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

Pregnancy period and early-life risk factors for inflammatory bowel disease: a Northern Finland birth cohort 1966 study

BACKGROUND

The pathogenesis of inflammatory bowel disease (IBD) has not been fully elucidated. The aim of this study was to analyze the pregnancy period, perinatal period, and infancy period risk factors for IBD in a well-characterized birth cohort from Northern Finland.

METHODS

The Northern Finland Birth Cohort 1966 (NFBC1966) population comprises mothers living in the two northernmost provinces of Finland, Oulu, and Lapland, with dates of delivery between Jan 1st and Dec 31st, 1966 (12 055 mothers, 12 058 live-born children, 96.3% of all births during 1966). IBD patients were identified using hospital registries (from 1966 to 2020) and Social Insurance Institution (SII) registry reimbursement data for IBD drugs (from 1978 to 2016). The data were analyzed by Fisher's exact test and logistic regression.

RESULTS

In total, 6972 individuals provided informed consent for the use of combined SII and hospital registry data. Of those, 154 (2.1%) had IBD (113 [1.6%] had ulcerative colitis (UC), and 41 (0.6%) had Crohn's disease (CD)). According to multivariate analysis, maternal smoking > 10 cigarettes/day during pregnancy was associated with a nearly 6-fold increased risk of CD in the offspring (OR 5.78, 95% CI 1.70-17.3). Breastfeeding (OR = 0.18, 95% CI 0.08-0.44) and iron supplementation during the first year of life (OR = 0.43, 95% CI 0.21-0.89) were negatively associated with CD.

CONCLUSIONS

Smoking during pregnancy was associated with the risk of CD while Breastfeeding and oral iron supplementation at infancy were negatively associated with the risk of CD later in life.

Dextran sodium sulfate (DSS)-induced colitis is alleviated in mice after administration of flavone-derived NRF2-activating molecules

Inflammatory Bowel Disease (IBD) is a chronic and relapsing inflammatory condition characterized by severe symptoms such as diarrhea, fatigue, and weight loss. Growing evidence underscores the direct involvement of the nuclear factor-erythroid 2-related factor 2 (NRF2) in the development and progression of IBD, along with its associated complications, including colorectal cancer. The NRF2 pathway plays a crucial role in cellular responses to oxidative stress, and dysregulation of this pathway has been implicated in IBD. Flavones, a significant subclass of flavonoids, have shown pharmacological impacts in various diseases including IBD, through the NRF2 signaling pathway. In this study, we conducted a screening of compounds with a flavone structure and identified NJK15003 as a promising NRF2 activator. NJK15003 demonstrated potent NRF2 activation, as evidenced by the upregulation of downstream proteins, promoter activation, and NRF2 nuclear translocation in IBD cellular models. Treatment with NJK15003 effectively restored the protein levels of tight junctions in cells treated with dextran sodium sulfate (DSS) and in DSS-treated mice, suggesting its potential to protect cells from barrier integrity disruption in IBD. In DSS-treated mice, the administration of NJK15003 resulted in the prevention of body weight loss, a reduction in colon length shortening, and a decrease in the disease activity index. Furthermore, NJK15003 treatment substantially alleviated inflammatory responses and apoptotic cell death in the colon of DSS-treated mice. Taken together, this study proposes the potential utility of NRF2-activating flavone compounds, exemplified by NJK15003, for the treatment of IBD.

Differential expression of serum miR-486 and miR-25 in ulcerative colitis and Crohn's disease: Correlations with disease activity, extent, and location

Novel reliable biomarkers of inflammatory bowel disease (IBD) are clinically imperative due to potential limitations of endoscopic techniques. MicroRNAs (miRNAs) have emerged as non-invasive biomarkers of IBD; however, the full disease-specific miRNAs signature for IBD subtypes remains elusive. We evaluated the diagnostic role of circulating miR-486 and miR-25 in IBD patients and their potential ability to discriminate IBD subtypes; ulcerative colitis (UC) and Crohn's disease (CD). Sixty UC patients, 60 CD patients, and 60 healthy controls were recruited. Serum miRNA expression was determined using RT-qPCR. Bioinformatics was employed for target gene and protein-protein interaction (PPI) network analyses. Serum miR-486 was upregulated in CD patients, but didn't change in UC patients compared to controls. Conversely, serum miR-25 was decreased in both CD and UC patients compared to controls. Only miR-486 was differentially expressed between UC and CD patients. Receiver-operating characteristic analysis revealed that serum miR-486 was superior in CD diagnosis (AUC=0.945) and significantly distinguished CD and UC patients, whereas miR-25 showed discriminative potential for both UC and CD from controls. In the multivariate logistic analysis only miR-486 was associated with the risk of CD diagnosis. Serum miR-486 was correlated with CD activity index and location of disease in CD patients, whereas miR-25 was correlated with the type/extent of UC. PPI network analysis revealed common target genes and signaling pathways for both miRNAs. Conclusively, serum miR-486 and miR-25 might serve as new biomarkers of IBD, with serum miR-486 could be employed in risk stratification of IBD subtypes and has the ground for clinical utility in CD diagnosis, whereas miR-25 has potential for UC and CD diagnosis.

Treatment of Active Crohn's Disease in Children Using Partial Enteral Nutrition Combined with a Modified Crohn's Disease Exclusion Diet: A Pilot Prospective Cohort Trial on Clinical and Endoscopic Outcomes

BACKGROUND

Partial enteral nutrition (PEN) coupled with the Crohn's disease (CD) exclusion diet (CDED) was shown to be effective in inducing clinical remission in paediatric CD. There are currently no robust data on the endoscopic outcomes of PEN. The aim of this study was to evaluate the clinical and endoscopic rates of remission after PEN combined with a modified CDED (mCDED) adjusted to the local cuisine in comparison with exclusive enteral nutrition (EEN) for the induction of remission.

METHODS

Between June 2017 and February 2021, a prospective cohort study on children with active CD, treated with PEN + mCDED or EEN, was performed at a single tertiary centre.

RESULTS

During the study period, 54 patients were screened and 15 were excluded according to the exclusion criteria, with six patients excluded in the first two days due to intolerance of the enteral formula. Fourteen patients were included in the PEN and 19 in the EEN group. They were assessed at Weeks 0, 1, 3 and 6, using clinical and laboratory parameters. Endoscopy was performed at Weeks 0 and 6. Clinical remission rates per protocol analysis were 84.6% in the PEN group and 81.3% in the EEN group (p = 0.99). At Week 6, an endoscopic response (a decline in the Simple Endoscopic Score for CD (SES-CD) > 50%) was observed in 84.6% of patients on PEN and in 68.8% on EEN treatment (p = 0.41). Endoscopic remission (SES-CD ≤ 2) was achieved in 53.8% of patients in the PEN group and in 50.0% in the EEN group (p = 0.99), while the mucosal healing rates (SES-CD = 0) were 38.5% with PEN and 43.8% with EEN (p = 0.99). A significant decline in the clinical and endoscopic activity scores was observed in both groups.

CONCLUSION

Our study suggests that PEN + mCDED could be effective in inducing endoscopic remission and mucosal healing in active paediatric CD patients. Here, we present an analysis of the data from our cohort of patients and our real-world experience with PEN + mCDED.

Mucosal expression of PI3, ANXA1, and VDR discriminates Crohn's disease from ulcerative colitis

Differential diagnosis of inflammatory bowel disease (IBD) to Crohn's disease (CD) or ulcerative colitis (UC) is crucial for treatment decision making. With the aim of generating a clinically applicable molecular-based tool to classify IBD patients, we assessed whole transcriptome analysis on endoscopy samples. A total of 408 patient samples were included covering both internal and external samples cohorts. Whole transcriptome analysis was performed on an internal cohort of FFPE IBD samples (CD, n = 16 and UC, n = 17). The 100 most significantly differentially expressed genes (DEG) were tested in two external cohorts. Ten of the DEG were further processed by functional enrichment analysis from which seven were found to show consistent significant performance in discriminating CD from UC: PI3, ANXA1, VDR, MTCL1, SH3PXD2A-AS1, CLCF1, and CD180. Differential expression of PI3, ANXA1, and VDR was reproduced by RT-qPCR, which was performed on an independent sample cohort of 97 patient samples (CD, n = 44 and UC, n = 53). Gene expression levels of the three-gene profile, resulted in an area under the curve of 0.84 (P = 0.02) in discriminating CD from UC, and therefore appear as an attractive molecular-based diagnostic tool for clinicians to distinguish CD from UC.

