P for trend = 0.003; and IBS: adjusted OR for 1 allergic disease: 1.40 [95% CI, 1.15-1.69], 2 allergic diseases 1.47 [95% CI, 1.12-1.91], and 3 or more allergic diseases: 2.22 [95% CI, 1.45-3.28], P for trend = 0.001). Additionally, the concomitant existence of multiple allergic diseases was also demonstrated to have a trend that correlated with the overlap of FD and IBS (P for trend = 0.018).

Conclusion

Allergic disease multimorbidity is positively correlated with the prevalence of FD and IBS in a young population.

Cordyceps militaris polysaccharide alleviates ovalbumin-induced allergic asthma through the Nrf2/HO-1 and NF-κB signaling pathways and regulates the gut microbiota

Polysaccharides, as one of the main types of bioactive components of Cordyceps militaris, have anti-allergic asthma effects. Herein, an ovalbumin-induced allergic asthma mouse model was established to assess the potential mechanisms of the separated and purified Cordyceps militaris polysaccharide (CMP). CMP is an α-pyranose with a molecular weight of 15.94 kDa that consists of Glc, Man, Gal, Xyl, Ara and GlcA in a molar ratio of 81.25:21.96:13.88:3.92:3.58:1.00. CMP improved inflammatory cytokine levels, alleviated the histopathological changes in the lung and intestinal tissues, regulated the expression of mRNA and proteins related to oxidative stress and inflammatory pathways, reversed gut dysbiosis at the phylum and family levels and improved microbiota function in allergic asthma mice. Moreover, it was found that the levels of inflammatory cytokines in lung tissue of mice were significantly correlated with some intestinal microbial communities. Overall, CMP improved oxidative stress and the inflammatory response in allergic asthma mice by regulating the Nrf2/HO-1 and NF-κB signaling pathways, which may be closely correlation with maintaining the stability of the gut microbiota.

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.

Immune Activation in Functional Dyspepsia: Bystander Becoming the Suspect

Disorders of gut-brain interaction (DGBI), formerly termed functional gastrointestinal disorders (FGID), are highly prevalent although exact pathophysiological mechanisms remain unclear. Intestinal immune activation has been recognized, but increasing evidence supports a pivotal role for an active inflammatory state in these disorders. In functional dyspepsia (FD), marked eosinophil and mast cell infiltration has been repeatedly demonstrated and associations with symptoms emphasize the relevance of an eosinophil-mast cell axis in FD pathophysiology. In this Review, we highlight the importance of immune activation in DGBI with a focus on FD. We summarize eosinophil biology in both homeostasis and inflammatory processes. The evidence for immune activation in FD is outlined with attention to alterations on both cellular and molecular level, and how these may contribute to FD symptomatology. As DGBI are complex and multifactorial conditions, we shed light on factors associated to, and potentially influencing immune activation, including bidirectional gut-brain interaction, allergy and the microbiota. Crucial studies reveal a therapeutic benefit of treatments targeting immune activation, suggesting that specific anti-inflammatory therapies could offer renewed hope for at least a subset of DGBI patients. Lastly, we explore the future directions for DGBI research that could advance the field. Taken together, emerging evidence supports the recognition of FD as an immune-mediated organic-based disorder, challenging the paradigm of a strictly functional nature.

Colonic Mucosal Immune Activation in Mice with Ovalbumin-Induced Allergic Airway Disease: Association between Allergic Airway Disease and Irritable Bowel Syndrome

Recent studies on the pathophysiology of irritable bowel syndrome (IBS) have focused on the role of mast cells (MCs) in intestinal mucosal immunity. A link between allergic airway diseases (AADs) and IBS has been suggested because both diseases have similar pathophysiology. We aimed to investigate whether the induction of AAD in mice could lead to inflammation of the colonic mucosa, similar to IBS. We also evaluated whether this inflammatory response could be suppressed by administering a therapeutic agent. Mice were divided into three groups: control, AAD-induced, and salbutamol-treated. An AAD mouse model was established by intraperitoneal injection and nasal challenge with ovalbumin. Mice with AAD were intranasally administered salbutamol. Analyses of cytokine levels, MC count, and tryptase levels in the intestinal mucosa were performed to compare the changes in inflammatory responses among the three groups. Inflammation was observed in the intestinal mucosa of mice in the AAD group. This inflammation in AAD mice was suppressed after salbutamol treatment. Our study demonstrates that AAD induces an inflammatory response similar to that in IBS, suggesting a possible association between IBS and AADs. In patients with IBS with such allergic components, salbutamol may have the potential to alleviate the inflammatory response.

The structure of health in Europe: The relationships between morbidity, functional limitation, and subjective health

The main objective of this study is to explore the relationships between the three commonly used proxies of health, morbidity, functional limitation, and subjective health, using the most recent data from 18 European countries. The existing studies on the topic are outdated, limited to the United States and to elderly population. Data on 32,679 respondents of the European Social Survey (2014) were analyzed using structural equation modeling. The results suggest that (a) morbidity and functional limitation lead to poorer self-rated health, and (b) morbidity increases the probability of reporting functional limitation(s). Moreover, functional limitation mediates the relationship between morbidity and self-rated health. The model as a whole holds across both genders and all age groups. However, specific tests (SEM multi-group analyses, t-tests) show differences in the health structure between all seven subsamples compared with each other. When both gender and age are taken into account the differences in the structure of health seem to diminish, apart from the elderly, suggesting that the health structure of the elderly differs from others. It is recommended for policy planners to acknowledge the group differences when shaping the policies and health services.

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First study to test a structure of health model on Europeans of all adult ages.

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Morbidity affects functional limitation and subjective health.

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Functional limitation has a negative effect on subjective health.

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Morbidity also affects subjective health indirectly via functional limitation.

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The model is stable across the groups despite some differences in the effect magnitudes.

Allergy-related diseases in childhood and risk for abdominal pain-related functional gastrointestinal disorders at 16 years-a birth cohort study

BACKGROUND

Studies on allergy-related diseases in relation to abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) in children are few and results are contradictory. We examined the associations between childhood allergy-related diseases and adolescent AP-FGIDs in general and irritable bowel syndrome (IBS) in particular.

METHOD

Prospective population-based birth cohort study of 4089 children born in Sweden 1994-1996. We analysed data from 2949 children with complete follow-up at 16 years (y) and no diagnosis of inflammatory bowel disease or coeliac disease at 12y or 16y. Asthma, rhinitis, eczema, and food hypersensitivity (FH) were assessed through questionnaires at 1-2y, 4y, 8y, 12y, and 16y. AP-FGIDs and IBS were assessed through questionnaires at 16y and defined according to the Rome III criteria. Associations between childhood allergy-related diseases and any AP-FGID and IBS and 16y respectively were examined using binomial generalized linear models with a log link function and described as relative risk with 95% confidence intervals.

