Environmental risk factors in inflammatory bowel disease: a population-based case-control study in Asia-Pacific

ESPEN guideline: Clinical nutrition in inflammatory bowel disease

INTRODUCTION

The ESPEN guideline presents a multidisciplinary focus on clinical nutrition in inflammatory bowel disease (IBD).

METHODOLOGY

The guideline is based on extensive systematic review of the literature, but relies on expert opinion when objective data were lacking or inconclusive. The conclusions and 64 recommendations have been subject to full peer review and a Delphi process in which uniformly positive responses (agree or strongly agree) were required.

RESULTS

IBD is increasingly common and potential dietary factors in its aetiology are briefly reviewed. Malnutrition is highly prevalent in IBD - especially in Crohn's disease. Increased energy and protein requirements are observed in some patients. The management of malnutrition in IBD is considered within the general context of support for malnourished patients. Treatment of iron deficiency (parenterally if necessary) is strongly recommended. Routine provision of a special diet in IBD is not however supported. Parenteral nutrition is indicated only when enteral nutrition has failed or is impossible. The recommended perioperative management of patients with IBD undergoing surgery accords with general ESPEN guidance for patients having abdominal surgery. Probiotics may be helpful in UC but not Crohn's disease. Primary therapy using nutrition to treat IBD is not supported in ulcerative colitis, but is moderately well supported in Crohn's disease, especially in children where the adverse consequences of steroid therapy are proportionally greater. However, exclusion diets are generally not recommended and there is little evidence to support any particular formula feed when nutritional regimens are constructed.

CONCLUSIONS

Available objective data to guide nutritional support and primary nutritional therapy in IBD are presented as 64 recommendations, of which 9 are very strong recommendations (grade A), 22 are strong recommendations (grade B) and 12 are based only on sparse evidence (grade 0); 21 recommendations are good practice points (GPP).

Smoking influences the need for surgery in patients with the inflammatory bowel diseases: a systematic review and meta-analysis incorporating disease duration

Background

Studies examining the association between smoking and the need for surgery in patients with Crohn’s disease and ulcerative colitis have reached inconsistent conclusions. These studies often do not differentiate between patients undergoing early surgery and patients having surgery later in their disease course. Our study examined the association between smoking status and time to first bowel resection in patients with Crohn’s disease and ulcerative colitis.

Methods

We searched MEDLINE and EMBASE for studies (n = 12) reporting on the association between smoking status (current, former, and never) and surgery in IBD, and incorporated disease duration in the analysis. Hazard ratios (HR) with 95% confidence intervals (CI) were pooled across studies using random effects models.

Results

Current smokers with Crohn’s disease were at increased risk of intestinal resection compared to never smokers (HR 1.27, 95% CI 1.08 to 1.49); however, there was no difference in the need for surgery when comparing former and never smokers (HR 1.11, 95% CI 0.95 to 1.30). In patients with ulcerative colitis, there was no difference in the need for colectomy when comparing current smokers to never smokers (HR 0.98, 95% CI 0.67 to 1.44). Former smokers with ulcerative colitis were at increased risk of colectomy (HR 1.38, 95% CI 1.04 to 1.83) compared to never smokers.

Conclusions

Current smokers with Crohn’s disease are at increased risk of surgery, while former smokers with ulcerative colitis have increased risk of colectomy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0555-8) contains supplementary material, which is available to authorized users.

miR-301a promotes intestinal mucosal inflammation through induction of IL-17A and TNF-α in IBD

OBJECTIVE

MicroRNA (miR)-301a is known to be involved in the tumourigenesis and pathogenesis of several autoimmune diseases, but it remains unclear whether miR-301a is associated with the pathogenesis of IBD.

METHODS

miR-301a expression was assessed in peripheral blood mononuclear cells (PBMC) and inflamed mucosa of patients with IBD by quantitative real-time-PCR. Peripheral blood CD4+ T cells were transduced with lentivirus-encoding pre-miR-301a (LV-miR-301a) or a reverse complementary sequence of miR-301a (LV-anti-miR-301a), and their differentiation and activation were investigated in vitro. Antisense miR-301a was administered into mice during trinitrobenzene sulphonic acid (TNBS)-induced colitis to determine its role in colitis.

