The Interaction between Stress and Inflammatory Bowel Disease in Pediatric and Adult Patients

Background: Inflammatory bowel diseases (IBDs) have seen an exponential increase in incidence, particularly among pediatric patients. Psychological stress is a significant risk factor influencing the disease course. This review assesses the interaction between stress and disease progression, focusing on articles that quantified inflammatory markers in IBD patients exposed to varying degrees of psychological stress. Methods: A systematic narrative literature review was conducted, focusing on the interaction between IBD and stress among adult and pediatric patients, as well as animal subjects. The research involved searching PubMed, Scopus, Medline, and Cochrane Library databases from 2000 to December 2023. Results: The interplay between the intestinal immunity response, the nervous system, and psychological disorders, known as the gut-brain axis, plays a major role in IBD pathophysiology. Various types of stressors alter gut mucosal integrity through different pathways, increasing gut mucosa permeability and promoting bacterial translocation. A denser microbial load in the gut wall emphasizes cytokine production, worsening the disease course. The risk of developing depression and anxiety is higher in IBD patients compared with the general population, and stress is a significant trigger for inducing acute flares of the disease. Conclusions: Further large studies should be conducted to assess the relationship between stressors, psychological disorders, and their impact on the course of IBD. Clinicians involved in the medical care of IBD patients should aim to implement stress reduction practices in addition to pharmacological therapies.

Comorbidity Between Inflammatory Bowel Disease and Asthma and Allergic Diseases: A Genetically Informed Study

BACKGROUND

Little is known about shared origins between inflammatory bowel disease (IBD) and allergic diseases (asthma, allergic rhinitis, and eczema). We aimed to expand current knowledge on the etiological sources of comorbidities between these disorders using a range of genetically informed methods.

METHODS

Within-individual and familial co-aggregation analysis was applied to 2 873 445 individuals born in Sweden from 1987 to 2014 and their first- and second-degree relatives. Quantitative genetic modeling was applied to 38 723 twin pairs to decompose the genetic and environmental sources for comorbidity. Polygenic risk score analysis between IBD and allergic diseases was conducted in 48 186 genotyped twins, and linkage disequilibrium score regression was applied using publicly available data to explore the genetic overlap.

RESULTS

IBD was associated with asthma (adjusted odds ratio [aOR], 1.35; 95% confidence interval [CI], 1.30 to 1.40), allergic rhinitis (aOR, 1.27; 95% CI, 1.20 to 1.34), and eczema (aOR, 1.47; 95% CI, 1.38 to 1.56), with similar estimates for ulcerative colitis or Crohn's disease. The ORs for familial co-aggregation decreased with decreasing genetic relatedness. Quantitative genetic modeling revealed little evidence of common genetic factors between IBD and allergic diseases (eg, IBD and allergic rhinitis; genetic correlation ra = 0.06; 95% CI, -0.03 to 0.15) but did reveal some evidence of unique environmental factors between IBD and eczema (re = 0.16; 95% CI, 0.00 to 0.32). Molecular genetic analyses were similarly null for IBD and allergic diseases, except for a slight association between Crohn's disease polygenic risk score and eczema (OR, 1.09; 95% CI, 1.06 to 1.12).

CONCLUSIONS

We found little evidence to support a shared origin between IBD and any allergic disease but weak evidence for shared genetic and unique environmental components for IBD and eczema.

Dissecting the genetic overlap between three complex phenotypes with trivariate MiXeR

Comorbidities are an increasing global health challenge. Accumulating evidence suggests overlapping genetic architectures underlying comorbid complex human traits and disorders. The bivariate causal mixture model (MiXeR) can quantify the polygenic overlap between complex phenotypes beyond global genetic correlation. Still, the pattern of genetic overlap between three distinct phenotypes, which is important to better characterize multimorbidities, has previously not been possible to quantify. Here, we present and validate the trivariate MiXeR tool, which disentangles the pattern of genetic overlap between three phenotypes using summary statistics from genome-wide association studies (GWAS). Our simulations show that the trivariate MiXeR can reliably reconstruct different patterns of genetic overlap. We further demonstrate how the tool can be used to estimate the proportions of genetic overlap between three phenotypes using real GWAS data, providing examples of complex patterns of genetic overlap between diverse human traits and diseases that could not be deduced from bivariate analyses. This contributes to a better understanding of the etiology of complex phenotypes and the nature of their relationship, which may aid in dissecting comorbidity patterns and their biological underpinnings.

