Environmental factors in the development of chronic inflammation: a case-control study on risk factors for Crohn's disease within New Zealand

Association of diet and outdoor time with inflammatory bowel disease: a multicenter case-control study using propensity matching analysis in China

Objective

To investigate the association between dietary and some other environmental factors and the risk of inflammatory bowel diseases (IBD) in Chinese population.

Materials and methods

A multicenter case-control study was conducted involving 11 hospitals across China. A total of 1,230 subjects were enrolled consecutively, and diet and environmental factor questionnaires were collected. IBD patients were matched with healthy controls (HC) using propensity-score matching (PSM) at a 1:1 ratio with a caliper value of 0.02. Multivariate conditional logistic regression analyses were performed to evaluate the associations between diet, environmental factors, and IBD.

Results

Moderate alcohol and milk consumption, as well as daily intake of fresh fruit, were protective factors for both Crohn's disease (CD) and ulcerative colitis (UC). Conversely, the consumption of eggs and chocolate increased the risk of IBD. Outdoor time for more than 25% of the day was a protective factor only for CD. In eastern regions of China, CD patients had higher egg consumption and less outdoor time, while UC patients consumed more chocolate. IBD patients from urban areas or with higher per capita monthly income consumed more fruit, eggs, and chocolate.

Conclusions

This study reveals an association between specific foods, outdoor time, and the emergence of IBD in the Chinese population. The findings emphasize the importance of a balanced diet, sufficient outdoor time and activities, and tailored prevention strategies considering regional variations.

Tobacco Smoke Exposure in Early Childhood and Later Risk of Inflammatory Bowel Disease: A Scandinavian Birth Cohort Study

OBJECTIVES

To examine the association between early-life smoking exposure and later risk of inflammatory bowel disease [IBD].

METHODS

We followed 115663 participants from the Norwegian Mother, Father and Child [MoBa] and All Babies in Southeast Sweden [ABIS] cohorts from birth [1997-2009] through 2021. IBD was identified through national patient registers. Validated questionnaire data defined maternal smoking during pregnancy, maternal environmental tobacco smoke [ETS] exposure during pregnancy, and child ETS exposure by ages 12 and 36 months. Cox regression was used to estimate adjusted hazard ratios [aHRs] for sex, maternal age, education level, parental IBD, and origin. Cohort-specific estimates were pooled using a random-effects model.

RESULTS

During 1 987 430 person-years of follow-up, 444 participants developed IBD [ABIS, 112; MoBa, 332]. Any vs no maternal smoking during pregnancy yielded a pooled aHR of 1.30 [95% CI = 0.97-1.74] for offspring IBD. Higher level of maternal smoking during pregnancy (compared with no smoking, average ≥6 cigarettes/day: pooled aHR = 1.60 [95% CI = 1.08-2.38]) was associated with offspring IBD, whereas a lower smoking level was not (average 1-5 cigarettes/day: pooled aHR = 1.09 [95% CI = 0.73-1.64]). Child ETS exposure in the first year of life was associated with later IBD (any vs no ETS, pooled aHR = 1.32 [95% CI = 1.03-1.69]). Estimates observed for child ETS exposure by 36 months were similar but not statistically significant.

CONCLUSIONS

In this prospective Scandinavian cohort study, children exposed to higher levels of maternal smoking during pregnancy or ETS during the first year of life were at increased risk of later IBD.

Antibiotic Exposure and Risk of New-Onset Inflammatory Bowel Disease: A Systematic Review and Dose-Response Meta-Analysis

BACKGROUND & AIMS

The association between antibiotic exposure and inflammatory bowel disease (IBD) remains controversial, especially whether there is a dose-response relationship. We aimed to conduct a systematic review and meta-analysis to thoroughly evaluate the risk of new-onset IBD associated with antibiotic exposure.

METHODS

Four databases were searched from their inception to September 30, 2023 for all relevant studies. The risk estimates were pooled together using random-effects models, and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated, stratified by IBD subtype, age, exposure period, study type, and antibiotic classes. Dose-response relationship between the number of antibiotic prescriptions and IBD risk was assessed using generalized least squares regression analysis.

RESULTS

Twenty-eight studies involving 153,027 patients with IBD were included. Antibiotic exposure was significantly associated with an increased risk of new-onset IBD for prescription-based studies (pooled OR, 1.41; 95% CI, 1.29-1.53) and for questionnaire-based studies (pooled OR, 1.35; 95% CI, 1.08-1.68). This association existed for both Crohn's disease and ulcerative colitis, as well as in children and adults for prescription-based studies. The majority of antibiotic classes were associated with an increased IBD risk, with metronidazole (OR, 1.70; 95% CI, 1.38-2.10) and quinolones (OR, 1.56; 95% CI, 1.37-1.77) having relatively higher risk estimates. A positive nonlinear dose-response association was observed between the number of antibiotic prescriptions and IBD risk.

CONCLUSIONS

Antibiotic exposure was significantly associated with an increased risk of new-onset IBD, and a positive nonlinear dose-response relationship was observed. Antibiotic stewardship may be important for reducing IBD risk.

An Overview of the Influence of Breastfeeding on the Development of Inflammatory Bowel Disease

The first 1000 days of life is a critical period that contributes significantly to the programming of an individual's future health. Among the many changes that occur during this period early in life, there is growing evidence that the establishment of healthy gut microbiota plays an important role in the prevention of both short- and long-term health problems. Numerous publications suggest that the quality of the gut microbiota colonisation depends on several dietary factors, including breastfeeding. In this respect, a relationship between breastfeeding and the risk of inflammatory bowel disease (IBD) has been suggested. IBDs are chronic intestinal diseases, and perinatal factors may be partly responsible for their onset. We review the existence of links between breastfeeding and IBD based on experimental and clinical studies. Overall, despite encouraging experimental data in rodents, the association between breastfeeding and the development of IBD remains controversial in humans, partly due to the considerable heterogeneity between clinical studies. The duration of exclusive breastfeeding is probably decisive for its lasting effect on IBD. Thus, specific improvements in our knowledge could support dietary interventions targeting the gut microbiome, such as the early use of prebiotics, probiotics or postbiotics, in order to prevent the disease.

Nutrition in Patients with Inflammatory Bowel Diseases: A Narrative Review

Inflammatory bowel diseases (IBD) affect the gastrointestinal tract: they include Crohn’s disease (CD) and ulcerative colitis (UC). Each has a different phenotypic spectrum, characterized by gastrointestinal and extra-intestinal manifestations. People living with IBD are very interested in diet, but little is known about the impact of diet on these patients; no guidelines are available yet. In this review, we analyze the dietary patterns of patients with IBD and the approach to the choices of foods both in adults and pediatric patients. Very often, IBD patients report an intentional avoidance of gluten to manage the disease; furthermore, a proportion of IBD patients believe that dairy products worsen their symptoms and that avoidance may help the disease. They have a low compliance with the Mediterranean Diet, which is considered to have potential benefits but is little used in practice. In conclusion, the review underscores the pivotal role of nutritional counselling in IBD patients, and the importance of future clinical studies to evaluate the beneficial effects of dietary recommendations in the management of IBD.

Systematic review with meta-analysis: environmental and dietary differences of inflammatory bowel disease in Eastern and Western populations

BACKGROUND

While the incidence of inflammatory bowel disease (IBD) has stabilised in the West, it is still increasing in several newly industrialised countries.

AIMS

To investigate whether the environmental and dietary risk factors for IBD differ between Eastern and Western populations METHODS: We systematically searched PubMed, Embase, and Web of Science for studies published from inception through June 30, 2020. Data were pooled using a random effects model.

RESULTS

Overall, 255 studies were assessed. We identified 25 risk factors for IBD, seven of which were noted in both Eastern and Western populations: family history of Crohn's disease [CD] or ulcerative colitis [UC], former smoking (CD/UC), smoking (CD), appendicectomy (CD), tonsillectomy (CD), meat and meat products (CD), and vitamin D deficiency (UC). The remaining factors, including urban living, current smoking, antibiotics, oral contraceptives, caesarean section, isotretinoin, total energy, fat, cholesterol, fatty acids and their sub-classifications, eggs, and soft drinks, were associated with an increased risk of IBD in Western or Eastern populations only. We identified 21 protective factors for IBD, among which eight were common in the East and West: farm animals (CD/UC), Helicobacter pylori infection (CD/UC), multiple births (CD), physical activity (CD), history of breastfeeding (CD), pets (UC), current smoking (UC), and coffee intake (UC). Ten factors conferred protection against IBD in Western populations only, whereas eight factors conferred protection against IBD in Eastern populations only.

