Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases

Revolution in diet therapy for inflammatory bowel disease

Until recently, diet as a therapeutic tool to treat inflammatory bowel disease (IBD) has not been proven effective. Nearly a century in the making we are in the grips of a revolution in diet therapies for IBD, driven by emerging data revealing diet as a key environmental factor associated with IBD susceptibility, and observational studies suggesting that dietary intake may play a role in the disease course of established IBD. This review summarizes the current evidence for diets trialed as induction and maintenance therapy for IBD. For Crohn's disease, exclusive enteral nutrition and the Crohn's disease exclusion diet with partial enteral nutrition are supported by emerging high-quality evidence as induction therapy, but are short-term approaches that are not feasible for prolonged use. Data on diet as maintenance therapy for Crohn's disease are conflicting, with some studies supporting fortification, and others suppression, of certain food components. For ulcerative colitis, data are not as robust for diet as induction and maintenance therapy; however, consistent themes are emerging, suggesting benefits for diets that are plant-based, high in fiber and low in animal protein. Further studies for both Crohn's disease and ulcerative colitis are eagerly awaited, which will allow specific recommendations to be made. Until this time, recommendations default to population based healthy eating guidelines.

Residential mobility and childhood inflammatory bowel disease: a nationwide case-control study

PURPOSE

To examine the association of residential mobility, as a proxy for environmental influences, with childhood inflammatory bowel disease (IBD) risk.

METHODS

Using nationwide register-based dataset, all 2038 IBD cases in Finland diagnosed at ages less than 15 years in 1992-2016 were individually matched by sex and age with five controls employing risk set sampling. Complete residential histories of the subjects were constructed from birth until the index date (diagnosis date of the case). Movement patterns were assessed by age, distance, and demographics of the departure and destination municipalities. Conditional logistic regression was employed to estimate the association between movements and IBD risk.

RESULTS

Overall, residential movement was associated with a slightly decreased odds ratio (OR) for childhood IBD (OR 0.97, 95% confidence interval (CI) 0.95-1.00 for each movement). Further examination showed reduced ORs for moving to rural municipalities (OR 0.94, 95% CI 0.90-0.98) and to distances less than 50 km (OR 0.96, 95% CI 0.93-0.99). In disease subtype analyses, the effect mainly persisted in ulcerative colitis.

CONCLUSIONS

Our findings suggest lower childhood IBD risk associated with residential mobility. The effect was found in ulcerative colitis, but not in Crohn's disease. Movements to nearby and rural areas may reduce IBD risk, though this requires further investigation.

Holistic healthcare in inflammatory bowel disease: time for patient-centric approaches?

Inflammatory bowel disease (IBD) is an emerging global disease characterised by chronic inflammation of the gastrointestinal tract. However, IBD is also manifested by several extraintestinal symptoms which, along with the intestinal symptoms, impact on the mental and emotional well-being of patients. Despite therapeutic advancements, only one-third of the diagnosed patients receiving approved medical treatments achieve short-term to medium-term remission. Consequently, patients who do not get successfully treated might resort to using complementary and alternative approaches to manage their symptoms, with or without consulting their treating clinician. Despite their possible potential, such approaches have various risks stemming from unknown adverse reactions and possible interference with medically approved therapies. In this study, we present the results of a well-performed literature review where we included randomised clinical trials which have assessed the efficacy of complementary approaches and dietary therapy on at least one of the following four outcomes: clinical remission, endoscopic remission, modulation of molecular biomarkers or quality of life metrics. By pointing out intraoutcome and interoutcome concordance, we identified possible candidates for clinical adoption and further study in larger randomised clinical trials covering the broad spectrum of IBD heterogeneity. We finally proposed a patient-centric clinical care model and a series of recommendations for stakeholders, with special attention to complementary approaches and dietary strategies, aimed at achieving holistic remission.

Where Do We Stand in the Behavioral Pathogenesis of Inflammatory Bowel Disease? The Western Dietary Pattern and Microbiota-A Narrative Review

Despite the increasing knowledge with regard to IBD (inflammatory bowel disease), including ulcerative colitis (UC) and Crohn’s disease (CD), the etiology of these conditions is still not fully understood. Apart from immunological, environmental and nutritional factors, which have already been well documented, it is worthwhile to look at the possible impact of genetic factors, as well as the composition of the microbiota in patients suffering from IBD. New technologies in biochemistry allow to obtain information that can add to the current state of knowledge in IBD etiology.

Tailoring Multi-omics to Inflammatory Bowel Diseases: All for One and One for All

Inflammatory bowel disease [IBD] has a multifactorial origin and originates from a complex interplay of environmental factors with the innate immune system at the intestinal epithelial interface in a genetically susceptible individual. All these factors make its aetiology intricate and largely unknown. Multi-omic datasets obtained from IBD patients are required to gain further insights into IBD biology. We here review the landscape of multi-omic data availability in IBD and identify barriers and gaps for future research. We also outline the various technical and non-technical factors that influence the utility and interpretability of multi-omic datasets and thereby the study design of any research project generating such datasets. Coordinated generation of multi-omic datasets and their systemic integration with clinical phenotypes and environmental exposures will not only enhance understanding of the fundamental mechanisms of IBD but also improve therapeutic strategies. Finally, we provide recommendations to enable and facilitate generation of multi-omic datasets.

Ginsenoside Rk3 Ameliorates Obesity-Induced Colitis by Regulating of Intestinal Flora and the TLR4/NF-κB Signaling Pathway in C57BL/6 Mice

Obesity-induced colonic inflammation-stimulated colitis is one of the main causes of colorectal cancer. Dietary phytochemicals are considered to be an effective strategy for relieving obesity-induced inflammatory diseases such as diabetes and colitis. Ginsenoside Rk3 (Rk3) is the main bioactive component of ginseng. Our previous study has demonstrated that Rk3 can effectively alleviate obesity-induced type 2 diabetes, but whether it plays a beneficial role in obesity-induced colitis remains poorly understood. Here, we found that Rk3 intervention repaired the intestinal barrier dysfunction by increasing the expression of the tight junction proteins (zonula occludens-1, claudin, and occludin), and reduced colonic inflammatory cytokine levels, oxidative stress, and macrophage infiltration in high-fat diet-induced mice. Importantly, Rk3 effectively ameliorated the metabolic dysbiosis of intestinal flora with significantly decreased Firmicute/Bacteroidete ratios and suppressed the inflammatory cascade by inhibiting the TLR4/NF-κB signaling pathway. Taken together, our findings indicate that Rk3 can be used as a potential natural anti-inflammatory agent to reduce chronic obesity-induced colitis.