RESULTS

The prevalence of any AP-FGID and IBS at 16y were 12.0% and 6.0% respectively. Eczema at 1-2y, 4y, and 8y, and FH at 12y and 16y were associated with an increased risk for any AP-FGID at 16y. Asthma and FH at 12y and 16y were associated with an increased risk for IBS at 16y. The relative risk for IBS at 16y increased with increasing number of concurrent allergy-related diseases at 16y, but linear trend for relative risk was only borderline statistically significant (P for trend = 0.05).

CONCLUSIONS

This prospective population-based study demonstrated positive associations between childhood allergy-related diseases and adolescent AP-FGIDs, including IBS, implicating shared pathophysiology among these disorders.

Functional abdominal pain disorders and asthma: two disorders, but similar pathophysiology?

INTRODUCTION

Functional abdominal pain disorders (FAPDs) and asthma are common ailments affecting both children and adults worldwide. Multiple studies have demonstrated an association between these two disorders. However, the exact reason for this observed association is not apparent.

AREAS COVERED

The current review has explored available literature and outlined multiple underlying pathophysiological mechanisms, common to both asthma and FAPDs, as possible reasons for this association.

EXPERT OPINION

Smooth muscle dysfunction, hypersensitivity and hyper-responsiveness, mucosal inflammation, and barrier dysfunction involving gastrointestinal and respiratory tracts are the main underlying pathophysiological mechanisms described for the generation of symptoms in FAPDs and asthma. In addition, alterations in neuroendocrine regulatory functions, immunological dysfunction, and microbial dysbiosis have been described in both disorders. We believe that the pathophysiological processes that were explored in this article would be able to expand the mechanisms of the association. The in-depth knowledge is needed to be converted to therapeutic and preventive strategies to improve the quality of care of children suffering from FAPDs and asthma.

Prevalence and Symptom Characteristics of Irritable Bowel Syndrome Among Bronchial Asthma Patients in Pakistan

INTRODUCTION

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that leads to a variety of symptoms including abdominal discomfort and change in stool frequency and consistency. Asthma is a common disease of the airway. Some studies have suggested that a relationship between IBS and asthma exist, while others have contradicted the claim. This study aims to determine the prevalence of IBS in asthmatic patients and compare their symptoms with symptoms of IBS patients in non-asthmatic patients.

METHODOLOGY

In this case-control study, 100 known and documented asthmatic patients were included as cases, and 100 non-asthmatic healthy patients were included as controls from July to August 2019. These patients were given a questionnaire based on ROME II criteria for the diagnosis of IBS. Prevalence and symptoms of IBS were compared between cases and controls. A probability level, P < 0.05 was considered significant.  Result: IBS was found in 41 out of 100 asthma patients (41%) and 18 out of 100 controls (18%) with a P-value of 0.0005 and was more common in females in both asthmatic (63.41%) and non-asthmatic patients (66.66%). Symptoms such as abdominal pain/distress (63.41% vs. 11.11%, P-value: 0.0013) and bloating (82.92% vs. 33.33%, P-value: 0.0005) were significantly higher in asthmatic patient with IBS compared to non-asthmatic patient with IBS.

CONCLUSION

Prevalence of IBS among asthma patients was significantly higher as compared to non-asthmatics. Routine screening of asthma patients and further studies to understand the pathogenesis underlying association between IBS and asthma should be conducted to detect and manage such patients effectively.

The impact of allergic rhinitis on gastrointestinal disorders among young adults

BACKGROUND

An association between allergic rhinitis (AR) and digestive diseases (DDs) has been reported; however, studies have only focused on the prevalence of DDs in populations of patients with AR. In individuals with specific DDs, the impact of AR on the frequency of clinical visits for each DD has not been studied. Moreover, the association between topical steroid usage for AR and DDs has not been investigated.

METHODS

Data from 16 526 men and 18 438 women, aged 21 to 30 years, were collected from a national database. Individuals were separated into the AR and non-AR groups. Eight common DDs were studied: (1) gastroesophageal reflux disease (GERD), (2) gastritis and duodenitis, (3) peptic ulcers, (4) irritable bowel syndrome, (5) gastric functional disease, (6) intestinal functional disease, (7) gastroenteritis and colitis, and (8) constipation. The rate of each DD was compared between groups. In individuals with specific DDs, the frequency of clinical visits for each DD was also compared between groups. Between users and nonusers of topical steroids in the AR group, the rate of DDs was compared.

RESULTS

Significant associations were observed between all eight DDs and AR in both sexes. In comparison to the non-AR group, women with AR visited clinics more frequently for gastritis/duodenitis, gastric and intestinal functional disease, gastroenteritis/colitis, and constipation, while men with AR visited clinics more frequently for gastritis/duodenitis, gastric functional disease, gastroenteritis/colitis, and constipation. Female topical-steroid users with AR had higher rates of GERD, irritable bowel syndrome, gastric or intestinal functional disease, and gastritis/colitis. Male topical-steroid users with AR had higher rates of GERD and peptic ulcers.

CONCLUSION

AR was associated with DDs in both sexes. However, the influence of AR on clinical visit frequency varied among specific DD groups. Topical steroid usage for AR was associated with some DDs, but the association requires future evaluation.

Association between Irritable Bowel Syndrome and Allergic Diseases: To Make a Case for Aeroallergen

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease and the most common cause of prolonged abdominal pain and bowel disturbances in the developed world. While initially thought to be functional or psychosomatic in nature, IBS is now recognized as a heterogeneous group of conditions. A subset of IBS patients and patients with allergic diseases share some characteristic inflammatory features. In fact, atopic children show an increased likelihood of developing IBS as adults. Given these findings, a subset of IBS may be suffering from allergy-related gut diseases. In this review, we present the allergy-related comorbidities of IBS, including genetic, environmental, and immunologic factors. We discuss studies demonstrating an increased sensitization of IBS patients to aeroallergens compared to food allergens. We then postulate potential pathophysiological mechanisms underlying both IBS and aeroallergens in the gut, followed by potential implications in the screening and treatment of allergies in IBS patients.