CONCLUSIONS

Numerous environmental and dietary factors influenced the development of IBD in both Western and Eastern populations, whereas certain factors influenced IBD risk differently in these populations.

Alcohol consumption and risk of inflammatory bowel disease among three prospective US cohorts

BACKGROUND AND AIMS

There are limited data on alcohol dose and types and risk of Crohn's Disease (CD) and Ulcerative Colitis (UC). We therefore sought to comprehensively examine the association between alcohol consumption and risk of CD and UC.

METHODS

We conducted a prospective cohort study of 237,835 participants from the Nurses' Health Study, Nurses' Health Study II, and Health Professional Follow-Up Study. Alcohol consumption was obtained through questionnaires submitted every four years; additional covariates were obtained at two or four-year intervals. Cases were confirmed independently by two physicians through medical record review. We used Cox proportional hazards regression to estimate age and multivariable-adjusted hazards ratios and 95% confidence intervals.

RESULTS

Across 5,170,474 person-years of follow-up, 370 cases of CD and 486 cases of UC were documented. Increased consumption of alcohol intake was not associated with CD (Ptrend = 0.455) or UC (Ptrend = 0.745). Compared to non-users, the MV-adjusted HRs for 15.0 + g/day of alcohol intake group were 0.84 (95% CI 0.56, 1.24) for CD and 1.08 (95% CI 0.77, 1.51) for UC. In analyses of alcohol subtypes, we observed that only moderate consumption of beer (>1-4 servings/week) was marginally associated with reduced risk of CD, while consumption of >4 servings/week of liquor was associated with an increased risk of UC.

CONCLUSION

This prospective study did not identify a relationship between overall alcohol consumption and risk of CD or UC. Our suggestive associations between alcohol types and risk of CD and UC deserve additional investigation.

Emerging Comorbidities in Inflammatory Bowel Disease: Eating Disorders, Alcohol and Narcotics Misuse

Inflammatory bowel disease (IBD) is a chronic and potentially devastating condition of the digestive tract which is exemplified by increasing prevalence worldwide, byzantine pathogenesis with a poorly defined role of the environmental factors, and complex clinical demonstration. As a systemic disease, IBD may progress with a wide spectrum of extraintestinal manifestations (EMs) and comorbidities affecting different organs and systems, from anaemia, undernutrition, and cancer to those which are often neglected like anxiety and depression. Evolving IBD epidemiology and changing environment are reflected by an expanding list of IBD-related comorbidities. In contrast to the well-established role of smoking the connection between alcohol and IBD is still debatable on many levels, from pathogenesis to complications. Furthermore, little is known about narcotics use in IBD patients, even if there are obvious factors that may predispose them to narcotics as well as alcohol misuse. Last but not least, the question arises what is the prevalence of eating disorders in IBD. In our paper, we aimed to discuss the current knowledge on alcohol and drugs misuse and eating disorders as emerging extraintestinal comorbidities in IBD.

Sweetpotato Leaves Inhibit Lipopolysaccharide-Induced Inflammation in RAW 264.7 Macrophages via Suppression of NF-κB Signaling Pathway

Limited information is available regarding the health-promoting activities of sweetpotato leaves (SPL). The present study investigated antioxidant and anti-inflammatory effects, and phenolic contents in 29 SPL cultivars harvested in 2018 and 2019. Extracts showed total phenolic contents 9.4–23.1 mg gallic acid equivalent/g, and DPPH radical scavenging activity indicated 36.6–247.3 mM of Trolox equivalent/g. SPL extracts were identified to contain bioactive components such as, chlorogenic acid (11.7–22.1 μg/mg), 3,4-dicaffeoylquinic acid (16.3–59.9 μg/mg), 3,5-dicaffeoylquinic acid (50.9–72.7 μg/mg), chlorophyll B (6.1–12.3 μg/mg), lutein (1.9–4.9 μg/mg), chlorophyll A (2.7–4.3 μg/mg) and β-carotene (0.1 ≤ μg/mg). RAW 264.7 murine macrophage cells were pretreated with 100–200 μg/mL of SPL extracts and 20 μM of dexamethasone, and inflammation was stimulated by lipopolysaccharide (LPS, 100 ng/mL) treatment for 24 h. In LPS-treated cells, prostaglandin E2 production and COX-2 expression were not downregulated by pretreatment of SPL extracts. However, SPL pretreated cells showed significant suppression of nitric oxide (NO), TNF-α, and IL-1β levels under the LPS-induced inflammatory condition. In addition, SPL extracts induced an anti-inflammatory effect in LPS-stimulated RAW 264.7 cells through suppression of NF-κB nuclear translocation, IKK-α and IκB-α phosphorylation, and iNOS expression. These results indicate that SPL extract can be utilized as a functional food ingredient.

Early life exposures and the risk of inflammatory bowel disease: Systematic review and meta-analyses

BACKGROUND

Early life exposures impact immune system development and therefore the risk of immune-mediated diseases, including inflammatory bowel disease (IBD). We systematically reviewed the impact of pre-, peri‑, and postnatal exposures up to the age of five years on subsequent IBD diagnosis.

METHODS

We identified case-control and cohort studies reporting on the association between early life environmental factors and Crohn's disease (CD), ulcerative colitis (UC), or IBD overall. Databases were search from their inception until May 24th, 2019 until July 14th, 2020. We conducted meta-analyses for quantitative review of relevant risk factors that were comparable across studies and qualitative synthesis of the literature for a wide range of early life exposures, including maternal health and exposures during pregnancy, perinatal factors, birth month and related-factors, breastfeeding, hygiene-related factors and social factors, immigration, antibiotics, offspring health, including infections, and passive smoking. PROSPERO registration: CRD42019134980.

FINDINGS

Prenatal exposure to antibiotics (OR 1.8; 95% CI 1.2-2.5) and tobacco smoke (OR 1.5; 95% CI 1.2-1.9), and early life otitis media (OR 2.1; 95% CI 1.2-3.6) were associated with IBD. There was a trend towards an association between exposure to antibiotics in infancy and IBD (OR: 1.7, 95% CI 0.97, 2.9), supported by positive data on population-based data. Breastfeeding was protective against IBD. Other early life risk factors had no association with IBD, but data were limited and heterogenous.

INTERPRETATION

Early life is an important period of susceptibility for IBD development later in life. Tobacco smoke, infections and antibiotics were associated positively, and breastfeeding was associated negatively with IBD. Our findings offer an opportunity to develop primary prevention strategies.

FUNDING

This study did not receive any funding.

Filling the gap between risk assessment and molecular determinants of tumor onset

In the past two decades, a ponderous epidemiological literature has causally linked tumor onset to environmental exposure to carcinogens. As consequence, risk assessment studies have been carried out with the aim to identify both predictive models of estimating cancer risks within exposed populations and establishing rules for minimizing hazard when handling carcinogenic compounds. The central assumption of these works is that neoplastic transformation is directly related to the mutational burden of the cell without providing further mechanistic clues to explain increased cancer onset after carcinogen exposure. Nevertheless, in the last few years, a growing number of studies have implemented the traditional models of cancer etiology, proposing that neoplastic transformation is a complex process in which several parameters and crosstalk between tumor and microenvironmental cells must be taken into account and integrated with mutagenesis. In this conceptual framework, the current strategies of risk assessment that are solely based on the 'mutator model' require an urgent update and revision to keep pace with advances in our understanding of cancer biology. We will approach this topic revising the most recent theories on the biological mechanisms involved in tumor formation in order to envision a roadmap leading to a future regulatory framework for a new, protective policy of risk assessment.