Let Food Be Thy Medicine-Its Role in Crohn's Disease

The food we eat is thought to play a role in both the increasing incidence as well as the course of Crohn's disease. What to eat and what to avoid is an increasingly important question for both patients and physicians. Restrictive diets are widely adopted by patients and carry the risk of inducing or worsening malnutrition, without any guarantees on anti-inflammatory potential. Nevertheless, exploration of novel therapies to improve long-term management of the disease is desperately needed and the widespread use of exclusive enteral nutrition in the induction of paediatric Crohn's disease makes us wonder if a similar approach would be beneficial in adult patients. This narrative review discusses the current clinical evidence on whole food diets in achieving symptomatic and inflammatory control in Crohn's disease and identifies knowledge gaps with areas for future research.

Long-Term Follow-Up, Association between CARD15/NOD2 Polymorphisms, and Clinical Disease Behavior in Crohn's Disease Surgical Patients

Background

CARD15/NOD2 is the most significant genetic susceptibility in Crohn's disease (CD) even though a relationship between the different polymorphisms and clinical phenotype has not been described yet. The study is aimed at analyzing, in a group of CD patients undergoing surgery, the relationship between CARD15/NOD2 polymorphisms and the clinical CD behavior after a long-term follow-up, in order to identify potential clinical biomarkers of prognosis.

Methods

191 surgical CD patients were prospectively characterized both for the main single nucleotide polymorphisms of CARD15/NOD2 and for many other environmental risk factors connected with the severe disease form. After a mean follow-up of 7.3 years, the correlations between clinical features and CD natural history were analyzed.

Results

CARD15/NOD2 polymorphisms were significantly associated with younger age at diagnosis compared to wild type cases (p < 0.05). Moreover, patients carrying a 3020insC polymorphism presented a larger Δ between diagnosis and surgery (p = 0.0344). Patients carrying an hz881 and a 3020insC exhibited, respectively, a lower rate of responsiveness to azathioprine (p = 0.012), but no difference was found in biologic therapy. Finally, the risk of surgical recurrence was significantly associated, respectively, to age at diagnosis, to familial CD history, to diagnostic delay, to arthritis, and to the presence of perioperative complications.

Conclusions

3020insC CARD15 polymorphism is associated with an earlier CD onset, and age at CD diagnosis < 27 years was confirmed to have a detrimental effect on its clinical course. In addition, the familiarity seems to be connected with a more aggressive postoperative course. Finally, for the first time, we have observed a lower rate of responsiveness to azathioprine in patients carrying an hz881 and a 3020insC.

The Association Between Caesarean Section and Inflammatory Bowel Disease in Childhood and Young Adulthood: Findings From 2 Retrospective Cohort Studies

OBJECTIVE

The aim of the study was to examine the association of Caesarean section (CS) with inflammatory bowel disease (IBD) in Nova Scotian children.

METHODS

The study consisted of 2 retrospective cohorts in the Canadian province of Nova Scotia: all births between 1988 and 2014 (n = 262,729) linked with a clinical registry of all children diagnosed with IBD at the IWK Health Centre, Halifax (Clinical Cohort) and all births from 1989 to 1993 (n = 42,999) linked with provincial administrative health data (Administrative Cohort). The primary outcome was a diagnosis of IBD; the outcome in the Administrative Cohort was ascertained using a previously validated algorithm. Information on the exposures and confounding variables was obtained from the Nova Scotia Atlee Perinatal Database. The association between CS and time to diagnosis of IBD was examined using survival analysis.

RESULTS

The population incidence of IBD in the Clinical and Administrative Cohort were 13.0 and 20.6, respectively, per 100,000 person-years; 23% and 19% of children were born by CS in the 2 cohorts. There was no association of CS with IBD in the 2 cohorts.

CONCLUSIONS

Findings from 2 population-based cohorts in Atlantic Canada did not provide any evidence for an association between CS and IBD in childhood and young adulthood.

Crohn's disease and environmental contamination: Current challenges and perspectives in exposure evaluation

Although the incidence of Crohn's disease has increased worldwide over the past 30 years, the disorder's exact causes and physiological mechanisms have yet to be determined. Given that genetic determinants alone do not explain the development of Crohn's disease, there is growing interest in "environmental" determinants. In medical science, the term "environment" refers to both the ecological and social surroundings; however, most published studies have focused on the latter. In environmental and exposure sciences, the term "environment" mostly relates to contamination of the biotope. There are many unanswered questions on how environmental hazards might contribute to the pathogenesis of Crohn's disease. Which pollutants should be considered? Which mechanisms are involved? And how should environmental contamination and exposure be evaluated? The objective was to perform a systematic review of the literature on Crohn's disease and environmental contamination. We searched the PubMed, Google Scholar, Scopus, ISI Web of Science and Prospero databases. We considered all field studies previous to April 2019 conducted on human health indicators, and evaluating exposure to all type of physical, biological and chemical contamination of the environment. The lack of clear answers to date can be ascribed to the small total number of field studies (n = 16 of 39 publications, most of which were conducted by pioneering medical scientists), methodological differences, and the small number of contaminants evaluated. This make it impossible to conduct a coherent and efficient meta-analysis. Based on individual analysis of available studies, we formulated five recommendations on improving future research: (i) follow up the currently identified leads - especially metals and endocrine disruptors; (ii) explore soil contamination; (iii) gain a better knowledge of exposure mechanisms by developing transdisciplinary studies; (iv) identify the most plausible contaminants by developing approaches based on the source-to-target distance; and (v) develop registries and cohort-based analyses.

A food pyramid, based on a review of the emerging literature, for subjects with inflammatory bowel disease

Emerging literature suggests that diet plays an important modulatory role in inflammatory bowel disease (IBD) through the management of inflammation and oxidative stress. The aim of this narrative review is to evaluate the evidence collected up till now regarding optimum diet therapy for IBD and to design a food pyramid for these patients. The pyramid shows that carbohydrates should be consumed every day (3 portions), together with tolerated fruits and vegetables (5 portions), yogurt (125ml), and extra virgin olive oil; weekly, fish (4 portions), white meat (3 portions), eggs (3 portions), pureed legumes (2 portions), seasoned cheeses (2 portions), and red or processed meats (once a week). At the top of the pyramid, there are two pennants: the red one means that subjects with IBD need some personalized supplementation and the black one means that there are some foods that are banned. The food pyramid makes it easier for patients to decide what they should eat.

Nutrition, IBD and Gut Microbiota: A Review

Inflammatory bowel disease (IBD) is a chronic relapsing–remitting systemic disease of the gastrointestinal tract, characterized by an inflammatory process that requires lifelong treatment. The underlying causes of IBD are still unclear, as this heterogeneous disorder results from a complex interplay between genetic variability, the host immune system and environmental factors. The current knowledge recognizes diet as a risk factor for the development of IBD and attributes a substantial pathogenic role to the intestinal dysbiosis inducing an aberrant mucosal immune response in genetically predisposed individuals. This review focused on the clinical evidence available that considers the impact of some nutrients on IBD onset and the role of different diets in the management of IBD and their effects on the gut microbiota composition. The effects of the Specific Carbohydrate Diet, low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet, gluten free diet, anti-inflammatory diet and Mediterranean diet are investigated with regard to their impact on microbiota and on the evolution of the disease. At present, no clear indications toward a specific diet are available but the assessment of dysbiosis prior to the recommendation of a specific diet should become a standard clinical approach in order to achieve a personalized therapy.