Oral Delivery of Bioactive Glass-Loaded Core-Shell Hydrogel Microspheres for Effective Treatment of Inflammatory Bowel Disease

Resolving inflammation and promoting intestinal tissue regeneration are critical for inflammatory bowel disease (IBD) treatment. Bioactive glass (BG) is a clinically approved bone graft material and has been shown to modulate inflammatory response, but it is unknown whether BG can be applied to treat IBD. Here, it is reported that BG attenuates pro-inflammatory response of lipopolysaccharide (LPS)-stimulated macrophages and hence reduces inflammatory damage to intestinal organoids in vitro. In addition, zein/sodium alginate-based core-shell microspheres (Zein/SA/BG) are developed for oral delivery of BG, which helps prevent premature dissolution of BG in the stomach. The results show that Zein/SA/BG protects BG from a gastric-simulated environment while dissolved in an intestinal-simulated environment. When administered to acute and chronic colitis mice model, Zein/SA/BG significantly reduces intestinal inflammation, promotes epithelial tissue regeneration, and partially restores microbiota homeostasis. These findings are the first to reveal the therapeutic efficacy of BG against IBD, which may provide a new therapeutic approach at low cost for effective IBD treatment.

Frequency and clinical significance of histologic upper gastrointestinal tract findings in children with inflammatory bowel disease

OBJECTIVE

Assessment of the upper gastrointestinal tract (UGI) may enable more personalized treatment strategies in pediatric inflammatory bowel disease (IBD). However, data on the frequency and significance of these findings remain limited.

METHODS

Data on 132 pediatric IBD patients with systematic UGI sampling were collected and the baseline characteristics and presence of complications compared between those with and without histological UGI findings. The control group comprised 162 children who received no diagnoses.

RESULTS

Seventy-six children had ulcerative colitis (UC), 47 Crohn's disease (CD) and nine IBD unclassified. UGI findings were more common in IBD patients than controls (69.7% vs. 30.9%, respectively, p < .001), particularly in the stomach (62.1% vs. 16.8%; p < .001). Among IBD patients, findings were more common in CD than in UC (80.9% vs. 63.2%; p = .038), particularly in the duodenum (21.3% vs. 2.6%, p = .001). Four patients had UGI granulomas consistent with CD. Hypoalbuminemia (OR 3.22; 95% CI 1.18-8.79) and failure to thrive (2.82; 1.17-6.78) increased the likelihood of UGI findings in IBD. In CD, perianal morbidity was less common in those with than in those without UGI findings (13.2% vs. 44.4%; p = .032) whereas in UC, UGI findings increased the risk for co-morbidities (18.8% vs. 3.6%; p = .059). The long-term outcomes did not differ between patients with or without UGI findings.

CONCLUSIONS

Histologic UGI findings were more common in children with IBD than in children with no gastrointestinal diagnoses. In CD, UGI findings were more frequent than in UC, especially in the duodenum. In UC, UGI findings were associated with more complex disease.

The appendix‐mucosal immunity and tolerance in the gut: consequences for the syndromes of appendicitis and its epidemiology

The cause of appendicitis is unknown. A review is presented across diverse sources relating to the biology of the appendix and its perturbations. A mechanistic model of the function of the appendix is presented, and its application to the syndromes and consequences of appendicitis is described.

Sweeteners Maintain Epithelial Barrier Function Through the miR-15b/RECK/MMP-9 Axis, Remodel Microbial Homeostasis, and Attenuate Dextran Sodium Sulfate-Induced Colitis in Mice

Non-nutritive sweeteners are the most widely used food additives designed to provide sweetness and reduce caloric intake. Studies have confirmed a link between sweeteners and colitis, yet supporting scientific data remain exiguous and controversial. In this study, three common sweeteners (Saccharin sodium, Stevioside, and Sucralose) in acceptable daily intake dosage were added to water in order to determine their effects on dextran sodium sulfate-induced colitis in mice. Our results show that the three sweeteners meliorate colitis to varying degrees─Saccharin exerts the most pronounced effect, followed by Stevioside and Sucralose. Intake of sweeteners alleviates colitis symptoms, alters gut microbiota, reshapes the TH17/Treg balance, protects the intestinal barrier, and reduces inflammation. Most significantly, sweeteners can enhance the abundance of Mucispirillum and Alistipes, which are conducive to colitis recovery, and upregulate the expression of E-cadherin through the miR-15b/RECK/MMP-9 axis to improve intestinal barrier integrity. Moreover, by inhibiting the MMP-9/AKT/NF-κB pathway, inflammation is relieved, as reflected in the restoration of the Th17/Treg balance. Our results link the consumption of sweeteners to the remission of colitis, which provides new scientific evidence for the safe use of sweeteners.

OUP accepted manuscript

Crohn’s disease (CD) is associated with reduced quality of life, increased absenteeism and high direct medical costs resulting from frequent hospitalizations and surgeries. Tumor necrosis factor–alpha inhibitors (TNFi’s) have transformed the therapeutic landscape and enabled a shift from a symptom control to a treat-to-target strategy. The Effect of Tight Control Management on Crohn’s Disease (CALM) trial demonstrated tight control (TC), with TNFi dose changes informed by biochemical markers of inflammation, achieved higher mucosal healing rates compared with conventional management (CM) based on symptoms. A Markov model compared TC and CM strategies from the perspective of the Canadian public payer using patient-observation data from the CALM trial. A regression model estimated weekly CD Activity Index–based transition matrices over a 5-year horizon and included covariates to improve extrapolation of outcomes beyond the 48-week trial assessment period. Costs of CD-related hospitalizations, biomarker tests and adalimumab injections were sourced from public data. Other direct medical costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated. Absenteeism was monetized and included in a sensitivity analysis. Over the 5-year time horizon, TC reduced hospitalization costs by 64% compared with CM. Other direct medical costs were reduced by 22%; adalimumab costs increased by 38%, generating an ICER of $35,168 per QALY gained. Absenteeism costs were reduced by 54%, and, when that was included in the model, TC became dominant compared with CM. Management of CD with TC is cost-effective compared with CM in Canada and is dominant if indirect costs associated with absenteeism are included. Trial registration number: NCT01235689.

IL-10 as a Th2 Cytokine: Differences Between Mice and Humans

The discovery of IL-10 more than 30 years ago marked the beginning of our understanding of how cytokines regulate immune responses, based on cross-regulation between Th1 and Th2 cytokines. Although multiple cell types were shown to produce IL-10, its identity as a Th2 cytokine remained strong because it was rigidly associated with Th2 clones in mice, whereas both Th1 and Th2 clones could secrete IL-10 in humans. However, as new Th1/Th2 cell functionalities emerged, anti-inflammatory action of IL-10 gained more attention than its inhibitory effect on Th1 cells, which may occur as an indirect consequence of suppression of APCs. This notion is also supported by the discovery of regulatory T cells, whose suppressor functions involve the mediation of IL-10, among other molecules. From this perspective, we discuss the functionalities of IL-10 by highlighting important differences between mice and humans with an emphasis on the Th1 and Th2 paradigm.

Research progress of phosphodiesterase inhibitors in inflammatory bowel disease treatment

Inflammatory bowel disease is a recurrent chronic intestinal inflammatory disease with unknown etiology and no effective treatment. Phosphodiesterase (PDE) regulates a variety of physiological and pathophysiological processes by mediating the hydrolysis of intracellular second messengers cyclic adenosine monophosphate and cyclic guanosine monophosphate. In recent years, a series of researches suggest that PDE inhibitors such as several PDE4 inhibitors, PDE5 inhibitors (sildenafil, tadalafil and vardenafil), PDE3 inhibitors (cilostazol), PDE9 inhibitor (PF-04447943) and PDE3/PDE4 double inhibitor (pumafentrine) have ameliorating effect on experimental colitis in animals. In clinical trials, PDE4 inhibitor apremilast showed more therapeutic advantage than tetomilast. This article reviews the recent research progress of PDE inhibitors in treatment of inflammatory bowel disease.

Acute Gastroenteritis in the Etiology of Inflammatory Bowel Disease: Systematic Review and Meta-analysis

Background

Inflammatory bowel disease (IBD) consists of a spectrum of disorders including ulcerative colitis and Crohn's disease, with a rising incidence worldwide. However, despite this prevalence the etiology of IBD remains uncertain. It has been suggested that an episode of gastroenteritis may precipitate IBD.

Methods

Studies were identified using a literature search of Pubmed/Medline and Embase/Ovid. This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The primary outcome was incidence of new-onset IBD after gastroenteritis. Secondary outcomes included incidence of IBD after bacterial, viral, and parasitic gastrointestinal infections.

Results

Eleven studies (n = 923 608 patients) were included. Four studies assessed patients with gastroenteritis, subsequently developing IBD as the primary outcome. Patients with gastroenteritis had a higher incidence of subsequent IBD but this did not reach statistical significance (odds ratio [OR] 3.81, 95% CI 0.52-27.85, P = .19). Seven studies examined the incidence of antecedent gastroenteritis (primary outcome) in patients with a confirmed diagnosis of IBD, compared to the controlled population. There was no difference between incidence of antecedent gastroenteritis across the 2 population groups (OR 1.07, 95% CI 0.55-2.08, P = .85). There was no association between IBD and bacterial, viral, or parasitic infections.

