Environmental risk factors for inflammatory bowel diseases: a review

The impact of co-existing immune-mediated diseases on phenotype and outcomes in inflammatory bowel diseases

BACKGROUND

Inflammatory bowel diseases lead to progressive bowel damage and need for surgery. While the increase in prevalence of other immune-mediated diseases in IBD is well recognised, the impact of this on the natural history of IBD is unknown.

AIM

To determine the impact of concomitant immune-mediated diseases on phenotypes and outcomes in IBD.

METHODS

Patients with IBD enrolled in a prospective registry were queried about the presence of other immune-mediated diseases, defined as those where immune dysregulation plays a role in pathogenesis. Demographics and disease-related information were obtained. Subjects also completed measures of quality of life. Multivariable regression models compared disease phenotype and outcomes of IBD patients with and without other immune-mediated diseases.

RESULTS

The cohort included 2145 IBD patients among whom 458 (21%) had another immune-mediated disease. There was no difference in CD phenotype between the two groups. UC patients were more likely to have pancolitis in the presence of another immune-mediated disease (62%) compared to those without (52%, P = 0.02). IBD patients with another immune-mediated disease had higher rates of needing anti-TNF biologics [Odds ratio (OR) 1.31, 95% CI 1.05-1.63] and surgery (OR 1.26, 95% CI 0.99-1.61). The presence of another immune-mediated disease was also associated with lower disease-specific and general physical quality of life.

CONCLUSIONS

The presence of another immune-mediated disease in IBD patients was associated with higher likelihood of pancolonic involvement in UC, and a modest increase in need for IBD-related surgery and anti-TNF biological therapy. Such patients also experienced worse quality of life.

Understanding and Preventing the Global Increase of Inflammatory Bowel Disease

The inflammatory bowel diseases (IBDs) are contemporary conditions of industrialized societies. The prevalence of IBD continues to increase steadily in Western countries, and newly industrialized countries have a rapidly increasing incidence. The global spread of IBD appears to associate with Westernization of diets and environments, which affects the intestinal microbiome and increases the risk of IBD in genetically susceptible individuals. It is important to increase our understanding of these events to slow progression of IBD. We present a long-term plan to develop interventions that slow or stop the global increase in the incidence of IBD.

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).

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.

Exposure to Ambient Air Pollution and the Risk of Inflammatory Bowel Disease: A European Nested Case-Control Study

BACKGROUND

Industrialization has been linked to the etiology of inflammatory bowel disease (IBD).

AIM

We investigated the association between air pollution exposure and IBD.

METHODS

The European Prospective Investigation into Cancer and Nutrition cohort was used to identify cases with Crohn's disease (CD) (n = 38) and ulcerative colitis (UC) (n = 104) and controls (n = 568) from Denmark, France, the Netherlands, and the UK, matched for center, gender, age, and date of recruitment. Air pollution data were obtained from the European Study of Cohorts for Air Pollution Effects. Residential exposure was assessed with land-use regression models for particulate matter with diameters of <10 μm (PM10), <2.5 μm (PM2.5), and between 2.5 and 10 μm (PMcoarse), soot (PM2.5 absorbance), nitrogen oxides, and two traffic indicators. Conditional logistic regression analyses were performed to calculate odds ratios (ORs) with 95 % confidence intervals (CIs).

RESULTS

Although air pollution was not significantly associated with CD or UC separately, the associations were mostly similar. Individuals with IBD were less likely to have higher exposure levels of PM2.5 and PM10, with ORs of 0.24 (95 % CI 0.07-0.81) per 5 μg/m(3) and 0.25 (95 % CI 0.08-0.78) per 10 μg/m(3), respectively. There was an inverse but nonsignificant association for PMcoarse. A higher nearby traffic load was positively associated with IBD [OR 1.60 (95 % CI 1.04-2.46) per 4,000,000 motor vehicles × m per day]. Other air pollutants were positively but not significantly associated with IBD.

CONCLUSION

Exposure to air pollution was not found to be consistently associated with IBD.

