Common Genetic Variants Influence Circulating Vitamin D Levels in Inflammatory Bowel Diseases

Associations of dietary patterns with risk of gastrointestinal disorders: a prospective cohort study

Gastrointestinal (GI) disorders are highly prevalent and severely diminish life quality. It is yet unknown which dietary pattern is optimal for the prevention of GI disorders. Among 141 450 participants from UK Biobank with a median follow-up of 15 years, we comprehensively assessed 13 dietary patterns in relation to 6 GI disorders. Multivariable Cox proportional hazards models demonstrated that adherence to healthy diets was associated with lower risk of GI disorders, with the strongest associations observed for the Dietary Approaches to Stop Hypertension (DASH) diet (HRQ4 vs. Q1 = 0.85, 95% CI: 0.81, 0.88), the Alternate Mediterranean Diet (AMED) (HRQ4 vs. Q1 = 0.85, 95% CI: 0.81, 0.88), and the Alternate Healthy Eating Index-2010 (AHEI-2010) (HRQ4 vs. Q1 = 0.86, 95% CI: 0.82, 0.89). AHEI-2010 (HRs ranging from 0.76 to 0.90) and DASH (HRs ranging from 0.75 to 0.88) showed inverse associations with every individual GI disorder. Furthermore, comorbidities decreased significantly in number with higher AMED and DASH diet scores (P for trend <0.001). Finally, the associations of AHEI-2010, AMED and DASH with GI disorders diminished most intensely after removing the component of fruits or whole grains. The combined intake of fruits and whole grains was inversely associated with the risk of overall GI disorders (HRT3 vs. T1 = 0.89, 95% CI: 0.86, 0.93). In conclusion, AHEI-2010 and DASH were the most recommended dietary patterns for the prevention of GI disorders. Fruits and whole grains are the most significant contributors to the protective effect.

Genotype Prevalence of Lactose Deficiency, Vitamin D Deficiency, and the Vitamin D Receptor in a Chilean Inflammatory Bowel Disease Cohort: Insights from an Observational Study

Lactose intolerance (LI) and vitamin D deficiency (VDD) have been linked to inflammatory bowel disease (IBD). We conducted an observational study in 192 Chilean IBD patients to investigate the prevalence of a specific gene variant (LCT-13910 CC genotype) associated with LI and the prevalence of VDD/Vitamin D Receptor (VDR) gene variants. Blood samples were analyzed using Illumina's Infinium Global Screening Array. The LCT-13910 CC genotype was found in 61% of IBD patients, similar to Chilean Hispanic controls and lower than Chilean Amerindian controls. The frequency of the LCT-13910-C allele in Chilean IBD patients (0.79) was comparable to the general population and higher than Europeans (0.49). Regarding VDR and VDD variants, in our study, the rs12785878-GG variant was associated with an increased risk of IBD (OR = 2.64, CI = 1.61-4.32; p-value = 0.001). Sixty-one percent of the Chilean IBD cohort have a genetic predisposition to lactose malabsorption, and a significant proportion exhibit genetic variants associated with VDD/VDR. Screening for LI and VDD is crucial in this Latin American IBD population.

Association between Serum Vitamin D and Irritable Bowel Syndrome Symptoms in a Sample of Adults

Vitamin D may be associated with irritable bowel syndrome (IBS) pathways. This cross-sectional study evaluated the associations between serum Vitamin D and IBS symptoms in a sample of Lebanese adults. Participants (n = 230; mean (SD) age: 43.36 (16.05) years, 62.9% females) were adults, free of diseases affecting Vitamin D metabolism, and recruited from a large university and the surrounding community. Serum Vitamin D (25-hydroxyvitamin D) was assessed using an automated chemiluminescence micro-particle immunoassay kit. The Birmingham IBS Symptom Questionnaire total scale, and pain, constipation, and diarrhea subscales were used to study IBS symptoms. Four linear regression analyses were performed, taking respectively the total scale and each of the subscales as the dependent variable. Vitamin D was forced into each model. Covariates included sociodemographic and medical variables, fluid intake, physical activity, sleep quality, stress, and adherence to the Mediterranean diet. Mean (SD) serum Vitamin D was 17.53 (12.40) ng/mL and mean (SD) Birmingham IBS Symptom Questionnaire was 16.98 (15.16) (pain: 20.75 (23.63), constipation: 25.06 (29.99), diarrhea: 9.88 (13.37)). Serum Vitamin D was not associated with the total score, nor with any of the subscales (p > 0.05 for the four regression analyses). Serum Vitamin D was not associated with IBS symptoms in a sample of Lebanese adults, adding to the controversy in this field. Further understanding of the pathophysiological mechanisms involved in Vitamin D and IBS is warranted.