The Gut Microbiome in Inflammatory Bowel Diseases: Diagnostic and Therapeutic Implications

The incidence of chronic inflammatory bowel diseases (IBD) is rising worldwide, and the interaction between the mucosal immune system and the intestinal microbiota is crucial for the understanding of these diseases. Due to new technologies, the data published on the intestinal microbiota has increased rapidly in the recent years. While many findings are descriptive, reporting associations between disease and microbial populations, recent advancement in technology made it possible to ask and answer more functional questions and to elucidate complex interactions between the intestinal microbiota and the mucosal immune system. In addition, first trials influenced the intestinal microbiota with the intention to treat IBD. This review summarizes aspects of the physiological function as well as the inflammation-induced changes of the gut microbiota and the association between the gut microbiota and pathogenesis in IBD. In addition, diagnostic and therapeutic options for treating IBD are reviewed.

Dietary Composition and Effects in Inflammatory Bowel Disease

Dramatic changes in the environment and human lifestyle have been associated with the rise of various chronic complex diseases, such as inflammatory bowel disease (IBD). A dysbiotic gut microbiota has been proposed as a crucial pathogenic element, contributing to immune imbalances and fostering a proinflammatory milieu, which may be associated with disease relapses or even the initiation of IBD. In addition to representing important regulators of the mucosal immunity and the composition of the gut microbiota, food components have been shown to be potential environmental triggers of epigenetic modifications. In the context of chronic intestinal inflammation, dietary habits and specific food components have been implicated as important modulators of epigenetic mechanisms, including DNA methylation, which may predispose a person to the increased risk of the initiation and evolution of IBD. This review provides novel insights about how dietary factors may interact with the intestinal mucosa and modulate immune homeostasis by shaping the intestinal ecosystem, as well as the potential influence of diet in the etiopathogenesis and management of IBD.

Development of a Global Rating Scale for Inflammatory Bowel Disease

Background

The Global Rating Scale (GRS) is a web-based self-assessment quality improvement tool used to identify gaps in health care, change the focus to patient-centred care and standardize care. There are four levels of achievement ranging from basic-(D) to excellent-(A) service delivery. The goal was to develop a GRS for inflammatory bowel disease (IBD) to improve the quality of care for patients on a system level.

Methods

The IBD GRS was developed through an iterative process and modeled upon the successful endoscopy GRS programs in the United Kingdom and Canada. Dimensions, items and statements were drafted based on expert opinions, patient-informed quality indicators and best available evidence, then reviewed and modified by a core committee. A working group of IBD and GRS experts voted in-person to establish consensus on the inclusion and quality of statements.

Results

Two dimensions (Clinical Quality and Quality of Patient Experience), 10 items and 89 statements made up the IBD GRS. There was a 100% response rate for each of the 40 votes for statements in the IBD GRS. All statements within each level received a mean rating score between four (agree) and five (strongly agree). Revisions agreed upon during the voting process were incorporated into the IBD GRS. Group consensus was achieved on the inclusion of statements, and 10 items were selected as standards within the two dimensions.

Conclusions

We have developed the first IBD GRS with the aim of improving quality of care through ongoing evaluations and improvements by health care teams, focusing on patient-centred care.

Saponins regulate intestinal inflammation in colon cancer and IBD

The saponins are natural surface-active glycosides which are the principal components of many popular herbal medicinal plants such as ginseng, astragalus, and bupleurum. Recent studies have suggested that saponins can exert strong anti-inflammatory effects and induce immune homeostasis in many diseases. Intestinal-inflammation-related digestive diseases include inflammatory bowel disease (IBD), irritable bowel syndrome, intestinal ischemia-reperfusion injury, necrotizing enterocolitis and radiation proctitis, as well as intestinal inflammation caused by nonsteroidal anti-inflammatory drugs. The pathogenesis of these diseases is poorly understood, and the patients with these diseases suffer from mental stress and physical pain, while their families (and society) experience heavy economic losses. Results from animal experiments suggest that saponins can suppress intestinal inflammation, promote intestinal barrier repair, maintain the diversity of the intestinal flora, and decrease the incidence rate of colon-inflammation-related colon cancer. In this review, we discuss new findings regarding the effects of saponins on intestinal inflammation and digestive diseases with intestinal inflammation. In addition, we provide a summary of the underlying mechanism for saponins-induced treatment on intestinal-inflammation-related disease.

Influence of Environmental Factors in the Development and Outcomes of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), which mainly comprises Crohn's disease (CD) and ulcerative colitis (UC), is a term for chronic inflammatory diseases of the gut arising due to a dysregulated immune response to a dysbiotic gut microbiome on a background of genetic predisposition. However, genetics explains a small fraction of risk, and the external environment plays a large and important role in disease pathogenesis and natural history. Cigarette smoking, one of the earliest- and most-studied risk factors, increases the risk of CD onset and is associated with severe disease. In contrast, although smoking cessation increases the risk of UC onset and relapse, current smoking appears to be protective. Appendectomy is inversely associated with the risk of UC. Various dietary factors may influence risk of IBD, including an inverse association with dietary fiber. Exclusion diets have anecdotal reports of efficacy but lack evidence from rigorous clinical trials. Psychosocial factors such as depression, stress, and sleep disturbance play a role in onset as well as in determining natural history. There is an important need for rigorous studies robustly informing the association and mechanism(s) of influence of the external environment on IBD risk and for clinical trials examining the efficacy of alteration of the environment in ameliorating the course of IBD.

Medication non-adherence in inflammatory bowel diseases is associated with disability

Background/Aims

Medication non-adherence is common in inflammatory bowel diseases (IBD). The short-term consequences of non-adherence include increased disease relapse but the long-term impact upon patients in terms of daily functional impairment are less well characterized. Identifying negative outcomes, such as disability, may encourage adherence.

Methods

Consecutive ambulatory IBD subjects completed the Medication Adherence Rating Scale (MARS; non-adherence defined as ≤16), Inflammatory Bowel Diseases Disability Index (IBD-DI; disability: <3.5) and Beliefs about Medicines Questionnaire (high necessity/concerns: ≥16). The primary outcome was the association between medication non-adherence and disability. Secondary outcomes were the predictors of these outcomes.