Conclusions

In summary, our meta-analysis has shown that there is considerable heterogeneity in the literature regarding the role of gastroenteritis in the development of IBD. Further higher quality studies need to be performed to ascertain the true nature of this.

Epidemiologic trend of pediatric inflammatory bowel disease in Latin America: The Latin American Society for Pediatric Gastroenterology, Hepatology and Nutrition (LASPGHAN) Working Group

INTRODUCTION AND AIMS

The primary aim was to explore the epidemiologic trend of pediatric inflammatory bowel disease in Latin America, and the secondary aims were to obtain an overview of the diagnostic/therapeutic focus of the members of the LASPGHAN and examine the relation of case frequency to year, during the study period.

MATERIALS AND METHODS

Latin American pediatric gastroenterologists participated in an online survey, conducted through the SurveyMonkey platform, that investigated the yearly frequency of new inflammatory bowel disease patients within the time frame of 2005-2016, their disease variety, the gastrointestinal segments affected, and the diagnostic and treatment methods utilized. The correlation of new case frequency with each study year was evaluated.

RESULTS

A total of 607 patients were studied. The diagnoses were ulcerative colitis in 475 (78.3%) cases, Crohn's disease in 104 (17.1%), and inflammatory bowel disease D unclassified in 28 (4.6%). The trend in ulcerative colitis was a lineal increase in the frequency of new cases related to each study year, with a significant correlation coefficient. Pancolitis was found in 67.6% of the patients. The diagnostic methods included clinical data, endoscopy, and biopsies in more than 99% of the cases, and imaging studies were indicated selectively. Drug regimens were limited to 5-aminosalicylic acid derivatives, azathioprine, 6-mercaptopurine, infliximab, and adalimumab.

CONCLUSIONS

Pediatric inflammatory bowel disease in Latin America appears to have increased during the years included in the study period, with a predominance of moderate or severe ulcerative colitis. That lineal trend suggests the predictive likelihood of a gradual increase in the coming years, with possible epidemiologic and clinical implications.

Archive for Research in Child Health (ARCH) and Baby Gut: Study Protocol for a Remote, Prospective, Longitudinal Pregnancy and Birth Cohort to Address Microbiota Development and Child Health

The infant gut microbiome is shaped by numerous factors such as diet and the maternal microbiota and is also associated with later atopy and obesity. The Archive for Research in Child Health and Baby Gut (ARCHBG) cohort was established in 2015 to (1) understand how the development of the infant gut microbiota is associated with atopy, obesity, and gastrointestinal disease and (2) characterize the associations of maternal pre-pregnancy BMI and infant diet with the development of the gut microbiota. Study participants for ARCHBG are convenience samples recruited through two pipelines in Lansing and Traverse City, Michigan: (1) Archive for Research in Child Health (ARCH_GUT) and (2) BABY_GUT. A total of (n = 51) mother–infant dyads have been enrolled to date. This prospective cohort study collects maternal pre-pregnancy fecal samples, maternal data, child fecal samples at four timepoints (one week, six months, 12 months, and 24 months), and child data up to five years of age. All samples and data are collected remotely by mail, phone, or drop-off at select locations. Of all participants enrolled, 76.5% (n = 39) of infants have a complete record of stool samples. At least 88.2% (n = 45) of fecal samples were submitted at each timepoint. ARCHBG will allow for a nuanced understanding of the temporal development of the infant gut microbiome and numerous child health outcomes.

Neutrophil extracellular traps in inflammatory bowel diseases: Implications in pathogenesis and therapeutic targets

Crohn's disease (CD) and ulcerative colitis (UC) are the two main forms of inflammatory bowel disease (IBD). Among the various immune cells involved in IBD, neutrophils are the first to infiltrate and appear to contribute to the impairment of the epithelial barrier, destruction of tissues by oxidative and proteolytic damage, as well as to the perpetuation of inflammation by the release of cytokines and chemokines associated with pro-inflammatory effects. In addition to basic effector mechanisms, such as phagocytosis and chemotaxis, neutrophils can also form extracellular traps (NETs), which is made up of a mesh-like structure - which contains its chromatin (DNA + histones) together with granules and enzymes, such as myeloperoxidase (MPO) and neutrophilic elastase (NE) - and that acts as a trap that can result in the death of extracellular pathogens and/or can promote tissue damage. Recent evidence indicates that NETs also play an important and significant role in the pathogenesis of IBD. Previous studies have reported increased levels of NETs in tissue and serum samples from patients with IBD, as well as in experimental colitis. In this review, we discuss current knowledge about the formation of NETs and their role in the pathophysiology of IBD, pointing out potential mechanisms by which NETs promote tissue damage, as well as their involvement in complications associated with IBD. In addition, we propose potential targets for therapy to regulate the production of NETs, making it possible to expand the current spectrum of therapies for IBD.

PDE9 Inhibitor PF-04447943 Attenuates DSS-Induced Colitis by Suppressing Oxidative Stress, Inflammation, and Regulating T-Cell Polarization

Ulcerative colitis (UC) is a form of inflammatory bowel disease, which manifests as irritation or swelling and sores in the large intestine in a relapsing and remitting manner. In a dextran sulfate sodium sulfate (DSS)-induced UC model in female mice, we found that the levels of cyclic guanosine monophosphate (cGMP) are reduced, while the expression of phosphodiesterase 9A (PDE9A) is highest among all phosphodiesterase (PDEs). Since PDE9 has the highest affinity toward cGMP, we evaluated the selective PDE9 inhibitor PF-04447943 (PF) as a potential candidate for UC treatment. PF has been extensively studies in cognitive function and in sickle cell disease, but not in models for inflammatory bowel disease (IBD). Therefore, we used female C57BL/6 mice treated with 3% DSS alone or co-treated with PF or sulfasalazine (SASP) to study the body weight, colon length, histopathology, and measure superoxide dismutase (SOD), malondialdehyde (MDA), and cGMP level, as well as cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-17 (IL-17), interleukin-12/23 (IL-12/23), interleukin-10 (IL-10), and pathways including nuclear factor kappa B (NF-κB), signal transducer and activator of transcription 3 (STAT3), and inflammasome activation. In addition, the number of dendritic cells (DC) and regulatory T cells (Treg cell) was assessed in the spleen, lymph node, and colon using flow cytometry. DSS reduced the number of goblet cells, decreased colon lengths and body weights, all of them were attenuated by PF treatment. It also suppressed the elevated level of inflammatory cytokines and increased level the anti-inflammatory cytokine, IL-10. PF treatment also reduced the DSS-induced inflammation by suppressing oxidative stress, NF-κB, STAT3, and inflammasome activation, by upregulating nuclear factor erythroid 2-related factor 2 (Nrf-2) and its downstream proteins via extracellular signal-regulated kinase (ERK) phosphorylation. Importantly, PF reversed imbalance in Treg/T helper 17 cells (Th17) cells ratio, possibly by regulating dendritic cells and Treg developmental process. In summary, this study shows the protective effect of a PDE9A inhibitor in ulcerative colitis by suppressing oxidative stress and inflammation as well as reversing the Treg/Th17 cells imbalance.

Associations between participation in, intensity of, and time spent on leisure time physical activity and risk of inflammatory bowel disease among older adults (PA-IBD): a prospective cohort study

Background

Inflammatory bowel diseases (IBDs) are diseases of the immune system that share some genetic and lifestyle-related predisposing factors. Increasing incidences have been reported in all age groups. Based on experimental studies suggesting a role of physical activity on intestinal inflammation, this study aimed to investigate the association between leisure time physical activity and the risk of IBD in older adults.

Methods

The study is a prospective cohort study using Danish registry data and questionnaire data from the Danish “Diet, Cancer and Health” cohort. The outcome IBD was defined as having at least two main diagnoses of Crohn’s disease or ulcerative colitis registered in the National Patient Registry from the period between December 1993 and May 1997 with an average follow-up of 25 years. Cox proportional hazard models were used to estimate hazard-ratios for IBD onset associated with being physically active and with levels of the metabolic equivalent of task (MET) hours/week of physical activity and hours/week spent on six types of physical activity. All analyses were adjusted for potential confounders. Furthermore, the analyses were stratified according to age-group, occupational physical activity, smoking, BMI and work status to test for effect modification.

Results

In total, 54,645 men and women aged between 50 and 64 years were included, and of which there were 529 cases. When comparing physically active with inactive participants measured by MET hours/week there was no statistically significant difference in risk of IBD (0.89 [0.13; 6.27]), regardless of how participation was measured. Results did not indicate any dose-response effect when comparing quartile groups of MET hours/week (HR = 0.97 [0.76; 1.22], HR = 0.82 [0.64; 1.05] and HR = 0.83 [0.65; 1.07] or whether five of the six types of activities were compared with the lowest quartile as reference. For do-it-yourself-work, the third quartile of hours/week was associated with a higher risk of IBD compared to the second quartile of hours/week (HR = 1.44 [1.10; 1.90]. No effect modification was found.