Pleiotropic Effects of Vitamin D in Patients with Inflammatory Bowel Diseases

The multifaceted activity of vitamin D in patients with inflammatory bowel disease (IBD) presents a challenge for further research in this area. Vitamin D is involved in the regulation of bone mineral metabolism, it participates in the regulation of the immune system, and it is an underlying factor in the pathogenesis of IBD. Additionally, vitamin D affects Th1 and Th2 lymphocytes, influencing the release of cytokines and inhibiting tumor necrosis factor (TNF) expression and the wnt/β-catenin pathway. As far as IBDs are concerned, they are associated with microbiota dysbiosis, abnormal inflammatory response, and micronutrient deficiency, including vitamin D hypovitaminosis. In turn, the biological activity of active vitamin D is regulated by the vitamin D receptor (VDR) which is associated with several processes related to IBD. Therefore, in terms of research on vitamin D supplementation in IBD patients, it is essential to understand the metabolic pathways and genetic determinants of vitamin D, as well as to identify the environmental factors they are subject to, not only in view of osteoporosis prevention and therapy, but primarily concerning modulating the course and supplementation of IBD pharmacotherapy.

Diets for inflammatory bowel disease: What do we know so far?

In recent years, the role of diet in the pathogenesis of inflammatory bowel disease (IBD) has gained great interest within the scientific community. Eating habits from industrialised countries (the so-called western diet or WD) have been associated with a higher incidence of IBD in observational studies, although the dietary factors responsible for the development of the disease are still to be elucidated. Some components of the diet with proinflammatory potential may cause changes in immunity and intestinal microbiota, leading to the inflammatory reaction that causes IBD-related lesions. The quality of available evidence is low, due to methodological issues, such as the lack of intervention studies, small sample size and heterogeneity of studies. For this reason, scientific societies have offered their recommendations using clinical practice guidelines and consensus documents, in order to establish a common criterion in the nutritional treatment of patients with IBD. The objective of this review was to summarise the data published regarding diet in IBD and review the recommendations given by scientific societies.

Bone loss in patients with inflammatory bowel disease: cause, detection and treatment

PURPOSE OF REVIEW

Inflammatory bowel disease (IBD) is associated with bone loss leading to osteoporosis and increased fracture risk. Bone loss is the result of changes in the balanced process of bone remodeling. Immune cells and cytokines play an important role in the process of bone remodeling and it is therefore not surprising that cytokines as observed in IBD are involved in bone pathology. This review discusses the role of cytokines in IBD-associated bone loss, including the consequences for treatment.

RECENT FINDINGS

Many studies have been conducted that showed the effect of a single cytokine on bone cells in vitro, including interleukin (IL)-1β, IL-6, IL-8, IL-12/IL-23, IL-17, IL-18, IL-32 and interferon-γ. Recently new members of the IL-1 family (IL-1F) have been related to IBD but the consequences for bone health remain uncertain.

SUMMARY

Overall, patients have to deal with a cocktail of cytokines, present in their serum. The combination of cytokines can affect bone cells differently compared to the effects of a single cytokine. This implicates that treatment, focused on reducing the inflammation could work best for bone health as well. Vitamin D might also play a role in this.

Clinical evaluation of vitamin D status and its relationship with disease activity and changes of intestinal immune function in patients with Crohn's disease in the Chinese population

BACKGROUND

High prevalence of vitamin D deficiency has been found among Crohn's disease (CD) patients. Vitamin D probably participates in the pathogenesis of CD, but this idea remains controversial. This study was to investigate the levels of vitamin D in CD patients and analyze the relationship between vitamin D and intestinal inflammation.

METHODS

Vitamin D levels were measured by chemiluminescence immunoassay in 198 CD patients (96 in active, 102 in remission) and 100 healthy controls. The correlation between vitamin D levels and clinical parameters was analysed. The expression of intestinal tight junction (TJ) proteins in CD patients was measured by immunofluorescence staining. Treg and Th17 percentages in the peripheral blood were determined by flow cytometry.