Inflammatory bowel disease: exploring gut pathophysiology for novel therapeutic targets

Ulcerative colitis and Crohn's disease are the 2 major phenotypes of inflammatory bowel disease (IBD), which are influenced by a complex interplay of immunological and genetic elements, though the precise etiology still remains unknown. With IBD developing into a globally prevailing disease, there is a need to explore new targets and a thorough understanding of the pathophysiological differences between the healthy and diseased gut could unearth new therapeutic opportunities. In this review, we provide an overview of the major aspects of IBD pathogenesis and thereafter present a comprehensive analysis of the gut pathophysiology leading to a discussion on some of the most promising targets and biologic therapies currently being explored. These include various gut proteins (CXCL-10, GATA-3, NKG2D, CD98, microRNAs), immune cells recruited to the gut (mast cells, eosinophils, toll-like receptors 2, 4), dysregulated proinflammatory cytokines (interleukin-6, -13, -18, -21), and commensal microbiota (probiotics and fecal microbiota transplantation). We also evaluate some of the emerging nonconventional therapies being explored in IBD treatment focusing on the latest developments in stem cell research, oral targeting of the gut-associated lymphoid tissue, novel anti-inflammatory signaling pathway targeting, adenosine deaminase inhibition, and the beneficial effects of antioxidant and nutraceutical therapies. In addition, we highlight the growth of biologics and their targets in IBD by providing information on the preclinical and clinical development of over 60 biopharmaceuticals representing the state of the art in ulcerative colitis and Crohn's disease drug development.

Efficacy and Safety of Beclomethasone Dipropionate versus 5-Aminosalicylic Acid in the Treatment of Ulcerative Colitis: A Systematic Review and Meta-Analysis

Background

Ulcerative colitis (UC) is a chronic and remitting inflammatory disease that is characterized by chronic idiopathic inflammation of the colon and bloody diarrhea. Currently drug treatment is the main intervention for patients with mild to moderate UC. Mesalazine (5-ASA) and beclomethasone dipropionate (BDP) have been widely used for the treatment of UC and have yielded satisfactory results. This study compared the effectiveness of 5-ASA and BDP in the treatment of UC.

Methods

The PubMed, Medline, SinoMed, Embase, and Cochrane Librinary databases were searched for eligible studies. Data were extracted by two of the coauthors independently and were analyzed using RevMan statistical software, version 5.3. Weighted mean differences (WMDs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration’s Risk of Bias Tool was used to assess the risk of bias.

Results

Seven randomized controlled trials that compared BDP with 5-ASA in treating UC were identified as eligible. The methodological quality of the trials ranged from low to moderate. A pooled analysis of effectiveness based on the Disease Activity Index (DAI) or other assessment method after treatment revealed that in the treatment of UC, there are no obvious differences between BDP and 5-ASA in inducing remission and clinical improvement (OR = 0.76, 95% CI = 0.56–1.03, P = 0.08). The total numbers of adverse events associated with BDP and 5-ASA treatments for UC were similar (OR = 1.21, 95% CI = 0.71–2.09, P = 0.48). The safety profiles for these two drugs are good. According to subgroup-analysis, we found no obvious differences of clinical efficacy between BDP and 5-ASA no matter oral or enema administration was used in the treatment of UC. A sensitivity analysis demonstrated the stability of the pooled results.

Conclusion

During induction treatment of mild to moderate UC, there is no obvious difference between the two groups with respect to remission and clinical improvement. Given that the upper confidence limit for the OR barely exceeds 1.0 and that the p-value is close to 0.05 for this primary efficacy outcome as well as that the horizontal block lies to the left of the vertical line, it indicates that the clinical efficacy of BDP may be better than 5-ASA. However, taking into account that BDP has the risk of hypothalamic-pituitary-adrenal axis (HPA) suppression, 5-ASA has a potential advantage of safety in the treatment of mild to moderate UC.