The Influence of Breastfeeding, Cesarean Section, Pet Animals, and Urbanization on the Development of Inflammatory Bowel Disease: Data from the Swiss IBD Cohort Study

Introduction

The pathophysiology of inflammatory bowel disease (IBD) is incompletely understood. Current concepts imply that environmental factors (EFs) trigger disease onset as well as flares in genetically susceptible individuals.

Objective

The objective of this study is to analyze the association between IBD and various EFs, which may influence the pathogenesis of the disease.

Methods

2,294 patients from the Swiss IBD Cohort Study (SIBDCS) received a questionnaire regarding EF including mode of delivery, breastfeeding, animals in household, and place of residence. The control group comprised patients' childhood friends, who grew up in a similar environment ("friends cohort").

Results

A total of 1,111 questionnaires were returned from SIBDCS patients (response rate: 48.4%). Breastfeeding for <6 months was associated with a decreased risk for ulcerative colitis/indeterminate colitis (UC/IC) (OR: 0.473, p = 0.006). IBD patients reported less pet animals in the household than the control group (p = 0.004). The presence of cats or dogs (OR: 0.688, p = 0.015) and pet rodents (OR: 0.598, p = 0.001) in the household before the age of 20 was inversely associated with the risk for UC/IC.

Conclusion

The present study underlines the importance of EFs in the pathogenesis of IBD. Overall, the development of UC/IC seems to be more affected from environmental influences than from Crohn's disease. Our results imply a protective effect of possessing pet animals in household and short breastfeeding regarding the onset of UC/IC.

Antibiotic use and the development of inflammatory bowel disease: a national case-control study in Sweden

BACKGROUND

Use of antibiotics in early life has been linked with childhood inflammatory bowel disease (IBD), but data for adults are mixed, and based on smaller investigations that did not compare risk among siblings with shared genetic or environmental risk factors. We aimed to investigate the association between antibiotic therapy and IBD in a large, population-based study.

METHODS

In this prospective case-control study, we identified people living in Sweden aged 16 years or older, with a diagnosis of IBD based on histology and at least one diagnosis code for IBD or its subtypes (ulcerative colitis and Crohn's disease). We identified consecutive patients with incident IBD from the ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) study, cross-referenced with the Swedish Patient Register and the Prescribed Drug Register. We accrued data for cumulative antibiotic dispensations until 1 year before time of matching for patients and up to five general population controls per patient (matched on the basis of age, sex, county, and calendar year). We also included unaffected full siblings as a secondary control group. Conditional logistic regression was used to estimate multivariable-adjusted odds ratios (aORs) and 95% CIs for diagnosis of incident IBD.

FINDINGS

We identified 23 982 new patients with IBD (15 951 ulcerative colitis, 7898 Crohn's disease, 133 unclassified IBD) diagnosed between Jan 1, 2007, and Dec 31, 2016. 117 827 matched controls and 28 732 siblings were also identified. After adjusting for several risk factors, aOR in patients who had used antibiotics versus those who had never used antibiotics was 1·88 (95% CI 1·79-1·98) for diagnosis of incident IBD, 1·74 (1·64-1·85) for ulcerative colitis, and 2·27 (2·06-2·49) for Crohn's disease. aOR was higher in patients who had received one antibiotic dispensation (1·11, 1·07-1·15), two antibiotic dispensations (1·38, 1·32-1·44), and three or more antibiotic dispensations (1·55, 1·49-1·61) than patients who had none. Increased risk was noted for ulcerative colitis (aOR with three or more antibiotic dispensations 1·47, 95% CI 1·40-1·54) and Crohn's disease (1·64, 1·53-1·76) with higher estimates corresponding to broad-spectrum antibiotics. Similar but attenuated results were observed when siblings were used as the reference group, with an aOR of 1·35 (95% CI 1·28-1·43) for patients who had received three or more dispensations, compared with general population controls.

INTERPRETATION

Higher cumulative exposure to systemic antibiotic therapy, particularly treatments with greater spectrum of microbial coverage, may be associated with a greater risk of new-onset IBD and its subtypes. The association between antimicrobial treatment and IBD did not appear to differ when predisposed siblings were used as the reference controls. Our findings, if substantiated by longer-term prospective studies in humans or mechanistic preclinical investigations, suggest the need to further emphasise antibiotic stewardship to prevent the rise in dysbiosis-related chronic diseases, including IBD.

FUNDING

National Institutes of Health. Crohn's and Colitis Foundation.

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.

Dietary Guidance From the International Organization for the Study of Inflammatory Bowel Diseases

Recent evidence points to a plausible role of diet and the microbiome in the pathogenesis of both Crohn's disease (CD) and Ulcerative Colitis (UC). Dietary therapies based on exclusion of table foods and replacement with nutritional formulas and/or a combination of nutritional formulas and specific table foods may induce remission in CD. In UC, specific dietary components have also been associated with flare of disease. While evidence of varying quality has identified potential harmful or beneficial dietary components, physicians and patients at the present time do not have guidance as to which foods are safe, may be protective or deleterious for these diseases. The current document has been compiled by the nutrition cluster of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) based on the best current evidence to provide expert opinion regarding specific dietary components, food groups and food additives that may be prudent to increase or decrease in the diet of patients with inflammatory bowel diseases to control and prevent relapse of inflammatory bowel diseases.

Correlation between antibiotic use in childhood and subsequent inflammatory bowel disease: a systematic review and meta-analysis

Background: Antibiotic use leads to a cascade of inflammatory reaction in the gastrointestinal tract due to its association with a temporary disruption of human microbiome.Objectives: To explore the undetermined correlation between antibiotic use in childhood and subsequent inflammatory bowel disease (IBD).Methods: PUBMED, EMBASE and Cochrane Central Register of Controlled Trials were searched to identify related articles. We extracted and pooled the (adjusted) odds ratio (OR) and (adjusted) risk ratio (RR).Results: This systematic review and meta-analysis included 11 studies. The pooled OR of all 11 studies was 1.5 (95% confidence interval (CI): 1.22-1.85). The pooled ORs of the subsequent Crohn's disease and ulcerative colitis after antibiotic use in childhood were 1.59 (95% CI: 1.06-2.4) and 1.22 (95% CI: 0.82-1.8). The sensitivity analysis showed no change. The meta-regression showed there was not statistical significance for the publication year, research area and research methods. Egger's test showed publication bias in the IBD studies (p  =  .006  <  .05) but no publication bias for the CD (p  =  .275>.05) and UC studies (p  =  .537>.05).Conclusions: There was a positive association between antibiotic use in childhood and the subsequently risk of Crohn's disease in non-European countries in the west during 2010-2013. Children in the United States taking antibiotics will have a higher risk of subsequently IBD than Europe, Asia and Australia. Registration number: CRD42019147648 (PROSPERO).

Antibiotic Use in Childhood and Adolescence and Risk of Inflammatory Bowel Disease: A Case-Control Study in the UK Clinical Practice Research Datalink

BACKGROUND

Inflammatory bowel disease (IBD) causes serious morbidity and disability, and the incidence is increasing. The disease etiology is not well understood, though inflammatory reactions after antibiotic exposure may be associated with development of IBD. We investigated the association between IBD and prior antibiotic use.

METHODS

We conducted this case-control study among individuals in the United Kingdom Clinical Practice Research Datalink GOLD (CPRD GOLD). Each case of IBD was matched to 4 controls on age, sex, general practice, and registration year in the CPRD GOLD. Antibiotic exposure was classified by ever or never use, number of prescriptions, and class of antibiotic before the index date. Odds ratios were calculated using conditional logistic regression.

RESULTS

We identified 461 cases of ulcerative colitis (UC) and 683 cases of Crohn's disease (CD). There was no association between ever use of any antibiotic and UC (odds ratio [OR], 1.02; 95% confidence interval [CI], 0.72-1.44) or CD (OR, 1.01; 95% CI, 0.73-1.39) compared with never use. A slightly increased CD risk was observed among ever users of quinolones (OR, 1.76; 95% CI, 1.00-3.11) and metronidazole (OR, 1.43; 95% CI, 0.87-2.34) compared with never users. CD was associated with antibiotic exposure before age 5 (OR, 2.20; 95% CI, 0.75-6.43) in an analysis restricted to individuals followed from birth.