RESULTS

CD patients exhibited significantly lower 25(OH)D levels than healthy controls, especially in active CD patients. Serum 25(OH)D levels in CD patients were negatively correlated with the CD activity index (CDAI), the simple endoscopic score for CD (SES-CD), and inflammatory markers, including erythrocyte sedimentation rate (ESR), platelet (PLT) count and faecal calprotectin (FC) levels. Moreover, in patients with vitamin D deficiency, the expression of TJ proteins (Occludin, claudin-1, ZO-1 and JAM-1) in the intestinal mucosa was reduced, and Treg cells in the peripheral blood were decreased, while Th17 cells were increased compared to those with vitamin D sufficiency and controls.

CONCLUSIONS

Vitamin D deficiency in CD patients is common. Vitamin D is associated with disease activity and intestinal inflammation, which may affect the Treg/Th17 balance and the expression of gut TJ proteins.

[Inflammatory Bowel Disease and Vitamin D]

Vitamin D contributes to bone metabolism and acts as an immune modulator for both innate and adaptive immunity. The serum level of vitamin D has been associated with inflammatory diseases, such as inflammatory bowel disease (IBD). In epidemiologic studies, IBD patients have been shown to have low levels of vitamin D. The suboptimal circulating levels of vitamin D in IBD patients may be caused by low exposure to sunlight, dietary malabsorption, and the impaired conversion of active metabolites (1,25[OH]₂D). Recent studies have demonstrated that vitamin D deficiency in IBD can increase the chance of disease recurrence, IBD-related hospitalization or surgery, and deterioration of quality of life. Supplementation with vitamin D is therefore thought to reduce the risk of flare-ups and the improvement of the quality of life in IBD patients. This review aims to summarize the latest knowledge on the effects of vitamin D deficiency on IBD and the possible benefits of vitamin D supplementation in IBD patients.

Use of Narrative Concepts in Electronic Health Records to Validate Associations Between Genetic Factors and Response to Treatment of Inflammatory Bowel Diseases

Crohn's disease (CD) and ulcerative colitis (UC) are heterogeneous. With availability of therapeutic classes with distinct immunologic mechanisms of action, it has become imperative to identify markers that predict likelihood of response to each drug class. However, robust development of such tools has been challenging because of need for large prospective cohorts with systematic and careful assessment of treatment response using validated indices. Most hospitals in the United States use electronic health records (EHRs) that warehouse a large amount of narrative (free-text) and codified (administrative) data generated during routine clinical care. These data have been used to construct virtual disease cohorts for epidemiologic research as well as for defining genetic basis of disease states or discrete laboratory values.^1-3 Whether EHR-based data can be used to validate genetic associations for more nuanced outcomes such as treatment response has not been examined previously.

A posteriori dietary patterns and risk of inflammatory bowel disease: a meta-analysis of observational studies

Abstract. Inflammatory bowel disease (IBD) is a chronic inflammatory disorder which affects the gastrointestinal tract. Many factors, such as genetics, stress, and dietary patterns have been related to the risk of this disease. Adherence to a prudent/healthy dietary pattern, due to its antioxidant and anti-inflammatory properties, help to reduce the risk of many chronic diseases such as IBD. The results from previous studies regarding the association between dietary patterns and risk of IBD, including Crohn’s disease (CD) and ulcerative colitis (UC), are inconsistent. This meta-analysis was performed to evaluate the potential relations between dietary patterns and risk of CD and UC. PubMed and Scopus were searched up to October 2017 for eligible studies. Random-effects or fixed-effects models were used to pool the estimated risks for the highest versus the lowest category of extracted dietary patterns. A total of six studies, including four case-control and two cohort studies with 1099 cases and 263112 controls/participants were included in the meta-analysis. A decreased risk of CD was seen for the highest compared with the lowest categories of healthy dietary pattern (OR/RR = 0.39, 95%CI = 0.16–0.62), while no significant association with western dietary pattern was observed (OR/RR = 0.78, 95% CI: 0.51–1.04). Furthermore, no significant relationship was found between healthy (OR/RR = 0.61, 95%CI = 0.04–1.18, random effects) and western/unhealthy (OR/RR = 0.97, 95% CI: 0.67–1.26) dietary patterns and risk of UC. The results of the current meta-analysis showed that a healthy dietary pattern is associated with a lower risk of CD. Further studies are warranted to confirm these findings.

Incorporating natural language processing to improve classification of axial spondyloarthritis using electronic health records

OBJECTIVES

To develop classification algorithms that accurately identify axial SpA (axSpA) patients in electronic health records, and compare the performance of algorithms incorporating free-text data against approaches using only International Classification of Diseases (ICD) codes.