Application Prospect of Induced Pluripotent Stem Cells in Organoids and Cell Therapy

Since its inception, induced pluripotent stem cell (iPSC) technology has been hailed as a powerful tool for comprehending disease etiology and advancing drug screening across various domains. While earlier iPSC-based disease modeling and drug assessment primarily operated at the cellular level, recent years have witnessed a significant shift towards organoid-based investigations. Organoids derived from iPSCs offer distinct advantages, particularly in enabling the observation of disease progression and drug metabolism in an in vivo-like environment, surpassing the capabilities of iPSC-derived cells. Furthermore, iPSC-based cell therapy has emerged as a focal point of clinical interest. In this review, we provide an extensive overview of non-integrative reprogramming methods that have evolved since the inception of iPSC technology. We also deliver a comprehensive examination of iPSC-derived organoids, spanning the realms of the nervous system, cardiovascular system, and oncology, as well as systematically elucidate recent advancements in iPSC-related cell therapies.

Transcriptomic Profiling and Cellular Composition of Creeping Fat in Crohn's disease

BACKGROUND AND AIMS

Creeping fat [CF] is a poorly understood feature of Crohn's disease [CD], characterized by the wrapping of mesenteric adipose tissue [MAT] around the inflamed intestine. The aim of this study was to investigate the transcriptional profile and compositional features of CF.

METHODS

We collected 59 MAT samples: 23 paired samples from patients with CD (CF [CD-CF] and MAT around the uninflamed intestine [CD-MAT]) and 13 MAT samples from non-CD patients [Con-MAT]. Differentially expressed gene [DEG], functional pathway, cell deconvolution, and gene co-expression network analyses were performed.

RESULTS

By comparing three different MAT samples, we identified a total of 529 DEGs [|log2FoldChange| > 1.5; false discovery rate < 0.05]. Of these, 323 genes showed an incremental pattern from Con-MAT to CD-MAT, and to CD-CF, while 105 genes displayed a decremental pattern. Genes with an incremental pattern were related to immune cell responses, including B- and T-cell activation, while genes with a decremental pattern were involved in cell trafficking and migration. Cell deconvolution analysis revealed significant changes in cellular composition between the CD-CF and Con-MAT groups, with increased proportions of B-cells/plasma cells [p = 1.16 × 10-4], T-cells [p = 3.66 × 10-3], and mononuclear phagocytes [p = 3.53 × 10-2] in the CD-CF group. In contrast, only the B-cell/plasma cell component showed a significant increase [p = 1.62 × 10-2] in the CD-MAT group compared to Con-MAT.

CONCLUSION

The distinct transcriptional profiles and altered cellular components of each MAT found in our study provide insight into the mechanisms behind CF and highlight its possible role in the pathogenesis of CD.

The Incidence and Prevalence of Inflammatory Bowel Disease Continues to Increase in the Faroe Islands - A Cohort Study from 1960 to 2020

BACKGROUND AND AIMS

The highest reported incidence rate of inflammatory bowel disease [IBD], and especially of ulcerative colitis [UC], is found in the Faroe Islands. This study aimed to assess the incidence rate and temporal trends in prevalence over six decades.

METHODS

All incident and prevalent patients diagnosed with IBD between 1960 and 2020 from the nationwide and population-based Faroese IBD cohort were included in this study. All patients fulfilled the Copenhagen Diagnostic Criteria.