CONCLUSIONS

There was no association between UC or CD and overall prior use of antibiotics, though prior use of metronidazole and quinolones was associated with a slightly increased risk of CD. Antibiotic use in early childhood may increase the risk of CD.

A Comprehensive Review of the Diagnosis and Pharmacological Management of Crohn's Disease in the Elderly Population

Crohn's disease (CD) in the elderly is rising in prevalence, which is related to an increase in its incidence and improving life expectancies. There are differences in the presentation, natural history, and treatment of CD between adult-onset patients who progress to older age and patients who are initially diagnosed at an older age. Presentation at an older age may also delay or make diagnosis challenging due to accumulating co-morbidities that mimic inflammatory bowel disease. Differences exist between adult- and older-onset disease, yet many guidelines do not specifically distinguish the management of these two distinct populations. Identifying patients at high risk for progression or aggressive disease is particularly important as elderly patients may respond differently to medical and surgical treatment, and may be at higher risk for adverse effects. Despite newer agents being approved for CD, the data regarding efficacy and safety in the elderly are currently limited. Balancing symptom management with risks of medical and surgical therapy is an ongoing challenge and requires special consideration in these two distinct populations.

Beverage intake and risk of Crohn disease: A meta-analysis of 16 epidemiological studies

Epidemiological studies were controversial in the association between beverage intake and risk of Crohn disease (CD). This study aimed to investigate the role of beverage intake in the development of CD. A systematic search was conducted in public databases to identify all relevant studies, and study-specific relative risks (RRs) and 95% confidence intervals (CIs) were pooled using a random-effects model. Sixteen studies were identified with a total of 130,431 participants and 1933 CD cases. No significant association was detected between alcohol intake and CD risk (RR for the highest vs the lowest consumption level: 0.85, 95% CI 0.68-1.08), and coffee intake and the risk (RR 0.82, 95% CI 0.46-1.46). High intake of soft drinks was associated with CD risk (RR 1.42, 95% CI 1.01-1.98), and tea intake was inversely associated with CD risk (RR 0.70, 95% CI 0.53-0.93). In conclusion, high intake of soft drinks might increase the risk of CD, whereas tea intake might decrease the risk.

Escherichia coli Pathobionts Associated with Inflammatory Bowel Disease

Gut bacteria play a key role in initiating and maintaining the inflammatory process in the gut tissues of inflammatory bowel disease (IBD) patients, by supplying antigens or other stimulatory factors that trigger immune cell activation. Changes in the composition of the intestinal microbiota in IBD patients compared to that in healthy controls and a reduced diversity of intestinal microbial species are linked to the pathogenesis of IBD. Adherent invasive Escherichia coli (AIEC) has been linked to Crohn's disease (CD) patients, while diffusely adherent E. coli (DAEC) has been associated with ulcerative colitis (UC). Bacteriological analysis of intestinal biopsy specimens and fecal samples from IBD patients shows an increased number of E. coli strains belonging to the B2 phylogenetic group, which are typically known as extraintestinal pathogenic E. coli (ExPEC). Results from studies of both cell cultures and animal models reveal pathogenic features of these E. coli pathobionts, which may link them to IBD pathogenesis. This suggests that IBD-associated E. coli strains play a facilitative role during IBD flares. In this review, we explain IBD-associated E. coli and its role in IBD pathogenesis.

Fetal and early life antibiotics exposure and very early onset inflammatory bowel disease: a population-based study

OBJECTIVE

Earlier studies on antibiotics exposure and development of IBD (Crohn's disease (CD) and ulcerative colitis (UC)) may have been biased by familial factors and gastroenteritis. We aimed to estimate the association between antibiotics during pregnancy or infantile age and very early onset (VEO) IBD.

DESIGN

In this cohort study of 827 239 children born in Sweden between 2006 and 2013, we examined the link between exposure to systemic antibiotics and VEO-IBD (diagnosis <6 years of age), using Cox proportional hazard regression models. Information on antibiotics and IBD was retrieved from the nationwide population-based Swedish Prescribed Drug Register and the National Patient Register. We specifically examined potential confounding from parental IBD and gastroenteritis.

RESULTS

Children exposed to antibiotics during pregnancy were at increased risk of IBD compared with general population controls (adjusted HR (aHR) 1.93; 95% CI 1.06 to 3.50). Corresponding aHRs were 2.48 (95% CI 1.01 to 6.08) for CD and 1.25 (95% CI 0.47 to 3.26) for UC, respectively. For antibiotics in infantile age, the aHR for IBD was 1.11 (95% CI 0.57 to 2.15); for CD 0.72 (95% CI 0.27 to 1.92) and 1.23 (95% CI 0.45 to 3.39) for UC. Excluding children with gastroenteritis 12 months prior to the first IBD diagnosis retained similar aHR for antibiotics during pregnancy and CD, while the association no longer remained significant for IBD.

CONCLUSION

We found that exposure to antibiotics during pregnancy, but not in infantile age, is associated with an increased risk of VEO-IBD regardless of gastroenteritis. The risk increase for exposure in pregnancy may be due to changes in the microbiota.

An update on the role of gut microbiota in chronic inflammatory diseases, and potential therapeutic targets

The human microbiome plays a critical role in human health, having metabolic, protective, and trophic functions, depending upon its' exact composition. This composition is affected by a number of factors, including the genetic background of the individual, early life factors (including method of birth, length of breastfeeding) and nature of the diet and other environmental exposures (including cigarette smoking) and general life habits. It plays a key role in the control of inflammation, and in turn, its' composition is significantly influenced by inflammation. Areas covered: We consider metabolic, protective, and trophic functions of the microbiome and influences through the lifespan from post-partum effects, to diet later in life in healthy older adults, the effects of aging on both its' composition, and influence on health and potential therapeutic targets that may have anti-inflammatory effects. Expert commentary: The future will see the growth of more effective therapies targeting the microbiome particularly with respect to the use of specific nutrients and diets personalized to the individual.

The association between new generation oral contraceptive pill and the development of inflammatory bowel diseases

Background/Aims

To examine the association between use of oral contraceptive pills (OCPs) and the risk of developing inflammatory bowel diseases (IBD), in a modern cohort.

Methods

A prospective nested case-control study across sites in the Asia-Pacific region was conducted; involving female IBD cases and asymptomatic controls. Subjects completed a questionnaire addressing questions related to OCP use. Primary outcome was the risk of development of IBD of those exposed to OCP versus non-exposure. Secondary outcomes were development of Crohn's disease (CD) versus ulcerative colitis (UC), and whether age of first use of OCP use may be associated with risk of IBD.

Results

Three hundred and forty-eight female IBD cases (41% CD, median age: 43 years) and 590 female age-matched controls were recruited. No significant association was found between OCP use and the risk of IBD (odds ratio [OR], 1.65; 95% confidence interval, 0.77-3.13; P=0.22), CD (OR, 1.55) or UC (OR, 1.01). The lack of association persisted when results were adjusted for age and smoking. IBD cases commenced OCP use at a younger age than controls (18 years vs. 20 years, P=0.049).

Conclusions

In this large cohort of subjects from the Asia-Pacific region, we found a modest but not significantly increased risk of developing IBD amongst OCP users.

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.

Antibiotic Use and New-Onset Inflammatory Bowel Disease in Olmsted County, Minnesota: A Population-Based Case-Control Study

BACKGROUND AND AIMS

Several studies have suggested significant associations between environmental factors and the risk of developing inflammatory bowel disease [IBD]. However, data supporting the role of antibiotics are conflicting. The aim of this study was to evaluate the association between antibiotic use and new-onset IBD.

METHODS

We conducted a population-based case-control study using the Rochester Epidemiology Project of Olmsted County, Minnesota. We identified 736 county residents diagnosed with IBD between 1980 and 2010 who were matched to 1472 controls, based on age, sex and date of IBD diagnosis. Data on antibiotic use between 3 months and 5 years before IBD diagnosis were collected. Logistic regression models were used to estimate associations between antibiotic use and IBD, and were expressed as adjusted odds ratio [AOR] with 95% confidence interval [CI].