Results

A total of 173 subjects on IBD maintenance medications were recruited (98 Crohn's disease, 75 ulcerative colitis: median IBD-DI, -5.0; interquartile range [IQR], -14.0 to 4.0 and median MARS, 19.0; IQR, 18 to 20) of whom 24% were non-adherent. Disability correlated significantly with medication non-adherence (r=0.38, P<0.0001). Median IBD-DI for non-adherers was significantly lower than adherers (-16.0 vs. -2.0, P<0.0001). Predictors of disability included female sex (P=0.002), previous hospitalization (P=0.023), management in a referral hospital clinic (P=0.008) and medication concerns (P<0.0001). Non-adherence was independently associated with difficulty managing bowel movements (odds ratio [OR], 3.71; 95% confidence interval [CI], 1.50-9.16, P=0.005), rectal bleeding (OR, 2.69; 95% CI, 1.14-6.36; P=0.024) and arthralgia/arthritis (OR, 2.56; 95% CI, 1.11-5.92; P=0.028).

Conclusions

Medication non-adherence was associated with significantly increased disability in IBD. Female gender, higher disease severity and medication concerns were additional predictors of disability.

Ethnicity Influences Phenotype and Outcomes in Inflammatory Bowel Disease: A Systematic Review and Meta-analysis of Population-based Studies

BACKGROUND & AIMS

Inflammatory bowel diseases (IBDs) (Crohn's disease [CD], ulcerative colitis) are global diseases. Similarities and differences in disease presentation and outcomes across different geographic regions and ethnic groups have not been compared previously.

METHODS

We performed a systematic review and meta-analysis of population-based cohort studies examining the phenotype and outcome of IBD across ethnic groups categorized as Whites, Blacks, Hispanics, and Asians. Further stratification was performed by migration status (native or immigrant). Pooled proportions of disease location, behavior, medication, and surgery use were calculated by using a random-effects model and compared statistically.

RESULTS

Our final analysis included 198 unique studies reporting outcomes on 525,425 IBD patients (Caucasian, 65%; Asian, 30%; Hispanic, 2%; and Black, 1%). CD in Asians but not other ethnicities demonstrated a strong male predominance. Family history of IBD was infrequent in Asian patients. Both Black and Asian CD patients demonstrated perianal involvement more frequently. Surgery for both CD and UC was less common in Asians than Caucasians. Compared with native residents, a family history of IBD was reported more often among immigrant IBD patients, but no significant differences were noted in phenotype.

CONCLUSIONS

We demonstrate significant variation in the demographic distribution, familial predisposition, phenotype, and outcomes of IBD between Caucasians, Blacks, Hispanics, and Asians. There is need for further study to understand the biology behind this variation.

Genetic architecture: the shape of the genetic contribution to human traits and disease

Genetic architecture describes the characteristics of genetic variation that are responsible for heritable phenotypic variability. It depends on the number of genetic variants affecting a trait, their frequencies in the population, the magnitude of their effects and their interactions with each other and the environment. Defining the genetic architecture of a complex trait or disease is central to the scientific and clinical goals of human genetics, which are to understand disease aetiology and aid in disease screening, diagnosis, prognosis and therapy. Recent technological advances have enabled genome-wide association studies and emerging next-generation sequencing studies to begin to decipher the nature of the heritable contribution to traits and disease. Here, we describe the types of genetic architecture that have been observed, how architecture can be measured and why an improved understanding of genetic architecture is central to future advances in the field.

Smoking is associated with risk for developing inflammatory bowel disease including late onset ulcerative colitis: a prospective study

OBJECTIVES

Life style factors have been associated with inflammatory bowel disease (IBD) but there is a lack of data on the exposure of life styles factors before the onset of IBD. Our aim was to study the association between lifestyle factors and the development of IBD in a prospective setting.

MATERIALS AND METHODS

We performed a case control study of 72 patients who later developed ulcerative colitis (UC), 26 patients who developed Crohn's disease (CD) and 427 healthy controls from the Västerbotten intervention project matched for gender, age, year of health survey and area of residence. At recruitment, participants completed validated lifestyle questionnaires including data on alcohol intake. Information from this was used to assess the connection between lifestyle factors and later developing IBD.

RESULTS

For CD and UC, the median age at diagnosis was 53 and 52 years and median time of survey was 4 and 6 years before diagnosis, respectively. Multivariate odds ratio (OR) showed an association between never smoking and not developing IBD, including both UC and CD, OR (95% CI) 0.341 (0.136-0.853) and 0.473 (0.259-0.864), respectively. Marital status, educational level, alcohol consumption, reported physical activity and use of moist smokeless tobacco (snus) did not differ between patients and controls.

CONCLUSIONS

Smoking proves to be a risk factor for both CD and UC in this prospective case-control study. No association was seen for snus users, implying a non-nicotine pathogenic mechanism from combusted tobacco.

Inflammatory Diseases of the Gut

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are chronic inflammatory disorders of the gastrointestinal tract whose prevalence has been dramatically increasing over the past decade. New studies have shown that IBD is the second most common chronic inflammatory disease worldwide after rheumatoid arthritis, affecting millions of people mainly in industrialized countries. Symptoms of IBD include frequent bloody diarrhea, abdominal cramping, anorexia, abdominal distension, and emesis. Although the exact etiology is unknown, it has been postulated that immunological, microbial, environmental, nutritional, and genetic factors contribute to the pathogenesis and severity of IBD. Today, no treatment has consistently been shown to be successful in treating IBD. This review summarizes current research on the epidemiology, etiology, pathophysiology, and existing treatment approaches, including pharmaceutical and nutritional options for IBD.

The Impact of Ethnicity and Country of Birth on Inflammatory Bowel Disease Phenotype: a Prospective Cohort Study

BACKGROUND AND AIMS

The number of patients with inflammatory bowel disease [IBD], of non-Caucasian descent in Western Europe, is increasing. We aimed to explore the impact of ethnicity and country of birth on IBD phenotype.

METHODS

IBD patients treated in the eight University Medical Centers in The Netherlands [Dutch IBD Biobank] were divided into two groups according to their ethnicity: 1] Caucasian patients of Western and Central European descent [CEU]; and 2] patients of non-Caucasian descent [non-CEU]. The non-CEU group was subdivided according to country of birth, into: born in The Netherlands or Western Europe [non-CEU European born]; or born outside Western-Europe who migrated to The Netherlands [non-CEU non-European born]. Both comparisons were analysed for phenotype differences [by chi-square test].

RESULTS

The Dutch IBD Biobank included 2921 CEU patients and 233 non-CEU patients. Non-CEU Crohn's disease [CD] patients more often had upper gastro-intestinal disease [16% vs 8%, p = 0.001] and anal stenosis [10% vs 4%, p = 0.002] than CEU CD patients. The use of anti-tumour necrosis factor [TNF] agents and immunomodulators was higher in non-CEU IBD patients than in CEU IBD patients [45% vs 38%, p = 0.042] and [77% vs 66%, p = 0.001], respectively. Non-CEU IBD patients born in Europe [n = 116] were diagnosed at a lower age than non-CEU IBD patients born outside Europe [n = 115] [at 22.7 vs 28.9 years old, p < 0.001].

