Zinc intake and risk of Crohn’s disease and ulcerative colitis: a prospective cohort study

Allergic and Immunologic Perspectives of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated inflammatory condition primarily involving the gastrointestinal tract. It includes Crohn's disease (CD), ulcerative colitis (UC), and a less common phenotype-indeterminate colitis. It is thought to result from a complex interplay of environmental, microbial, and host factors including genetic factors, although the exact mechanism is not known. Dietary factors have been shown to play a role in the pathogenesis of IBD and can potentially alter the intestinal microbiota as well as disrupt the immune function in the gut. CD is characterized by transmural inflammation, sometimes associated with granulomatous lesions, and involves the entire gastrointestinal tract but often spares the rectum. UC is characterized by mucosal inflammation typically confined to the colon and rectum. Although IBD is mostly seen in western world, recent data suggests that the incidence and prevalence are increasing worldwide. Enteral nutrition has been shown to be effective in inducing remission in pediatric population with CD; however, there is mixed data in adult population. Nutritional deficiencies such as vitamin D and zinc deficiency are often noted in IBD patients. Several extraintestinal manifestations are noted in patients with IBD. Some of them parallel with the disease activity and others are independent of the disease course. Assessment of IBD disease activity clinically, radiologically, if indicated, biochemically and endoscopically is important to guide therapy in IBD. To ensure comprehensive care, it is important to assess associated conditions such as nutritional and psychological well-being, as well as age appropriate health maintenance status prior to starting treatment for IBD. Several biologic agents including anti-tumor necrosis factor alpha (anti-TNF-α) drugs, anti-integrins, and antibodies to the p40 subunit of IL12/23 are approved for induction and maintenance of remission of IBD. Steroids are also often used for induction. Anti-metabolites and thiopurines are also useful either as monotherapy or in combination regimens. Potential side effects of anti-TNF-α drugs such as serious infections, malignancy, worsening of heart failure, and infusion-related reactions should be considered prior to starting these drugs. Anti-TNF-α drugs with or without immunomodulators (azathioprine, 6-mercaptopurine, methotrexate) are often used for the induction and maintenance of remission. Treating to target of endoscopic and clinical remission provides the best long-term outcomes. Our knowledge and understanding of IBD has grown significantly. However, there are several unanswered questions on pathogenesis, disease behavior, and drivers of inflammation in various patient subgroups which require further research.

The Copper/Zinc Ratio Correlates With Markers of Disease Activity in Patients With Inflammatory Bowel Disease

BACKGROUND

Zinc (Zn) and copper (Cu) are trace elements that serve as cofactors in catalytic processes with impact on immune responses. In patients with inflammatory bowel disease (IBD), decreased levels of serum Zn and Cu have been observed. Here, we investigated the effect of inflammation on serum concentrations of these trace elements in patients with IBD.

METHODS

In this cross-sectional study, 98 patients with Crohn disease (CD) and 56 with ulcerative colitis (UC) were prospectively enrolled. Disease activity parameters, such as C-reactive protein (CRP) and fecal calprotectin (FC) were compared to serum Zn, Cu, and Cu/Zn ratio.

RESULTS

Zinc insufficiency was observed in 11.2% of patients with CD and 14.3% with UC, Cu insufficiency in 20.4% with CD and 7.1% with UC. Anemia, hypoalbuminemia, increased FC, and elevated CRP were more frequently present in Zn-insufficient patients with IBD. In contrast, lower serum CRP values and a trend to lower FC were observed in Cu-insufficient patients. In multiple linear regression models adjusted for age, gender, and serum albumin, CRP positively correlated with serum Cu (P < 0.001) and the Cu/Zn ratio in both CD and UC (P < 0.001) but not with serum Zn concentrations. FC levels correlated only with the Cu/Zn ratio in patients with UC (P < 0.038).

CONCLUSION

Systemic inflammation inversely affected the serum Zn and Cu concentrations and, consequently, resulted in an increased Cu/Zn ratio.

"Diet in the Etiopathogenesis of IBD: Is There A Culinary Culprit?"

Research suggests that diet plays a role in the development of inflammatory bowel disease (IBD). Eating more fiber, omega-3 fatty acids, and limiting food additives may lower risk. More research is needed to better understand diet factors that may protect against IBD.

Impact of Diet on Risk of IBD

Diet is an important factor influencing the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC). Several recent prospective cohorts have suggested various dietary factors may play a role in modifying the risk of these diseases. These include an inverse association between dietary fiber, fruit or vegetable intake and risk of CD and n-3 polyunsaturated fatty acids and UC. In addition to macro-nutrients, dietary additives such as emulsifiers may also play a role.