METHODS

An enriched cohort of 7853 eligible patients was created from electronic health records of two large hospitals using automated searches (⩾1 ICD codes combined with simple text searches). Key disease concepts from free-text data were extracted using NLP and combined with ICD codes to develop algorithms. We created both supervised regression-based algorithms-on a training set of 127 axSpA cases and 423 non-cases-and unsupervised algorithms to identify patients with high probability of having axSpA from the enriched cohort. Their performance was compared against classifications using ICD codes only.

RESULTS

NLP extracted four disease concepts of high predictive value: ankylosing spondylitis, sacroiliitis, HLA-B27 and spondylitis. The unsupervised algorithm, incorporating both the NLP concept and ICD code for AS, identified the greatest number of patients. By setting the probability threshold to attain 80% positive predictive value, it identified 1509 axSpA patients (mean age 53 years, 71% male). Sensitivity was 0.78, specificity 0.94 and area under the curve 0.93. The two supervised algorithms performed similarly but identified fewer patients. All three outperformed traditional approaches using ICD codes alone (area under the curve 0.80-0.87).

CONCLUSION

Algorithms incorporating free-text data can accurately identify axSpA patients in electronic health records. Large cohorts identified using these novel methods offer exciting opportunities for future clinical research.

Role of Diet in the Development and Management of Crohn's Disease

PURPOSE OF REVIEW

This article provides an updated review on the role of diet in the risk of developing Crohn's disease (CD) and CD management, areas of ongoing study.

RECENT FINDINGS

Higher intake of dietary fiber (fruit fiber) has been associated with a reduced risk for CD. The exclusive enteral nutrition (EEN) diet remains the most validated nutritional recommendation for inducing remission in CD. The specific carbohydrate diet (SCD) has demonstrated reductions in CD severity scores in conjunction with medical therapies, and larger trials on its efficacy are ongoing. Several new exclusion diets modeled after EEN and SCD have shown potential efficacy in smaller studies that warrant replication. There is a paucity of clear dietary recommendations for the reduction in risk of CD clinical relapse. There are various components of diet that likely impact risk for CD development and contribute to its disease course; however, studies are often limited in their size or ability to demonstrate mechanistic causation. Further studies including diets that aim to expand on the restrictive nature of EEN may lead to stronger evidence for a diet-based approach to CD management.

Nutritional interventions for the treatment of IBD: current evidence and controversies

Environmental factors, particularly diet, are the focus of current research as potential triggers of inflammatory bowel disease (IBD). Epidemiological cohort data showing a rapid increase of IBD in western countries and the emergence of IBD in developing countries paralleling the introduction of a western diet are indirect arguments linking food and food behaviour to intestinal inflammation. The successful use of exclusive enteral nutrition (EEN), now considered as first-line induction therapy for paediatric Crohn's disease (CD), is the strongest argument for a link between diet and IBD. Mechanistic studies revealed that EEN impacts intestinal microbiota composition and together with the exclusion of potentially harmful food ingredients this allows the control of intestinal inflammation and induces mucosal healing. However, the exclusivity character of EEN is a major drawback. Based on the data of EEN, the search for more tolerable and still effective diets has begun. Recent reports on the new CD exclusion diet (CDED), CD-TREAT, as well as the specific carbohydrate diet (SCD) provide the first promising results, further underlining the potential of diet to control inflammation in patients with CD by excluding certain food components. Ongoing research is trying to combine nutritional interventions with analyses of intestinal microbiota and their metabolic functions with the aim of correcting the intestinal dysbiosis that characterizes IBD. This research is promising and gives new hope to patients that have been looking for decades for nutritional interventions with the aim of stabilizing their disease course. There might even be potential for disease prevention in high-risk patients by excluding potentially harmful food components.

High-throughput phenotyping with electronic medical record data using a common semi-supervised approach (PheCAP)

Phenotypes are the foundation for clinical and genetic studies of disease risk and outcomes. The growth of biobanks linked to electronic medical record (EMR) data has both facilitated and increased the demand for efficient, accurate, and robust approaches for phenotyping millions of patients. Challenges to phenotyping with EMR data include variation in the accuracy of codes, as well as the high level of manual input required to identify features for the algorithm and to obtain gold standard labels. To address these challenges, we developed PheCAP, a high-throughput semi-supervised phenotyping pipeline. PheCAP begins with data from the EMR, including structured data and information extracted from the narrative notes using natural language processing (NLP). The standardized steps integrate automated procedures, which reduce the level of manual input, and machine learning approaches for algorithm training. PheCAP itself can be executed in 1-2 d if all data are available; however, the timing is largely dependent on the chart review stage, which typically requires at least 2 weeks. The final products of PheCAP include a phenotype algorithm, the probability of the phenotype for all patients, and a phenotype classification (yes or no).