CONCLUSION

Non-Caucasians had more severe disease behaviour than Caucasians. Non-CEU patients born in Europe were diagnosed at a lower age with IBD than those born outside Europe who migrated to The Netherlands.

Radioiodination and biological evaluation of mesalamine as a tracer for ulcerative colitis imaging

This study aims to evaluate newly radioiodinated mesalamine (Mes) as a tracer for ulcerative colitis imaging. Mes was labeled with [125I] with chloramine-T (Ch-T) as the oxidizing agent. Labeling factors such as pH, reaction temperature, reaction time, substrate amount and oxidizing agent amount were investigated to optimize the radiochemical yield (98.5%). The labeled compound was separated and purified using thin layer chromatography (TLC), paper electrophoreses and high performance liquid chromatography (HPLC). The biological distribution indicated that the radioiodinated mesalamine localization was highest (72.28%) in microbial model compared to normal mice (29.25%) at 120 min post injection. So, 125I-Mes could be considered as a new radiotracer for ulcerative colitis.

Genetic Polymorphisms in Fatty Acid Metabolism Modify the Association Between Dietary n3: n6 Intake and Risk of Ulcerative Colitis: A Prospective Cohort Study

INTRODUCTION

High intake of dietary n-3 polyunsaturated fatty acids (PUFA) is associated with a decreased risk of ulcerative colitis (UC) and Crohn's disease (CD). However, results have been heterogeneous suggesting that genetic variations in PUFA metabolism may modify this risk.

METHODS

We conducted a case-control study nested within 2 prospective cohorts, the Nurses' Health Study (NHS) and NHS II. Among women providing blood (n = 62,437) or buccal cells (n = 59,543) for genotyping, we confirmed new diagnoses of CD or UC. Dietary intake was assessed 4 years before diagnosis. Confirmed cases were matched 1:2 to controls. Subjects were genotyped for single nucleotide polymorphisms at CYP4F3, FADS1, and FADS2 loci. Conditional logistic regression models examined the interaction between genotype, n3:n6 PUFA intake and risk of CD and UC.

RESULTS

Our study included 101 CD and 139 UC patients matched to 495 controls. On multivariable analysis, high intake of n3:n6 PUFA (above median) demonstrated a trend toward reduced risk of UC (Odds ratio [OR] 0.71, 95% confidence interval [CI], 0.47-1.09, P = 0.11). High n3:n6 PUFA intake was associated with a reduced risk of UC in individuals with the GG/AG genotype at a single nucleotide polymorphism in CYP4F3 (OR 0.57, 95% CI, 0.32-0.99) but not those with the AA genotype (OR 0.95, 95% CI, 0.47-1.93) (P-interaction = 0.049). No gene-diet interactions were noted for CD.

CONCLUSIONS

The association between dietary n3:n6 PUFA intake and risk of UC may be modified variants at CYP4F3. Further gene-environment studies of the association between diet and IBD risk are warranted.

Solar radiation is inversely associated with inflammatory bowel disease admissions

OBJECTIVE

To explore the associations between latitude and solar radiation with inflammatory bowel disease admission rates in Chile, the country with the largest variation in solar radiation in the world.

PATIENTS AND METHODS

This is an ecological study, which included data on all hospital-admitted population for inflammatory bowel disease between 2001 and 2012, according to different latitudes and solar radiation exposures in Chile. The data were acquired from the national hospital discharge database from the Department of Health Statistics and Information of the Chilean Ministry of Health.

RESULTS

Between 2001 and 2012 there were 12,869 admissions due to inflammatory bowel disease (69% ulcerative colitis, 31% Crohn's disease). Median age was 36 years (IQR: 25-51); 57% were female. The national inflammatory bowel disease admission rate was 6.52 (95% CI: 6.40-6.63) per 100,000 inhabitants with increasing rates over the 12-year period. In terms of latitude, the highest admission rates for pediatric ulcerative colitis and Crohn's disease, as well as adult ulcerative colitis, were observed in the southernmost region with lowest annual solar radiation. Linear regression analysis showed that regional solar radiation was inversely associated with inflammatory bowel disease admissions in Chile (β: -.44, p = .03).

CONCLUSIONS

Regional solar radiation was inversely associated with inflammatory bowel disease admission rates in Chile; inflammatory bowel disease admissions were highest in the southernmost region with lowest solar radiation. Our results support the potential role of vitamin D deficiency on inflammatory bowel disease flares.

Influence of food and lifestyle on the risk of developing inflammatory bowel disease

BACKGROUND

The Barwon area in Australia has one of the highest incidence rates of inflammatory bowel disease (IBD) and therefore is an ideal location to study the impact of environmental exposures on the disease's development.

AIM

To study these exposures prior to the development of IBD in a population-based cohort.

METHOD

One hundred and thirty-two incident cases (81 Crohn disease (CD) and 51 ulcerative colitis (UC)) from an IBD registry and 104 controls replied to the International Organization of Inflammatory Bowel Diseases environmental questionnaire. This included 87 questions about pre-illness exposures that included childhood illnesses, vaccinations, breastfeeding, house amenities, pets and swimming, diet and smoking.

RESULTS

The factors associated with CD included smoking (odds ratio (OR): 1.42, confidence interval (CI): 1-2.02, P = 0.029); childhood events, including tonsillectomy (OR: 1.74, CI: 1.15-2.6, P = 0.003) and chicken pox infection (OR: 3.89, CI: 1.61-9.4, P = 0.005) and pre-diagnosis intake of frequent fast food (OR: 2.26, CI: 1.76-4.33, P = 0.003). In UC, the risk factors included smoking (OR: 1.39, CI: 1.1-1.92, P = 0.026) and pre-diagnosis intake of frequent fast food (OR: 2.91, CI: 1.54-5.58, P < 0.001), and high caffeine intake was protective (OR: 0.51, 95% CI: 0.3-0.87, P = 0.002). Other protective exposures for UC included high fruit intake (OR: 0.59, CI: 0.4-0.88, P = 0.003) and having pets as a child (OR: 0.36, CI: 0.2-0.79, P = 0.001).

CONCLUSION

This first Australian population-based study of environmental risk factors confirms that smoking, childhood immunological events and dietary factors play a role in IBD development; while high caffeine intake and pet ownership offer a protective effect.

Crohn’s disease environmental factors in the developing world: A case-control study in a statewide catchment area in Brazil

AIM

To identify environmental risk factors associated with the development of Crohn’s disease (CD) in order to re-assess the hygiene hypothesis.

METHODS

A hospital-based, case-control study was carried out with CD patients (n = 145) and controls (n = 163) representing a socioeconomically diverse statewide catchment area in Brazil. Controls were recruited from caregivers of patients seen in different outpatient clinics at the same hospital. A multi-item survey with 94 questions regarding family history of CD, perinatal and childhood circumstances, living conditions, tobacco use and familial socioeconomic status was carried out by interviewers.