Association between dietary iron and zinc intake and development of ulcerative colitis: A case-control study in Japan

BACKGROUND AND AIM

The prevalence of ulcerative colitis (UC) has been increasing in Japan. Trace elements, such as iron, zinc, magnesium, and copper, can cause digestive symptoms where there is a deficiency or excess. We focused on the dietary intake of trace elements and their associations with UC development.

METHODS

A multicenter, hospital-based case-control study was conducted in Japan. Cases were 127 newly diagnosed UC patients, and 171 age-matched and sex-matched hospital controls were recruited. We considered that UC patients had potentially changed their dietary habits due to disease symptoms. The dietary habits were investigated using a self-administered diet history questionnaire to analyze the dietary intakes and frequencies at two points, the previous 1 month and 1 year before.

RESULTS

In the assessment of dietary habits 1 year before, the highest intake of iron showed an increased odds ratio (OR) for UC on multivariate analysis (OR = 4.05, 95% confidence interval, 1.46-11.2, P < 0.01). The highest intake of zinc 1 year before showed a decreased OR for UC (OR = 0.39, 95% confidence interval, 0.18-0.85, P = 0.01). Intakes of magnesium and copper had no significant association with UC. Because most UC cases had experienced the first symptom of UC within the previous 11 months, these intakes at 1 year before represented an association with pre-illness dietary habits.

CONCLUSION

A high intake of iron has some effect on the development of UC. In contrast, a high intake of zinc has a protective effect on the development of UC.

Micronutrient Absorption and Related Outcomes in People with Inflammatory Bowel Disease: A Review

Inflammatory Bowel Disease (IBD) is a chronic disorder associated with immune dysregulation and chronic inflammation of the digestive tract. While it is poorly understood, the role of nutrition and nutrient status in the etiology of IBD and its associated outcomes has led to increased research relating to micronutrient deficiency. This review offers an overview of recent literature related to micronutrient absorption and outcomes in adults with IBD. Although the absorption and IBD-related outcomes of some micronutrients (e.g., vitamin D and iron) are well understood, other micronutrients (e.g., vitamin A) require further research. Increased research and clinician knowledge of the relationship between micronutrients and IBD may manifest in improved nutrient screening, monitoring, treatment, and outcomes for people living with IBD.

Circulating essential metals and lung cancer: Risk assessment and potential molecular effects

OBJECTIVE

Essential metals play important roles in the carcinogenic process. However, seldom longitudinal investigations have evaluated their roles in lung cancer development. We aimed to investigate the associations between multiple essential metals and lung cancer incidence and to explore the potential mechanisms.

METHODS

A nested case-control study of 440 incident lung cancer cases and 1:3 frequency matched 1320 healthy controls from the Dongfeng-Tongji Cohort was conducted. The baseline plasma concentrations of 11 essential metals (cobalt, copper, iron, manganese, molybdenum, rubidium, selenium, strontium, stannum, vanadium, and zinc) were measured, and their associations with lung cancer incidence were estimated. Effect of positive metal (zinc) on 4-year telomere attrition was then evaluated among an occupational cohort of 724 workers. We also assessed the transcriptional regulation effects of plasma zinc on mRNA expression profiles, and the expressions of zinc-related genes were further compared in pair-wised lung tumor and normal tissues.

RESULTS

Elevated plasma level of zinc was associated with lower incident risk of lung cancer [OR (95% CI) = 0.89 (0.79, 0.99)] and decreased 4-year telomere attrition [β (95% CI) = -0.73 (-1.27, -0.19)]. These effects were pronounced among males. In particularly, zinc could regulate the expressions of 8 cancer-related genes, including SOD1, APE, TP53BP1, WDR33, LAPTM4B, TRIT1, HUWE1, and ZNF813, which were over-expressed in lung tumor tissues.

CONCLUSIONS

We propose that high plasma zinc could prevent incident lung cancer, probably by slowing down telomere attrition and regulating the expressions of cancer-related genes. These results provided a new insight into lung cancer prevention.