Diet as Adjunctive Treatment for Inflammatory Bowel Disease: Review and Update of the Latest Literature

PURPOSE OF REVIEW

Diet plays an integral role in development of inflammatory bowel disease (IBD) and continues to act as a mediator of intestinal inflammation once disease sets in. Most clinicians provide little dietary guidance to IBD patients, in part due to lack of knowledge in nutrition and lack of available nutritional resources. The purpose of this review is to provide clinicians with a brief summary of the latest evidence behind diets popular among IBD patients, to highlight diets with known efficacy, and to provide guidance that may help busy practitioners.

RECENT FINDINGS

The latest studies show that exclusive enteral nutrition (EEN) remains the most effective diet for induction of remission in Crohn's disease (CD), either in the form of elemental, semi-elemental, or polymeric formulas. Recent studies also show that EEN can be useful in complicated CD including in enterocutaneous fistulas closure and to optimize nutrition in the pre-operative setting. Although new studies suggest that partial enteral nutrition supplemented with elimination diets may be beneficial in ulcerative colitis (UC) and CD, larger controlled studies are needed to support their use. The autoimmune diet also shows promise but lacks larger studies. Recent uncontrolled clinical studies evaluating the specific carbohydrate diet (SCD) suggest that this diet may improve biochemical markers of inflammation and induce mucosal healing, although larger studies are needed to support its use, especially because the SCD is very restrictive. Short-term use of the low FODMAP diet is appropriate when in the setting of an acute flare up and/or in stricturing disease, but long-term restriction of FODMAPs is not recommended given long-term changes observed in the microbiome. Recent studies suggest that avoidance of processed foods, packaged with preservatives and emulsifiers, may be important in decreasing intestinal inflammation; many of the recent popular diets share a common concept, avoidance of processed foods. In this review of the latest literature, we highlight that dietary studies are still in a rudimentary stage. Large prospective randomized control studies are underway evaluating head to head comparisons on the efficacy of some of these diets. We offer general guiding principles that may help gastroenterologists in the meantime.

The Role of Vitamin D in Inflammatory Bowel Disease: Mechanism to Management

Vitamin D has been linked to human health benefits that extend far beyond its established actions on calcium homeostasis and bone metabolism. One of the most well studied facets of extra-skeletal vitamin D is its activity as an immuno-modulator, in particular its potent anti-inflammatory effects. As a consequence, vitamin D deficiency has been associated with inflammatory diseases including inflammatory bowel disease (IBD). Low serum levels of the major circulating form of vitamin D, 25-hydroxyvitamin D (25-OH-D) are significantly more prevalent in patients with IBD, particularly in the winter and spring months when UV-induced synthesis of vitamin D is lower. Dietary malabsorption of vitamin D may also contribute to low serum 25(OH)D in IBD. The benefits of supplementation with vitamin D for IBD patients are still unclear, and improved vitamin D status may help to prevent the onset of IBD as well as ameliorating disease severity. Beneficial effects of vitamin D in IBD are supported by pre-clinical studies, notably with mouse models, where the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25-(OH)2D) has been shown to regulate gastrointestinal microbiota function, and promote anti-inflammatory, tolerogenic immune responses. The current narrative review aims to summarise the different strands of data linking vitamin D and IBD, whilst also outlining the possible beneficial effects of vitamin D supplementation in managing IBD in humans.

The role of diet in the aetiopathogenesis of inflammatory bowel disease

Crohn's disease and ulcerative colitis, collectively known as IBD, are chronic inflammatory disorders of the gastrointestinal tract. Although the aetiopathogenesis of IBD is largely unknown, it is widely thought that diet has a crucial role in the development and progression of IBD. Indeed, epidemiological and genetic association studies have identified a number of promising dietary and genetic risk factors for IBD. These preliminary studies have led to major interest in investigating the complex interaction between diet, host genetics, the gut microbiota and immune function in the pathogenesis of IBD. In this Review, we discuss the recent epidemiological, gene-environment interaction, microbiome and animal studies that have explored the relationship between diet and the risk of IBD. In addition, we highlight the limitations of these prior studies, in part by explaining their contradictory findings, and review future directions.