RESULTS

On the univariate analysis, predictive variables for CD included being male, under age of 40, a high education level, urban dweller, smaller family size, exposure to enteric pathogens and user of treated water (P < 0.005). On the multivariate analysis, variables significantly associated with CD were male gender (OR = 2.09), under age 40 (OR = 3.10), white (OR = 2.32), from a small family in childhood (OR = 2.34) and adulthood (OR = 3.02), absence of viral infections in childhood (OR = 2.23), exposure to enteric pathogens (OR = 2.41), having had an appendectomy (OR = 2.47) and prior or current smoker (OR = 2.83/1.12).

CONCLUSION

Most variables supporting the “hygiene hypothesis” are associated with the development of CD but are not independent predictors of the diagnosis.

Upregulation of Intestinal Barrier Function in Mice with DSS-Induced Colitis by a Defined Bacterial Consortium Is Associated with Expansion of IL-17A Producing Gamma Delta T Cells

Bacterial consortium transplantation (BCT) is a promising alternative to fecal microbiota transplantation in treating inflammatory bowel disease (IBD). Here, we showed that a defined bacterial consortium derived from healthy mice was able to enhance the intestinal barrier function of mice with dextran sulfate sodium (DSS)-induced colitis. Interestingly, we found that the bacterial consortium significantly promoted the expansion of IL-17A-producing γδT (γδT17) cells in colonic lamina propria, which was closely associated with changing of intestinal microbial composition. The increased IL-17A secretion upon treatment with microbial products derived from the bacterial consortium was accompanied with upregulation of TLR2 expression by γδT cells, and it might be responsible for the upregulation of mucosal barrier function through IL-17R-ACT1-mediated recovery of the disrupted occludin subcellular location. Changing of some specific microbial groups such as Bifidobacterium and Bacillus spp. was closely correlated with the promotion of TLR2⁺ γδT cells. Our results support that BCT can restore the alliance between commensal microbiota and intestinal γδT cells, which contributes to the improvement of intestinal barrier function. This study provides new insight into the development of bacteria transplantation therapy for the treatment of IBD.

LRRK2 but not ATG16L1 is associated with Paneth cell defect in Japanese Crohn's disease patients

BACKGROUND. Morphological patterns of Paneth cells are a prognostic biomarker in Western Crohn's disease (CD) patients, and are associated with autophagy-associated ATG16L1 and NOD2 variants. We hypothesized that genetic determinants of Paneth cell phenotype in other ethnic CD cohorts are distinct but also involved in autophagy. METHODS. We performed a hypothesis-driven analysis of 56 single nucleotide polymorphisms (SNPs) associated with CD susceptibility or known to affect Paneth cell function in 110 Japanese CD patients who underwent ileal resection. We subsequently performed a genome-wide association analysis. Paneth cell phenotype was determined by defensin-5 immunofluorescence. Selected genotype-Paneth cell defect correlations were compared to a Western CD cohort (n = 164). RESULTS. The average percentage of abnormal Paneth cells in Japanese CD was similar to Western CD (P = 0.87), and abnormal Paneth cell phenotype was also associated with early recurrence (P = 0.013). In contrast to Western CD, ATG16L1 T300A was not associated with Paneth cell defect in Japanese CD (P = 0.20). Among the 56 selected SNPs, only LRRK2 M2397T showed significant association with Paneth cell defect (P = 3.62 × 10^-4), whereas in the Western CD cohort it was not (P = 0.76). Pathway analysis of LRRK2 and other candidate genes with P less than 5 × 10^-4 showed connections with known CD susceptibility genes and links to autophagy and TNF-α networks. CONCLUSIONS. We found dichotomous effects of ATG16L1 and LRRK2 on Paneth cell defect between Japanese and Western CD. Genes affecting Paneth cell phenotype in Japanese CD were also associated with autophagy. Paneth cell phenotype also predicted prognosis in Japanese CD. FUNDING. Helmsley Charitable Trust, Doris Duke Foundation (grant 2014103), Japan Society for the Promotion of Science (KAKENHI grants JP15H04805 and JP15K15284), Crohn's and Colitis Foundation grant 274415, NIH (grants 1R56DK095820, K01DK109081, and UL1 TR000448).

The Faroese IBD Study: Incidence of Inflammatory Bowel Diseases Across 54 Years of Population-based Data

BACKGROUND AND AIMS

Inflammatory bowel diseases [IBDs] include Crohn's disease [CD], ulcerative colitis [UC], and IBD unclassified [IBDU]. In 2010 and 2011, the ECCO-EpiCom study found the worldwide highest incidence of inflammatory bowel disease [IBD] in the Faroe Islands: 83 per 100 000 [European Standard Population, ESP]. The present study assessed the long-term time trends in IBD incidence in the Faroese population.

METHODS

In this population-based study, data were retrieved from the National Hospital of the Faroe Islands and included all incident cases of CD, UC, and IBDU diagnosed between July 1960 and July 2014. Patients of all ages were included and diagnoses were defined according to the Copenhagen Diagnostic Criteria.

RESULTS

A total of 664 incident IBD patients were diagnosed: 113 with CD, 417 with UC, and 134 with IBDU. Of these, 51 [8%] were diagnosed with paediatric-onset IBD. Between 1960 and 1979, a total of 55 persons were diagnosed; 105 in 1980-89; 166 in 1990-99; 180 in 2000-09; and 158 in 2010-14. This represented an increase in the age-standardised IBD incidence rate from 7, 25, 40, and 42 to 74 per 100 000 [ESP]. For CD, the increase was from 1 to 10, for UC from 4 to 44, and for IBDU from 2 to 21 per 100 000 [ESP].

CONCLUSIONS

The high IBD incidence was found to be a relatively new phenomenon. The observed increase is unlikely to be an artefact resulting from, for instance, better registration. Our study indicated a real and increasing disease burden resulting from changing-so far unidentified-exposures.

Cardiovascular diseases and risk factors among Chinese immigrants

The aim of this study is to identify the prevalence of cardiovascular disease (CVD) and major CVD risk factors, including diabetes, hypertension, dyslipidemia, obesity and smoking among Chinese immigrants by a systematic review of studies from various countries. PubMed and the China National Knowledge Infrastructure databases were searched for studies of the prevalence of major CVDs and risk factors, and of CVD mortality among Chinese immigrants. The search identified 386 papers, 16 of which met the inclusion criteria for this review. In mainland China, there is a pattern of high stroke prevalence but low coronary heart disease (CHD) prevalence. Among Chinese immigrants, there is a much lower prevalence and mortality of stroke, but a higher prevalence and mortality of CHD, even though these are lower than the rates in immigrants of other ethnicities in the host country. The prevalence of CVD risk factors is also markedly different in immigrants. Compared with mainland Chinese, Chinese immigrants have a higher prevalence of diabetes and hypertension, higher serum cholesterol, poorer dietary patterns, and higher prevalence of obesity and smoking. Thus, the epidemiological pattern of CVD among Chinese immigrants changes compared with resident mainland Chinese. The less healthy environmental factor after immigration may be a major trigger in the adverse CVD status of Chinese immigrants. It is important for policy-makers to pay more attention to specific minority immigrant groups, and to implement more effective preventive measures to improve the health of immigrant populations.