RESULTS

Antibiotic use occurred in 455 IBD cases [61.8%] and 495 controls [33.6%] [p < 0.001]. In multivariate analysis, there were statistically significant associations between antibiotic use and new-onset IBD [AOR, 2.93; 95% CI, 2.40-3.58], Crohn's disease [CD] [AOR, 3.01; 2.27-4.00] and ulcerative colitis [UC] [AOR, 2.94; 95% CI, 2.23-3.88]. A cumulative duration of antibiotic use ≥ 30 days had the strongest AOR [6.01; 95% CI, 4.34-8.45]. AOR for those receiving antibiotics under the age of 18 years was 4.27 [95% CI, 2.39-7.91], 2.97 for age 18-60 years [2.36-3.75] and 2.72 for age > 60 years [1.60-4.67].

CONCLUSIONS

This population-based case-control study suggests a strong association between antibiotic use and the risk of both new-onset CD and new-onset UC. The risk was increased among all age-onset IBD.

Antibiotics exposure and risk of inflammatory bowel disease: a systematic review

AIM

The aim of this study was to critically assess all available evidence suggesting an association between antibiotic exposure and new onset of inflammatory bowel disease (IBD).

MATERIALS AND METHODS

This systematic review was conducted according to the PRISMA statement and eligible studies were identified through search of PubMed, Embase and the Cochrane Library. Data on patient demographics, antibiotic exposure and confounding factors were analyzed. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of eligible studies.

RESULTS

A total of 15 observational studies (10 case control and five cohort) including 8748 patients diagnosed with IBD were systematically reviewed. Antibiotic exposure was mostly associated with Crohn's disease but not with ulcerative colitis. In particular, penicillin's, cephalosporins, metronidazole and fluoroquinolones were most commonly associated with the onset of Crohn's disease. The impact of tetracycline-family antibiotics on the pathogenesis of IBD was not clear.

CONCLUSION

There may be an association between antibiotic exposure and the development of IBD; especially Crohn's disease. Even though, clinicians should be cautious when prescribing certain antibiotic regimens to patients with a strong family history of IBD, it should be emphasized that available data are not granular enough to reach any definitive conclusions.

Systematic review with meta-analysis: breastfeeding and the risk of Crohn's disease and ulcerative colitis

BACKGROUND

Breastfeeding is a modifiable factor that may influence development of inflammatory bowel diseases. However, literature on this has been inconsistent and not accounted for heterogeneity in populations and exposure.

AIM

To conduct a meta-analysis to examine the association between breastfeeding in infancy and risk of Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

A systematic search of Medline/PubMed and Embase was performed for full text, English-language literature through November 2016. Studies were included if they described breastfeeding in infancy in patients with CD or UC, and healthy controls. Data were pooled using a random effects model for analysis.

RESULTS

A total of 35 studies were included in the final analysis, comprising 7536 individuals with CD, 7353 with UC and 330 222 controls. Ever being breastfed was associated with a lower risk of CD (OR 0.71, 95% CI 0.59-0.85) and UC (OR 0.78, 95% CI 0.67-0.91). While this inverse association was observed in all ethnicity groups, the magnitude of protection was significantly greater among Asians (OR 0.31, 95% CI 0.20-0.48) compared to Caucasians (OR 0.78, 95% CI 0.66-0.93; P = .0001) in CD. Breastfeeding duration showed a dose-dependent association, with strongest decrease in risk when breastfed for at least 12 months for CD (OR 0.20, 95% CI 0.08-0.50) and UC (OR 0.21, 95% CI 0.10-0.43) as compared to 3 or 6 months.

CONCLUSION

Breastfeeding in infancy protects against the development of CD and ulcerative colitis.

The role of smoking and alcohol behaviour in the management of inflammatory bowel disease

In the era of increasing use of immunosuppressive and biologic therapy for inflammatory bowel disease, environmental influences remain important independent risk factors to modify the course of the disease, affect the need for surgery and recurrence rates post-surgical resection. The effect of smoking on inflammatory bowel disease has been established over the decades, however the exact mechanism of how smoking affects remains as area of research. Alcohol is also among the socio-environmental factors which has been recognised to cause a flare of symptoms in inflammatory bowel disease patients. Nonetheless, the exact relation to date is not fully understood, and various paradoxical results from different studies are still a point of controversy.

Exposure to oral contraceptives increases the risk for development of inflammatory bowel disease: a meta-analysis of case-controlled and cohort studies

BACKGROUND

The oral contraceptive pill (OCP) is a widely used method of contraception. There have been conflicting studies linking the use of OCPs to the development of inflammatory bowel disease (IBD). The intent of this meta-analysis is to better define the association between OCP exposure and the risk for development of IBD.

METHODS

A thorough search of multiple databases, including Scopus, Cochrane, MEDLINE/PubMed, and CINAHL, and abstracts from major gastroenterology meetings was performed (October, 2016). Studies reporting the development of IBD in patients with or without previous exposure to OCP, compared with healthy controls, were included. A meta-analysis was completed using the Mantel-Haenszel model to evaluate the risk of developing IBD in the setting of previous OCP exposure.

RESULTS

In a complete analysis of 20 studies, there appeared to be over a 30% increased risk for the development of IBD in patients exposed to OCP compared with patients not exposed to OCP [odds ratio (OR): 1.32, 95% confidence interval (CI): 1.17-1.49, P<0.001, I=14%]. More specifically, there was a 24% higher risk for developing Crohn's disease (OR: 1.24, 95% CI: 1.09-1.40, P<0.001; I=38%) and a 30% higher risk for developing ulcerative colitis (OR: 1.30, 95% CI: 1.13-1.49, I=26%) in patients exposed to OCP compared with those not exposed to the medication.

CONCLUSION

The use of OCP is associated with an increased risk for development of Crohn's disease and ulcerative colitis in the genetically susceptible host. The total duration, dose of OCP exposure, and the risk for development of IBD need to be better characterized.

Epidemiology of inflammatory bowel disease among participants of the Millennium Cohort: incidence, deployment-related risk factors, and antecedent episodes of infectious gastroenteritis

BACKGROUND

Crohn's disease (CD) and ulcerative colitis (UC) are two pathotypes of inflammatory bowel disease (IBD) with unique pathology, risk factors and significant morbidity.

AIM

To estimate incidence and identify IBD risk factors in a US military population, a healthy subset of the US population, using information from the Millennium Cohort Study.

METHODS

Incident IBD was identified from medical encounters from 2001 to 2009 or by self-report. Our primary risk factor of interest, infectious gastroenteritis, was identified from medical encounters and self-reported post-deployment health assessments. Other potential risk factors were assessed using self-reported survey responses and military personnel files. Hazard ratios were estimated using Cox proportional hazards analysis.

RESULTS

We estimated 23.2 and 21.9 diagnoses per 100 000 person-years, respectively, for CD and UC. For CD, significant risk factors included [adjusted hazard ratio (aHR), 95% confidence interval]: current smoking (aHR: 2.7, 1.4-5.1), two life stressors (aHR: 2.8, 1.4-5.6) and prior irritable bowel syndrome (aHR: 4.7, 1.5-15.2). There was no significant association with prior infectious gastroenteritis. There was an apparent dose-response relationship between UC risk and an increasing number of life stressors. In addition, antecedent infectious gastroenteritis was associated with almost a three-fold increase in UC risk (aHR: 2.9, 1.4-6.0). Moderate alcohol consumption (aHR: 0.4, 0.2-0.6) was associated with lower UC risk.

CONCLUSIONS

Stressful conditions and the high risk of infectious gastroenteritis in deployment operations may play a role in the development of IBD in military populations. However, observed differences in risk factors for UC and CD warrant further investigation.

The association between environmental exposures during childhood and the subsequent development of Crohn's disease: A score analysis approach

BACKGROUND

Environmental factors during childhood are thought to play a role in the aetiology of Crohn's Disease (CD). In South Africa, recently published work based on an investigation of 14 childhood environmental exposures during 3 age intervals (0-5, 6-10 and 11-18 years) has provided insight into the role of timing of exposure in the future development of CD. The 'overlapping' contribution of the investigated variables however, remains unclear. The aim of this study was to perform a post hoc analysis using this data and investigate the extent to which each variable contributes to the subsequent development of CD relative to each aforementioned age interval, based on a score analysis approach.