Gastroenteritis during infancy is a novel risk factor for allergic disease

Antibiotics during infancy, delivery, and breastfeeding affect the intestinal microbiota in early life and is associated with allergic disease. Gastroenteritis (GE) during infancy also affects intestinal microbiota in early life, however, its relationship to allergic disease has not been investigated.Data of 45,499 males and 49,430 females, from birth to 5 years of age, were collected from a national database in Taiwan. Subjects were categorized into early GE (GE within 0-6 months) and non-early GE group (no GE within 0-6 months). The rates of asthma (AS), allergic rhinitis (AR), and atopic dermatitis (AD) over 5 years were evaluated and compared between the groups. In patients with AS, AR, and AD, the number of clinical visits and drug prescriptions for the allergic disease was also evaluated to assess the effect of early GE on allergic disease.After adjusting for the effect of GE in later life and other factors, the rates of AS [OR (odds ratio) 1.54, 95% confidence interval (CI) 1.48-1.60], AR [OR 1.49, 95% CI 1.45-1.54], and AD [OR 1.40, 95% CI 1.33-1.47] were higher in the early GE group than in the non-early GE group. The magnitude of the increase was higher in females than in males. In those with AS, AR, and AD, the number of clinical visits and drug prescriptions was not different between the early GE and non-early GE groups. In children with early GE, good control of GE in the following years lowered the rate of allergic disease.Early-life GE was associated with increased rates of AS, AR, and AD in later life and this was trend more prominent in females.

Prevalence of food hypersensitivity in relation to IgE sensitisation to common food allergens among the general adult population in West Sweden

Background

The prevalence of self-experienced adverse reactions to foods seems to have an increasing trend in both adults and children. However, it is unclear if the prevalence of food hypersensitivity in the Swedish adult population is still rising, what symptoms are caused by different foods and which are the most common foods to which adults are more frequently IgE-sensitised.

Methods

In a cross-sectional study based on questionnaire responses, interviews and clinical examinations as part of the West Sweden Asthma Study, 1042 subjects from the general population, 17–78 years of age, living in Västra Götaland, Sweden, were included. The subjects reported symptoms for 56 specified foods and blood samples were taken to examine the IgE-sensitisation pattern for 9 common foods.

Results

Approximately 32% of adults reported food hypersensitivity, affecting mostly women and subjects less than 61 years old. The foods most often reported to cause adverse reactions were hazelnut (8.9%), apple (8.4%), milk (7.4%) and kiwi (7.3%). Less than one percent (0.9%) reported symptoms from ingestion of meat. Symptoms mostly affected the gastrointestinal tract (15%) and the skin (2.7%). Sixteen per cent were IgE-sensitised to common foods, most often to hazelnut (13.3%), peanut (4.9%) and almond (3.0%), while 5.9% reported symptoms and were IgE-sensitised to the same food, mainly to hazelnut (5.3%).

Conclusions

The prevalence of self-reported food hypersensitivity in West Sweden indicates a rising trend. The correspondence between self-reported symptoms and IgE-sensitisation to foods is generally poor, except for hazelnut and almond which exhibit moderate or fair correlation.

Association between functional abdominal pain disorders and asthma in adolescents: A cross-sectional study

AIM

To find the association between asthma and different types of functional abdominal pain disorders (FAPDs) among teenagers.

METHOD

A cross-sectional study was conducted among 13 to 15-year-old children from six randomly selected schools in Anuradhapura district of Sri Lanka. Data were collected using translated and validated self-administered questionnaires (Rome III questionnaire, International Study on Asthma and Allergies in Childhood questionnaire, and Pediatric Quality of Life Inventory 4.0) and administered under an examination setting after obtaining parental consent and assent.

RESULTS

Of the 1101 children included in the analysis, 157 (14.3%) had asthma and 101 (9.2%) had at least one FAPDs. Of children with asthma, 19.1% had at least one type of FAPDs. Prevalence rates of functional abdominal pain (FAP) (8.9% vs 3.3% in non-asthmatics), functional dyspepsia (FD) (2.5% vs 0.7%), and abdominal migraine (AM) (3.2% vs 0.4%) were higher in those with asthma (P < 0.05, multiple logistic regression analysis), but not in those with irritable bowel syndrome (4.5% vs 3.1%, P = 0.2). Severe abdominal pain (10.8% vs 4.6%), bloating (16.6% vs 9.6%), nausea (6.4% vs 2.9%), and anorexia (24.2% vs 16.2%) were more prevalent among asthmatics (P < 0.05). Lower gastrointestinal symptoms did not show a significant difference. Scores obtained for health related quality of life (HRQoL) were lower in those with asthma and FAPDs (P < 0.05, unpaired t-test).

CONCLUSION

Asthma is associated with three different types of FAPDs, namely, FD, AM, and FAP. HRQoL is significantly impaired in teenagers with asthma and FAPDs.

Prevalence of functional GI disorders among pediatric patients with persistent asthma

OBJECTIVE

Functional gastrointestinal (GI) disorders (FGIDs), such as irritable bowel syndrome, functional abdominal pain and dyspepsia, are common causes of chronic GI symptoms in children. Prior studies found high comorbidity of FGID and asthma. This study aimed to assess the prevalence and comorbidities of FGID among pediatric patients with asthma at a university-affiliated urban community hospital.

METHODS

This prospective, cross-sectional study assessed FGID prevalence, asthma control and symptoms of anxiety among pediatric patients with persistent asthma. The pediatric ROME III questionnaire was used to assess FGID. The Asthma Control Test assessed asthma control. The Beck Anxiety Inventory assessed symptoms of anxiety.

RESULTS

Of the 110 enrolled patients, 18 (16.4%) met the diagnostic criteria for FGID, of which 10 were consistent with the diagnosis of functional abdominal pain disorder. Patients with FGID had a significantly lower mean asthma control score than patients without FGID (11.5 ± 4.9 vs 14.8 ± 5.3, P = 0.03; Cohen's d = 0.6) and higher mean anxiety scores than those without FGID (P < 0.01). Asthma control predicted the presence of FGID (OR 0.90, 95% CI 0.80-0.99, P = 0.03). However, after adjusted for anxiety, asthma control no longer predicted FGID presence (adjusted OR 0.90, 95% CI 0.83-1.05, P = 0.23).

CONCLUSIONS

This study suggests a high prevalence of FGID among patients with persistent asthma. Moreover, patients with FGID had poor asthma control and increased anxiety. Clinicians should consider FGID in patients with poor asthma control and assess them for anxiety.

Risks for comorbidity in children with atopic disorders: an observational study in Dutch general practices

OBJECTIVE

This study aimed to investigate both atopic and non-atopic comorbid symptoms and diseases in children with physician-diagnosed atopic disorders (atopic eczema, asthma and allergic rhinitis).

METHODS

All children aged 0-18 years listed in a nationwide primary care database (the Netherlands Institute for Health Services Research-Primary Care Database) with routinely collected healthcare data in 2014 were selected. Children with atopic disorders were matched on age and gender with non-atopic controls within the same general practice. A total of 404 International Classification of Primary Care codes were examined. Logistic regression analyses were performed to examine the associations between the presence of atopic disorders and (non-)atopic symptoms and diseases by calculating ORs.