Conclusions

There was no association between physical activity and risk of IBD when comparing physically active with inactive participants. Neither did the results indicate any dose-response effect when comparing quartile groups of MET hours/week with the lowest quartile as reference. Do-it-yourself work, however, appeared to be associated with a higher risk of IBD when comparing the third quartile with the second quartile of hours/week. The study has clinical relevance by its contribution to the explanatory field of the causes of IBD. However, the study has some limitations, and further research is needed to clarify associations between physical activity and risk of IBD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10492-7.

Update on the therapeutic management of patients with either psoriatic arthritis or ulcerative colitis: focus on the JAK inhibitor tofacitinib

Psoriatic arthritis (PsA) and ulcerative colitis (UC) are immune-mediated diseases that cause significant burden worldwide. Recent advances in their management have improved patient outcomes. However, significant unmet needs still remain as not all patients respond to current treatments, and patients may lose responsiveness over time. An improved understanding of the pathophysiology of these diseases has brought about the development of novel disease-modifying agents, including interleukin inhibitors and, more recently, Janus kinase (JAK) inhibitors. With the approval of tofacitinib for the treatment of adults with active PsA and in adult patients with moderately-to-severely active UC, JAK inhibitors have recently entered the treatment armamentarium for PsA and UC. A number of other JAK inhibitors are also undergoing clinical development and are currently in phase III trials. This review provides an overview of the current therapeutic options for PsA and UC, with a focus on the JAK inhibitors.

Global associations of national economic wealth are more robust with inflammatory bowel diseases than with obesity

The inflammatory bowel diseases consisting of Crohn's and ulcerative colitis have expanded into previously low incidence areas of the world. The spread follows the relatively recent pandemic of global obesity. Pathological relations have been proposed between these two diseases. Both inflammatory bowel diseases and obesity originated in wealthier western societies marked by high gross domestic product per capita. The pathogenic influence of national wealth on the inflammatory bowel diseases has been recognized but are less clear with obesity. Parallel correlations of national wealth with obesity would further strengthen relations between these two diseases. Alternatively, diverging relations could suggest that obesity is less dependent on wealth. As such it would supports another earlier hypothesis that obesity depends on adoption of western diet which precedes national acquisition of wealth. Previously ecological modifiers of global disease patterns, including latitude and lactose digestion status have shown different influences on IBD compared with obesity. We evaluate. the influence of the Gross Domestic Product on these two diseases taking into consideration the former's relationship with ecological markers. Patterns of correlations could suggest contributing mechanisms how these ecological parameters influence some disease distributions. The literature and internet were searched for national rates of obesity, inflammatory bowel diseases, national gross domestic product per capita and national lactase distribution rates. National average latitudes were calculated previously. Pearson correlations were used to compare variables in three regions; global, European and Asian theaters. SAS statistical package was used and statistical significance was accepted at p < 0.05. Globally and in Europe correlations of gross domestic product were moderate and significant r = 0.55 and r = 0.6 respectively with Crohn's disease but weaker with ulcerative colitis. The results were negligible in Asia. Obesity was weakly correlated with gross domestic product globally r = 0.32 and negligible in Europe and Asia. In addition, gross domestic product was moderately correlated with latitude r = 0.6, and inversely with lactase non persistence r = -0.6 both globally and in Europe. This relationship is similar to that with inflammatory bowel diseases, but less related to obesity. Overall results suggest unequal effect of national wealth and industrialization on obesity and inflammatory bowel diseases. It has been suggested that western type diet precedes full industrialization and this could promote obesity.

Oxidative Stress in the Pathogenesis of Crohn's Disease and the Interconnection with Immunological Response, Microbiota, External Environmental Factors, and Epigenetics

Inflammatory bowel disease (IBD) is a complex multifactorial disorder in which external and environmental factors have a large influence on its onset and development, especially in genetically susceptible individuals. Crohn’s disease (CD), one of the two types of IBD, is characterized by transmural inflammation, which is most frequently located in the region of the terminal ileum. Oxidative stress, caused by an overabundance of reactive oxygen species, is present locally and systemically in patients with CD and appears to be associated with the well-described imbalanced immune response and dysbiosis in the disease. Oxidative stress could also underlie some of the environmental risk factors proposed for CD. Although the exact etiopathology of CD remains unknown, the key role of oxidative stress in the pathogenesis of CD is extensively recognized. Epigenetics can provide a link between environmental factors and genetics, and numerous epigenetic changes associated with certain environmental risk factors, microbiota, and inflammation are reported in CD. Further attention needs to be focused on whether these epigenetic changes also have a primary role in the pathogenesis of CD, along with oxidative stress.

Targeting desmosomal adhesion and signalling for intestinal barrier stabilization in inflammatory bowel diseases-Lessons from experimental models and patients

Inflammatory bowel diseases (IBD) such as Crohn's disease (CD) and Ulcerative colitis (UC) have a complex and multifactorial pathogenesis which is incompletely understood. A typical feature closely associated with clinical symptoms is impaired intestinal epithelial barrier function. Mounting evidence suggests that desmosomes, which together with tight junctions (TJ) and adherens junctions (AJ) form the intestinal epithelial barrier, play a distinct role in IBD pathogenesis. This is based on the finding that desmoglein (Dsg) 2, a cadherin-type adhesion molecule of desmosomes, is required for maintenance of intestinal barrier properties both in vitro and in vivo, presumably via Dsg2-mediated regulation of TJ. Mice deficient for intestinal Dsg2 show increased basal permeability and are highly susceptible to experimental colitis. In several cohorts of IBD patients, intestinal protein levels of Dsg2 are reduced and desmosome ultrastructure is altered suggesting that Dsg2 is involved in IBD pathogenesis. In addition to its adhesive function, Dsg2 contributes to enterocyte cohesion and intestinal barrier function. Dsg2 is also involved in enterocyte proliferation, barrier differentiation and induction of apoptosis, in part by regulation of p38MAPK and EGFR signalling. In IBD, the function of Dsg2 appears to be compromised via p38MAPK activation, which is a critical pathway for regulation of desmosomes and is associated with keratin phosphorylation in IBD patients. In this review, the current findings on the role of Dsg2 as a novel promising target to prevent loss of intestinal barrier function in IBD patients are discussed.

The Association of Gut Microbiota and Treg Dysfunction in Autoimmune Diseases

Autoimmune conditions affect 23 million Americans or 7% of the US population. There are more than 100 autoimmune disorders, affecting every major organ system in humans. This chapter aims to further explain Treg dysfunction autoimmune disorders, including monogenic primary immune deficiency such as immune dysregulation polyendocrinopathy, enteropathy, X-linked inheritance (IPEX) syndrome, and polygenic autoimmune diseases with Treg dysfunction such as multiple sclerosis (MS), inflammatory bowel disease (IBD), and food allergy. These conditions are associated with an abnormal small intestinal and colonic microbiome. Some disorders clearly improve with therapies aimed at microbial modification, including probiotics and fecal microbiota transplantation (FMT). Approaches to prevent and treat these disorders will need to focus on the acquisition and maintenance of a healthy colonic microbiota, in addition to more focused approaches at immune suppression during acute disease exacerbations.

Epidemiologic trend of pediatric inflammatory bowel disease in Latin America: The Latin American Society for Pediatric Gastroenterology, Hepatology and Nutrition (LASPGHAN) Working Group

INTRODUCTION AND OBJECTIVES

The primary aim was to explore the epidemiologic trend of pediatric inflammatory bowel disease in Latin America, and the secondary aims were to obtain an overview of the diagnostic/therapeutic focus of the members of the LASPGHAN and examine the relation of case frequency to year, during the study period.

MATERIALS AND METHODS

Latin American pediatric gastroenterologists participated in an online survey, conducted through the SurveyMonkey platform, that investigated the yearly frequency of new inflammatory bowel disease patients within the time frame of 2005 to 2016, their disease variety, the gastrointestinal segments affected, and the diagnostic and treatment methods utilized. The correlation of new case frequency with each study year was evaluated.

RESULTS

A total of 607 patients were studied. The diagnoses were ulcerative colitis in 475 (78.3%) cases, Crohn's disease in 104 (17.1%), and inflammatory bowel disease D unclassified in 28 (4.6%). The trend in ulcerative colitis was a lineal increase in the frequency of new cases related to each study year, with a significant correlation coefficient. Pancolitis was found in 67.6% of the patients. The diagnostic methods included clinical data, endoscopy, and biopsies in more than 99% of the cases, and imaging studies were indicated selectively. Drug regimens were limited to 5-aminosalicylic acid derivatives, azathioprine, 6-mercaptopurine, infliximab, and adalimumab.