Association of Polygenic Risk Scores for Multiple Cancers in a Phenome-wide Study: Results from The Michigan Genomics Initiative

Health systems are stewards of patient electronic health record (EHR) data with extraordinarily rich depth and breadth, reflecting thousands of diagnoses and exposures. Measures of genomic variation integrated with EHRs offer a potential strategy to accurately stratify patients for risk profiling and discover new relationships between diagnoses and genomes. The objective of this study was to evaluate whether polygenic risk scores (PRS) for common cancers are associated with multiple phenotypes in a phenome-wide association study (PheWAS) conducted in 28,260 unrelated, genotyped patients of recent European ancestry who consented to participate in the Michigan Genomics Initiative, a longitudinal biorepository effort within Michigan Medicine. PRS for 12 cancer traits were calculated using summary statistics from the NHGRI-EBI catalog. A total of 1,711 synthetic case-control studies was used for PheWAS analyses. There were 13,490 (47.7%) patients with at least one cancer diagnosis in this study sample. PRS exhibited strong association for several cancer traits they were designed for, including female breast cancer, prostate cancer, melanoma, basal cell carcinoma, squamous cell carcinoma, and thyroid cancer. Phenome-wide significant associations were observed between PRS and many non-cancer diagnoses. To differentiate PRS associations driven by the primary trait from associations arising through shared genetic risk profiles, the idea of "exclusion PRS PheWAS" was introduced. Further analysis of temporal order of the diagnoses improved our understanding of these secondary associations. This comprehensive PheWAS used PRS instead of a single variant.

A novel susceptibility locus in MST1 and gene-gene interaction network for Crohn's disease in the Chinese population

The incidence of Crohn's disease is increasing in many Asian countries, but considerable differences in genetic susceptibility have been reported between Western and Asian populations. This study aimed to fine-map 23 previously reported Crohn's disease genes and identify their interactions in the Chinese population by Illumina-based targeted capture sequencing. Our results showed that the genetic polymorphism A>G at rs144982232 in MST1 showed the most significant association (P = 1.78 × 10-5 ; odds ratio = 4.87). JAK2 rs1159782 (T>C) was also strongly associated with Crohn's disease (P = 2.34 × 10-4 ; odds ratio = 3.72). Gene-gene interaction analysis revealed significant interactions between MST1 and other susceptibility genes, including NOD2, MUC19 and ATG16L1 in contributing to Crohn's disease risk. Main genetic associations and gene-gene interactions were verified using ImmunoChip data set. In conclusion, a novel susceptibility locus in MST1 was identified. Our analysis suggests that MST1 might interact with key susceptibility genes involved in autophagy and bacterial recognition. These findings provide insight into the genetic architecture of Crohn's disease in Chinese and may partially explain the disparity of genetic signals in Crohn's disease susceptibility across different ethnic populations by highlighting the contribution of gene-gene interactions.

Differences in Clinical Course, Genetics, and the Microbiome Between Familial and Sporadic Inflammatory Bowel Diseases

BACKGROUND AND AIM

Family history is the strongest risk factor for developing Crohn's disease [CD] or ulcerative colitis [UC]. We investigated whether the proximity of relationship with the affected relative and concordance for type of inflammatory bowel disease [IBD] modifies the effect of family history on phenotype and disease severity.

METHOD

This cross-sectional study included patients with a confirmed diagnosis of IBD in a clinical registry. Family history of IBD was assessed by a questionnaire ascertaining presence of disease in a first-first-degree, second-second-degree or distant relative. Our primary outcomes were disease phenotype as per the Montreal classification and severity measured by need for immunomodulator, biologic, or surgical therapy. Genotyping was performed on the Immunochip and faecal samples were subjected to 16S rRNA microbiome sequencing.

RESULTS

Our study included 2136 patients with IBD [1197 CD, 939 UC]. Just under one-third [32%] of cases ere familial IBD [17% first-degree, 21% second-degree]. Familial IBD was diagnosed at an earlier age, both in CD [26 vs 28 years, p = 0.0006] and UC [29 vs 32 years, p = 0.01]. Among CD patients, a positive family history for CD was associated with an increased risk for complicated disease in the presence of an affected family member (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.07-2.03). However, this effect was significant only for first-degree relatives [OR 1.82, 95% CI 1.19-2.78].

CONCLUSIONS

A family history of CD in first-degree relatives was associated with complicated CD. Family history discordant for type of IBD or in distant relatives did not influence disease phenotype or natural history.