RESULTS

miR-301a expression was significantly upregulated in PBMC and inflamed mucosa of patients with IBD compared with healthy controls. Stimulation with tumour necrosis factor-α (TNF-α) significantly enhanced miR-301a expression in IBD CD4+ T cells, which was markedly reversed by anti-TNF-α mAb (Infliximab) treatment. Transduction of LV-miR-301a into CD4+ T cells from patients with IBD promoted the Th17 cell differentiation and TNF-α production compared with the cells with expression of LV-anti-miR-301a. SNIP1 as a functional target of miR-301a was reduced in miR-301a expression but increased in LV-anti-miR-301a expression. Knockdown of SNIP1 could enhance Th17 cell differentiation. Furthermore, intracolonical administration of antisense miR-301a in TNBS-induced mouse colitis model significantly decreased numbers of interleukin (IL)-17A+ cells and amounts of pro-inflammatory cytokines (eg, IL-17A, TNF-α) in inflamed colon.

CONCLUSIONS

Our data reveal a novel mechanism in which the elevated miR-301a in PBMC and inflamed mucosa of IBD promotes Th17 cell differentiation through downregulation of SNIP1. Blockade of miR-301a in vivo may serve as a novel therapeutic approach in the treatment of IBD.

Association between physical activity and inflammatory bowel disease risk: A meta-analysis

BACKGROUND

Previous studies of an association between physical activity and inflammatory bowel disease have yielded conflicting results.

AIM

This meta-analysis was conducted to clarify whether there is an association between physical activity and inflammatory bowel disease.

METHODS

The PubMed and Web of Science databases were searched for relevant studies published up to October 2015. Data were extracted and the summary relative risks (RRs) were calculated using a random effects or a fixed-effects model, according to heterogeneity.

RESULTS

Seven studies were included in the analysis. Relative to individuals with low physical activity, those who participated in high physical activity had an RR of 0.63 (95% CI, 0.50-0.79) for developing Crohn's disease. In stratified analyses, a significantly lower risk for Crohn's disease was associated with high physical activity in Europeans only (RR, 0.62; 95% CI, 0.43-0.91); population-based control studies (RR, 0.56; 95% CI, 0.41-0.76); and case-control studies (RR, 0.56; 95% CI, 0.41-0.75). The data of 6 studies were pooled to analyze the effect of physical activity on the risk of ulcerative colitis, and no significant association was found (RR, 0.82; 95% CI, 0.68-1.00).

CONCLUSIONS

The pooled results of observational studies support that physical activity has a protective effect against Crohn's disease.

Globalisation of inflammatory bowel disease: perspectives from the evolution of inflammatory bowel disease in the UK and China

The UK and China provide unique historical perspectives on the evolution of the incidence of inflammatory bowel disease, which might provide insight into its pathogenesis. Historical records from the UK document the emergence of ulcerative colitis during the mid-1800s, which was later followed by the recognition of Crohn's disease in 1932. During the second half of the 20th century, the incidence of inflammatory bowel disease rose dramatically in high-income countries. Globalisation at the turn of the 21st century led to rapid economic development of newly industrialised countries such as China. In China, the modernisation of society was accompanied by the recognition of a sharp rise in the incidence of inflammatory bowel disease. The prevalence of inflammatory bowel disease is expected to continue to rise in high-income countries and is also likely to accelerate in the developing world. An understanding of the shared and different environmental determinants underpinning the pathogenesis of inflammatory bowel disease in western and eastern countries is essential to implement interventions that will blunt the rising global burden of inflammatory bowel disease.

Eosinophilic esophagitis: What can we learn from Crohn's disease?

Eosinophilic esophagitis (EoE) is an emerging esophageal inflammatory disorder affecting children and young adults. As a relatively new disease, EoE is still burdened by frequent diagnostic and therapeutic pitfalls in clinical practice. This manuscript posits a number of similarities with Crohn's disease, which may help optimize EoE patient management. Commonalities include epidemiologic trends (Westernized diseases, rising incidence, early-life risk factors), diagnostic considerations (symptoms are poor predictors of disease activity, difficulties in disease activity assessment) and therapeutic issues (similar natural history and therapeutic goals, induction and maintenance phases, combination of drug and endoscopic treatment, potential drug interchangeability, long-term unsolved issues). Physicians devoted to EoE should learn from the extraordinary achievements fulfilled in Crohn's disease: increased disease awareness, multidisciplinary specialized clinics, structured childhood and transition programs, and an ongoing roadmap for personalized treatments, including genetic susceptibility, risk factors for progression, genotype-phenotype correlation, drug monitoring and microbial data.