The Gut Microbiota in Immune-Mediated Inflammatory Diseases

The collection of microbes and their genes that exist within and on the human body, collectively known as the microbiome has emerged as a principal factor in human health and disease. Humans and microbes have established a symbiotic association over time, and perturbations in this association have been linked to several immune-mediated inflammatory diseases (IMID) including inflammatory bowel disease, rheumatoid arthritis, and multiple sclerosis. IMID is a term used to describe a group of chronic, highly disabling diseases that affect different organ systems. Though a cornerstone commonality between IMID is the idiopathic nature of disease, a considerable portion of their pathobiology overlaps including epidemiological co-occurrence, genetic susceptibility loci and environmental risk factors. At present, it is clear that persons with an IMID are at an increased risk for developing comorbidities, including additional IMID. Advancements in sequencing technologies and a parallel explosion of 16S rDNA and metagenomics community profiling studies have allowed for the characterization of microbiomes throughout the human body including the gut, in a myriad of human diseases and in health. The main challenge now is to determine if alterations of gut flora are common between IMID or, if particular changes in the gut community are in fact specific to a single disease. Herein, we review and discuss the relationships between the gut microbiota and IMID.

Microbiome, Metabolome and Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD) is a multifactorial disorder that conceptually occurs as a result of altered immune responses to commensal and/or pathogenic gut microbes in individuals most susceptible to the disease. During Crohn’s Disease (CD) or Ulcerative Colitis (UC), two components of the human IBD, distinct stages define the disease onset, severity, progression and remission. Epigenetic, environmental (microbiome, metabolome) and nutritional factors are important in IBD pathogenesis. While the dysbiotic microbiota has been proposed to play a role in disease pathogenesis, the data on IBD and diet are still less convincing. Nonetheless, studies are ongoing to examine the effect of pre/probiotics and/or FODMAP reduced diets on both the gut microbiome and its metabolome in an effort to define the healthy diet in patients with IBD. Knowledge of a unique metabolomic fingerprint in IBD could be useful for diagnosis, treatment and detection of disease pathogenesis.

Ulcerative Colitis: Update on Medical Management

Ulcerative colitis (UC) is a chronic inflammatory bowel disease whose pathogenesis is multifactorial and includes influences from genes, the environment, and the gut microbiome. Recent advances in diagnosis and treatment have led to significant improvement in managing the disease. Disease monitoring with the use of therapeutic drug monitoring, stool markers, and assessment of mucosal healing have garnered much attention. The recent approval of vedolizumab for treatment of moderate to severe UC has been a welcome addition. Newer biologics, including those targeting the Janus tyrosine kinase (JAK) pathway, are on the horizon to add to the current armamentarium of anti-TNF alpha and anti-integrin therapies. The recent publication of the SCENIC consensus statement on surveillance and management of dysplasia in UC patients supports the use of chromoendoscopy over random biopsies in detecting dysplasia. This review highlights these recent advances along with others that have been made with ulcerative colitis.

The effect of NOD2 on the microbiota in Crohn's disease

Recent advancements toward the treatment of Crohn's disease (CD) indicate great promise for long-term remission. CD patients suffer from a complex host of dysregulated interactions between their innate immune system and microbiome. The most predominant link to the onset of CD is a genetic mutation in the innate immune receptor nucleotide-binding oligomerization domain-containing 2 (NOD2). NOD2 responds to the presence of bacteria and stimulates the immune response. Mutations to NOD2 promote low diversity and dysbiosis in the microbiome, leading to impaired mucosal barrier function. Current treatments suppress the immune response rather than enhancing the function of this critical protein. New progress toward stabilizing NOD2 signaling through its interactions with chaperone proteins holds potential in the development of novel CD therapeutics.

Overlapping irritable bowel syndrome and inflammatory bowel disease: less to this than meets the eye?