Environmental triggers in IBD: a review of progress and evidence

A number of environmental factors have been associated with the development of IBD. Alteration of the gut microbiota, or dysbiosis, is closely linked to initiation or progression of IBD, but whether dysbiosis is a primary or secondary event is unclear. Nevertheless, early-life events such as birth, breastfeeding and exposure to antibiotics, as well as later childhood events, are considered potential risk factors for IBD. Air pollution, a consequence of the progressive contamination of the environment by countless compounds, is another factor associated with IBD, as particulate matter or other components can alter the host's mucosal defences and trigger immune responses. Hypoxia associated with high altitude is also a factor under investigation as a potential new trigger of IBD flares. A key issue is how to translate environmental factors into mechanisms of IBD, and systems biology is increasingly recognized as a strategic tool to unravel the molecular alterations leading to IBD. Environmental factors add a substantial level of complexity to the understanding of IBD pathogenesis but also promote the fundamental notion that complex diseases such as IBD require complex therapies that go well beyond the current single-agent treatment approach. This Review describes the current conceptualization, evidence, progress and direction surrounding the association of environmental factors with IBD.

Large Registry Epidemiology in IBD

There are different types of large registries which can be harnessed for inflammatory bowel disease research. Not one registry can answer all types of research questions. It is important for both the researchers using the registries and readers of the reports generated, to be aware of the different strengths and weaknesses of each registry and whether the questions posed can reliably be answered. In this review, the use of large administrative databases/registries are discussed in the context of studying descriptive epidemiology, outcomes of inflammatory bowel disease, pharmacoepidemiology, and etiologic research.

Genetic risk factors for serious infections in inflammatory bowel diseases

INTRODUCTION

Immunosuppression, the cornerstone of management of Crohn's disease (CD) and ulcerative colitis (UC) (inflammatory bowel diseases; IBD) is associated with an increased risk of serious infections that is inadequately predicted by clinical risk factors. The role of genetics in determining susceptibility to infections is unknown.

METHODS

From a prospective-consented patient registry, we identified IBD patients with serious infections requiring hospitalization. Analysis was performed to identify IBD-related and non-IBD related immune response loci on the Immunochip that were associated with serious infections and a genetic risk score (GRS) representing the cumulative burden of the identified single nucleotide polymorphisms was calculated. Multivariable logistic regression used to identify effect of clinical and genetic factors.

RESULTS

The study included 1333 IBD patients (795 CD, 538 UC) with median disease duration of 13 years. A total of 133 patients (10%) had a serious infection requiring hospitalization. Patients with infections were more likely to have CD and had shorter disease duration. The most common infections were skin and soft-tissue, respiratory and urinary tract infections. Eight IBD risk loci and two other polymorphisms were significantly associations with serious infections. Each one point increase in the infection GRS was associated with a 50% increase in risk of infections (OR = 1.53, 95% CI = 1.37-1.70) (p = 1 × 10^-14), confirmed on multivariable analysis. Genetic risk factors improved performance of a model predicting infections over clinical covariates alone (p < 0.001).

CONCLUSIONS

Genetic risk factors may predict susceptibility to infections in patients with IBD.

The Importance and Challenges of Dietary Intervention Trials for Inflammatory Bowel Disease

Inflammatory bowel disease is believed to be caused by a combination of genetic and environmental stimuli such as our diet. Diets high in meat and fats and low in fruits and vegetables have been associated with new-onset inflammatory bowel disease. This has triggered interest in using dietary modification as a treatment. The 3 principle models of dietary intervention are supplementation with selected dietary components, exclusion of selected dietary components, or use of dietary formulas in place of a normal diet. Despite the high level of interest in dietary interventions as a treatment for inflammatory bowel disease, few well-designed clinical trials have been conducted to firmly establish the optimal diet to induce or maintain remission. This may be in part related to the challenges of conducting dietary intervention trials. This review examines these challenges and potential approaches to be used in dietary intervention trials.

Vedolizumab Therapy Is Associated with an Improvement in Sleep Quality and Mood in Inflammatory Bowel Diseases

INTRODUCTION

Poor sleep, depression, and anxiety are common in patients with inflammatory bowel diseases (IBD) and associated with increased risk of relapse and poor outcomes. The effectiveness of therapies in improving such psychosocial outcomes is unclear but is an important question to examine with increasing selectivity of therapeutic agents.