RESULTS

Overall, 873 individuals were diagnosed with IBD during the study period, 559 [64%] with UC, 151 [17%] with Crohn's disease, and 163 [19%] with IBD unclassified. A total of 59 patients had paediatric-onset IBD. The incidence of IBD continued to increase throughout the study period, as the age-standardized incidence rate started at 8 per 100 000 person-years [py] [European Standard Population, ESP] in 1960-79 and reached 70 by 2010-20. In 2021, the age-standardized period prevalence was 1414 per 100 000 persons. The IBD incidence was unevenly distributed among the islands with Sandoy having the highest rate of 106 per 100 000 py in 2010-2020.

CONCLUSIONS

The incidence of IBD continues to increase in the Faroe Islands, mainly driven by UC. The incidence shows an uneven geographical distribution, which suggests an adverse interaction between unknown environmental factors and genetic traits. The prevalence in 2021 corresponded to 1.3% of the Faroese population. Environmental risk factors are suspected to impact this homogeneous high-risk population; however, the reason for this is unclear.

Validation of the ACE [Albumin, CRP, and Endoscopy] Index in Acute Colitis: Analysis of the CONSTRUCT dataset

BACKGROUND AND AIMS

In 2020 we reported the ACE Index in acute colitis which used biochemical and endoscopic parameters to predict steroid non-response on admission in patients with acute ulcerative colitis [UC]. We aimed to validate the ACE Index in an independent cohort.

METHODS

The validation cohort comprised patients screened as eligible for inclusion in the CONSTRUCT study, a prospective, randomized, placebo-controlled trial which compared the effectiveness of treatment with infliximab vs ciclosporin in patients admitted with acute UC. The CONSTRUCT cohort database was reviewed at The Edinburgh IBD Unit and the same biochemical and endoscopic variables and cut-off values as those in the derivation cohort were applied to the validation cohort.

RESULTS

In total, 800 patients were identified; 62.5% [55/88] of patients with a maximum ACE Index of 3 did not respond to intravenous [IV] steroids (positive predictive value [PPV] 62.5%, negative predictive value [NPV] 79.8%). Furthermore, 79.8% [158/198] of patients with an ACE Index of 0 responded to IV steroids [PPV 79.8%, NPV 62.5%]. Receiver operator characteristic [ROC] curve analysis produced an area under the curve [AUC] of 0.663 [p < 0.001].

CONCLUSIONS

We have now reported and externally validated the ACE Index in acute colitis in a combined cohort of over 1000 patients from across the UK. The ACE Index may be used in conjunction with clinical judgement to help identify patients admitted with active UC who are at high risk of not responding to IV steroids. Further studies are required to improve objectivity and accuracy of assessment.

Transcriptome-wide association studies associated with Crohn's disease: challenges and perspectives

Crohn's disease (CD) is regarded as a lifelong progressive disease affecting all segments of the intestinal tract and multiple organs. Based on genome-wide association studies (GWAS) and gene expression data, transcriptome-wide association studies (TWAS) can help identify susceptibility genes associated with pathogenesis and disease behavior. In this review, we overview seven reported TWASs of CD, summarize their study designs, and discuss the key methods and steps used in TWAS, which affect the prioritization of susceptibility genes. This article summarized the screening of tissue-specific susceptibility genes for CD, and discussed the reported potential pathological mechanisms of overlapping susceptibility genes related to CD in a certain tissue type. We observed that ileal lipid-related metabolism and colonic extracellular vesicles may be involved in the pathogenesis of CD by performing GO pathway enrichment analysis for susceptibility genes. We further pointed the low reproducibility of TWAS associated with CD and discussed the reasons for these issues, strategies for solving them. In the future, more TWAS are needed to be designed into large-scale, unified cohorts, unified analysis pipelines, and fully classified databases of expression trait loci.

Genome-wide association study and Mendelian randomization analyses provide insights into the causes of early-onset colorectal cancer

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC; diagnosed <50 years of age) is rising globally; however, the causes underlying this trend are largely unknown. Colorectal cancer (CRC) has strong genetic and environmental determinants, yet common genetic variants and causal modifiable risk factors underlying EOCRC are unknown. We conducted the first EOCRC-specific genome-wide association study (GWAS) and Mendelian randomization analyses to explore germline genetic and causal modifiable risk factors associated with EOCRC.