Though distinct in terms of pathology, natural history and therapeutic approach, irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) have some features in common. These include shared symptomatology and largely similar demographics. However, in most instances, clinical presentation, together with laboratory, imaging and endoscopic findings will readily permit the differentiation of active IBD from IBS. More problematic is the situation where a subject with IBD, in apparent remission, continues to complain of symptoms which, in aggregate, satisfy commonly employed criteria for the diagnosis of IBS. Access to methodologies, such the assay for levels of calprotectin in feces, now allows identification of ongoing inflammation in some such individuals and prompts appropriate therapy. More challenging is the IBD patient with persisting symptoms and no detectable evidence of inflammation; is this coincident IBS, IBS triggered by IBD or an even more subtle level of IBD activity unrecognized by available laboratory or imaging methods? Arguments can be advanced for each of these proposals; lacking definitive data, this issue remains unresolved. The occurrence of IBS-type symptoms in the IBD patient, together with some data suggesting a very subtle level of 'inflammation' or 'immune activation' in IBS, raises other questions: is IBS a prodromal form of IBD; and are IBS and IBD part of the spectrum of the same disease? All of the available evidence indicates that the answer to both these questions should be a resounding 'no'. Indeed, the whole issue of overlap between IBS and IBD should be declared moot given their differing pathophysiologies, contrasting natural histories and divergent treatment paths. The limited symptom repertoire of the gastrointestinal tract may well be fundamental to the apparent confusion that has, of late, bedeviled this area.

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.

Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

AIM: To evaluate ATP-binding cassette (ABC) transporters in colonic pathophysiology as they had recently been related to colorectal cancer (CRC) development.

METHODS: Literature search was conducted on PubMed using combinations of the following terms: ABC transporters, ATP binding cassette transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohns disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein (P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP), Abcb1/Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function.

RESULTS: Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes in relation to colitis was suggested by the animal studies. The finding that colitis was preceded by altered gut bacterial composition suggests that deletion of Abcb1 leads to fundamental changes of host-microbiota interaction. Also, high fat diet increases the frequency and severity of colitis in specific pathogen-free Abcb1 KO mice. The Abcb1 KO mice might thus serve as a model in which diet/environmental factors and microbes may be controlled and investigated in relation to intestinal inflammation. Potential molecular mechanisms include defective transport of inflammatory mediators and/or phospholipid translocation from one side to the other of the cell membrane lipid bilayer by ABC transporters affecting inflammatory response and/or function of tight junctions, phagocytosis and vesicle trafficking. Also, diet and microbes give rise to molecules which are potential substrates for the ABC transporters and which may additionally affect ABC transporter function through nuclear receptors and transcriptional regulation. Another critical role of ABCB1 was suggested by the finding that ABCB1 expression identifies a subpopulation of pro-inflammatory Th17 cells which were resistant to treatment with glucocorticoids. The evidence for the involvement of ABCC2 and ABCG2 in colonic pathophysiology was weak.

CONCLUSION: ABCB1, diet, and gut microbes mutually interact in colonic inflammation, a well-known risk factor for CRC. Further insight may be translated into preventive and treatment strategies.

Association Between Inflammatory Bowel Disease and Vitamin D Deficiency: A Systematic Review and Meta-analysis

BACKGROUND

Vitamin D plays a role in several immune-mediated diseases, but its association with inflammatory bowel disease (IBD) is unclear. We conducted a systematic review and meta-analysis to assess the association between IBD and vitamin D deficiency.

METHODS

We searched electronic databases from inception to December 2014 for observational studies reporting the presence of vitamin D deficiency (defined as serum 25-hydroxycholecalciferol [25(OH)D] level of ≤20 ng/mL) in IBD patients and having a control group without IBD. Odds ratios (ORs) were combined using a random-effects model. Meta-regression was performed using latitude as a moderator. Study quality was assessed using the Newcastle-Ottawa scale.

RESULTS

Out of 816 citations, 14 eligible studies were identified, comprising 1891 participants (938 IBD cases and 953 controls). Meta-analysis showed that patients with IBD had 64% higher odds of vitamin D deficiency when compared with controls (OR = 1.64; 95% confidence interval, 1.30-2.08; I = 7%; P < 0.0001). Patients with ulcerative colitis had more than double the odds of vitamin D deficiency when compared with normal controls (OR = 2.28; 95% confidence interval, 1.18-4.41; I = 41%; P = 0.01). Latitude did not influence the association between IBD and vitamin D deficiency (P = 0.34). Generalizability of our results might be limited as we summarized unadjusted ORs, because of nonavailability of adjusted ORs in individual studies.