RESULTS

Having one of the atopic disorders significantly increased the risk of having other atopic-related symptoms, even if the child was not registered as having the related atopic disorder. Regarding non-atopic comorbidity, children with atopic eczema (n=15 530) were at significantly increased risk for (infectious) skin diseases (OR: 1.2-3.4). Airway symptoms or (infectious) diseases (OR: 2.1-10.3) were observed significantly more frequently in children with asthma (n=7887). Children with allergic rhinitis (n=6835) had a significantly distinctive risk of ear-nose-throat-related symptoms and diseases (OR: 1.5-3.9). Neither age nor gender explained these increased risks.

CONCLUSION

General practitioners are not always fully aware of relevant atopic and non-atopic comorbidity. In children known to have at least one atopic disorder, specific attention is required to avoid possible insufficient treatment and unnecessary loss of quality of life.

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.

Atopic children and use of prescribed medication: A comprehensive study in general practice

PURPOSE

A comprehensive and representative nationwide general practice database was explored to study associations between atopic disorders and prescribed medication in children.

METHOD

All children aged 0-18 years listed in the NIVEL Primary Care Database in 2014 were selected. Atopic children with atopic eczema, asthma and allergic rhinitis (AR) were matched with controls (not diagnosed with any of these disorders) within the same general practice on age and gender. Logistic regression analyses were performed to study the differences in prescribed medication between both groups by calculating odds ratios (OR); 93 different medication groups were studied.

RESULTS

A total of 45,964 children with at least one atopic disorder were identified and matched with controls. Disorder-specific prescriptions seem to reflect evidence-based medicine guidelines for atopic eczema, asthma and AR. However, these disorder-specific prescriptions were also prescribed for children who were not registered as having that specific disorder. For eczema-related medication, about 3.7-8.4% of the children with non-eczematous atopic morbidity received these prescriptions, compared to 1.4-3.5% of the non-atopic children. The same pattern was observed for anti-asthmatics (having non-asthmatic atopic morbidity: 0.8-6.2% vs. controls: 0.3-2.1%) and AR-related medication (having non-AR atopic morbidity: 4.7-12.5% vs. controls: 2.8-3.1%). Also, non-atopic related medication, such as laxatives and antibiotics were more frequently prescribed for atopic children.

CONCLUSIONS

The present study shows that atopic children received more prescriptions, compared to non-atopic children. Non-atopic controls frequently received specific prescriptions for atopic disorders. This indicates that children with atopic disorders need better monitoring by their GP.

Sugarcane bagasse dietary fiber as an adjuvant therapy for stable chronic obstructive pulmonary disease: a four-center, randomized, double-blind, placebo-controlled study

OBJECTIVE

To evaluate the efficacy and safety of sugarcane bagasse dietary fiber as an adjuvant therapy for improving quality of life in patients with stable chronic obstructive pulmonary disease (COPD).

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled trial. A total of 196 participants were randomized into a trial group (treated with 6 g/day sugarcane bagasse plus conventional treatment, n = 98) and a control group (treated with placebo plus conventional treatment, n = 98). All efficacy analyses were performed according to the intention-to-treat (ITT) principle. A per-protocol analysis set (PPS) was used to analyze the cases that completed the clinical trial with good compliance. The trial period was 30 days, with a 6-month follow-up. Pre- and post-treatment pulmonary symptom scores (cough, sputum, wheezing, and dyspnea) were recorded for both groups. The St. George's Respiratory Questionnaire (SGRQ) and the modified Medical Research Council (mMRC) dyspnea scale were assessed before treatment and at the end of the 6-month follow- up.

RESULTS

The ITT population was 178 and the PPS population was 166. Post-treatment pulmonary clinical symptoms and severity of dyspnea (mMRC and SGRQ evaluation) were significantly improved in both the trial group and the control group (ITT and PPS: P < 0.05). However, there was no statistical difference between the two groups in post-treatment pulmonary symptoms and mMRC. There was a greater reduction in the SGRQ subscales of activity, effect and total score in the trial group compared with the control group (ITT and PPS: P < 0.01). There was no statistical difference in pre- and post-treatment safety variables in either group.

CONCLUSION

Sugarcane bagasse combined with conventional treatment improved quality of life in patients with stable COPD. Sugarcane bagasse appears to be a safe herbal medicine with potential for treating patients with stable COPD when taken orally as an adjuvant therapy.

Intake of high fructose corn syrup sweetened soft drinks, fruit drinks and apple juice is associated with prevalent coronary heart disease, in U.S. adults, ages 45-59 y

BACKGROUND

Intake of high excess free fructose (EFF) beverages, including high fructose corn syrup (HFCS), sweetened soft drinks, fruit drinks, and apple juice, may be associated with childhood asthma, adult idiopathic chronic bronchitis/ COPD, and autoimmune arthritis, possibly due to underlying fructose malabsorption. Fructose malabsorption may contribute to the intestinal in situ formation of advanced glycation end-products (enFruAGEs) that travel to other tissues and promote inflammation. Chronic respiratory conditions and arthritis are comorbidities of coronary heart disease (CHD). The objective of this study was to investigate the association between intake of high EFF beverages and CHD.

METHODS

In this cross sectional study (NHANES 2003-2006) of adults, aged 45-59 y, n = 1230, the exposure variables were non-diet soft drinks, and any combination of high EFF beverages including non-diet soft drinks, fruit drinks, and apple juice. Analyses of diet soft drinks, diet fruit drinks, and orange juice (non/low EFF beverages) were included for comparison. The outcome was self-reported history of coronary heart disease and/or angina (CHD). Rao Scott Ҳ2 was used for prevalence differences and logistic regression for associations, adjusted for age, sex, race-ethnicity, BMI, socio-economic status, health insurance coverage, smoking, physical activity level, hypertension, energy intake, fruit and vegetable intake, glycated hemoglobin, pre-diabetes, and diabetes.

RESULTS

Intake of any combination of HFCS sweetened soft drinks, fruit drinks, and apple juice (tEFF) was significantly associated with CHD in adults aged 45-59 y. Adults consuming tEFF ≥5 times/wk. were 2.8 times more likely to report CHD than ≤3 times/mo consumers (OR 2.82; 95% CI 1.16-6.84; P = 0.023), independent of all covariates.

CONCLUSION

HFCS sweetened soft drinks, fruit drinks, and apple juice may contribute to CHD, a common comorbidity of chronic respiratory conditions and autoimmune arthritis, possibly due to the high ratio of fructose to glucose in these beverages. Underlying fructose malabsorption may contribute to the intestinal in situ formation of pro-inflammatory enFruAGEs, that are eventually absorbed and induce inflammation of the coronary arteries. Additional research is needed.