PATIENTS AND METHODS

We conducted a genome-wide association study meta-analysis of 6,176 EOCRC cases and 65,829 controls from Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), Colorectal Transdisciplinary study (CORECT), Colon Cancer Family Registry (CCFR), and UK Biobank. We then used the EOCRC GWAS to investigate 28 modifiable risk factors using two-sample Mendelian randomization (MR).

RESULTS

We found two novel risk loci for EOCRC at 1p34.1 and 4p15.33, not previously associated with CRC risk. We identified a deleterious coding variant (rs36053993, G396D) at polyposis-associated DNA repair gene MUTYH (OR=1.80 [95%CI=1.47-2.22]) but show that most of the common genetic susceptibility was from non-coding signals enriched in epigenetic markers present in gastrointestinal tract cells. We identified new EOCRC susceptibility genes, and in addition to pathways such as TGFβ, SMAD, BMP, and PI3K signaling, our study highlights a role for insulin signaling and immune/infection-related pathways in EOCRC. In our MR analyses, we found novel evidence of probable causal associations for higher levels of body size and metabolic factors - such as body fat percentage, waist circumference, waist to hip ratio, basal metabolic rate, and fasting insulin - higher alcohol drinking and lower education attainment, with increased EOCRC risk.

CONCLUSION

Our novel findings indicate inherited susceptibility to EOCRC and suggest modifiable lifestyle and metabolic targets that could also be used to risk stratify individuals for personalized screening strategies or other interventions.

Identification of a Novel NLRP12 Frameshift Mutation (Val730Glyfs∗41) by Whole-Exome Sequencing in Patients with Crohn’s Disease

NLRP12 encodes the nucleotide-binding leucine-rich repeat-containing receptor 12 protein and has been linked to familial cold autoinflammatory syndrome 2 (FCAS2). Previous studies have reported that NLRP12 protein can dampen inflammatory responses in DSS-induced mice colitis. To date, only four alterations in the NLRP12 gene have been associated with Crohn’s disease (CD). Here, we reported a novel heterozygous NLRP12 frameshift mutation (c.2188dupG, p.Val730Glyfs${}^{\ast }$41) identified by whole-exome sequencing in the proband with CD. The Sanger sequencing confirmed that his sister and father also carried this NLRP12 mutation, which cosegregated well with the CD phenotype. In silico analysis predicted this mutation to be disease-causing. Patients heterozygous for this mutation exhibited decreased NLRP12 protein levels in the peripheral blood and colon. Functional assays showed that mutant NLRP12 plasmid-transfected HEK293T cells exhibited significantly lower NLRP12 mRNA and protein levels than wild-type plasmid-transfected cells. The nonsense-mediated decay inhibitor NMDI14 significantly increased NLRP12 mRNA and protein levels in mutant plasmid-transfected cells. Overall, our results demonstrated that this heterozygous NLRP12 mutation (c.2188dupG) resulted in decreased NLRP12 expression, which might contribute to the mechanism underlying CD.

Clinical use of biologics for Crohn's disease in adults: lessons learned from real-world studies

INTRODUCTION

The therapeutic armamentarium for managing Crohn's disease (CD) has expanded significantly in recent decades. Several biologics with three different mechanisms of action [anti-tumor necrosis factor (TNF)-α, anti-integrin α4β7, and anti-IL 12/23] are currently available to manage CD.

AREA COVERED

This narrative review aims to summarize the most significant efficacy and safety data on the use of infliximab (IFX), adalimumab (ADA), vedolizumab (VDZ) and ustekinumab (UST) for the treatment of CD obtained from studies conducted in the real world (RW), compared to the results of randomized clinical trials (RCTs).

EXPERT OPINION

RW studies reported that biologic agents included in this analysis have higher remission rates and lower adverse event rates than findings from RCTs for treating patients with CD. All biological agents have proven effective and safe in RW studies, even when using biosimilars or switching to subcutaneous administration of the molecules for which they are available. Finally, anti-TNF-α agents, particularly IFX, have a higher rate of adverse events (AEs) than VDZ and UST. Therefore, patients at higher risk of AEs may benefit from other biologics than anti-TNF-α. However, further long-term RW studies are needed to confirm these findings.