CONCLUSIONS

IBD is significantly associated with having higher odds of vitamin D deficiency. Well-designed randomized controlled trials and longitudinal studies are needed to further explain the role of vitamin D in IBD pathogenesis and its therapy.

Methotrexate for the Management of Crohn's Disease in Children

OBJECTIVE

To review the literature evaluating methotrexate as a treatment option for Crohn's disease (CD) in pediatric patients.

DATA SOURCES

A search of PubMed electronic database (1966 to August 2015) and secondary resources was performed using the terms methotrexate, Crohn's, and inflammatory bowel disease. Other relevant articles cited within identified articles were also utilized.

STUDY SELECTION AND DATA EXTRACTION

Data sources were limited to English-language studies that included children less than 18 years of age. In total, 10 clinical studies met the criteria.

DATA SYNTHESIS

Awareness of the risk of hepatosplenic T-cell lymphoma associated with anti-tumor necrosis factor and thiopurine therapies has renewed interest in methotrexate to treat CD in children. According to data from 10 predominantly retrospective studies, children treated with oral or subcutaneous methotrexate once weekly had remission rates of 25% to 53% at 1 year. Adverse effects most often included nausea and vomiting, elevated liver function tests, headache, and hematological toxicity. The evidence to support methotrexate is limited by inconsistent study design and poorly described dosage regimens. It has been most frequently evaluated in patients with prior thiopurine exposure and has not been thoroughly evaluated as first-line therapy.

CONCLUSIONS

Based on results of retrospective studies, methotrexate is useful in the treatment of pediatric CD in those who fail thiopurine therapy. Remission rates with methotrexate are similar to those for thiopurine therapy, although no studies directly compare these agents. Although preliminary results are promising, prospective studies are needed to assess the use of methotrexate as initial first-line therapy in the pediatric CD population.

Vitamin D Deficiency Associated with Disease Activity in Patients with Inflammatory Bowel Diseases

BACKGROUND

Evidence exists on the association between vitamin D deficiency and inflammatory bowel diseases (IBD).

AIMS

To investigate whether vitamin D level is associated with disease activity and quality of life in IBD patients.

METHODS

This cross-sectional study was conducted on known adult IBD patients referred to an outpatient clinic of gastroenterology in Isfahan city, Iran. Disease activity was evaluated using the Simplified Crohn's Disease Activity Index and Simple Clinical Colitis Activity Index. Quality of life was assessed with the Short-Inflammatory Bowel Disease Questionnaire. Serum 25[OH]D was measured using the radioimmunoassay method. Vitamin D deficiency and insufficiency were defined as concentration of <50 and 50-75 nmol/L, respectively.

RESULTS

Studied subjects were 85 ulcerative colitis and 48 Crohn's disease patients (54.1% females) with mean age of 42.0 ± 14.0 years. Vitamin D deficiency and insufficiency were present in 52 (39.0%) and 24 (18.0%) patients, respectively. Thirty patients (22.5%) had active disease who, compared with patients in remission, had more frequent low vitamin D levels (80 vs. 50.4%, P = 0.005). Quality of life was not different between patients with low and those with normal vitamin D levels (P = 0.693). In the logistic regression model, low vitamin D was independently associated with active disease status, OR (95% CI) = 5.959 (1.695-20.952).

CONCLUSIONS

We found an association between vitamin D deficiency/insufficiency and disease activity in IBD patients. Prospective cohorts and clinical trials are required to clarify the role of vitamin D deficiency and its treatment in clinical course of IBD.

Food allergy among Iranian children with inflammatory bowel disease: A preliminary report

BACKGROUND

Evidence has shown a link between allergic disease and inflammatory bowel diseases (IBDs). We investigated food allergy in Iranian pediatric IBD patients.

MATERIALS AND METHODS

A cross-sectional study was conducted on a consecutive sample of children with newly diagnosed IBD referring to Mofid Children's University Hospital in Tehran (Iran) between November 2013 and March 2015. Data on age, gender, history of cow's milk allergy (CMA), IBD type, routine laboratory tests, and colonoscopic and histopathological findings were gathered. Food allergy was assessed with the skin prick test (SPT).