Inflammatory bowel disease in India - Past, present and future

There is rising incidence and prevalence of inflammatory bowel disease (IBD) in India topping the Southeast Asian (SEA) countries. The common genes implicated in disease pathogenesis in the West are not causal in Indian patients and the role of "hygiene hypothesis" is unclear. There appears to be a North-South divide with more ulcerative colitis (UC) in north and Crohn's disease (CD) in south India. IBD in second generation Indian migrants to the West takes the early onset and more severe form of the West whereas it retains the nature of its country of origin in migrants to SEA countries. The clinical presentation is much like other SEA countries (similar age and sex profile, low positive family history and effect of smoking, roughly similar disease location, use of aminosalicylates for CD, low use of biologics and similar surgical rates) with some differences (higher incidence of inflammatory CD, lower perianal disease, higher use of aminosalicylates and azathioprine and lower current use of corticosteroids). UC presents more with extensive disease not paralleled in severity clinically or histologically, follows benign course with easy medical control and low incidence of fulminant disease, cancer, complications, and surgery. UC related colorectal cancer develop in an unpredictable manner with respect to disease duration and site questioning the validity of strict screening protocol. About a third of CD patients get antituberculosis drugs and a significant number presents with small intestinal bleed which is predominantly afflicted by aggressive inflammation. Biomarkers have inadequate diagnostic sensitivity and specificity for both. Pediatric IBD tends to be more severe than adult. Population based studies are needed to address the lacunae in epidemiology and definition of etiological factors. Newer biomarkers and advanced diagnostic techniques (in the field of gastrointestinal endoscopy, molecular pathology and genetics) needs to be developed for proper disease definition and treatment.

Blockade of PLD2 Ameliorates Intestinal Mucosal Inflammation of Inflammatory Bowel Disease

Background. Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronically remittent and progressive inflammatory disorders. Phospholipase D2 (PLD2) is reported to be involved in the pathogenesis of several inflammatory diseases. However, the exact role of PLD2 in IBD is obscure. Methods. PLD2 expression was determined in peripheral blood cells and inflamed mucosa from patients with IBD by qRT-PCR. Colonic biopsies were also obtained from CD patients before and after infliximab (IFX) treatment to examine PLD2 expression. PLD2 selective inhibitor (CAY10594) was administrated daily by oral gavage in DSS-induced colitis mice. Bone marrow neutrophils from colitis mice were harvested to examine the migration using Transwell plate. Results. PLD2 was found to be significantly increased in peripheral blood cells and inflamed mucosa in patients with active IBD. Treatment with IFX could significantly decrease PLD2 expression in intestinal mucosa in patients with CD. Moreover, blockade of PLD2 with CAY10594 could markedly ameliorate DSS-induced colitis in mice and promote neutrophil migration. Conclusions. PLD2 plays a critical role in the pathogenesis of IBD. Blockade of PLD2 may serve as a new therapeutic approach for treatment of IBD.

Environmental Hygiene and Risk of Inflammatory Bowel Diseases: A Systematic Review and Meta-analysis

BACKGROUND

According to the hygiene hypothesis, individuals raised in a sanitary environment have a higher risk of developing inflammatory bowel diseases (IBD). However, results have been inconsistent. We conducted this systematic review of factors related to environmental hygiene and risk of IBD, Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

A systematic search was performed on MEDLINE between 1980 and 2015 to identify studies of the association between IBD and contact with pets and farm animals, number of siblings, bedroom sharing in childhood, and access to personal toilet and hot water. Random- or fixed-effect meta-analyses were performed, and analysis further stratified based on ethnicity of the included cohort.

RESULTS

A total of 29 relevant studies were included. Having a pet (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.63-0.88) and contact with farm animals was inversely associated with risk of IBD (OR, 0.45; 95% CI, 0.31-0.60). However, the strength of association with farm animals was statistically stronger in non-white cohorts (OR, 0.27; 95% CI, 0.02-0.53) than in white cohorts (OR, 0.55; 95% CI, 0.45-0.65) (P = 0.028). Access to toilet (OR, 0.71; 95% CI, 0.56-0.85) and hot water (OR, 0.67; 95% CI, 0.44-0.89) was inversely associated with UC in non-white populations but not whites. Having more than 2 siblings was inversely associated with risk of CD.