Prevalence of Irritable Bowel Syndrome in Singapore and Its Association with Dietary, Lifestyle, and Environmental Factors

Background/Aims

The prevalence of irritable bowel syndrome (IBS) has risen considerably over the past decade in Singapore. We aim to explore the contribution of changes in diet, lifestyle and habits that may contribute to the increased prevalence and development of IBS.

Methods

This is a survey-based cross-sectional population study aimed to gather demographic, socio-economical, lifestyle, dietary, antibiotic usage and other related information. Subjects were adult male or female Singaporeans aged 21 years or above. Association of the factors gathered with the presence or absence of IBS (by Rome III criteria) was assessed using chi-square or Fisher's exact test. Variables with a level of statistical significance of 0.1 or less in the univariate analysis were entered into a stepwise logistic regression model.

Results

A total of 297 subjects participated in the study (female 60.3%). Overall, 20.9% subjects fulfilled the Rome III IBS criteria. Univariate analysis showed that IBS was associated with pet ownership, antibiotic usage, late dinner, (> 9 PM) and consumption of Western meals, coffee, and bread. The multivariate logistic regression analyses showed that IBS was independently associated with being a pet owner (P = 0.008; OR, 2.5; 95% CI, 1.278-5.037).

Conclusions

The prevalence of IBS was 20.9% using the Rome III criteria in our study. The association between IBS and pet ownership will need further investigation.

Co-morbidities and cognitive status in a cohort of teenagers with asthma

BACKGROUND

There is limited data regarding co-morbidities and cognitive status of asthma during childhood and adolescence. The aim of the current study was to explore the presence of co-morbidities and cognitive status in a large cohort of teenagers with asthma.

METHODS

The medical records of 314,897 consecutive 17-year-old males, undergoing comprehensive medical and cognitive evaluation prior to recruitment for military service, were reviewed. The prevalence of co-morbidities and a cognitive assessment in subjects with asthma were compared to those without asthma. Both a univariate and multivariate logistic regression analysis were performed.

RESULTS

Active asthma was documented in 21,728 (6.9%) subjects: 3.3% were diagnosed with mild intermittent asthma, and 3.6% with persistent asthma. A significant positive correlation between a higher cognitive score and prevalence of asthma was found (P < 0.001), with a 55% increased prevalence of asthma in the subjects with the highest cognitive score compared to those with the lowest score. The following co-morbidities were significantly more prevalent in asthmatics compared to non-asthmatics: chronic rhinitis (35% vs. 5%), atopic dermatitis (2% vs. 0.4%), urticaria (1% vs. 0.3%), anaphylaxis (0.4% vs. 0.1%), chronic sinusitis (0.4% vs. 0.1%), overweight with body mass index (BMI) above 25 kg/m(2) (20% vs. 17%) and underweight with BMI less than 17 kg/m(2) (3.2% vs. 2.8%), irritable bowel syndrome (IBS) (1% vs. 0.5%), and thyroid disorders(0.4% vs. 0.2%). Chronic rhinitis and sinusitis, atopic dermatitis, IBS, and thyroid disorders were all significantly more prevalent in persistent compared to intermittent asthma (P < 0.001).

CONCLUSIONS

In adolescence, a higher cognitive status was associated with a higher rate of asthma. Chronic rhinitis was the most prevalent co-morbidity and was found in one third of adolescent asthmatics. Other allergic diseases, chronic sinusitis, over and underweight, IBS, and thyroid disorders were also more prevalent in asthmatics. Pediatr Pulmonol. 2016; 51:901-907. © 2016 Wiley Periodicals, Inc.

Functional Gastrointestinal Symptoms Are Associated with Higher Serum Total IgE Levels, but Less Atopic Sensitization

BACKGROUND

The relation of gastrointestinal (GI) complaints to IgE-mediated allergy is not well understood. Increased numbers of "IgE-armed" mast cells have been observed in duodenal mucosa of patients with functional GI complaints.

AIMS

To explore whether total IgE and atopic sensitization were associated with functional GI complaints.

METHODS

Levels of serum total and specific IgE and GI complaints were measured in 161 patients and in a general population sample of 478 persons. Standard inhalant allergens were measured in the patient group, and selected inhalant allergens in the general population. GI complaints were assessed by two standardized questionnaires. The associations between GI complaints and total IgE were analyzed in multiple regression models.

RESULTS

GI complaints were positively associated with higher total IgE levels (all: b = 0.028, p = 0.012; patient group: b = 0.038, p = 0.072; general population: b = 0.038, p = 0.005), but negatively associated with atopic sensitization (all: b = -11.256, p = 0.181; patient group: b = -85.667, p < 0.001; general population: b = -14.394, p = 0.083). The relationship between total IgE and GI complaints was consistent among sensitized and non-sensitized persons, among men and women, and across age groups.

CONCLUSION

Serum total IgE was positively associated with GI complaints, while atopic sensitization was inversely associated with GI complaints. This suggests that IgE-mediated immunology plays a role in the pathophysiology of functional GI complaints. The biological mechanisms reflected in higher total IgE levels, but less atopic sensitization, warrant further studies.

Immunoglobulin E in irritable bowel syndrome: another target for treatment? A case report and literature review

Irritable bowel syndrome (IBS) is notoriously difficult to treat and this situation is unlikely to change until the pathophysiology is better understood. There is no doubt that IBS is a multifactorial condition but it is likely that the relative contribution of the various factors involved varies from patient to patient. Consequently, in some individuals one mechanism may have such a strong effect that its elimination may lead to a substantial improvement in symptoms. This paper describes a patient with severe asthma and IBS where the administration of an anti-Immunoglobulin E (IgE) monoclonal antibody not only improved her asthma but also resulted in an almost complete resolution of her IBS symptoms. This observation suggests that some form of allergic process, which may be mediated by IgE, might be driving IBS in some patients and there is evidence from the literature that atopy is more common in this condition. Therefore, in patients with IBS and atopy where the response to standard treatment is poor, it may be worth considering targeting the allergic diathesis. Possible approaches include skin testing with food antigens followed by an appropriate exclusion diet or pharmacological mast cell stabilization.

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.

Food allergy in irritable bowel syndrome: The case of non-celiac wheat sensitivity

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, having a prevalence of 12%-30% in the general population. Most patients with IBS attribute their symptoms to adverse food reactions. We review the role of diet in the pathogenesis of IBS and the importance of dietary factors in the management of these patients. The MEDLINE electronic database (1966 to Jan 2015) was searched using the following keywords: "food", "diet", "food allergy", "food hypersensitivity", "food intolerance", "IBS", "epidemiology", "pathogenesis", "pathophysiology", "diagnosis", "treatment". We found 153 eligible papers; 80 were excluded because: not written in English, exclusive biochemical and experimental research, case reports, reviews, and research otherwise not relevant to our specific interest. We selected 73 papers: 43 original papers, 26 reviews and 4 letters to the editor. These papers focused on IBS pathogenesis, the association between IBS and atopy, and between IBS and food allergy, the relationship between IBS and non-celiac wheat sensitivity, the role of diet in IBS. Pending further scientific evidence, a cautious approach is advisable but the concept of food allergy should be included as a possible cause of IBS, and a dietary approach may have a place in the routine clinical management of IBS.