CONCLUSIONS

Pediatric inflammatory bowel disease in Latin America appears to have increased during the years included in the study period, with a predominance of moderate or severe ulcerative colitis. That lineal trend suggests the predictive likelihood of a gradual increase in the coming years, with possible epidemiologic and clinical implications.

Effects of Vitamin D3 on Intestinal Flora in a Mouse Model of Inflammatory Bowel Disease Treated with Rifaximin

BACKGROUND Rifaximin is an antimicrobial agent used to treat inflammatory bowel disease (IBD). Vitamin D3 can control IBD due to its effects on inflammatory cytokines. The purpose of this study was to assess the effect of vitamin D3 on the intestinal flora of a dextran sulfate sodium (DSS)-induced mouse model treated with rifaximin. MATERIAL AND METHODS The mouse model of IBD was developed using DSS (4%) administered via the drinking water. Twenty-four male C57BL6 mice were divided into the control group with a normal diet (N=6), the DSS group with a normal diet (N=6), the DSS group with a normal diet treated with rifaximin (N=6), and the DSS group with a normal diet treated with rifaximin and vitamin D3 (N=6). After 14 days, the colonic tissue was studied histologically. Serum levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1ß (IL-1ß) and enzyme-linked immunosorbent assay (ELISA) were used to measure the level of IL-6 and P65, and phospho-p65 was measured by western blot. 16S rRNA gene sequencing was used to analyze fecal samples. RESULTS In the DSS mouse model of IBD, rifaximin reduced the inflammation severity of the colon and reduced the expression of phospho-p65, p65, TNF-alpha, and IL-6. In the DSS+rifaximin+vitamin D3 group, the therapeutic influences of rifaximin, in terms of weight loss and colonic disease activity, were significantly reduced, and the gut microbiota of the mice were completely changed in composition and diversity. CONCLUSIONS In a mouse model of IBD, treatment with vitamin D3 significantly increased the metabolism of rifaximin and reduced its therapeutic effects.

Knowledge and awareness of biosimilars and shared decision-making among gastroenterology team members in Colorado, USA

Background: There are gaps in gastroenterologist team members' understanding of various topics related to biosimilars. We aimed to examine perspectives, views, and attitudes toward biosimilar and shared decision-making (SDM) among gastroenterology team members in Colorado, USA. The ultimate goal was to increase knowledge and awareness of biosimilars and SDM. Research design and methods: We developed educational materials focused on biosimilars and SDM and distributed them to each participating gastroenterology office. Subsequently, we conducted a survey of all team members from participating offices. Results: Responses were obtained from 54 gastroenterology team members. Most respondents identified the correct answer regarding biosimilars, the nocebo effect, and SDM. Almost half (47.2%) of respondents scored their level of awareness regarding biosimilars prior to reading our educational materials as poor, and nearly one quarter (26.4%) indicated so for SDM. Improvement in scores after reading our materials was significant for both biosimilars and SDM (i.e. biosimilar: z = 6.276, p-value <0.001 and SDM z = 6.328, p-value <0.001). Conclusions: Educational efforts effectively increased the low baseline knowledge and awareness of biosimilars and SDM among gastroenterology team members. More educational projects focused on biosimilars and SDM are needed to reduce the nocebo effect and prevent hampering of the cost-savings of biosimilars.

High-throughput sequencing provides insights into oral microbiota dysbiosis in association with inflammatory bowel disease

Although the prevalence of inflammatory bowel disease (IBD) has been increasing worldwide, the etiology remains elusive. Investigating oral microbiota dysbiosis is essential to understanding IBD pathogenesis. Our study evaluated variations in salivary microbiota and identified potential associations with IBD. The saliva microbiota of 22 IBD patients and 8 healthy controls (HCs) was determined using 16S ribosomal RNA (rRNA) gene sequencing and analyzed using QIIME2. A distinct saliva microbiota dysbiosis in IBD, characterized by alterations in microbiota biodiversity and composition, was identified. Saccharibacteria (TM7), Absconditabacteria (SR1), Leptotrichia, Prevotella, Bulleidia, and Atopobium, some of which are oral biofilm-forming bacteria, were significantly increased. Moreover, levels of inflammatory cytokines associated with IBD were elevated and positively correlated with TM7 and SR1. Functional variations include down-regulation of genetic information processing, while up-regulation of carbohydrate metabolism and protein processing in the endoplasmic reticulum in IBD. Our data implicate salivary microbiota dysbiosis involving in IBD pathogenesis.

Changing Patterns of Relationships Between Geographic Markers and IBD: Possible Intrusion of Obesity

Background

Latitude and lactase digestion status influence incidence and prevalence rates of some noncommunicable diseases. Latitudinal correlations helped define beneficial roles of vitamin D in many diseases like inflammatory bowel disease (IBD). In view of recent global expansion of IBD and population migrations, we reexamine relations with these markers. As these changes also paralleled the pandemic of obesity, we explore possible interactions with IBD.

Methods

We undertook a literature review to compare rates of obesity, Crohn's disease and ulcerative colitis with the geographic markers of lactase digestion status, average population-weighted national latitude, and national yearly sunshine exposure. Pearson correlations were used throughout to determine r correlation factors. Statistical significance was accepted at P <0.05 using 2-tailed tests.

Results

Forty-seven countries were matched with various data sets that could be analyzed (range of availability was 49%-85%). While global correlations of IBD with latitude and lactase status remain similar to previous analyses, in Europe and Asia, outcomes were different. Global outcome contains a statistical paradox related to combining countries from Europe and Asia. Obesity showed moderate global correlations with IBD but weak and negligible correlations in Europe and Asia. There was also a weak global correlation with latitude.

Conclusions

It is suggested that global correlations point to parallel geographic spread of IBD and obesity. The lack of latitudinal relations with obesity suggests reduced vitamin D effect. The paradox supports epidemiological differences in western and eastern IBD. Obesity combined with IBD may contribute to different relations, partly due to variable vitamin D effects.

Obacunone Protects Against Ulcerative Colitis in Mice by Modulating Gut Microbiota, Attenuating TLR4/NF-κB Signaling Cascades, and Improving Disrupted Epithelial Barriers

Obacunone, a natural limonoid compound abundantly distributed in citrus fruits, possesses various biological properties, such as antitumor, antioxidant, and antiviral activities. Recent studies suggested an anti-inflammatory activity of obacunone in vitro, but its efficacy on intestinal inflammation remains unknown. This study was designed to evaluate the effects and mechanisms of obacunone in ameliorating intestinal inflammation in a mouse model of ulcerative colitis (UC). We found that obacunone efficiently alleviated the severity of dextran sulfate sodium (DSS)-induced mouse UC by modulating the abnormal composition of the gut microbiota and attenuating the excessive activation of toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling. The intestinal epithelial barrier was disrupted in DSS colitis mice, which was associated with activation of inflammatory signaling cascades. However, obacunone promoted the expression of tight junction proteins (TJP1 and occludin) and repressed the activation of inflammatory signaling cascades. In summary, our findings demonstrated that obacunone attenuated the symptoms of experimental UC in mice through modulation of the gut microbiota, attenuation of TLR4/NF-κB signaling cascades, and restoration of intestinal epithelial barrier integrity.

Rutaecarpine inhibits KEAP1-NRF2 interaction to activate NRF2 and ameliorate dextran sulfate sodium-induced colitis

Inflammatory bowel disease (IBD) represents a group of chronic relapsing intestinal disorders. Rutaecarpine (RUT), isolated from the Traditional Chinese Medicine (TCM) of Evodia rutaecarpa, was reported to suppress IBD. However, the mechanism by which RUT ameliorates dextran sulfate sodium (DSS)-induced IBD is largely unknown. By use of nuclear factor-erythroid 2-related factor 2 (NRF2) knockout mice, cell-based studies, surface plasmon resonance (SPR), western blotting analysis, and molecular docking studies, the mechanism by which RUT affects DSS-induced colitis was explored. In DSS-treated wild-type mice but not in Nrf2-null mice, RUT significantly improved colitis as revealed by rescued body weight loss, improved histology and inflammation, and induced expression of NRF2 target genes in colon and ileum. Cell-based studies showed that RUT significantly increased the LD₅₀ for hydrogen peroxide (H₂O₂)-induced cell damage, activated NRF2 nuclear translocation, and suppressed the production of reactive oxygen species in H₂O₂-treated HCT116 cells, activated NRF2 luciferase reporter activities in HCT116 cells and HepG2 cells, and induced expression of NRF2 target genes in primary intestinal epithelial cells. Molecular docking in silico and SPR assays indicated that RUT interacted with kelch-like ECH-associated protein 1 (KEAP1), and extracellular incubation studies revealed that RUT bound to the KEAP1 kelch domain with a calculated equilibrium dissociation constant K_d of 19.6 μM. In conclusion, these results demonstrate that RUT ameliorates DSS-induced colitis, dependent on NRF2, and could be a potential therapeutic option for IBD patients. Mechanistically, RUT potentiates NRF2 nuclear translocation to upregulate NRF2-mediated antioxidant response by directly inhibiting KEAP1-NRF2 interaction.