RESULTS

A total of 28 patients including 19 ulcerative colitis (UC), 7 Cronh's disease (CD), and two with unclassified colitis with a mean age of 8.3 ± 4.4 years. (57.1% females, 42.9% were studied. History of CMA was present in eight patients (28.6%). Seventeen patients (60.7%) had at least one food allergy (68.4% of UC vs. 42.9% of CD, P = 0.230). Ten patients (35.7%) had multiple food allergies (36.8% of UC vs. 42.9% of CD, P > 0.999). Common allergic foods were cow's milk (28.6%), beef, seafood, albumen, wheat, and walnuts (each 10.7%), and peanuts and chestnuts (each 7.1%). The SPT showed CMA in 68.4% (8/17) of UC but none of the CD patients (P = 0.077).

CONCLUSION

Food allergy is frequent in Iranian pediatric IBD patients with CMA being the most common observed allergy. The CMA seems to be more frequent in UC than in CD patients.

Chronic cigarette smoke exposure induces microbial and inflammatory shifts and mucin changes in the murine gut

Inflammatory bowel diseases (IBD) are complex multifactorial diseases characterized by an inappropriate host response to an altered commensal microbiome and dysfunctional mucus barrier. Cigarette smoking is the best known environmental risk factor in IBD. Here, we studied the influence of chronic smoke exposure on the gut microbiome, mucus layer composition and immune factors in conventional mice. We compared smoke-exposed with air-exposed mice (n = 12) after a smoke exposure of 24 weeks. Both Illumina sequencing (n = 6) and denaturing gradient gel electrophoresis (n = 12) showed that bacterial activity and community structure were significantly altered in the colon due to smoke exposure. Interestingly, an increase of Lachnospiraceae sp. activity in the colon was observed. Also, the mRNA expression of Muc2 and Muc3 increased in the ileum, whereas Muc4 increased in the distal colon of smoke-exposed mice (n = 6). Furthermore, we observed increased Cxcl2 and decreased Ifn-γ in the ileum, and increased Il-6 and decreased Tgf-β in the proximal colon. Tight junction gene expression remained unchanged. We infer that the modulating role of chronic smoke exposure as a latently present risk factor in the gut may be driven by the altered epithelial mucus profiles and changes in microbiome composition and immune factors.

High C-Reactive Protein Is Associated with Poor Sleep Quality Independent of Nocturnal Symptoms in Patients with Inflammatory Bowel Disease

BACKGROUND

Sleep disruption is common in inflammatory bowel diseases (IBD). However, studies demonstrating a similar prevalence in irritable bowel syndrome suggest that nighttime disruption due to diarrhea and abdominal pain may be key drivers of poor sleep quality. Whether inflammation is associated with poor sleep independently has not been examined previously.

METHODS

This single-center study included subjects with IBD recruited to an ongoing prospective registry who completed a questionnaire assessing sleep quality and mood. Inflammatory marker levels [C-reactive protein (CRP), erythrocyte sedimentation rate] and clinical disease activity including nighttime disruption on the day of enrollment were obtained from the medical record. Logistic regression models were used to identify predictors of sleep quality.

RESULTS

The study included 131 subjects (72 women) with a median age of IBD diagnosis of 25 years. Twenty-three subjects (19 %) had a high C-reactive protein level (≥8 mg/dL). Poor sleep was more common in those with high CRP levels than with normal values (70 vs. 39 %, p = 0.009). This association remained significant on multivariate analysis [Odds ratio (OR) 4.12, 95 % confidence interval (CI) 1.38-12.29]. Adjusting for the presence of nighttime disruption did not significant alter this association (OR 3.16, 95 % CI 1.01-9.90). High CRP correlated with poor sleep even in patients not experiencing nocturnal symptoms (n = 101, OR 4.89, 95 % CI 1.24-19.36).

CONCLUSION

High CRP is associated with poor sleep quality in IBD independent of the presence of nighttime disruptions, suggesting that a relationship exists between circulating inflammatory markers and sleep.