The overlap of atopy and functional gastrointestinal disorders among 23,471 patients in primary care

BACKGROUND

Activation of the immune system has been demonstrated in atopy and functional gastrointestinal disorders (FGIDs). Previous data from our group have suggested a connection between immune dysregulation, FGIDs and mood disorders.

AIM

To investigate if these data translate to clinical practice and examine connections from the perspective of FGIDs to determine whether atopy and FGIDs are connected via mood disorders.

METHODS

Evidence of irritable bowel syndrome (IBS), functional dyspepsia (FD) and constipation was sought from the medical records of 30,000 primary care records over a minimum 5 year period. The same records yielded diagnoses of four atopic conditions (asthma, eczema, allergic rhinitis/hay fever and conjunctivitis).

RESULTS

Atopic conditions were found in excess among all FGID groups considered when compared with controls. In the groups with IBS alone (OR = 1.43, 1.29-1.58), FD alone (OR = 1.41, 1.26-1.58) and those with multiple FGIDs (OR = 1.92, 1.75-2.12) there was elevated prevalence of asthma compared with controls without a FGID. Across disorders the excess was generally highest among patients diagnosed with multiple FGIDs (rhinitis/hay fever OR = 3.74, 3.32-4.20; conjunctivitis OR = 3.00, 2.49-3.62) and was only partly explained by a common association between both FGIDs and atopic conditions with mood disorders, although not for every atopic/FGID combination (rhinitis/hay fever OR = 2.60, 2.29-2.96, conjunctivitis OR = 2.34, 1.90-2.87).

CONCLUSIONS

Irritable bowel syndrome, functional dyspepsia and constipation share an association with atopy that is only partly explained via a common connection with mood disorders. These data have important implications for understanding both the pathophysiology of functional gastrointestinal disorders and development of new treatments.

Atopy and the gastrointestinal tract--a review of a common association in unexplained gastrointestinal disease

In addition to diseases conventionally associated with atopy there is increasing recognition that atopy is also linked to a spectrum of gastrointestinal (GI) manifestations, including food allergy, primary eosinophilic GI disease, functional gastrointestinal disorders, gluten interactions, gastroesophageal reflux disease and inflammatory bowel disease. These associations may be underpinned by shared genetic susceptibilities, initiation of related immune pathways and common patterns of exposure to environmental cues, including allergen/pathogen encounters and variations in the composition of the intestinal microbiota. Further scrutiny of GI diseases with prominent allergic-type immune responses may yet redefine treatment paradigms for these common and important atopy-associated diseases. Looking forward, interventions by manipulation of the microbiota or host immune responses hold promise, but there is still room for further exploration of this novel field of host susceptibility, host-microbe interactions and atopy-associated GI diseases.

Rhinitis in a community elderly population: relationships with age, atopy, and asthma

BACKGROUND

Rhinitis is one of the most frequent medical conditions. However, there is sparse epidemiologic evidence for rhinitis in the elderly population.

OBJECTIVE

To investigate the prevalence of rhinitis in elderly adults and its relations to asthma and other comorbidities.

METHODS

A cross-sectional analysis was performed using the baseline dataset of the Korean Longitudinal Study on Health and Aging, a community-based elderly population cohort in Korea (≥65 years old). Structured questionnaires were used to define rhinitis, asthma, and comorbidity, and allergen skin prick tests were used to define atopy. Health-related quality of life was assessed by short-form 36 questionnaires.

RESULTS

In total, 982 elderly adults (98.2%) were included in the present study. The prevalence of rhinitis was 25.6% and did not decrease until 90 years of age. The prevalence of atopy was 17.2% (18.8% in participants with rhinitis), and atopy did not show a significant association with rhinitis. In multivariate logistic regression analyses, relations between asthma and rhinitis were significant. Among comorbid conditions, none were significantly associated with rhinitis. In the short-form 36 questionnaire analyses, rhinitis was independently related to a decrease in the physical aspects of quality of life.

CONCLUSION

The present study found a high prevalence of nonallergic rhinitis in elderly participants, which was significantly related to asthma and quality of life.

Specific Link between Lung and Large Intestine: A New Perspective on Neuropeptide Secretion in Lung with Herbal Laxative Stimulation

Background. To investigate the specific link between lung and large intestine. Methods. Rat COPD-like model was prepared. Mirabilite or Chinese rhubarb was administrated intragastrically to stimulate the large intestine. Histological analysis of lung inflammation was assessed. The tissues levels of SP, VIP, NK1R, VIPR1, and VIPR2 were measured by using ELISA kits. In addition, mouse model of allergic asthma was prepared. Mirabilite was administrated intragastrically to stimulate the large intestine. Airway responsiveness and lung inflammation were assessed. The tissues levels of SP, VIP, NKA, NKB, NK1R, VIPR1, and VIPR2 were measured by using ELISA kits. Results. Stimulating the intestine with Mangxiao or Dahuang, SP, NK-1R, VIP, VIPR1, and VIPR2 were significantly increased in intestine tissues of rats with COPD and mice with asthma. Meanwhile, the SP and NK1R were significantly decreased, while VIP, VIPR1, and VIPR2 were significantly increased in lung tissues. An abnormal secretion of SP and VIP can be observed in other tissues; however, no marked changes were found in the receptors. The NKA and NKB levels were similar in lung tissues of mice with asthma among groups. Conclusions. Stimulating intestine with Mangxiao or Dahuang can specifically regulate the secretion of SP, VIP, and the receptors in lung tissues.

The role of eosinophils and mast cells in intestinal functional disease

Functional gastrointestinal disorders (FGIDs) are common and currently defined by a symptom-based classification with no discernable pathology. In functional dyspepsia (FD), the duodenum is now implicated as a key area where symptoms originate.This is attributed to immune activation with increasing evidence indicating a role for duodenal eosinophilia. In irritable bowel syndrome (IBS), mastocytosis has been documented throughout the small and large intestine. Eosinophils and mast cells are an important link between innate and adaptive immunity, and are important in allergic type TH2 inflammation. Eosinophils may give rise to symptoms due to release of preformed cytokine proteins, which trigger neural excitation, muscle spasm, and pain. The close relationship of mast cells to nerves in IBS may similarly give rise to symptoms. Genetic studies also support of the role of innate immunity in FGIDs. The data supporting a prime role for eosinophils and mast cells in subsets of FD and IBS has become credible, and these data should be used to implement advances in diagnosis and therapeutic trials.