An immunogenetic basis for lung cancer risk

Cancer risk is influenced by inherited mutations, DNA replication errors, and environmental factors. However, the influence of genetic variation in immunosurveillance on cancer risk is not well understood. Leveraging population-level data from the UK Biobank and FinnGen, we show that heterozygosity at the human leukocyte antigen (HLA)-II loci is associated with reduced lung cancer risk in smokers. Fine-mapping implicated amino acid heterozygosity in the HLA-II peptide binding groove in reduced lung cancer risk, and single-cell analyses showed that smoking drives enrichment of proinflammatory lung macrophages and HLA-II+ epithelial cells. In lung cancer, widespread loss of HLA-II heterozygosity (LOH) favored loss of alleles with larger neopeptide repertoires. Thus, our findings nominate genetic variation in immunosurveillance as a critical risk factor for lung cancer.

Early-life exposures and the microbiome: implications for IBD prevention

The early-life period is one of microbiome establishment and immune maturation. Early-life exposures are increasingly being recognised to play an important role in IBD risk. The composition of functions of the gut microbiome in the prenatal, perinatal, and postnatal period may be crucial towards development of health or disease, including IBD, later in life. We herein present a comprehensive summary of the interplay between early-life factors and microbiome perturbations, and their association with risk of IBD. In addition, we provide an overview of host and external factors in early life that are known to impact gut microbiome maturation and exposures implicated in IBD risk. Considering the emerging concept of IBD prevention, we propose strategies to minimise maternal and offspring exposure to potentially harmful variables and recommend protective measures during pregnancy and the postpartum period. This holistic view of early-life factors and microbiome signatures among mothers and their offspring will help frame our current understanding of their importance towards IBD pathogenesis and frame the roadmap for preventive strategies.

CAGI, the Critical Assessment of Genome Interpretation, establishes progress and prospects for computational genetic variant interpretation methods

BACKGROUND

The Critical Assessment of Genome Interpretation (CAGI) aims to advance the state-of-the-art for computational prediction of genetic variant impact, particularly where relevant to disease. The five complete editions of the CAGI community experiment comprised 50 challenges, in which participants made blind predictions of phenotypes from genetic data, and these were evaluated by independent assessors.

RESULTS

Performance was particularly strong for clinical pathogenic variants, including some difficult-to-diagnose cases, and extends to interpretation of cancer-related variants. Missense variant interpretation methods were able to estimate biochemical effects with increasing accuracy. Assessment of methods for regulatory variants and complex trait disease risk was less definitive and indicates performance potentially suitable for auxiliary use in the clinic.

CONCLUSIONS

Results show that while current methods are imperfect, they have major utility for research and clinical applications. Emerging methods and increasingly large, robust datasets for training and assessment promise further progress ahead.

Comparison of endoscopic healing and durability between infliximab originator and CT-P13 in pediatric patients with inflammatory bowel disease

Background and aims

Favourable clinical data were published on the efficacy of CT-P13, the first biosimilar of infliximab (IFX), in pediatric inflammatory bowel disease (IBD); however, few studies have compared the effect on endoscopic healing (EH) and drug retention rate between the IFX originator and CT-P13. Therefore, we aimed to compare EH and the drug retention rate between the IFX originator and CT-P13.

Methods

Children with Crohn's disease (CD) and ulcerative colitis (UC)/IBD-unclassified (IBD-U) at 22 medical centers were enrolled, with a retrospective review conducted at 1-year and last follow-up. Clinical remission, EH and drug retention rate were evaluated.

Results

We studied 416 pediatric patients with IBD: 77.4% had CD and 22.6% had UC/IBD-U. Among them, 255 (61.3%) received the IFX originator and 161 (38.7%) received CT-P13. No statistically significant differences were found between the IFX originator and CT-P13 in terms of corticosteroid-free remission and adverse events. At 1-year follow-up, EH rates were comparable between them (CD: P=0.902, UC: P=0.860). The estimated cumulative cessation rates were not significantly different between the two groups. In patients with CD, the drug retention rates were 66.1% in the IFX originator and 71.6% in the CT-P13 group at the maximum follow-up period (P >0.05). In patients with UC, the drug retention rates were 49.8% in the IFX originator and 56.3% in the CT-P13 group at the maximum follow-up period (P >0.05).