CONCLUSIONS

Several factors pertaining to reduced environmental hygiene are inversely associated with risk of IBD. However, underlying ethnicity influences susceptibility to the effect of these factors.

Disease-related knowledge and smoking behavior of patients with Crohn's disease

BACKGROUND

Patients' knowledge poses effects on quality of life, treatment adherence and coping skills in the management of Crohn's disease. Smoking is the most established risk factor and associated with a more severe course.

AIMS

We aimed to investigate the status of patients' knowledge on Crohn's disease in China, and explore the relationship between patients' knowledge and smoking behavior.

METHODS

Web-based questionnaires were created including a validated Crohn's and Colitis Knowledge Score applied to all participants and the Fagerström Test for Nicotine Dependence to smokers. The sociodemographic data, disease characteristics and smoking status were recorded. Patients were enrolled through invitation emails and Internet advertising. Current and ex-smokers were re-visited 6 months after enrollment.

RESULTS

923 patients completed valid questionnaires with the knowledge score of 12.18±4.61. Disease duration and educational status were independent predictors of the knowledge score by multiple linear regression analysis. The smoking rate was 8.2%. Low knowledge score was related with smoking behavior but not nicotine dependence, and smoking relapse during 6 months after enrollment.

CONCLUSIONS

Patients' education should be a priority considering its impacts on many factors including smoking. Extra attention should be given to those from countryside area or having low family income and educational achievement.

Diet, gut microbes, and the pathogenesis of inflammatory bowel diseases

The rising incidence of inflammatory bowel diseases in recent decades has notably paralleled changing lifestyle habits in Western nations, which are now making their way into more traditional societies. Diet plays a key role in IBD pathogenesis, and there is a growing appreciation that the interaction between diet and microbes in a susceptible person contributes significantly to the onset of disease. In this review, we examine what is known about dietary and microbial factors that promote IBD. We summarize recent findings regarding the effects of diet in IBD epidemiology from prospective population cohort studies, as well as new insights into IBD-associated dysbiosis. Microbial metabolism of dietary components can influence the epithelial barrier and the mucosal immune system, and understanding how these interactions generate or suppress inflammation will be a significant focus of IBD research. Our knowledge of dietary and microbial risk factors for IBD provides important considerations for developing therapeutic approaches through dietary modification or re-shaping the microbiota. We conclude by calling for increased sophistication in designing studies on the role of diet and microbes in IBD pathogenesis and disease resolution in order to accelerate progress in response to the growing challenge posed by these complex disorders.

The Same Intestinal Inflammatory Disease despite Different Genetic Risk Factors in the East and West?

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory disease with unknown etiology. It is likely caused by a complex interplay between genetic, immunologic and environmental factors. Although IBD is still relatively uncommon in Asia, a multitude of studies have shown that it is an emerging disease around the world. Recent insights have highlighted both the similarities and differences amongst Asian and Western IBD patients.

SUMMARY

The annual incidence of IBD in the East is still low compared with the West, but there are differences between different regions of Asia. Time trend studies have shown that the incidence of IBD is on the rise. Some notable differences in the clinical manifestations of IBD between the East and West have also been noted. 'Westernization' of lifestyle may encompass various social and environmental changes that account for the emergence of IBD in our population, although genetics also plays a role in disease pathogenesis. Diagnosis and treatment challenges include limited access to medical care in certain areas, limited availability and high cost of medications, lack of insurance reimbursement, paucity of multidisciplinary teams for the management of complicated IBD cases, and a high prevalence of endemic infections. Currently, the risk of colorectal cancer is lower in the East than in the West, but cancer rates will likely approach that of the West in the future as the prevalence of IBD continues to rise.

KEY MESSAGES

Measures to improve access to diagnostic tools, increase the availability of medication, and provide adequate multidisciplinary care for IBD patients will become increasingly important in Asia. Differences between the East and West will provide a unique opportunity for global collaboration in basic and clinical research to further our understanding of the disease entity and also provide more locoregional data to healthcare providers and policymakers to make informed decisions and policy changes when tackling the rising burden of IBD in Asia.