Association and symptom characteristics of irritable bowel syndrome among bronchial asthma patients in Kuwait

CONTEXT:

Excess prevalence of irritable bowel syndrome in asthma has been reported, suggesting a link between these two conditions.

AIMS:

To investigate the association between irritable bowel syndrome (IBS) and asthma, and explore the symptoms of IBS among asthma patients in Kuwait.

SETTINGS AND DESIGN:

Case control study.

METHODS:

In a tertiary center, for allergy and asthma, 138 patients aged 20-65 years, with asthma, diagnosed clinically and by spirometry, were compared with 145 healthy, non-asthmatic controls matched for age, gender and nationality. Cases and controls completed a self-administered questionnaire of irritable bowel syndrome diagnosis (ROME II criteria).

STATISTICAL ANALYSIS USED:

The data were analyzed using SPSS software, and proportions were tested with Chi-square or Fisher's test. Odds ratio (OR) with 95% Confidence Interval (CI) were calculated to identify the associated risk factors. The demographic variables were selected for logistic regression analysis.

RESULTS:

A significantly large proportion (39.13%) of asthmatics had IBS as compared to 7.93% controls (P < 0.001). A higher proportion of females with IBS were observed in cases and controls (74%, 61.54%). IBS was seen in 87% cases using inhalers, and in 13% with additional oral theophylline (P < 0.001). As many as 66.6% cases, had IBS with relatively short duration of asthma (1-5 years, P < 000). Predominant symptoms of IBS in asthmatics were abdominal discomfort or distension (64.8% vs. 11.5%), (P < 0.000, OR = 14.1; 95%CI: 3.748-53.209), bloated feeling of abdomen (74.1% vs. 34.62% (P < 0.001, OR = 5.38; 95%CI:1.96-14.84)), increased frequency of stools (63%, P < 0.006).

CONCLUSIONS:

Irritable bowel syndrome in asthmatics was significantly high, more in the female asthmatics. Abdominal discomfort, persistent bloated feeling, increased frequency of passing stools were the most common IBS symptoms observed.

Irritable bowel syndrome - An inflammatory disease involving mast cells

Irritable bowel syndrome (IBS) is traditionally defined as a functional disorder - that is the presence of symptoms in the absence of demonstrable pathological abnormalities. In recent times, low grade inflammatory infiltrates in both the small and large bowel of some patients with IBS - often rich in mast cells, along with serological markers of low grade inflammation have focussed attention on IBS as an inflammatory disease. The observation that mast cells often lie in close association to enteric neurons, and in-vitro and in-vivo animal studies demonstrating that mast cell mediators may influence enteric motility provides a biologically plausible causal mechanism in IBS. Pilot studies on patients with IBS using the mast cell stabiliser sodium cromoglycate ('proof of concept') have been encouraging. The essential question remains why mast cells infiltrate the bowel of IBS patients. A disturbance of the 'brain-gut axis' is the current favoured hypothesis, whereby childhood stress or psychiatric comorbidity act via neuro-immune mechanisms to modulate low grade inflammation. An alternative hypothesis is that food allergy may be responsible. Serum specific IgE, and skin prick tests are not elevated in IBS patients, suggesting type 1 IgE mediated food allergy is not the cause. However questionnaire based studies indicate IBS patients have higher rates of atopic disease, and increased bronchial reactivity to methacholine has been demonstrated. In this review, we highlight the potential role of mast cells in IBS, and current and future research directions into this intriguing condition.

Irritable bowel syndrome - An inflammatory disease involving mast cells

Irritable bowel syndrome (IBS) is traditionally defined as a functional disorder - that is the presence of symptoms in the absence of demonstrable pathological abnormalities. In recent times, low grade inflammatory infiltrates in both the small and large bowel of some patients with IBS - often rich in mast cells, along with serological markers of low grade inflammation have focussed attention on IBS as an inflammatory disease. The observation that mast cells often lie in close association to enteric neurons, and in-vitro and in-vivo animal studies demonstrating that mast cell mediators may influence enteric motility provides a biologically plausible causal mechanism in IBS. Pilot studies on patients with IBS using the mast cell stabiliser sodium cromoglycate ('proof of concept') have been encouraging. The essential question remains why mast cells infiltrate the bowel of IBS patients. A disturbance of the 'brain-gut axis' is the current favoured hypothesis, whereby childhood stress or psychiatric comorbidity act via neuro-immune mechanisms to modulate low grade inflammation. An alternative hypothesis is that food allergy may be responsible. Serum specific IgE, and skin prick tests are not elevated in IBS patients, suggesting type 1 IgE mediated food allergy is not the cause. However questionnaire based studies indicate IBS patients have higher rates of atopic disease, and increased bronchial reactivity to methacholine has been demonstrated. In this review, we highlight the potential role of mast cells in IBS, and current and future research directions into this intriguing condition.

Food: the forgotten factor in the irritable bowel syndrome

After years of inattention, there is a growing body of evidence to suggest that dietary constituents at least exacerbate symptoms and perhaps contribute to the pathogenesis of the irritable bowel syndrome (IBS). Although patients with IBS self-report food allergies more often than the general population, the evidence suggests that true food allergies are relatively uncommon. Less clearly defined food intolerances may be an important contributor to symptoms in IBS patients. This article reviews the literature supporting a causal link between food and the symptoms of IBS as well as the evidence supporting dietary interventions as a means of managing IBS symptoms.

Functional somatic syndromes, anxiety disorders and the upper airway: a matter of paradigms

The relationship between the functional somatic syndromes, anxiety disorders and the upper airway (particularly, sleep disordered breathing) remains ambiguous. This ambiguity, despite a growing body of research supporting a relationship, may result from the absence of a paradigm to explain how upper airway dysfunction can promote disorders commonly associated with one's mental health. This review models the functional somatic syndromes and anxiety disorders as consequences of chronically increased hypothalamic-pituitary-adrenal axis activity. It then examines the literature supporting a relationship between these disorders and upper airway dysfunction during wakefulness and sleep. Finally, building upon an existing paradigm of neural sensitization, sleep disordered breathing is linked to functional somatic syndromes and anxiety disorders through chronic activation of the hypothalamic-pituitary-adrenal axis.

Is there an association between wheezing and constipation in preschool children? Explanations from a longitudinal birth cohort

OBJECTIVE

To assess whether wheezing and atopic dermatitis were associated with constipation in preschool children and to what extent shared risk factors contribute to this relationship.