Metabolite-Sensing G Protein-Coupled Receptors Connect the Diet-Microbiota-Metabolites Axis to Inflammatory Bowel Disease

Increasing evidence has indicated that diet and metabolites, including bacteria- and host-derived metabolites, orchestrate host pathophysiology by regulating metabolism, immune system and inflammation. Indeed, autoimmune diseases such as inflammatory bowel disease (IBD) are associated with the modulation of host response to diets. One crucial mechanism by which the microbiota affects the host is signaling through G protein-coupled receptors (GPCRs) termed metabolite-sensing GPCRs. In the gut, both immune and nonimmune cells express GPCRs and their activation generally provide anti-inflammatory signals through regulation of both the immune system functions and the epithelial integrity. Members of GPCR family serve as a link between microbiota, immune system and intestinal epithelium by which all these components crucially participate to maintain the gut homeostasis. Conversely, impaired GPCR signaling is associated with IBD and other diseases, including hepatic steatosis, diabetes, cardiovascular disease, and asthma. In this review, we first outline the signaling, function, expression and the physiological role of several groups of metabolite-sensing GPCRs. We then discuss recent findings on their role in the regulation of the inflammation, their existing endogenous and synthetic ligands and innovative approaches to therapeutically target inflammatory bowel disease.

Impact of red meat, processed meat and fibre intake on risk of late-onset chronic inflammatory diseases: prospective cohort study on lifestyle factors using the Danish 'Diet, Cancer and Health' cohort (PROCID-DCH): protocol

INTRODUCTION

Chronic inflammatory diseases (CIDs) (Crohn's disease, ulcerative colitis, psoriasis, psoriatic arthritis, rheumatoid arthritis and multiple sclerosis) are diseases of the immune system that have some shared genetic and environmental predisposing factors, but still few studies have investigated the effects of lifestyle on disease risk of several CIDs. The primary aim of this prospective cohort study is to investigate the impact of fibre, red meat and processed meat on risk of late-onset CID, with the perspective that results of this study can contribute in supporting future diet recommendations for effective personalised prevention.

METHODS AND ANALYSIS

The study will use data from 57 053 persons from the prospective Danish cohort study 'Diet, Cancer and Health' together with National Health Registry data. The follow-up period is from December 1993 to December 2018. Questionnaire data on diet and lifestyle were collected at entry to the Diet, Cancer and Health study. The outcome CID is defined as having a diagnosis of one of the CIDs registered in the National Patient Registry or, for multiple sclerosis, in the Danish Multiple Sclerosis Registry during follow-up and being treated with a drug used for the specific disease. The major outcome of the analyses will be to detect variability in risk of late onset of any CID and, if power allows, disease risk of late onset of each CID diagnosis between persons with different fibre and red meat, and processed meat intake. The outcome will be adjusted for age, sex, body mass index, physical activity, energy, alcohol, fermented dairy products, education, smoking status, hormone replacement therapy and comorbidity.

ETHICS AND DISSEMINATION

The study is approved by the Danish Data Protection Agency (2012-58-0018). The core study is an open register-based cohort study. The study does not need approval from the Ethics committee or Institutional Review Board by Danish law. Study findings will be disseminated through peer-reviewed journals, patient associations and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT03456206; Post-results.

Contribution of Zinc and Zinc Transporters in the Pathogenesis of Inflammatory Bowel Diseases

Intestinal epithelial cells cover the surface of the intestinal tract. The cells are important for preserving the integrity of the mucosal barriers to protect the host from luminal antigens and pathogens. The mucosal barriers are maintained by the continuous and rapid self-renewal of intestinal epithelial cells. Defects in the self-renewal of these cells are associated with gastrointestinal diseases, including inflammatory bowel diseases and diarrhea. Zinc is an essential trace element for living organisms, and zinc deficiency is closely linked to the impaired mucosal integrity. Recent evidence has shown that zinc transporters contribute to the barrier function of intestinal epithelial cells. In this review, we describe the recent advances in understanding the role of zinc and zinc transporters in the barrier function and homeostasis of intestinal epithelial cells.

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

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

Lipid and Bile Acid Dysmetabolism in Crohn's Disease

Crohn's disease is one of the systemic autoimmune diseases. It commonly affects the small intestine and colon but may involve any portion of the gastrointestinal tract from the mouth to the anus. The most affected area by Crohn's disease is the distal part of the small intestine, in which the bile acid molecules are most efficiently reabsorbed. Bile acids form mixed micelles together with fatty acids, which function as a transport vehicle to deliver fatty acids to the apical membrane of enterocytes for absorption. Therefore, if the terminal ileum is impaired, bile acid malabsorption may occur, which may cause congenital diarrhoea in Crohn's disease. Similarly, the impairment of the terminal ileum also induces fatty acid malabsorption, which may influence the role of fatty acids in Crohn's disease. In contrast, a recent study reported that multidrug resistance protein 1 (MDR1) regulated effector T-cell function in the ileum from bile acid-driven oxidative stress and MDR1 loss of function in a subset of patients with Crohn's disease. However, the role of consumption of fatty acids in Crohn's disease remains to be fully elucidated. This review is aimed at providing an overview of some recent developments in research of Crohn's disease from comprehensive perspective with a focus on the connection between disease location and behaviour, lipid diets, and bile acid malabsorption.