Treatment of inflammatory bowel disease in Asia: the results of a multinational web-based survey in the 2(nd) Asian Organization of Crohn's and Colitis (AOCC) meeting in Seoul

Background/Aims

Inflammatory bowel disease (IBD) management guidelines have been released from Western countries, but no adequate data on the application of these guidelines in Asian countries and no surveys on the treatment of IBD in real practice exist. Since there is a growing need for a customized consensus for IBD treatment in Asian countries, Asian Organization of Crohn's and Colitis performed a multinational survey of medical doctors who treat IBD patients in Asian countries.

Methods

A questionnaire was developed between August 2013 and November 2013. It was composed of 4 domains: personal information, IBD diagnosis, IBD treatment, and quality of IBD care. Upon completion of the questionnaire, a web-based survey was conducted between 17 March 2014 and 12 May 2014.

Results

In total, 353 medical doctors treating IBD from ten Asian countries responded to the survey. This survey data suggested a difference in available medical treatments (budesonide, tacrolimus) among Asian countries. Therapeutic strategies regarding refractory IBD (acute severe ulcerative colitis [UC] refractory to intravenous steroids and refractory Crohn's disease [CD]) and active UC were coincident, however, induction therapies for mild to moderate inflammatory small bowel CD are different among Asian countries.

Conclusions

This survey demonstrated that current therapeutic approaches and clinical management of IBD vary among Asian countries. Based on these results and discussions, we hope that optimal management guidelines for Asian IBD patients will be developed.

WISP1 Is Increased in Intestinal Mucosa and Contributes to Inflammatory Cascades in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is mainly characterized by intestinal tissue damage, which is caused by excessive autoimmune responses poorly controlled by corresponding regulatory mechanisms. WISP1, which belongs to the CCN protein family, is a secreted matricellular protein regulating several inflammatory pathways, such as Wnt/β-catenin pathway, and has been reported in several diseases including cancer. Here we examined the expression, regulatory mechanisms, and functions of WISP1 in IBD. WISP1 mRNA and protein expression was upregulated in colonic biopsies and lamina propria mononuclear cells (LPMC) of IBD patients compared with those of healthy controls. Tumor necrosis factor- (TNF-) α induced WISP1 expression in LPMC from healthy controls. Consistently, WISP1 mRNA expression was downregulated in colonic biopsies from IBD patients who had achieved clinical remission with infliximab (IFX). Furthermore, WISP1 expression was also found to be increased in colons from 2,4,6-trinitrobenzenesulfonic acid- (TNBS-) induced mice compared with those from control mice. Further studies confirmed that administration of rWISP1 could aggravate TNBS-induced colitis in vivo. Therefore, we concluded that WISP1 is increased in IBD and contributes to the proinflammatory cascades in the gut.

Tonsillectomy and the risk of inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Tonsillectomy remains a controversial environmental factor in the etiology of inflammatory bowel disease (IBD). This meta-analysis aims to elucidate a more defined role of tonsillectomy in the development of IBD.

METHODS

Four databases, including PubMed, EMBASE, the Cochrane Library, and Web of Science, were searched for studies exploring the association between tonsillectomy and the risk of IBD. The pooled estimates of odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random effects model. Heterogeneity was assessed using chi-squared and I(2) statistical analysis. A funnel plot was performed to assess publication bias.

RESULTS

A total of 23 observational studies involving 19 569 patients were included in our meta-analysis. Of these, 17 studies investigated the association between tonsillectomy and Crohn's disease (CD), and 22 studies explored its relationship with ulcerative colitis (UC). Overall, a positive relationship between tonsillectomy and development of CD (OR 1.37, 95% CI: 1.16-1.62) was observed, while there was no association between tonsillectomy and UC (OR 0.94, 95% CI: 0.84-1.05). When ORs were adjusted for smoking, the pooled OR for CD increased to 1.66 (95% CI: 1.03-2.68) and, for UC, changed to 1.03 (95% CI: 0.74-1.44).

CONCLUSIONS

This meta-analysis demonstrates that tonsillectomy is associated with an increased risk of developing CD. We found no evidence to suggest that tonsillectomy exerts a protective effect on the development of UC, as is the case with appendectomy. Further prospective studies are required to confirm the validity of these observations.