Conclusions

The IFX originator and CT-P13 demonstrated comparable therapeutic response including EH, clinical remission, drug retention rate and safety in pediatric IBD.

TH17 cell: a double-edged sword in the development of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic nonspecific inflammatory disease of the gastrointestinal tract, and its pathogenesis has not been fully understood. Extensive dysregulation of the intestinal mucosal immune system is critical in the development and progression of IBD. T helper (Th) 17 cells have the characteristics of plasticity. They can transdifferentiate into subpopulations with different functions in response to different factors in the surrounding environment, thus taking on different roles in regulating the intestinal immune responses. In this review, we will focus on the plasticity of Th17 cells as well as the function of Th17 cells and their related cytokines in IBD. We will summarize their pathogenic and protective roles in IBD under different conditions, respectively, hoping to further deepen the understanding of the pathological mechanisms underlying IBD and provide insights for future treatment.

Sustained Increase in Pediatric Inflammatory Bowel Disease Incidence Across the South West United Kingdom Over the Last 10 Years

BACKGROUND

Pediatric inflammatory bowel disease (pIBD) incidence has increased over the last 25 years. We aim to report contemporaneous trends across the South West United Kingdom.

METHODS

Data were provided from centers covering the South West United Kingdom (Bristol, Oxford, Cardiff, Exeter, and Southampton), with a total area at-risk population (<18 years of age) of 2 947 534. Cases were retrieved from 2013 to 2022. Incident rates were reported per 100 000 at-risk population, with temporal trends analyzed through correlation. Subgroup analysis was undertaken for age groups (0-6, 6-11, and 12-17 years of age), sex, and disease subtype. Choropleth maps were created for local districts.

RESULTS

In total, 2497 pIBD cases were diagnosed between 2013 and 2022, with a mean age of 12.6 years (38.7% female). Diagnosis numbers increased from 187 to 376, with corresponding incidence rates of 6.0 per 100 000 population per year (2013) to 12.4 per 100 000 population per year (2022) (b = 0.918, P < .01). Female rates increased from 5.1 per 100 000 population per year in 2013 to 11.0 per 100 000 population per year in 2022 (b = 0.865, P = .01). Male rates increased from 5.7 per 100 000 population per year to 14.4 per 100 000 population per year (b = 0.832, P = .03). Crohn's disease incidence increased from 3.1 per 100 000 population per year to 6.3 per 100 000 population per year (b = 0.897, P < .01). Ulcerative colitis increased from 2.3 per 100 000 population per year to 4.3 per 100 000 population per year (b = 0.813, P = .04). Inflammatory bowel disease unclassified also increased, from 0.6 per 100 000 population per year to 1.8 per 100 000 population per year (b = 0.851, P = .02). Statistically significant increases were seen in those ≥12 to 17 years of age, from 11.2 per 100 000 population per year to 24.6 per 100 000 population per year (b = 0.912, P < .01), and the 7- to 11-year-old age group, with incidence rising from 4.4 per 100 000 population per year to 7.6 per 100 000 population per year (b = 0.878, P = .01). There was no statistically significant increase in very early onset inflammatory bowel disease (≤6 years of age) (b = 0.417, P = .231).

CONCLUSIONS

We demonstrate significant increases in pIBD incidence across a large geographical area including multiple referral centers. Increasing incidence has implications for service provision for services managing pIBD.