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.

Low serum zinc levels predict presence of depression symptoms, but not overall disease outcome, regardless of ATG16L1 genotype in Crohn's disease patients

BACKGROUND

Zinc deficiency (ZD) in Crohn's disease (CD) is considered a frequent finding and may exacerbate CD activity. ZD is associated with depression in non-CD patients. We aimed to assess the prevalence of ZD in CD patients in clinical remission, its association with mood disturbances and to analyze a potential impact on future disease course.

METHODS

Zinc levels from CD patients in clinical remission at baseline and an uncomplicated disease course within the next 3 years (n = 47) were compared with those from patients developing complications (n = 50). Baseline symptoms of depression and anxiety were measured with the Hospital Anxiety and Depression scale.

RESULTS

Mean zinc level in the 97 patients (40.4 ± 15.7 years, 44.3% males) was 18.0 ± 4.7 μmol/l. While no ZD (<11 μmol/l) was observed, we found low zinc levels (<15.1 μmol/l) in 28 patients (28.9%). Males had higher zinc levels compared with females (19.4 ± 5.7 versus 16.8 ± 3.3, p = 0.006). Patients with low zinc levels more often reported depression symptoms compared with patients with higher levels (27.3 versus 9.4%, p = 0.047). In a multivariate analysis, zinc levels were an independent negative predictor for depression symptoms [odds ratio (OR) 0.727, 95% confidence interval (CI) 0.532-0.993, p = 0.045]. Zinc levels of patients with a complicated disease course were not different from those of patients without (17.7 ± 4.3 versus 18.3 ± 5.1, n.s.). Baseline zinc levels did not predict disease outcome regardless of ATG16L1 genotype.

CONCLUSION

Low-normal zinc levels were an independent predictor for the presence of depression symptoms in CD patients. Zinc levels at baseline did not predict a complicated disease course, neither in CD patients overall, nor ATG16L1^T300A carriers.

Impact of red and processed meat and fibre intake on treatment outcomes among patients with chronic inflammatory diseases: protocol for a prospective cohort study of prognostic factors and personalised medicine

INTRODUCTION

Chronic inflammatory diseases (CIDs) are frequently treated with biological medications, specifically tumour necrosis factor inhibitors (TNFi)). These medications inhibit the pro-inflammatory molecule TNF alpha, which has been strongly implicated in the aetiology of these diseases. Up to one-third of patients do not, however, respond to biologics, and lifestyle factors are assumed to affect treatment outcomes. Little is known about the effects of dietary lifestyle as a prognostic factor that may enable personalised medicine. The primary outcome of this multidisciplinary collaborative study will be to identify dietary lifestyle factors that support optimal treatment outcomes.

METHODS AND ANALYSIS

This prospective cohort study will enrol 320 patients with CID who are prescribed a TNFi between June 2017 and March 2019. Included among the patients with CID will be patients with inflammatory bowel disease (Crohn's disease and ulcerative colitis), rheumatic disorders (rheumatoid arthritis, axial spondyloarthritis, psoriatic arthritis), inflammatory skin diseases (psoriasis, hidradenitis suppurativa) and non-infectious uveitis. At baseline (pretreatment), patient characteristics will be assessed using patient-reported outcome measures, clinical assessments of disease activity, quality of life and lifestyle, in addition to registry data on comorbidity and concomitant medication(s). In accordance with current Danish standards, follow-up will be conducted 14-16 weeks after treatment initiation. For each disease, evaluation of successful treatment response will be based on established primary and secondary endpoints, including disease-specific core outcome sets. The major outcome of the analyses will be to detect variability in treatment effectiveness between patients with different lifestyle characteristics.

ETHICS AND DISSEMINATION

The principle goal of this project is to improve the quality of life of patients suffering from CID by providing evidence to support dietary and other lifestyle recommendations that may improve clinical outcomes. The study is approved by the Ethics Committee (S-20160124) and the Danish Data Protecting Agency (2008-58-035). Study findings will be disseminated through peer-reviewed journals, patient associations and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT03173144; Pre-results.