Orofacial granulomatosis: a questionnaire study among Norwegian dental clinicians

Aims

To evaluate awareness on orofacial granulomatosis (OFG) and oral Crohn disease (oral CD) among Norwegian dental clinicians.

Methods

A precoded questionnaire (QuestBack) was sent electronically to dentists and dental hygienists treating children and adolescents in the public dental service (PDS) in Norway. Data on the clinicians’ knowledge of OFG and oral CD related to working experience were analysed by Chi square tests and bivariate logistic regression analyses.

Results

A total of 1097 clinicians were invited to participate, 778 dentists and 319 dental hygienists; 48.2% returned the completed form. Fifty-four percent of the participants had ≥ 10 year experience of clinical practice. Two-thirds (68.4%) of the dentists and all but one of the dental hygienists graduated in Norway. Approximately half of the respondents were aware of OFG (41.2%) and oral CD (57.8%). One-quarter (24.6%) reported that they most likely had seen a patient with OFG and 20.6% with oral CD. Recently graduated dentists (≤ 10 years ago) were more aware of OFG and oral CD than those who graduated > 10 years ago (p ≤ 0.001). Regarding dental hygienists, this difference was observed for OFG only (p < 0.05). Country of education did not affect the clinicians’ reported knowledge. Approximately 90% would refer a patient suspected of having OFG or oral CD either to a dental specialist or to a physician.

Conclusion

The high prevalence of clinicians observing OFG and oral CD in this study may indicate that OFG and/or oral CD are under-reported and that OFG in particular is more common than hitherto believed. The high frequency of awareness was promising for the benefit of the patients.

The Functional Role of Fecal Microbiota Transplantation on Dextran Sulfate Sodium-Induced Colitis in Mice

Increasingly studies revealed that dysbiosis of gut microbiota plays a pivotal role in the pathogenesis of ulcerative colitis (UC). Fecal microbiota transplantation (FMT) has drawn more and more attention and become an important therapeutic approach. This study aims to examine the facts about the effective components and look into potential mechanisms of FMT. Colitis was induced by 3% (w/v) dextran sulfate sodium (DSS) in drinking water for 7 days. Colitis mice were administered by oral gavage with fecal suspension, fecal supernatant, fecal bacteria, or boiling-killed fecal bacteria from healthy controls and the disease activity index was monitored daily. On the seventh day, mice were euthanized. The length, histological score, parameters related to inflammation, gut barrier functions of the colon, activities of digestive protease and β-glucuronidase in feces were measured. All of the four fecal components showed certain degree of efficacy in DSS-induced colitis, while transplantation of fecal suspension showed the most potent effect as demonstrated by less body weight loss, lower disease activity scores, more expression of tight junction proteins and TRAF6 and IκBα, less expression of TNF-α, IL-1β, IL-10, TLR-4, and MyD88 in gut tissue, as well as restoration of fecal β-glucuronidase and decreases in fecal digestive proteases. These results provide a novel insight into the possible mechanism of FMT and may help to improve and optimize clinical use of FMT.

Identification of Epigenetic Methylation Signatures With Clinical Value in Crohn's Disease

INTRODUCTION

DNA methylation is an epigenetic mechanism that regulates gene expression and represents an important link between genotype, environment, and disease. It is a reversible and inheritable mechanism that could offer treatment targets. We aimed to assess the methylation changes on specific genes previously associated with Crohn's disease (CD) and to study their possible associations with the pathology.

METHODS

We included 103 participants and grouped them into 2 cohorts (a first [n = 31] and a second validation [n = 72] cohort), with active CD (aCD) and inactive CD (iCD) and healthy participants (CTR). DNA was obtained from the peripheral blood and analyzed by the Agena platform. The selected genes were catalase (CAT), α-defensin 5 (DEFA5), FasR, FasL, tumor necrosis factor (TNF), TNFRSF1A, TNFRSF1B, PPA2, ABCB1, NOD2, PPARγ, and PKCζ. We used the elastic net algorithm and R software.

RESULTS

We studied 240 CpGs. Sixteen CpGs showed differential methylation profiles among aCD, iCD, and CTR. We selected for validation those with the greatest differences: DEFA5 CpG_11; CpG_13; CAT CpG_31.32; TNF CpG_4, CpG_12; and ABCB1 CpG_21. Our results validated the genes DEFA5 (methylation gain) and TNF (methylation loss) with P values < 0.001. In both cases, the methylation level was maintained and did not change with CD activity (aCD vs iCD). The subanalysis comparison between aCD and iCD showed significant differential methylation profiles in other CpGs: TNF, FAS, ABCB1, CAT, and TNFRS1BF genes.

DISCUSSION

The methylation status of DEFA5 and TNF genes provides a signature biomarker that characterizes patients with CD and supports the possible implication of the environment and the immune system in CD pathogenesis.

Changing epidemiology of immune-mediated inflammatory diseases in immigrants: A systematic review of population-based studies

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are systemic diseases of multifactorial etiology that share aberrant immune responses as the common final pathway. With rising globalization, their incidence is increasing in developing countries and among immigrants. Our primary objective was to systematically review the epidemiology of IMIDs in immigrants and conduct a meta-analysis to estimate the risk of IMIDs in immigrant populations according to their origin and destination countries.

METHODS

We systematically searched five biomedical databases and reviewed population-based studies, from inception through August 2018, that reported incidence or prevalence data of inflammatory bowel disease (IBD), multiple sclerosis (MS), type 1 diabetes (T1D), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ankylosing spondylitis (AS) or psoriasis and psoriatic arthritis (PPA) among immigrants and the host population.

RESULTS

The incidence and prevalence of IMIDs among immigrants differ from host populations, and evolve over subsequent generations. The risk of IBD among immigrants approximates that in hosts, especially among South Asians, with ulcerative colitis incidence changing prior to Crohn's disease incidence. MS risk is highest in Iranian immigrants, T1D in African immigrants and SLE in African and Iraqi immigrants. Data on other IMIDs are sparse. Significant heterogeneity between the studies precluded meta-analysis.

CONCLUSION

Based on our systematic review, the epidemiology of IMIDs among immigrants varies according to native and host countries, immigrant generation, and IMID type. The rapid evolution suggests a role for non-genetic factors and gene-environment interactions. Future studies should focus on these pattern shifts, given implications of rising global burden of IMIDs and immigration.

Epigenetics of Inflammatory Bowel Disease: Unraveling Pathogenic Events

Epigenetics has emerged as a new and promising field in recent years. Because there exists a need to find new biomarkers and improve diagnosis, prognosis, and drug response for inflammatory bowel diseases, the research on epigenetic biomarkers for molecular diagnostics encourages the translation of this field from the bench to the clinical practice. In this review, we present an overview of the current knowledge and its potential applicability of this emerging field in inflammatory bowel diseases.

Bryostatin-1 ameliorated experimental colitis in Il-10-/- Mice by protecting the intestinal barrier and limiting immune dysfunction

Bryostatin‐1 (Bry‐1) has been proven to be effective and safe in clinical trials of a variety of immune‐related diseases. However, little is known about its effect on Crohn's disease (CD). We aimed to investigate the impact of Bry‐1 on CD‐like colitis and determine the mechanism underlying this effect. In the present study, 15‐week‐old male Il‐10^−/− mice with spontaneous colitis were divided into positive control and Bry‐1‐treated (Bry‐1, 30 μg/kg every other day, injected intraperitoneally for 4 weeks) groups. Age‐matched, male wild‐type (WT) mice were used as a negative control. The effects of Bry‐1 on colitis, intestinal barrier function and T cell responses as well as the potential regulatory mechanisms were evaluated. We found that the systemic delivery of Bry‐1 significantly ameliorated colitis in Il‐10^−/− mice, as demonstrated by decreases in the disease activity index (DAI), inflammatory score and proinflammatory mediator levels. The protective effects of Bry‐1 on CD‐like colitis included the maintenance of intestinal barrier integrity and the helper T cell (Th)/regulatory T cell (Treg) balance. These effects of Bry‐1 may act in part through nuclear factor erythroid 2‐related factor 2 (Nrf2) signalling activation and STAT3/4 signalling inhibition. The protective effect of Bry‐1 on CD‐like colitis suggests Bry‐1 has therapeutic potential in human CD, particularly given the established clinical safety of Bry‐1.