Genetics and Pathogenesis of Inflammatory Bowel Disease

We are currently in an exciting time when our understanding of genetic underpinnings of inflammatory bowel disease (IBD) has undergone a revolution, based in large part on novel genotyping and sequencing technologies. With >160 susceptible loci identified for IBD, the goal is now to understand at a fundamental level the function of these susceptibility alleles. Determining the clinical relevance of how these susceptible genes shape the development of IBD is also a high priority. The main challenge is to understand how the environment and microbiome play a role in triggering disease in genetically susceptible individuals, as the interactions may be complex. To advance the field, novel in vitro and mouse models that are designed to interrogate complex genetics and functionally test hypotheses are needed. Ultimately, the goal of genetics studies will be to translate genetics to patients with IBD and improve their care.

Changing epidemiological trends of inflammatory bowel disease in Asia

Inflammatory bowel disease (IBD) has become more common in Asia over the past few decades. The rate of increase in prevalence of the disease varies greatly in Asia, with several countries in East Asia experiencing a more than doubled increase in IBD prevalence over the past decade. Historically, ulcerative colitis (UC) is more common than Crohn's disease (CD) in Asia. However, a reverse trend is beginning to appear in more developed countries in Asia such as Japan, Korea, and Hong Kong. While Asian IBD patients share many similarities with their Western counterparts, there are important differences with significant clinical implications. In Asia, there are more men with CD, more ileo-colonic involvement in CD, less familial aggregation, fewer extra-intestinal manifestations and worse clinical outcomes for older-onset patients with UC. These differences are likely related to the different genetic makeup and environmental exposures in different regions. Evaluation of the differences and rates in epidemiologic trends may help researchers and clinicians estimate disease burden and understand the reasons behind these differences, which may hold the key to unravel the etiology of IBD.

Influence of environmental factors on the onset and course of inflammatory bowel disease

Numerous environmental factors have been linked with inflammatory bowel disease. These include smoking, diet, hygiene, drugs, geographical and psychosocial factors. These factors may either increase the risk of or protect against developing this condition and can also affect the course of illness in a positive or negative manner. A number of studies have examined the influence of environmental factors on inflammatory bowel diseases as a whole as well as on ulcerative colitis and Crohn’s disease separately. As there are differences in the pathogenesis of ulcerative colitis and Crohn’s disease, the effect of environmental factors on their onset and course is not always similar. Some factors have shown a consistent association, while reports on others have been conflicting. In this article we discuss the current evidence on the roles of these factors on inflammatory bowel disease, both as causative/protective agents and as modifiers of disease course.

Perinatal characteristics, older siblings, and risk of ankylosing spondylitis: a case-control study based on national registers

Background

The effect of circumstances and exposures early in life on the risk of developing ankylosing spondylitis (AS) is largely unknown. The purpose of this study was to determine whether perinatal characteristics predict development of AS.

Methods

AS cases (n = 1960; 59 % men) were defined as listed with a diagnosis of AS at least once in the Swedish National Patient Register and registered in the Swedish Medical Birth Register (born ≥1973). Population controls were retrieved from the Swedish Population Register (n = 8378; mean 4.3 controls/case), matched on birth year, sex and county. Odds ratios (OR) for developing AS were determined through conditional logistic regression, with regard to: birth weight, birth order, season of birth, maternal age, gestational length, size for gestational age, type of birth, mode of delivery, congenital malformations, mothers’ country of birth, mothers’ civil status and size of delivery unit.

Results

In the univariate analyses statistically significant increases in risk for developing AS were observed for having older siblings (OR 1.18; 95 % Cl 1.06–1.30). No association was observed for the remainder of analysed exposures, although there was a weak association with birth weight below 3000 g (OR 1.19; 95 % CI 1.04–1.37), though not for “low birth weight” <2500 g (OR 0.90; 95 % CI 0.70–1.16). The increase in risk associated with having older siblings was consistent in a multivariate analysis adjusting for possible confounders (OR 1.23; 95 % Cl 1.09–1.39). The direction and magnitude of the point estimates were also consistent in several sensitivity analyses and when stratifying by sex.

Conclusions

Having older siblings was associated with an increased risk for developing AS. These results need to be repeated and confirmed in other cohorts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0917-1) contains supplementary material, which is available to authorized users.