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.

Review article: changes in the epidemiology of inflammatory bowel disease-clues for aetiology

BACKGROUND

The changing epidemiology of inflammatory bowel disease (IBD) in both the developed and developing worlds may provide insights into disease aetiology. Factors that impact on the gut microbiome are leading aetiological candidates.

AIM

To review epidemiological studies and trends that identify risk factors for the development of IBD.

METHODS

Studies that identified factors associated with the development of IBD differentially in children and adults were reviewed. There was a focus on epidemiological studies and on studies that involve the gut microbiome.

RESULTS

Use of antibiotics has been shown to be associated with development of Crohn's disease in childhood (odds ratio, OR = 2.75, 95% CI 1.72-4.38). Breastfeeding has been protective against developing IBD (OR=0.69, 95% CI 0.51-0.94), but there is a paucity of data exploring duration of breastfeeding and timing of introduction of bottled milk or table food. Antibiotics and diet changes can also impact on adults enhancing the risk for IBD. Both smoking (OR=1.76, 95% CI 1.40-2.22) and oral contraceptives (relative risk=1.46, 95% CI 1.26-1.70) increase the risk for Crohn's disease and their use is associated with worse outcomes in Crohn's disease. It is unclear if their impact is mediated through the gut microbiome.

CONCLUSIONS

A leading aetiological clue for IBD based on epidemiological studies is the antecedent use of antibiotics both for children and adults. Some dietary changes may be a risk for adults but there is a paucity of dietary data in children prior to IBD development. Both antibiotic use and dietary changes have the potential to impact the gut microbiome, which in turn can alter the gut immune response.

A Proposal for a Study on Treatment Selection and Lifestyle Recommendations in Chronic Inflammatory Diseases: A Danish Multidisciplinary Collaboration on Prognostic Factors and Personalised Medicine

Chronic inflammatory diseases (CIDs), including Crohn’s disease and ulcerative colitis (inflammatory bowel diseases, IBD), rheumatoid arthritis, psoriasis, psoriatic arthritis, spondyloarthritides, hidradenitis suppurativa, and immune-mediated uveitis, are treated with biologics targeting the pro-inflammatory molecule tumour necrosis factor-α (TNF) (i.e., TNF inhibitors). Approximately one-third of the patients do not respond to the treatment. Genetics and lifestyle may affect the treatment results. The aims of this multidisciplinary collaboration are to identify (1) molecular signatures of prognostic value to help tailor treatment decisions to an individual likely to initiate TNF inhibitor therapy, followed by (2) lifestyle factors that support achievement of optimised treatment outcome. This report describes the establishment of a cohort that aims to obtain this information. Clinical data including lifestyle and treatment response and biological specimens (blood, faeces, urine, and, in IBD patients, intestinal biopsies) are sampled prior to and while on TNF inhibitor therapy. Both hypothesis-driven and data-driven analyses will be performed according to pre-specified protocols including pathway analyses resulting from candidate gene expression analyses and global approaches (e.g., metabolomics, metagenomics, proteomics). The final purpose is to improve the lives of patients suffering from CIDs, by providing tools facilitating treatment selection and dietary recommendations likely to improve the clinical outcome.

Modifiable Environmental Factors in Inflammatory Bowel Disease

PURPOSE OF REVIEW

Environmental factors may influence predisposition to develop inflammatory bowel diseases (Crohn's disease, ulcerative colitis) or alter its natural history by modification of both the host immune response and intestinal microbial composition. The purpose of this review is to translate such evidence into clinical practice by a focus on interventional studies that have modified such environmental influences to improve disease outcomes.

RECENT FINDINGS

Several environmental influences have been identified in the recent literature including tobacco use, diet, antibiotics, vitamin D deficiency, stress, appendectomy, and oral contraceptive use. Some risk factors have similar influences on both Crohn's disease and ulcerative colitis while others are disease-specific or have divergent effects. Emerging epidemiologic evidence has confirmed the association of many of these factors with incident disease using prospective data. In addition, laboratory data has supported their mechanistic plausibility and relevance to intestinal inflammation.