Dietary Composition and Effects in Inflammatory Bowel Disease

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

Westernized Diet is the Most Ubiquitous Environmental Factor in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a collective term for Crohn disease and ulcerative colitis, is a polygenic disease thought to be triggered by environmental factors. A Western or westernized lifestyle may be a major driver of the growing incidence of IBD. IBD may represent dysregulated mucosal inflammation to gut microbiota. Despite many review articles on environmental factors in IBD, no consensus exists regarding which factor contributes most to trigger the onset of IBD. Identification and recognition of major environmental factors are prerequisite for effective disease treatment and prevention. Representative environmental factors such as smoking, breastfeeding, nonsteroidal anti-inflammatory drugs, antibiotic use in childhood, oral contraceptives, and appendectomy do not correlate with disease onset in most patients with IBD. In contrast, diet appears to be important in most cases of IBD. Diets rich in animal protein (risk factor) and deficient in dietary fiber (preventive factor) are characteristic of westernized diets in affluent societies. Recent research shows that westernized diets are associated with a reduced gut microbial diversity (dysbiosis), which may result in increased susceptibility to IBD and other common chronic diseases. Plant-based diets rich in dietary fiber are associated with increased microbial diversity. Recent reports on IBD therapy that replaced westernized diets with plant-based diets achieved far better outcomes than those previously reported in the literature. We believe that westernized diet-associated gut dysbiosis is the most ubiquitous environmental factor in IBD. Adoption of this concept may have the potential to provide a better quality of life for patients with IBD.

Bacterial β-glucuronidase alleviates dextran sulfate sodium-induced colitis in mice: A possible crucial new diagnostic and therapeutic target for inflammatory bowel disease

OBJECTIVE

Inflammatory bowel diseases (IBD) including ulcerative colitis and Crohn's disease are devastating diseases of the gut. At present, all the treatments are mainly targeting symptoms like inflammation. The disease remains regarded as incurable, largely due to lacking of knowledge on its etiology. Our previous studies suggested that impaired inactivation of digestive proteases by deconjugated bilirubin in experimental colitis, thus bacterial β-glucuronidase for catalyzing the reaction, may have played critical role in the pathogenesis of IBD.

METHODS

We first analyzed β-glucuronidase activity in gut tissue and feces of mice by a colitis model. Then the effect of β-glucuronidase on experimental colitis was investigated in detail by administration of β-glucuronidase (from E. coli) and fecal material transplantation to mice with 3% DSS in drinking water for 7 days.

RESULTS

Mice with colitis showed unchanged activity of β-glucuronidase in colon tissue but decreased activity in feces. Treatment with bacterial β-glucuronidase at 100 U or above alleviated DSS-induced colitis as demonstrated by the less body weight loss, less disease activity score, increased expression of tight junction proteins and decreased gut permeability, decreases in MPO, TNF-α, IL-1β, TLR-4 and MyD88, and increase in IL-10 and IκBα in gut, restored fecal β-glucuronidase and gut microbiota along with decreases in fecal digestive proteases. Transplantation of fecal material from control to colitis mice showed similar effects as treatment with β-glucuronidase.

CONCLUSIONS

Bacterial β-glucuronidase showed strong inhibition on colitis along with the reduction in fecal digestive proteases, which may be a crucial diagnostic and therapeutic target for IBD.

The Multifactorial Etiopathogeneses Interplay of Inflammatory Bowel Disease: An Overview

The gastrointestinal system where inflammatory bowel disease occurs is central to the immune system where the innate and the adaptive/acquired immune systems are balanced in interactions with gut microbes under homeostasis conditions. This article overviews the high-throughput research screening on multifactorial interplay between genetic risk factors, the intestinal microbiota, urbanization, modernization, Westernization, the environmental influences and immune responses in the etiopathogenesis of inflammatory bowel disease in humans. Inflammatory bowel disease is an expensive multifactorial debilitating disease that affects thousands new people annually worldwide with no known etiology or cure. The conservative therapeutics focus on the established pathology where the immune dysfunction and gut injury have already happened but do not preclude or delay the progression. Inflammatory bowel disease is evolving globally and has become a global emergence disease. It is largely known to be a disease in industrial-urbanized societies attributed to modernization and Westernized lifestyle associated with environmental factors to genetically susceptible individuals with determined failure to process certain commensal antigens. In the developing nations, increasing incidence and prevalence of inflammatory bowel disease (IBD) has been associated with rapid urbanization, modernization and Westernization of the population. In summary, there are identified multiple associations to host exposures potentiating the landscape risk hazards of inflammatory bowel disease trigger, that include: Western life-style and diet, host genetics, altered innate and/or acquired/adaptive host immune responses, early-life microbiota exposure, change in microbiome symbiotic relationship (dysbiosis/dysbacteriosis), pollution, changing hygiene status, socioeconomic status and several other environmental factors have long-standing effects/influence tolerance. The ongoing multipronged robotic studies on gut microbiota composition disparate patterns between the rural vs. urban locations may help elucidate and better understand the contribution of microbiome disciplines/ecology and evolutionary biology in potentially protecting against the development of inflammatory bowel disease.

Paediatric inflammatory bowel disease: review with a focus on practice in low- to middle-income countries

Inflammatory bowel disease (IBD) should be considered in any child with a persistently altered bowel habit. Growth failure may be a consequence and there may also be extra-intestinal manifestations. Oesophago-gastroduodenoscopy and colonoscopy and conventional histopathology are the diagnostic tools of choice in IBD. The identification and management of children with IBD in resource-poor settings is difficult and there are few data on its prevalence in low- and middle-income countries. The main challenges are a lack of resources and infrastructure including trained personnel in settings where there are other priorities for maintaining the health and wellbeing of children. The identification and management of children with inflammatory bowel conditions often depends on the enthusiasm, skill and commitment of a few dedicated individuals. Abbreviations: ADA: Adalimumab; CD: Crohn disease; ECCO: European Crohn's and Colitis Organisation; EEN: exclusive enteral nutrition; ESPGHAN: European Society for Paediatric Gastroenterology Hepatology and Nutrition; FMT: faecal microbiota transplantation; GDP: gross domestic product; HIC: high-income countries; IBD: inflammatory bowel disease; IBDU: inflammatory bowel disease unclassified; IC: ileocolonoscopy; IFX: infliximab; IPAA: ileal pouch anal anastomosis; LMIC: low- and middle-income countries; MH: mucosal healing; OGD: oesophago-gastroduodenoscopy; PCDAI: Paediatric Crohn's Disease Activity Index; PIBD: paediatric inflammatory bowel disease; PUCAI: Paediatric Ulcerative Colitis Activity Index; UC: ulcerative colitis; UGIT: upper gastrointestinal tract; VEO-IBD: very early-onset IBD; WLE: white light endoscopy; 5-ASA: 5 aminosalicylic acid; 6-MP: 6-mercaptopurine.

Stress Triggers Flare of Inflammatory Bowel Disease in Children and Adults

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease characterized by chronic and relapsing manifestations. It is noteworthy that the prevalence of IBD is gradually increasing in both children and adults. Currently, the pathogenesis of IBD remains to be completely elucidated. IBD is believed to occur through interactions among genetics, environmental factors, and the gut microbiota. However, the relapsing and remitting course of IBD underlines the importance of other modifiers, such as psychological stress. Growing evidence from clinical and experimental studies suggests that stress acts as a promoting or relapsing factor for IBD. Importantly, recent studies have reported an increasing incidence of anxiety or depression in both children and adults with IBD. In this article, we review the mechanisms by which stress affects IBD, such as via impaired intestinal barrier function, disturbance of the gut microbiota, intestinal dysmotility, and immune and neuroendocrine dysfunction. With regard to both children and adults, we provide recent evidence to describe how stress can affect IBD at various stages. Furthermore, we emphasize the importance of mental healing and discuss the value of approaches targeting stress in clinical management to develop enhanced strategies for the prevention and treatment of IBD.

Inflammatory Bowel Disease Etiology: Current Knowledge

Non-specific inflammatory bowel diseases (IBD) include Crohn’s disease (CD) and ulcerative colitis (UC). Both diseases are characterized by chronic inflammation of unclear etiology. The inflammatory bowel diseases incidence is continuously observed to rise. Colon inflammatory response is a physiological process which occurrence is indispensable as an organisms’ defense reaction. The inflammation may be caused by internal factors associated with body’s cells as well as external factors, such as infections and exposition for inflammatory agents. Until recently, IBD have been classified as autoimmune diseases, today they seem to be associated with gut barrier disorders or dysbiosis. Factors that predispose to inflammatory bowel diseases include: genetic factors, dysbiosis and so called western-type diet, natural components such as gluten and lactose. In addition, the development of the disease is favored by: cigarette smoking, phosphate, nanomolecules, sodium chloride, emulgents, carrageenan, carboxymethylcellulose, pollution, maltodextrin. IBD affects whole the body, causing serious medical consequences. Symptoms like anxiety and chronic stress, that occur commonly, can lead to depressive disorders. Quantitative and qualitative dietary deficiency caused by absorption disorders, may promote the occurrence of osteoporosis and osteopenia. In addition, dysbiosis coexisting with alterations in intestinal permeability can lead to the development of nonalcoholic fatty liver disease. IBD medical consequences include also systemic complications, associated with the extra gastrointestinal manifestations’ occurrence.