METHODS

This prospective cohort enrolled patients with moderate-to-severe CD or UC starting biologic therapy with vedolizumab or anti-tumor necrosis factor α agents (anti-TNF). Sleep quality, depression, and anxiety were measured using validated short-form NIH PROMIS questionnaires assessing sleep and mood quality over the past 7 days. Disease activity was assessed using validated indices. Improvement in sleep and mood scores from baseline was assessed, and regression models were used to identify determinants of sleep quality.

RESULTS

Our study included 160 patients with IBD (49 anti-TNF, 111 Vedolizumab) among whom half were women and the mean age was 40.2 years. In the combined cohort, we observed a statistically significant and meaningful decrease in mean scores from baseline (52.8) by week 6 (49.8, p = 0.002). Among vedolizumab users, sleep T-score improved from baseline (53.6) by week 6 (50.7) and persisted through week 54 (46.5, p = 0.009). Parallel reductions in depression and anxiety were also noted (p < 0.05 by week 6). We observed no difference in improvement in sleep, depression, and anxiety between vedolizumab and anti-TNF use at week 6.

CONCLUSIONS

Both vedolizumab and anti-TNF biologic therapies were associated with improvement in sleep and mood quality in IBD.

Inflammatory Bowel Disease: Influence and Implications in Reproduction

The incidence and prevalence of inflammatory bowel disease (IBD) continues to rise with time, signifying its emergence as a global disease. Clinical onset of IBD, comprising Crohn's disease and ulcerative colitis, typically occurs before or at peak reproductive age. Although active disease in female patients is associated with reduced fertility and adverse obstetric outcomes in pregnancy, the molecular mechanisms underlying this altered reproductive course, and its impact on IBD transmission to offspring, remain poorly understood. Clinical and experimental studies have now begun to elucidate the hormonal, environmental, and microbial factors that modulate immune-reproductive cross talk in IBD and define their impact on maternal health, fetal development, and heritability of disease risk. Evolving insight into maternal-fetal imprinting in IBD has important implications for patient counseling and disease management during pregnancy and may help predict clinical outcomes for both mother and child.

Systematic review and meta-analysis of lactose digestion, its impact on intolerance and nutritional effects of dairy food restriction in inflammatory bowel diseases

BACKGROUND

Relationships between inflammatory bowel disease and lactose containing foods remain controversial and poorly defined regarding symptoms, nutritional outcomes, and epidemiologic associations for lactose maldigestion.

METHODS

A literature review was performed using Pub Med, Cochrane library and individual references, to extract data on lactose maldigestion prevalence in inflammatory bowel diseases. A meta-analysis was done using selected articles, to determine odds ratios of maldigestion. Information was collected about symptoms, impact on pattern of dairy food consumption, as well as the effects of dairy foods on the course of inflammatory bowel diseases.

RESULTS

A total of 1022 articles were evaluated, 35 articles were retained and 5 studies were added from review articles. Of these 17 were included in meta-analysis which showed overall increased lactose maldigestion in both diseases. However increased risk on sub analysis was only found in Crohn's in patients with small bowel involvement. Nine additional studies were reviewed for symptoms, with variable outcomes due to confounding between lactose intolerance and lactose maldigestion. Fourteen studies were evaluated for dairy food effects. There was a suggestion that dairy foods may protect against inflammatory bowel disease. Nutritional consequences of dairy restrictions might impact adversely on bone and colonic complications.

CONCLUSIONS

Lactose maldigestion in inflammatory bowel disease is dependent on ethnic makeup of the population and usually not disease. No bias of increased disease prevalence was noted between lactase genotypes. Intolerance symptoms depend on several parameters besides lactose maldigestion. Dairy foods may decrease risks of inflammatory bowel disease. Dairy restrictions may adversely affect disease outcome.

Patient Electronic Health Records as a Means to Approach Genetic Research in Gastroenterology

Electronic health records (EHRs) are being increasingly utilized and form a unique source of extensive data gathered during routine clinical care. Through use of codified and free text concepts identified using clinical informatics tools, disease labels can be assigned with a high degree of accuracy. Analysis linking such EHR-assigned disease labels to a biospecimen repository has demonstrated that genetic associations identified in prospective cohorts can be replicated with adequate statistical power and novel phenotypic associations identified. In addition, genetic discovery research can be performed utilizing clinical, laboratory, and procedure data obtained during care. Challenges with such research include the need to tackle variability in quality and quantity of EHR data and importance of maintaining patient privacy and data security. With appropriate safeguards, this novel and emerging field of research offers considerable promise and potential to further scientific research in gastroenterology efficiently, cost-effectively, and with engagement of patients and communities.