Potential Impact of Diet on Treatment Effect from Anti-TNF Drugs in Inflammatory Bowel Disease

We wanted to investigate the current knowledge on the impact of diet on anti-TNF response in inflammatory bowel diseases (IBD), to identify dietary factors that warrant further investigations in relation to anti-TNF treatment response, and, finally, to discuss potential strategies for such investigations. PubMed was searched using specified search terms. One small prospective study on diet and anti-TNF treatment in 56 patients with CD found similar remission rates after 56 weeks among 32 patients with good compliance that received concomitant enteral nutrition and 24 with poor compliance that had no dietary restrictions (78% versus 67%, p = 0.51). A meta-analysis of 295 patients found higher odds of achieving clinical remission and remaining in clinical remission among patients on combination therapy with specialised enteral nutrition and Infliximab (IFX) compared with IFX monotherapy (OR 2.73; 95% CI: 1.73-4.31, p < 0.01, OR 2.93; 95% CI: 1.66-5.17, p < 0.01, respectively). In conclusion, evidence-based knowledge on impact of diet on anti-TNF treatment response for clinical use is scarce. Here we propose a mechanism by which Western style diet high in meat and low in fibre may promote colonic inflammation and potentially impact treatment response to anti-TNF drugs. Further studies using hypothesis-driven and data-driven strategies in prospective observational, animal and interventional studies are warranted.

Zinc Transporter 3 (ZnT3) in the Enteric Nervous System of the Porcine Ileum in Physiological Conditions and during Experimental Inflammation

Zinc transporter 3 (ZnT3) is a member of the solute-linked carrier 30 (SLC 30) zinc transporter family. It is closely linked to the nervous system, where it takes part in the transport of zinc ions from the cytoplasm to the synaptic vesicles. ZnT3 has also been observed in the enteric nervous system (ENS), but its reactions in response to pathological factors remain unknown. This study, based on the triple immunofluorescence technique, describes changes in ZnT3-like immunoreactive (ZnT3-LI) enteric neurons in the porcine ileum, caused by chemically-induced inflammation. The inflammatory process led to a clear increase in the percentage of neurons immunoreactive to ZnT3 in all "kinds" of intramural enteric plexuses, i.e., myenteric (MP), outer submucous (OSP) and inner submucous (ISP) plexuses. Moreover, a wide range of other active substances was noted in ZnT3-LI neurons under physiological and pathological conditions, and changes in neurochemical characterisation of ZnT3⁺ cells in response to inflammation depended on the "kind" of enteric plexus. The obtained results show that ZnT3 is present in the ENS in a relatively numerous and diversified neuronal population, not only in physiological conditions, but also during inflammation. The reasons for the observed changes are not clear; they may be connected with the functions of zinc ions and their homeostasis disturbances in pathological processes. On the other hand, they may be due to adaptive and/or neuroprotective processes within the pathologically altered gastrointestinal tract.

Zinc Deficiency is Associated with Poor Clinical Outcomes in Patients with Inflammatory Bowel Disease

BACKGROUND

Zinc plays a pivotal role in wound repair, tissue regeneration, and the immune response. Although zinc deficiency is common in patients with inflammatory bowel disease (IBD), the impact of low serum zinc levels on disease course is not known.

METHODS

Patients enrolled in a prospectively collected IBD registry with at least 2 serum zinc measurements were included in the analysis. Using a logistic regression model, rates of IBD-related surgeries, IBD-related hospitalizations, and IBD-related complications were evaluated after a diagnosis of zinc deficiency (serum concentration <0.66 μg/mL) compared with those with normal zinc concentrations. In patients who were zinc deficient, outcomes were also analyzed between those who had normalization of zinc levels within 12 months and those who remained deficient.

RESULTS

A total of 773 patients with Crohn's disease (CD) and 223 with ulcerative colitis (UC) were included in the analysis. After adjusting for covariates, zinc deficiency was associated with an increased risk of subsequent hospitalizations, surgeries, and disease-related complications in patients with CD and UC (CD: hospitalizations, odds ratio 1.44, 95% confidence interval [1.02-2.04]; surgeries, 2.05 [1.38-3.05]; complications, 1.50 [1.04-2.15]; UC: hospitalizations, 2.14 [1.07-4.29]; surgeries, 1.64 [0.59-4.52]; complications, 1.97 [0.94-4.11]). Normalization of zinc was associated with improvement in these outcomes in patients with both CD and UC.

CONCLUSIONS

Patients with IBD with serum zinc deficiency are more likely to have adverse disease-specific outcomes. As these outcomes improve with normalization of zinc, the results from this study support the role for close monitoring and replacement of zinc in patients with IBD.

ESPEN guideline: Clinical nutrition in inflammatory bowel disease

INTRODUCTION

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

METHODOLOGY

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

RESULTS

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

CONCLUSIONS

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