METHODS

Three methods were used for the score analysis. Two methods employed the subgrouping of one or more (similar) variables (methods A and B), with each subgroup assigned a score value weighting equal to one. For comparison, the third approach (method 0) involved no grouping of the 14 variables. Thus, each variable held a score value of one.

RESULTS

Results of the score analysis (Method 0) for the environmental exposures during 3 age intervals (0-5, 6-10 and 11-18 years) revealed no significant difference between the case and control groups. By contrast, results from Method A and Method B revealed a significant difference during all 3 age intervals between the case and control groups, with cases having significantly lower exposure scores (approximately 30% and 40% lower, respectively).

CONCLUSION

Results from the score analysis provide insight into the 'compound' effects from multiple environmental exposures in the aetiology of CD.

No association of alcohol use and the risk of ulcerative colitis or Crohn's disease: data from a European Prospective cohort study (EPIC)

BACKGROUND/OBJECTIVES

The role of long-term alcohol consumption for the risk of developing ulcerative colitis (UC) and Crohn's disease (CD) is unclear. For the first time, to prospectively assess the role of pre-disease alcohol consumption on the risk of developing UC or CD.

SUBJECTS/METHODS

Nested within the European Prospective Investigation into Cancer and Nutrition (EPIC-IBD), incident UC and CD cases and matched controls where included. At recruitment, participants completed validated food frequency and lifestyle questionnaires. Alcohol consumption was classified as either: non-use, former, light (⩽0.5 and 1 drink per week), below the recommended limits (BRL) (⩽1 and 2 drinks per day), moderate (⩽2.5 and 5 drinks per day), or heavy use (>2.5 and >5 drinks per day) for women and men, respectively; and was expressed as consumption at enrolment and during lifetime. Conditional logistic regression was applied adjusting for smoking and education, taking light users as the reference.

RESULTS

Out of 262 451 participants in six countries, 198 UC incident cases/792 controls and 84 CD cases/336 controls were included. At enrolment, 8%/27%/32%/23%/11% UC cases and 7%/29%/40%/19%/5% CD cases were: non-users, light, BRL, moderate and heavy users, respectively. The corresponding figures for lifetime non-use, former, light, BRL, moderate and heavy use were: 3%/5%/23%/44%/19%/6% and 5%/2%/25%/44%/23%/1% for UC and CD cases, respectively. There were no associations between any categories of alcohol consumption and risk of UC or CD in the unadjusted and adjusted odds ratios.

CONCLUSION

There was no evidence of associations between alcohol use and the odds of developing either UC or CD.

Effect of Alcoholic Intoxication on the Risk of Inflammatory Bowel Disease: A Nationwide Retrospective Cohort Study

PURPOSE

This study investigated whether alcoholic intoxication (AI) increases the risk of inflammatory bowel disease (IBD) by using a population-based database in Taiwan.

METHODS

This retrospective matched-cohort study included 57 611 inpatients with new-onset AI (AI cohort) and 230 444 randomly selected controls (non-AI cohort). Each patient was monitored for 10 years to individually identify those who were subsequently diagnosed with Crohn disease (CD) and ulcerative colitis (UC) during the follow-up period. Cox proportional hazard regression analysis was conducted to determine the risk of IBD in patients with AI compared with controls without AI.

RESULTS

The incidence rate of IBD during the 10-year follow-up period was 2.69 per 1 000 person-years and 0.49 per 1 000 person-years in the AI and non-AI cohorts, respectively. After adjustment for age, sex, and comorbidity, the AI cohort exhibited a 3.17-fold increased risk of IBD compared with the non-AI cohort (hazard ratio [HR] = 3.17, 95% confidence interval [CI] = 2.19-4.58). Compared with the non-AI cohort, the HRs of CD and UC were 4.40 and 2.33 for the AI cohort, respectively. After stratification for the severity of AI according to the duration of hospital stay, the adjusted HRs exhibited a significant correlation with the severity; the HRs of IBD were 1.76, 6.83, and 19.9 for patients with mild, moderate, and severe AI, respectively (p for the trend < .0001).

CONCLUSION

The risk of IBD was higher in patients with AI and increased with the length of hospital stay.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Advances in nutritional therapy in inflammatory bowel diseases: Review

Inflammatory bowel diseases (IBD), including ulcerative colitis and Crohn's disease are chronic, life-long, and relapsing diseases of the gastrointestinal tract. Currently, there are no complete cure possibilities, but combined pharmacological and nutritional therapy may induce remission of the disease. Malnutrition and specific nutritional deficiencies are frequent among IBD patients, so the majority of them need nutritional treatment, which not only improves the state of nutrition of the patients but has strong anti-inflammatory activity as well. Moreover, some nutrients, from early stages of life are suspected as triggering factors in the etiopathogenesis of IBD. Both parenteral and enteral nutrition is used in IBD therapy, but their practical utility in different populations and in different countries is not clearly established, and there are sometimes conflicting theories concerning the role of nutrition in IBD. This review presents the actual data from research studies on the influence of nutrition on the etiopathogenesis of IBD and the latest findings regarding its mechanisms of action. The use of both parenteral and enteral nutrition as therapeutic methods in induction and maintenance therapy in IBD treatment is also extensively discussed. Comparison of the latest research data, scientific theories concerning the role of nutrition in IBD, and different opinions about them are also presented and discussed. Additionally, some potential future perspectives for nutritional therapy are highlighted.

Diet and nutritional factors in inflammatory bowel diseases

Inflammatory bowel disease (IBD) development is affected by complex interactions between environmental factors, changes in intestinal flora, various predisposing genetic properties and changes in the immune system. Dietary factors seem to play an underestimated role in the etiopathogenesis and course of the disease. However, research about food and IBD is conflicting. An excessive consumption of sugar, animal fat and linoleic acid is considered a risk factor for IBD development, whereas a high fiber diet and citrus fruit consumption may play a protective role. Also, appropriate nutrition in particular periods of the disease may facilitate achieving or prolonging remissions and most of all, improve the quality of life for patients. During disease exacerbation, a low fiber diet is recommended for most patients. In the remission time, an excessive consumption of alcohol and sulfur products may have a negative effect on the disease course. Attempts are also made at employing diets composed in detail in order to supplement IBD therapy. A diet with a modified carbohydrate composition, a semi-vegetarian diet and a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols are under investigation. Due to chronic inflammation as well as side effects of chronically used medications, patients with IBD are also at increased risk of nutritional factor deficiencies, including iron, calcium, vitamin D, vitamin B12, folic acid, zinc, magnesium and vitamin A. It should also be remembered that there is no single common diet suitable for all IBD patients; each of them is unique and dietary recommendations must be individually developed for each patient, depending on the course of the disease, past surgical procedures and type of pharmacotherapy.

Vitamin D Deficiency Increases the Risk for Moderate to Severe Disease Activity in Crohn's Disease Patients in South Africa, Measured by the Harvey Bradshaw Index

OBJECTIVE

Vitamin D has immunoregulatory properties and appears to influence disease outcomes in patients with Crohn's disease (CD). The primary aim of this study was to evaluate the association between vitamin D status and CD activity in South Africa.

METHODS

In a cross-sectional study performed between September 2011 and January 2013, serum 25-hydroxyvitamin D (25(OH)D) was measured in 186 consecutive patients with CD seen at 2 inflammatory bowel disease (IBD) centers and 199 healthy controls in the Western Cape, South Africa. Lifestyle and clinical variables were identified using an investigator-administered questionnaire, as well as clinical examination and patient case notes. Vitamin D status was evaluated in 2 ways: ≤ 20 ng/mL vs ≥ 21 ng/mL and ≤ 29 ng/mL vs ≥ 30 ng/mL. Disease activity was measured by the Harvey Bradshaw Index (HBI). Various 25(OH)D threshold concentrations for predicting a higher HBI score were also investigated.