Asia Pacific Consensus Statements on Crohn's disease. Part 1: Definition, diagnosis, and epidemiology: (Asia Pacific Crohn's Disease Consensus--Part 1)

Inflammatory bowel disease (IBD) was previously thought to be rare in Asia, but emerging data indicate rising incidence and prevalence of IBD in the region. The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology with the goal of developing best management practices, coordinating research, and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis, and management of Crohn's disease. The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses, and treatment availability. It does not intend to be all comprehensive and future revisions are likely to be required in this ever-changing field.

The global burden of IBD: from 2015 to 2025

Over 1 million residents in the USA and 2.5 million in Europe are estimated to have IBD, with substantial costs for health care. These estimates do not factor in the 'real' price of IBD, which can impede career aspirations, instil social stigma and impair quality of life in patients. The majority of patients are diagnosed early in life and the incidence continues to rise; therefore, the effect of IBD on health-care systems will rise exponentially. Moreover, IBD has emerged in newly industrialized countries in Asia, South America and Middle East and has evolved into a global disease with rising prevalence in every continent. Understanding the worldwide epidemiological patterns of IBD will prepare us to manage the burden of IBD over time. The goal of this article is to establish the current epidemiology of IBD in the Western world, contrast it with the increase in IBD in newly industrialized countries and forecast the global effects of IBD in 2025.

High School Diet and Risk of Crohn's Disease and Ulcerative Colitis

BACKGROUND

Diet may play an important role in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC); yet, there are few prospective studies of dietary factors. None have examined the association between adolescent diet and risk of inflammatory bowel diseases (CD and UC).

METHODS

This study included women enrolled in Nurses' Health Study II who completed a validated high school dietary questionnaire in 1998. We examined the effect of dietary patterns (prudent or Western diet) and individual components of each patterns. We documented incident cases of CD and UC through 2011 based on physician review of medical records and used Cox proportional hazards models adjusting for confounders to estimate hazard ratios and confidence intervals for CD and UC.

RESULTS

Over 763,229 person-years of follow-up, we identified 70 incident cases of CD and 103 cases of UC. Compared with women in the lowest quartile of a prudent diet score (characterized by greater intake of fruits, vegetables, and fish), women in the highest quartile had a 53% lower risk of CD (hazard ratio, 0.47; 95% confidence interval, 0.23-0.98; P trend = 0.04). Specifically, greater intake of fish (P trend = 0.01) and fiber (P trend = 0.06) were associated with lower risk of CD. In contrast, Western diet score was not associated with risk of CD. Neither dietary patterns nor individual food or nutrient groups was associated with UC.

CONCLUSIONS

Adolescent diet is associated with risk of CD, but not UC, offering insights into disease pathogenesis.

Reduced incidence of Crohn's disease in systemic sclerosis: a nationwide population study

Background

To date, there has been no studies to evaluate the incidence of Crohn’s disease in systemic sclerosis patients. The goals of this study were to evaluate the incidence of Crohn’s disease and its relationship with sex and age in patients with systemic sclerosis.

Methods

We enrolled patients with systemic sclerosis and controls from Taiwan’s Registry of Catastrophic Illness Database and National Health Insurance Research Database. Every systemic sclerosis patient was matched to at most three controls by sex, age, month and year of initial diagnosis of systemic sclerosis. The standardized incidence ratio (SIR) of Crohn’s disease in systemic sclerosis patients, and 95 % confidence interval (95 % CI) were calculated. Cox hazard regression was used to calculate the hazard ratio (HR).

Results

The study enrolled 2,829 patients with systemic sclerosis and 8,257 controls. Male and female patients with systemic sclerosis both had lower rates of incident Crohn’s disease (SIR: 0.18, 95 % CI = 0.05–0.62; SIR: 0.10, 95 % CI = 0.05–0.21, respectively). The risk of incident Crohn’s disease in systemic sclerosis was still lower than in controls when we stratified the patients according to their ages. In Cox hazard regression, the hazard rates of Crohn’s disease were lower in systemic sclerosis patients after adjusting for genders and ages (HR: 0.12, 95 % CI = 0.06–0.21, p < 0.001).

Conclusions

Systemic sclerosis is associated with decreased incidence of, irrespective of sex and age of the patients.