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.

Incidence of appendicitis according to region of origin in first- and second-generation immigrants and adoptees in Sweden. A cohort follow-up study

BACKGROUND

Geographic variations in incidence of appendicitis and proportion of perforations suggest environmental or genetic etiological factors. We study incidence of appendicitis and proportion of perforations according to geographical origin in immigrants and international adoptees in Sweden.

METHODS

A cohort of 11,557,566 Swedish residents - 277,104 first- and 377,773 second-generation immigrants and 57,304 adoptees - was followed from 1988 till 2010. Differences in proportion of operation for perforated appendicitis and negative appendectomy and standardized incidence ratios (SIR) of perforated and non-perforated appendicitis associated with geographic origin was analyzed.

RESULTS

High incidence rates are seen in first- and second-generation immigrants from South America for perforated (SIR 1.58 and 1.81, respectively) and non-perforated appendicitis (SIR 1.18 and 1.22, respectively), and in adoptees from South America for non-perforated appendicitis (SIR 1.07). Low incidence rates are seen for perforated appendicitis in first-generation immigrants and adoptees from Asia (SIR 0.74 and 0.56, respectively), and for non-perforated appendicitis in immigrants from Africa and Asia (SIR 0.69 and 0.76 in first-generation, 0.51 and 0.74 in second-generation, respectively) and in adoptees from Asia (SIR 0.71). A high proportion of perforated appendicitis is associated with a low incidence rate of non-perforated appendicitis but no increase in the incidence rate of perforated appendicitis.

CONCLUSIONS

The association of different incidence of appendicitis with geographic origin which remains over generations and is seen in adoptees suggest genetic etiologic factors. The proportion of perforation can be high without an increased incidence rate of perforation and is therefore an imperfect indicator of quality of care.

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.

Type I interferons for induction of remission in ulcerative colitis

BACKGROUND

Interferons (IFNs) are cytokines which possess immunoregulatory properties and have been used to successfully treat a number of chronic inflammatory disorders. It has been postulated that Type I IFNs may be able to re-establish the Th1/Th2 balance in Th2 predominant diseases like ulcerative colitis.

OBJECTIVES

To systematically evaluate the efficacy and safety of type I IFN therapy for induction of remission in ulcerative colitis.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL, the Cochrane IBD/FBD group specialised register, and ClinicalTrials.gov from inception to August 8, 2014. Reference lists of trials and review articles, as well as recent proceedings from major gastroenterology meetings were manually searched.

SELECTION CRITERIA

Randomised controlled trials of type I IFNs for induction of remission in UC were included. The study population included patients of any age with active ulcerative colitis. There were no exclusions based on type, dose or duration of IFN treatment.

DATA COLLECTION AND ANALYSIS

Two independent authors reviewed studies for eligibility, extracted the data and assessed study quality using the Cochrane risk of bias tool. The overall quality of the evidence supporting the outcomes was evaluated using the GRADE criteria. The primary outcome was induction of remission of ulcerative colitis. Secondary outcomes included: time to remission, mean change in disease activity index score, clinical, histological or endoscopic improvement, improvement in quality of life, and adverse events. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for dichotomous outcomes. We calculated the mean difference and corresponding 95% confidence interval for continuous outcomes. Meta-analysis was performed using RevMan 5.3.5 software.

MAIN RESULTS

Six studies were eligible for inclusion (517 patients). Five studies compared type I IFNs to placebo injections (485 patients) and a single study compared IFNs to prednisolone enemas in patients with left-sided colitis (32 patients). The active comparator study was rated as high risk of bias due to an open-label design. Three studies were rated as unclear risk of bias for random sequence generation and allocation concealment. Two studies described as double blind were rated as unclear risk of bias for blinding. There was no significant benefit of type I IFNs over placebo for inducing clinical remission or improvement in patients with active ulcerative colitis. Thirty-six per cent (87/242) of patients in the type I IFNs group achieved clinical remission by 8 to 12 weeks compared to 30% (36/120) of placebo patients (RR 1.16, 95% CI 0.84 to 1.58; 4 studies, 362 patients). A GRADE analysis indicated that the overall quality of the evidence supporting the outcome clinical remission was moderate due to sparse data (123 events). Fifty-six per cent (149/264) of patients in the type I IFNs group improved clinically by 8 to 12 weeks compared to 48% (77/161) of placebo patients (RR 1.16, 95% CI 0.96 to 1.40; 4 studies, 425 patients). A GRADE analysis indicated that the overall quality of the evidence supporting the outcome clinical improvement was moderate due to sparse data (226 events). Patients who received type I IFNs were significantly more likely to withdraw from the studies due to adverse events than those who received placebo. Seven per cent (18/42) of type I IFNs patients withdrew due to adverse events compared to 2% (3/152) of placebo patients (RR 3.16, 95% CI 1.06 to 9.40). A GRADE analysis indicated that the overall quality of the evidence supporting the outcome withdrawal due to adverse events was low due to very sparse data (21 events). The study comparing type I IFNs to prednisolone enemas found no difference between the treatment groups in quality of life or disease activity scores. Common adverse events included headaches, arthralgias, myalgias, fatigue, back pain, nausea, application site reactions, rigors, and fevers. There were no statistically significant differences in the other secondary outcomes.

AUTHORS' CONCLUSIONS

Moderate quality evidence suggests that type I IFNs are not effective for the induction of remission in UC. In addition, there are concerns regarding the tolerability of this class of treatment.

Inflammatory Bowel Disease Environmental Risk Factors: A Population-Based Case-Control Study of Middle Eastern Migration to Australia

BACKGROUND & AIMS

The incidences of the inflammatory bowel diseases (IBDs) Crohn's disease (CD) and ulcerative colitis (UC) are increasing, indicating gene-environment interactions. Migrants from low-IBD-prevalence countries to a high-prevalence country may help identify the relative contribution of environmental risk factors compared with native Caucasians.

METHODS

This prospective case-control study evaluated IBD environmental risk factors of Middle Eastern migrants (MEM) in Australia compared with matched Caucasian IBD subjects, MEM controls, Caucasian controls, and controls in the Middle East using adjusted odds ratios (aOR).