RESULTS

On multiple log-binomial regression analysis, higher HBI scores and not having taken vitamin D supplementation in the 6 months prior to enrollment were identified as risk factors for vitamin D deficiency in patients with CD, defined either as ≤ 20 ng/mL or as ≤ 29 ng/mL (p < 0.03). Compared to patients with HBI < 5, those with HBI ≥ 8 were 2.5 times more likely to have 25(OH)D concentrations ≤ 21 ng/mL (prevalence risk [PR] = 2.5; 95% confidence interval [CI], 1.21-6.30). The risk was similar, though not as high, when defined as ≤ 29 ng/mL (PR = 2.0; 95% CI, 1.13-3.51). When vitamin D deficiency was defined as <20, <30, <40, and <50 ng/mL, the sensitivity and specificity obtained were 44.9% and 78.8%; 75.5% and 62.4%; 86.7% and 44.7%; and 92.9% and 23.5%, respectively (area under the curve = 0.71; p < 0.0001).

CONCLUSION

Low serum 25(OH)D was associated with increased CD activity in a South African cohort.

The Influence of Second-Hand Cigarette Smoke Exposure during Childhood and Active Cigarette Smoking on Crohn's Disease Phenotype Defined by the Montreal Classification Scheme in a Western Cape Population, South Africa

Background

Smoking may worsen the disease outcomes in patients with Crohn’s disease (CD), however the effect of exposure to second-hand cigarette smoke during childhood is unclear. In South Africa, no such literature exists. The aim of this study was to investigate whether disease phenotype, at time of diagnosis of CD, was associated with exposure to second-hand cigarette during childhood and active cigarette smoking habits.

Methods

A cross sectional examination of all consecutive CD patients seen during the period September 2011-January 2013 at 2 large inflammatory bowel disease centers in the Western Cape, South Africa was performed. Data were collected via review of patient case notes, interviewer-administered questionnaire and clinical examination by the attending gastroenterologist. Disease phenotype (behavior and location) was evaluated at time of diagnosis, according to the Montreal Classification scheme. In addition, disease behavior was stratified as ‘complicated’ or ‘uncomplicated’, using predefined definitions. Passive cigarette smoke exposure was evaluated during 3 age intervals: 0–5, 6–10, and 11–18 years.

Results

One hundred and ninety four CD patients were identified. Cigarette smoking during the 6 months prior to, or at time of diagnosis was significantly associated with ileo-colonic (L3) disease (RRR = 3.63; 95%CI, 1.32–9.98, p = 0.012) and ileal (L1) disease (RRR = 3.54; 95%CI, 1.06–11.83, p = 0.040) compared with colonic disease. In smokers, childhood passive cigarette smoke exposure during the 0–5 years age interval was significantly associated with ileo-colonic CD location (RRR = 21.3; 95%CI, 1.16–391.55, p = 0.040). No significant association between smoking habits and disease behavior at diagnosis, whether defined by the Montreal scheme, or stratified as ‘complicated’ vs ‘uncomplicated’, was observed.

Conclusion

Smoking habits were associated with ileo-colonic (L3) and ileal (L1) disease at time of diagnosis in a South African cohort.

Infections Requiring Hospitalization as Predictors of Pediatric-Onset Crohn's Disease and Ulcerative Colitis

Objectives. To assess the relationship between infections and the risk of pediatric-onset inflammatory bowel disease (IBD). Methods. We conducted a nested case-control study of 501 incident cases aged ≤17 years and 9,442 controls who were members of Kaiser Permanente Northern California for at least one consecutive year between 1996 and 2006. IBD was confirmed and the incidence date was adjudicated by pediatric gastroenterologists. Hospitalized infections were identified from the principal diagnosis code of electronic inpatient records. Medications to treat infections were identified during the hospitalization. Conditional logistic regression was used to assess the associations between hospitalized infections, medications, and Crohn's disease and ulcerative colitis. Results. In the year prior to diagnosis, both hospitalized infection of any system (OR 6.3; 95% CI 1.6–23.9) and hospitalized intestinal infection (OR 19.4; 95% CI 2.6–143.2) were associated with CD. Hospitalized infections of any system were inversely associated with UC after excluding the year prior to diagnosis (OR 0.4; 95% CI 0.2–0.9). No UC case had a hospitalized gastrointestinal infection prior to diagnosis. Conclusion. Infections appear to play opposite roles prior to the diagnosis of CD and UC. Infections may be associated with an increased risk of CD and a decreased risk of UC.

Exposome in IBD: recent insights in environmental factors that influence the onset and course of IBD

It is generally agreed that environmental factors trigger the onset and cause flares of inflammatory bowel disease. Although we have learned much about genetic susceptibility factors of inflammatory bowel disease in recent years, our knowledge on these environmental factors is limited. The sum of all environmental factors a human is exposed to during lifetime has been termed the exposome. The challenge of investigating the exposome is discussed in this overview. The environmental exposure of a subject causes changes in the intestinal microbiota and subsequently changes the epigenetic imprinting of the mucosa and the associated immune system. Some relevant environmental factors have been investigated in recent years in inflammatory bowel disease and other (auto)inflammatory disease. These factors can be categorized in air pollution, diet, drugs, stress, infections, water pollution, food additives, and lifestyle. Examples from those categories and their potential pathophysiological mechanism are discussed.

Antibiotics associated with increased risk of new-onset Crohn's disease but not ulcerative colitis: a meta-analysis

OBJECTIVES

The objective of this study was to perform a meta-analysis investigating antibiotic exposure as a risk factor for developing inflammatory bowel disease (IBD).

METHODS

A literature search using Medline, Embase, and Cochrane databases was performed to identify studies providing data on the association between antibiotic use and newly diagnosed IBD. Included studies reported Crohn's disease (CD), ulcerative colitis (UC), or a composite of both (IBD) as the primary outcome and evaluated antibiotic exposure before being diagnosed with IBD. A random-effects meta-analysis was conducted to determine overall pooled estimates and 95% confidence intervals (CIs).

RESULTS

A total of 11 observational studies (8 case-control and 3 cohort) including 7,208 patients diagnosed with IBD were analyzed. The pooled odds ratio (OR) for IBD among patients exposed to any antibiotic was 1.57 (95% CI 1.27-1.94). Antibiotic exposure was significantly associated with CD (OR 1.74, 95% CI 1.35-2.23) but was not significant for UC (OR 1.08, 95% CI 0.91-1.27). Exposure to antibiotics most markedly increased the risk of CD in children (OR 2.75, 95% CI 1.72-4.38). All antibiotics were associated with IBD, with the exception of penicillin. Exposure to metronidazole (OR 5.01, 95% CI 1.65-15.25) or fluoroquinolones (OR 1.79, 95% CI 1.03-3.12) was most strongly associated with new-onset IBD.

CONCLUSIONS

Exposure to antibiotics appears to increase the odds of being newly diagnosed with CD but not UC. This risk is most marked in children diagnosed with CD.

Job strain and the risk of inflammatory bowel diseases: individual-participant meta-analysis of 95,000 men and women

Background and Aims

Many clinicians, patients and patient advocacy groups believe stress to have a causal role in inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis. However, this is not corroborated by clear epidemiological research evidence. We investigated the association between work-related stress and incident Crohn's disease and ulcerative colitis using individual-level data from 95 000 European adults.

Methods

We conducted individual-participant data meta-analyses in a set of pooled data from 11 prospective European studies. All studies are a part of the IPD-Work Consortium. Work-related psychosocial stress was operationalised as job strain (a combination of high demands and low control at work) and was self-reported at baseline. Crohn's disease and ulcerative colitis were ascertained from national hospitalisation and drug reimbursement registers. The associations between job strain and inflammatory bowel disease outcomes were modelled using Cox proportional hazards regression. The study-specific results were combined in random effects meta-analyses.

Results

Of the 95 379 participants who were free of inflammatory bowel disease at baseline, 111 men and women developed Crohn's disease and 414 developed ulcerative colitis during follow-up. Job strain at baseline was not associated with incident Crohn's disease (multivariable-adjusted random effects hazard ratio: 0.83, 95% confidence interval: 0.48, 1.43) or ulcerative colitis (hazard ratio: 1.06, 95% CI: 0.76, 1.48). There was negligible heterogeneity among the study-specific associations.