Epidemiology and risk factors for IBD

IBD, comprising Crohn's disease and ulcerative colitis, is a chronic immunologically mediated disease at the intersection of complex interactions between genetics, environment and gut microbiota. Established high-prevalence populations of IBD in North America and Europe experienced the steepest increase in incidence towards the second half of the twentieth century. Furthermore, populations previously considered 'low risk' (such as in Japan and India) are witnessing an increase in incidence. Potentially relevant environmental influences span the spectrum of life from mode of childbirth and early-life exposures (including breastfeeding and antibiotic exposure in infancy) to exposures later on in adulthood (including smoking, major life stressors, diet and lifestyle). Data support an association between smoking and Crohn's disease whereas smoking cessation, but not current smoking, is associated with an increased risk of ulcerative colitis. Dietary fibre (particularly fruits and vegetables), saturated fats, depression and impaired sleep, and low vitamin D levels have all been associated with incident IBD. Interventional studies assessing the effects of modifying these risk factors on natural history and patient outcomes are an important unmet need. In this Review, the changing epidemiology of IBD, mechanisms behind various environmental associations and interventional studies to modify risk factors and disease course are discussed.

Experimental colitis in mice is attenuated by topical administration of chlorogenic acid

Epidemiological data suggest that the consumption of polyphenol-rich foods reduces the incidence of cancer, coronary heart disease, and inflammation. Chlorogenic acid (CGA), an ester of caffeic and quinic acids, is one of the most abundant polyphenol compounds in human diet with proven biological effectiveness both in vitro and in vivo. The aim of the study is to investigate the possible anti-inflammatory effect of CGA in the gastrointestinal (GI) tract and its mechanism of action. We used a well-established model of colitis, induced by intracolonic (i.c.) administration of trinitrobenzenesulfonic acid (TNBS) in mice. The anti-inflammatory effect of CGA in the colon was evaluated based on the clinical and macroscopic and microscopic parameters. To investigate the mechanism of protective action of CGA, myeloperoxidase (MPO), H2O2, and NF-κB levels were assessed in the colon tissue. CGA administered i.c. at the dose of 20 mg/kg (two times daily) protected against TNBS-induced colitis more effectively than the same dose administered orally (p.o.), as evidenced by significantly lower macroscopic and ulcer scores. Furthermore, CGA (20 mg/kg, i.c.) reduced neutrophil infiltration, as demonstrated by decreased MPO activity. Moreover, CGA suppressed activation of NF-κB, as evidenced by lower levels of phospho-NF-κB/NF-κB ratio in the tissue. CGA did not affect the oxidative stress pathways. CGA exhibits anti-inflammatory properties through reduction of neutrophil infiltration and inhibition of NF-κB-dependent pathways. Our results suggest that CGA may have the potential to become a valuable supplement in the treatment of GI diseases.

Early life environment and natural history of inflammatory bowel diseases

Background

Early life exposures may modify risk of inflammatory bowel diseases (IBD; Crohn’s disease (CD), ulcerative colitis (UC)). However, the relationship between early life exposures and natural history of IBD has not been previously examined.

Methods

This single center study included patients with CD or UC recruited in a prospective IBD registry. Enrolled patients completed a detailed environmental questionnaire that assessed various early life environmental exposures. Our primary outcome was requirement for disease-related surgery in CD and UC. Logistic regression models defined independent effect of early life exposures, adjusting for potential confounders.

Results

Our study included 333 CD and 270 UC patients. Just over half were female with a median age at diagnosis of 25 years. One-third of the cohort had history of bowel surgery (31%) and nearly half had used at least one biologic agent (47%). Among those with CD, being breastfed was associated with reduced risk of CD-related surgery (34% vs. 55%), while childhood cigarette smoke exposure was associated with increased risk. On multivariate analysis, history of being breastfed (odds ratio (OR) 0.21, 95% confidence interval [CI] 0.09–0.46) and cigarette smoke exposure as a child (OR 2.17, 95% CI 1.10–4.29) remained independently associated with surgery. None of the early life variables influenced disease phenotype or outcome in UC.

Conclusion

A history of being breastfed was associated with a decreased risk while childhood cigarette smoke exposure was associated with an increased risk of surgery in patients with CD. Further investigation to examine biological mechanisms is warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-014-0216-8) contains supplementary material, which is available to authorized users.