RESULTS

A total of 795 subjects were recruited: 154 MEM cases (75 CD; 79 UC), 153 MEM controls, 162 Caucasian cases (85 CD; 77 UC), 173 Caucasian controls, and 153 controls in Lebanon. Smoking increased CD risk in MEM and Caucasians and reduced UC risk in Caucasians (aOR, 0.77; 95% CI, 0.41-0.98) but not MEM (aOR, 1.45; 95% CI, 0.80-2.62). Antibiotic use reduced the risk of MEM CD (aOR, 0.27; 95% CI, 0.11-0.67) and UC (aOR, 0.38; 95% CI, 0.18-0.80), but increased the risk in Caucasians (CD: aOR, 5.24; 95% CI, 2.13-12.90; and UC: aOR, 6.82; 95% CI, 2.67-17.38). Most hygiene markers (rural dwelling, pet ownership, pet feeding, and farm animal contact) reduced CD and UC risk in MEM (P < .05). In contrast, in Caucasians these hygiene markers lacked significance. Other significant risk factors include IBD family history, appendectomy, tonsillectomy, and breastfeeding.

CONCLUSIONS

Differential IBD environmental risk factors exist between migrants and native Caucasians, indicating a dynamic interplay between environmental factors and IBD risk for immigrants that is distinct to those factors most relevant in native Caucasians.

Combinatorial effects of diet and genetics on inflammatory bowel disease pathogenesis

Inflammatory bowel disease (IBD) encompasses a group of disorders affecting the gastrointestinal tract characterized by acute and chronic inflammation. These are complex and multifactorial disorders that arise in part from a genetic predisposition. However, the increasing incidence of IBD in developing countries suggests that environmental factors, such as diet, are also critical components of disease susceptibility. Evidence suggests that consumption of a Western diet, enriched with saturated fat, refined carbohydrates, and food additives, is associated with increased IBD risk. Dietary components, such as omega-6 fatty acids, long-chain fatty acids, protein, and digestible carbohydrates, may contribute to IBD pathogenesis through altering intestinal microbiota, increasing intestinal permeability, and promoting inflammation; whereas omega-3 fatty acids, medium chain triglycerides, and nondigestible carbohydrates improve these parameters and intestinal health. However, the limited amount of prospective studies, small sample sizes, and the heterogeneity of disease subtype result in inconsistencies between studies and difficulty in conclusively determining the specific effects of diet on intestinal homeostasis. There are no standard clinical dietary recommendations for patients with IBD. However, exclusionary diet interventions have shown some efficacy in relieving symptoms or inducing remission, suggesting more research is needed to fully understand how diet influences disease behavior or combines with other IBD risk factors to promote disease. This review focuses on the associations of various dietary components and IBD risk in clinical studies and genetically susceptible IBD models.

Should we systematically test patients with clinically isolated syndrome for auto-antibodies?

Background:

Several autoimmune diseases (ADs) can mimic multiple sclerosis (MS). For this reason, testing for auto-antibodies (auto-Abs) is often included in the diagnostic work-up of patients with a clinically isolated syndrome (CIS).

Objective:

The purpose was to study how useful it was to systematically determine antinuclear-antibodies, anti-SSA and anti-SSB in a non-selected cohort of CIS patients, regarding the identification of other ADs that could represent an alternative diagnosis.

Methods:

From a prospective CIS cohort, we selected 772 patients in which auto-Ab levels were tested within the first year from CIS. Baseline characteristics of auto-Ab positive and negative patients were compared. A retrospective revision of clinical records was then performed in the auto-Ab positive patients to identify those who developed ADs during follow-up.

Results:

One or more auto-Ab were present in 29.4% of patients. Only 1.8% of patients developed other ADs during a mean follow-up of 6.6 years. In none of these cases the concurrent AD was considered the cause of the CIS. In all cases the diagnosis of the AD resulted from the development of signs and/or symptoms suggestive of each disease.

Conclusion:

Antinuclear-antibodies, anti-SSA and anti-SSB should not be routinely determined in CIS patients but only in those presenting symptoms suggestive of other ADs.

Epidemiology and temporal trends (2000-2012) of inflammatory bowel disease in adult patients in a central region of Spain

BACKGROUND AND AIM

A growing incidence of inflammatory bowel disease (IBD) has been reported recently in southern Europe, with records of pediatric cases confirming these tendencies in Spain. Data on adult populations, however, have not been provided for over 10 years and need to be updated.

PATIENTS AND METHODS

A multicenter retrospective registry of all adult patients with a diagnosis of IBD, including both Crohn's disease (CD) and ulcerative colitis (UC), attending five public hospitals covering a population of 514 368 inhabitants, was assessed.

RESULTS

In 2012, the prevalence of CD and UC in adults was 137.17/100 000 inhabitants (95% confidence interval 114-160) and 99.84/100 000 inhabitants (95% confidence interval 79-119), respectively. The mean incidence rate during the period 2000-2012 of CD and UC was 8.9 and 5.6/100 000 inhabitants per year, respectively. Most of our patients (75.55%) had been diagnosed during the last 13 years. CD affected both sexes equally; a trend toward a progressive increase in the age at diagnosis, ileal location, and inflammatory behavior was documented for CD patients. In contrast, UC affected male patients with a higher frequency (57.8%; P=0.015), specifically those older than 40 years of age. Age at UC onset tended to increase progressively from 2000 to 2012 (P<0.001), but the extension on the disease remained unchanged.

CONCLUSION

IBD is a highly prevalent disorder in our region, reaching the incidence of CD similar to the figures provided for Northern Europe. Changes in IBD localization, behavior, and age at diagnosis were documented during the period 2000-2012.

SIRT2 deficiency modulates macrophage polarization and susceptibility to experimental colitis

BACKGROUND

SIRT2 belongs to a highly conserved family of NAD+-dependent deacylases, consisting of seven members (SIRT1-SIRT7), which vary in subcellular localizations and have substrates ranging from histones to transcription factors and enzymes. Recently SIRT2 was revealed to play an important role in inflammation, directly binding, deacetylating, and inhibiting the p65 subunit of NF-κB.

METHODS

A Sirt2 deficient mouse line (Sirt2-/-) was generated by deleting exons 5-7, encoding part of the SIRT2 deacetylase domain, by homologous recombination. Age- and sex-matched Sirt2-/- and Sirt2+/+ littermate mice were subjected to dextran sulfate sodium (DSS)-induced colitis and analyzed for colitis susceptibility.

RESULTS

Sirt2-/- mice displayed more severe clinical and histological manifestations after DSS colitis compared to wild type littermates. Notably, under basal condition, Sirt2 deficiency does not affect the basal phenotype and intestinal morphology Sirt2 deficiency, however, affects macrophage polarization, creating a pro-inflammatory milieu in the immune cells compartment.

CONCLUSION

These data confirm a protective role for SIRT2 against the development of inflammatory processes, pointing out a potential role for this sirtuin as a suppressor of colitis. In fact, SIRT2 deletion promotes inflammatory responses by increasing NF-κB acetylation and by reducing the M2-associated anti-inflammatory pathway. Finally, we speculate that the activation of SIRT2 may be a potential approach for the treatment of inflammatory bowel disease.