Conclusions

Our findings suggest that job strain, an indicator of work-related stress, is not a major risk factor for Crohn's disease or ulcerative colitis.

Candidate genes involved in beneficial or adverse responses to commonly eaten brassica vegetables in a New Zealand Crohn's disease cohort

Crohn’s disease (CD) is one of the two manifestations of inflammatory bowel disease. Particular foods are thought with CD to exacerbate their illness. Vegetables, especially Brassicaceae, are often shunned by people with CD because of the negative effects they are alleged to have on their symptoms. Brassicaceae supply key nutrients which are necessary to meet recommended daily intakes. We sought to identify the candidate genes involved in the beneficial or adverse effects of Brassicaceae most commonly eaten, as reported by the New Zealand adults from the “Genes and Diet in Inflammatory Bowel disease Study” based in Auckland. An analysis of associations between the single nucleotide polymorphisms (SNPs) and the beneficial or adverse effects of the ten most commonly eaten Brassicaceae was carried out. A total of 37 SNPs were significantly associated with beneficial effects (p = 0.00097 to 0.0497) and 64 SNPs were identified with adverse effects (p = 0.0000751 to 0.049). After correcting for multiple testing, rs7515322 (DIO1) and rs9469220 (HLA) remained significant. Our findings show that the tolerance of some varieties of Brassicaceae may be shown by analysis of a person’s genotype.

The winding road to understanding the neonatal origins of inflammatory gastrointestinal disorders

Beginning with the observation that birth weight correlates with increased risk of cardiovascular disease, the concept of neonatal programming, that the environmental influence on fetal and neonatal development results in modification of the risk profile for adult disease, has begun to emerge as an important component to understanding the origin of chronic diseases of many different organ systems. Until recently, the gastrointestinal system has not been considered. Our understanding of the pathogenesis of many intestinal inflammatory disorders is still incomplete; however, a brief review of what is known reveals several opportunities for the early intraluminal environment to affect the development of the intestinal immune system. Early clinical observations such as the increased risk of celiac disease observed in those born by cesarean section and the protective effect of breast-feeding against inflammatory bowel disease and celiac disease support the role of neonatal programming in the development of chronic inflammatory gastrointestinal disease. Additional, more robust clinical studies are needed to confirm this role. Furthermore, examination of the possible mechanisms of immune phenotype modification is necessary.

The role of Vitamin D level and related single nucleotide polymorphisms in Crohn's disease

New Zealand has one of the highest rates of Crohn's Disease (CD) in the world, and there is much speculation as to why this might be. A high risk of CD has been associated with deficient or insufficient levels of Vitamin D (Vit D), lifestyle as well as various genetic polymorphisms. In this study we sought to analyse the relevance of serum Vit D levels, lifestyle and genotype to CD status. Serum samples were analysed for 25-OH-Vitamin D levels. DNA was isolated from blood and cheek-swabs, and Sequenom and ImmunoChip techniques were used for genotyping. Serum Vit D levels were significantly lower in CD patients (mean = 49.5 mg/L) than those found in controls (mean = 58.9 mg/L, p = 4.74 × 10⁻⁶). A total of seven single nucleotide polymorphisms were examined for effects on serum Vit D levels, with adjustment for confounding variables. Two variants: rs731236[A] (VDR) and rs732594[A] (SCUBE3) showed a significant association with serum Vit D levels in CD patients. Four variants: rs7975232[A] (VDR), rs732594[A] (SCUBE3), and rs2980[T] and rs2981[A] (PHF-11) showed a significant association with serum Vit D levels in the control group. This study demonstrates a significant interaction between Vit D levels and CD susceptibility, as well as a significant association between Vit D levels and genotype.

The interplay between fiber and the intestinal microbiome in the inflammatory response

Fiber intake is critical for optimal health. This review covers the anti-inflammatory roles of fibers using results from human epidemiological observations, clinical trials, and animal studies. Fiber has body weight-related anti-inflammatory activity. With its lower energy density, a diet high in fiber has been linked to lower body weight, alleviating obesity-induced chronic inflammation evidenced by reduced amounts of inflammatory markers in human and animal studies. Body weight-unrelated anti-inflammatory activity of fiber has also been extensively studied in animal models in which the type and amount of fiber intake can be closely monitored. Fermentable fructose-, glucose-, and galactose-based fibers as well as mixed fibers have shown systemic and local intestinal anti-inflammatory activities when plasma inflammatory markers and tissue inflammation were examined. Similar anti-inflammatory activities have also been demonstrated in some human studies that controlled total fiber intake. The anti-inflammatory activities of synbiotics (probiotics plus fiber) were reviewed as well, but there was no convincing evidence indicating higher efficacy of synbiotics compared with that of fiber alone. Adverse effects have not been observed with the amount of fiber intake or supplementation used in studies, although patients with Crohn's disease may be more sensitive to inulin intake. Several possible mechanisms that may mediate the body weight-unrelated anti-inflammatory activity of fibers are discussed based on the in vitro and in vivo evidence. Fermentable fibers are known to affect the intestinal microbiome. The immunomodulatory role of the intestinal microbiome and/or microbial metabolites could contribute to the systemic and local anti-inflammatory activities of fibers.

Antibiotic exposure and IBD development among children: a population-based cohort study

OBJECTIVE

To determine whether childhood antianaerobic antibiotic exposure is associated with the development of inflammatory bowel disease (IBD).

METHODS

This retrospective cohort study employed data from 464 UK ambulatory practices participating in The Health Improvement Network. All children with ≥ 2 years of follow-up from 1994 to 2009 were followed between practice enrollment and IBD development, practice deregistration, 19 years of age, or death; those with previous IBD were excluded. All antibiotic prescriptions were captured. Antianaerobic antibiotic agents were defined as penicillin, amoxicillin, ampicillin, penicillin/β-lactamase inhibitor combinations, tetracyclines, clindamycin, metronidazole, cefoxitin, carbapenems, and oral vancomycin.

RESULTS

A total of 1072426 subjects contributed 6.6 million person-years of follow-up; 748 developed IBD. IBD incidence rates among antianaerobic antibiotic unexposed and exposed subjects were 0.83 and 1.52/10000 person-years, respectively, for an 84% relative risk increase. Exposure throughout childhood was associated with developing IBD, but this relationship decreased with increasing age at exposure. Exposure before 1 year of age had an adjusted hazard ratio of 5.51 (95% confidence interval [CI]: 1.66-18.28) but decreased to 2.62 (95% CI: 1.61-4.25) and 1.57 (95% CI: 1.35-1.84) by 5 and 15 years, respectively. Each antibiotic course increased the IBD hazard by 6% (4%-8%). A dose-response effect existed, with receipt of >2 antibiotic courses more highly associated with IBD development than receipt of 1 to 2 courses, with adjusted hazard ratios of 4.77 (95% CI: 2.13-10.68) versus 3.33 (95% CI: 1.69-6.58).

CONCLUSIONS

Childhood antianaerobic antibiotic exposure is associated with IBD development.

Role of nutrition and microbiota in susceptibility to inflammatory bowel diseases

Inflammatory bowel diseases (IBDs), Crohn's disease (CD), and ulcerative colitis (UC) are chronic inflammatory conditions, which are increasing in incidence, prevalence, and severity, in many countries. While there is genetic susceptibility to IBD, the probability of disease development is modified by diet, lifestyle, and endogenous factors, including the gut microbiota. For example, high intakes of mono- and disaccharides, and total fats consistently increases the risk developing both forms of IBD. High vegetable intake reduces the risk of UC, whereas increased fruit and/or dietary fiber intake appears protective against CD. Low levels of certain micronutrients, especially vitamin D, may increase the risk of both diseases. Dietary patterns may be even more important to disease susceptibility than the levels of individual foods or nutrients. Various dietary regimes may modify disease symptoms, in part through their actions on the host microbiota. Both probiotics and prebiotics may modulate the microflora, and reduce the likelihood of IBD regression. However, other dietary factors affect the microbiota in different ways. Distinguishing cause from effect, and characterizing the relative roles of human and microbial genes, diet, age of onset, gender, life style, smoking history, ethnic background, environmental exposures, and medications, will require innovative and internationally integrated approaches.