METHODS

A population-based sample of 4651 preschool children was used. At the age of 24, 36 and 48 months, a parental report of functional constipation was available according to the Rome II criteria, and data on atopic dermatitis and wheezing were available using age-adapted questionnaires from the International Study of Asthma and Allergies in Childhood. Stepwise multivariate analyses were performed to assess whether body mass index, infection exposure, food allergy and infant nutrition, and parental stress explained the association between wheezing, atopic dermatitis and constipation.

RESULTS

Out of 4651 children, 12-17% had functional constipation between 24 and 48 months. Symptoms of wheezing decreased from 20% to 12% and atopic dermatitis decreased from 30% to 18% at the age of 24 and 48 months respectively. Between the age of 24 and 48 months, wheezing symptoms were significantly associated with functional constipation (OR 1.17; 1.02 to 1.34) but these results were mainly explained by the child's exposure to infections and use of antibiotics (adjusted odds ratio 1.08; 95% CI 0.95 to 1.24). No significant association was found between symptoms of atopic dermatitis and functional constipation (OR 1.08; 95% CI 0.94 to 1.23).

CONCLUSIONS

These findings suggest that functional constipation coexists with wheezing in childhood but is mainly explained by the child's infection exposure and use of antibiotics. Therefore, an independent association between respiratory symptoms and functional bowel disorders as suggested in previous studies is questionable.

Diarrhoea in a large prospective cohort of European travellers to resource-limited destinations

BACKGROUND

Incidence rates of travellers' diarrhoea (TD) need to be updated and risk factors are insufficiently known.

METHODS

Between July 2006 and January 2008 adult customers of our Centre for Travel Health travelling to a resource-limited country for the duration of 1 to 8 weeks were invited to participate in a prospective cohort study. They received one questionnaire pre-travel and a second one immediately post-travel. First two-week incidence rates were calculated for TD episodes and a risk assessment was made including demographic and travel-related variables, medical history and behavioural factors.

RESULTS

Among the 3100 persons recruited, 2800 could be investigated, resulting in a participation rate of 89.2%. The first two-weeks incidence for classic TD was 26.2% (95%CI 24.5-27.8). The highest rates were found for Central Africa (29.6%, 95% CI 12.4-46.8), the Indian subcontinent (26.3%, 95%CI 2.3-30.2) and West Africa (21.5%, 95%CI 14.9-28.1). Median TD duration was 2 days (range 1-90). The majority treated TD with loperamide (57.6%), while a small proportion used probiotics (23.0%) and antibiotics (6.8%). Multiple logistic regression analysis on any TD to determine risk factors showed that a resolved diarrhoeal episode experienced in the 4 months pre-travel (OR 2.03, 95%CI 1.59-2.54), antidepressive comedication (OR 2.11, 95%CI 1.17-3.80), allergic asthma (OR 1.67, 95%CI 1.10-2.54), and reporting TD-independent fever (OR 6.56, 95%CI 3.06-14.04) were the most prominent risk factors of TD.

CONCLUSIONS

TD remains a frequent travel disease, but there is a decreasing trend in the incidence rate. Patients with a history of allergic asthma, pre-travel diarrhoea, or of TD-independent fever were more likely to develop TD while abroad.

Implications of eosinophilia in the normal duodenal biopsy - an association with allergy and functional dyspepsia

BACKGROUND

Allergy and functional gastrointestinal disorders have been associated with eosinophilia in duodenal mucosa.

AIM

To assess the prevalence of eosinophilia in duodenal biopsies of patients attending for oesophogastroduodenoscopy and delineate associated clinical conditions.

METHODS

A total of 155 patients (mean age 55 years, 59% women) with normal duodenal biopsies were randomly selected for audit from histopathology files. Eosinophil counts in five high power fields (HPFs) were assessed. Records were analysed for symptoms, diagnosis and medications; patients were divided into five groups based on upper gastrointestinal (UGI) symptom profiles, including a control group of those without predominant UGI symptoms. The prevalence of duodenal eosinophilia (defined as >22/5HPFs a priori) was calculated.

RESULTS

In the control group, the mean duodenal eosinophil count was 15/5HPFs; prevalence of duodenal eosinophilia was 22.5%. In postprandial distress syndrome (PDS), both mean eosinophil counts (20.2/5HPF, P < 0.04) and prevalence of duodenal eosinophilia (47.3%, P < 0.04) were significantly higher. Duodenal eosinophilia was significantly associated with allergy (OR 5.04, 95% CI 2.12-11.95, P < 0.001). There was no association with irritable bowel syndrome or medications.

CONCLUSIONS

Subtle duodenal eosinophilia is relatively common in routine oesophogastroduodenoscopy and previously overlooked; it is associated with allergy and may indicate a hypersensitivity mechanism in some patients with PDS including early satiety.

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.

Whither dyspepsia? A historical perspective of functional dyspepsia, and concepts of pathogenesis and therapy in 2009

Functional dyspepsia is a highly prevalent but heterogeneous disorder; multiple pathogenetic mechanisms are likely involved but the underlying causal pathways in functional dyspepsia remain obscure. The term functional dyspepsia was popularized by the famed Walter Alvarez at the Mayo Clinic early last century. Prominent Australian gastroenterologists who have contributed to our understanding of functional dyspepsia include Peter Baume, Barry Marshall, Douglas Piper, Nick Talley, John Kellow, and Gerald Holtmann. Specific dyspeptic symptoms have not generally correlated very well with any particular physiologic disturbance, although gastric disaccommodation and duodenal eosinophilia have been linked to early satiety in this condition. Genetic markers have been tentatively identified, and functional dyspepsia can follow bacterial gastroenteritis. No objective diagnostic tools for functional dyspepsia are currently agreed upon, although meal induction of symptoms appears reproducible and may have diagnostic utility. The symptomatic criteria for functional dyspepsia (Rome III criteria) are based on expert consensus and the exclusion of organic causes. Various therapeutic modalities for functional dyspepsia have been explored; however, empirical approaches are still employed for the treatment of functional dyspepsia. Better approaches for functional dyspepsia are likely to follow an improved understanding of the underlying pathophysiological abnormalities.

Functional gastrointestinal disorders and the potential role of eosinophils

The eosinophil-mast cell-neural pathway may be important in the pathophysiology of functional gastrointestinal disorders characterized by unexplained abdominal pain, disordered defecation, or meal-related discomfort. There is evidence that duodenal eosinophils are increased in functional dyspepsia, whereas mast cells are increased in the lower gut in irritable bowel syndrome, directly supporting a role for a hypersensitivity-type reaction in these disorders. The trigger may be a pathogen, food, or other allergen in the gut mucosa. This trigger may evoke eosinophils, mast cells, and other components to cascade to up-regulate serotonin release, with modulation of the enteric and central nervous systems, creating a vicious cycle. If correct, this theory suggests treatment should specifically target the eosinophil-mast cell pathway.