Chronic regional intestinal inflammatory disease: A trans-species slow infection?

Crohn's disease and ulcerative colitis in humans and paratuberculosis in domestic and wild ruminants can be defined as chronic regional intestinal inflammatory diseases (CRIID). This review is a literature overview on these diseases in humans, non-human primates, dogs, cats, rabbits, equids and ruminants with a focus on pathological and microbiological features aimed identifying common characteristics that could lead to a unified pathological classification for a better understanding of their mechanisms and causes. The result is a framework of inflammatory forms throughout the different species indicative of common mechanisms of the slow infection type characterized by a time course varying from weeks to months or even years, and where the inflammatory component would be more prominent in the intestinal interphase between host and environment and be morphologically characterized by an infiltrate ranging from lymphoplasmacytic to histiocytic. This should provide new insights for causation demonstration and therapeutic approaches in human IBD.

Effects of Azithromycin on Behavior, Pathologic Signs, and Changes in Cytokines, Chemokines, and Neutrophil Migration in C57BL/6 Mice Exposed to Dextran Sulfate Sodium

Here we characterized the murine dextran sulfate sodium (DSS) model of acute colitis. Specifically, we evaluated azithromycin and metronidazole treatment regimens to assess their effects on animal wellbeing, pathologic changes, barrier function, cytokine and chemokine profiles, and neutrophil migration in colon tissue. Azithromycin treatment significantly reduced the severity of colitis, as assessed through body weight change, water consumption, macroscopic lesions, and animal behaviors (activity level, climbing, and grooming), but did not alter food consumption or feeding behavior. Mucosal barrier function (evaluated by using FITC-labeled dextran) was decreased after DSS exposure; azithromycin did not significantly alter barrier function in mice with colitis, whereas metronidazole exacerbated the colitis-related deficit in barrier function. In addition, metronidazole appeared to exacerbate disease as assessed through water consumption and animal behaviors (overall activity, climbing, grooming, and drinking) but had no effect on weight loss, macroscopic lesions, or eating behavior. Pathologic changes were typical for DSS treatment. Antibiotic treatment resulted in reduced levels of proinflammatory cytokines and chemokines and decreased neutrophil adhesion and emigration in DSS-exposed mice. The results highlight the importance of clinical and behavioral assessments in addition to laboratory evaluation as tools to evaluate animal welfare and therapeutic efficacy in disease models. Data from this study suggest that azithromycin may convey some benefits in the mouse DSS colitis model through modulation of the immune response, including neutrophil migration into tissues, whereas metronidazole may exacerbate colitis.

The Impact of Inflammatory Bowel Disease in Canada 2018: A Scientific Report from the Canadian Gastro-Intestinal Epidemiology Consortium to Crohn's and Colitis Canada

Canada has among the highest rates of IBD in the world, and the number of people living with these disorders is growing rapidly. This has placed a high burden on the health care system and on the Canadian economy—a burden that is only expected to grow in the future. It is important to understand IBD and its impact on Canadian society in order to appropriately plan for health care expenditures, reduce the burden on patients and their families, and improve the quality of life for those afflicted with IBD. In Canada, there is a lack of public awareness of the impact of Crohn’s disease and ulcerative colitis. Raising awareness is crucial to reducing the social stigma that is common with these diseases and to help individuals maximize their overall quality of life. A better public understanding of IBD can also help to raise and direct funds for research, which could lead to improved treatments and, ultimately, to a cure. This report from Canadian clinicians and researchers to Crohn’s and Colitis Canada makes recommendations aimed at the public, policy-makers, scientific funding agencies, charitable foundations and patients regarding future directions for advocacy efforts and areas to emphasize for research spending. The report also identifies gaps in knowledge in the fields of clinical, health systems and epidemiological research.

The Impact of Inflammatory Bowel Disease in Canada 2018: Epidemiology

Canada has among the highest incidence and prevalence of inflammatory bowel disease (IBD) in the world. After decades of rising incidence of IBD in Canada during the 20th Century, the prevalence of IBD in 2018 is 0.7% of the Canadian population. Forecasting models predict that prevalence of IBD will continue to rise to 1.0% of the population by 2030. In 2018, the number of Canadians living with IBD is approximately 270,000 and is predicted to rise to 403,000 Canadians in 2030. Inflammatory bowel disease affects all age groups with adolescents and young adults at highest risk of diagnosis. Canadians of all ethnicities are being diagnosed with IBD including known high-risk groups such as Ashkenazi Jews and offspring of South Asian immigrants who were previously thought to be low risk. Moreover, IBD has evolved into a global disease with rising incidence in newly industrialized countries in Asia and South America. The causes of IBD remain unsolved; however, the high rates of disease in Western countries and its emergence in newly industrialized countries suggest that environmental factors associated with urbanization, modernization, or Western diets may be pertinent to understanding the pathogenesis of the disease.

Highlights

1. Canada continues to have among the highest prevalence of IBD in the world.

2. Today, approximately 270,000 Canadians live with IBD. By 2030 it is estimated that nearly 403,000 Canadians will have a diagnosis of IBD.

3. Inflammatory bowel disease has become a worldwide disease with increasing rates in Asia, Africa, and South America—continents where IBD was rarely diagnosed prior to 1990.

4. The causes of IBD are unknown, but the high rates of disease over the past 60 years in Western countries and the emergence of disease in developing countries suggest that factors associated with urbanization, modernization, or Western diets may be pertinent to understanding the pathogenesis of the disease.

5. Many of the leading hypotheses as to the causes of IBD tie in with alteration of the gut microbiome, the suite of organisms that reside in the bowel and maintain bowel health throughout life.

Key Summary Points

1. The incidence (the number of new diagnoses annually) of IBD rose throughout the 20th century in Canada and then stabilized at the turn of the 21st century.

2. The prevalence (the total number of diagnosed persons in the population) of IBD in Canada is among the highest in the world.

3. Today, 270,000 (0.7%, or 7 in 1000) Canadians are estimated to live with IBD. By 2030, that number is expected to rise to 403,000 Canadians (1% or 1 in 100).

4. Inflammatory bowel disease can be diagnosed at any age. However, the age groups that are most likely to be diagnosed are adolescents and young adults from 20 to 30 years of age.

5. Inflammatory bowel disease in Canada affects the lives of Canadians of all ethnicities, including known high-risk groups such as Ashkenazi Jews, and those thought previously to be at low risk, such as first-generation offspring of South Asian immigrants.

6. Canadian health policy makers will need to prepare the Canadian health care system for the rising burden of IBD.

7. As newly industrialized countries in Asia, Africa, and South America are transitioning to a Westernized society, IBD has emerged and its incidence in these countries is rising rapidly.

8. The gut microbiome includes microorganisms that maintain digestive health. Thus, changes in the microbiome, which may change the immune system’s response to triggers, may be important in initiating and perpetuating IBD.

9. A number of factors can alter the gut microbiome and early childhood may be a particularly important time such that breastfeeding, early life diet, use of antibiotics, infections, and other environmental exposures may impact the gut microbiome in such a way that facilitates developing IBD.

10. Smoking is associated with an increased risk and worsening disease course of Crohn’s disease. Quitting smoking is associated with an increased risk of developing ulcerative colitis. Therefore, never initiating smoking can mitigate the risk for IBD. Educational programs aimed at those at-risk for IBD should emphasize the risk of starting to smoke tobacco.

11. Modifying exposure to environmental risk factors associated with the Westernization of society (e.g., Western diet and lifestyles) may provide an avenue for reducing the risk of IBD in Canada and worldwide.

Gaps in Knowledge and Future Directions

1. While the incidence of IBD appears to be stabilizing in some regions in Canada, IBD may be occurring more frequently in certain populations such as in children, South Asians, Ashkenazi Jews, and immigrants. Future research should focus on the changing demographics of IBD in Canada.

2. The prevalence of IBD will rise steadily over the next decade. To enable better health care system planning and to respond adequately to the increasing burden of IBD, ongoing surveillance of the epidemiology and health services utilization of IBD in Canada is necessary.

3. Most studies have focused on the mortality associated with IBD. Future research is necessary to assess health-adjusted life expectancy and overall life expectancy for those living with IBD.

4. Analyses of resources, infrastructure, and personnel need to be modeled into the future in order to prepare our health care system for the rising burden of IBD.

5. Research on the interaction between genes, microbes, and our environment will inform our understanding of the pathogenesis of IBD, information necessary to prevent IBD in the future.