Mucosal host-microbe interactions associate with clinical phenotypes in inflammatory bowel disease

Disrupted host-microbe interactions at the mucosal level are key to the pathophysiology of IBD. This study aimed to comprehensively examine crosstalk between mucosal gene expression and microbiota in patients with IBD. To study tissue-specific interactions, we perform transcriptomic (RNA-seq) and microbial (16S-rRNA-seq) profiling of 697 intestinal biopsies (645 derived from 335 patients with IBD and 52 from 16 non-IBD controls). Mucosal gene expression patterns in IBD are mainly determined by tissue location and inflammation, whereas the mucosal microbiota composition shows a high degree of individual specificity. Analysis of transcript-bacteria interactions identifies six distinct groups of inflammation-related pathways that are associated with intestinal microbiota (adjusted P < 0.05). An increased abundance of Bifidobacterium is associated with higher expression of genes involved in fatty acid metabolism, while Bacteroides correlates with increased metallothionein signaling. In patients with fibrostenosis, a transcriptional network dominated by immunoregulatory genes is associated with Lachnoclostridium bacteria in non-stenotic tissue (adjusted P < 0.05), while being absent in CD without fibrostenosis. In patients using TNF-α-antagonists, a transcriptional network dominated by fatty acid metabolism genes is linked to Ruminococcaceae (adjusted P < 0.05). Mucosal microbiota composition correlates with enrichment of intestinal epithelial cells, macrophages, and NK-cells. Overall, these data demonstrate the presence of context-specific mucosal host-microbe interactions in IBD, revealing significantly altered inflammation-associated gene-taxa modules, particularly in patients with fibrostenotic CD and patients using TNF-α-antagonists. This study provides compelling insights into host-microbe interactions that may guide microbiota-directed precision medicine and fuels the rationale for microbiota-targeted therapeutics as a strategy to alter disease course in IBD.

Priority index for critical Covid-19 identifies clinically actionable targets and drugs

While genome-wide studies have identified genomic loci in hosts associated with life-threatening Covid-19 (critical Covid-19), the challenge of resolving these loci hinders further identification of clinically actionable targets and drugs. Building upon our previous success, we here present a priority index solution designed to address this challenge, generating the target and drug resource that consists of two indexes: the target index and the drug index. The primary purpose of the target index is to identify clinically actionable targets by prioritising genes associated with Covid-19. We illustrate the validity of the target index by demonstrating its ability to identify pre-existing Covid-19 phase-III drug targets, with the majority of these targets being found at the leading prioritisation (leading targets). These leading targets have their evolutionary origins in Amniota ('four-leg vertebrates') and are predominantly involved in cytokine-cytokine receptor interactions and JAK-STAT signaling. The drug index highlights opportunities for repurposing clinically approved JAK-STAT inhibitors, either individually or in combination. This proposed strategic focus on the JAK-STAT pathway is supported by the active pursuit of therapeutic agents targeting this pathway in ongoing phase-II/III clinical trials for Covid-19.

Health Services Utilization and Specialist Care in Pediatric Inflammatory Bowel Disease: A Multiprovince Population-Based Cohort Study

BACKGROUND

Patterns of health services utilization among children with inflammatory bowel disease (IBD) are important to understand as the number of children with IBD continues to increase. We compared health services utilization and surgery among children diagnosed <10 years of age (Paris classification: A1a) and between 10 and <16 years of age (A1b).

METHODS

Incident cases of IBD diagnosed <16 years of age were identified using validated algorithms from deterministically linked health administrative data in 5 Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario, Quebec) to conduct a retrospective cohort study. We compared the frequency of IBD-specific outpatient visits, emergency department visits, and hospitalizations across age groups (A1a vs A1b [reference]) using negative binomial regression. The risk of surgery was compared across age groups using Cox proportional hazards models. Models were adjusted for sex, rural/urban residence location, and mean neighborhood income quintile. Province-specific estimates were pooled using random-effects meta-analysis.

RESULTS

Among the 1165 (65.7% Crohn's) children with IBD included in our study, there were no age differences in the frequency of hospitalizations (rate ratio [RR], 0.88; 95% confidence interval [CI], 0.74-1.06) or outpatient visits (RR, 0.95; 95% CI, 0.78-1.16). A1a children had fewer emergency department visits (RR, 0.70; 95% CI, 0.50-0.97) and were less likely to require a Crohn's-related surgery (hazard ratio, 0.49; 95% CI, 0.26-0.92). The risk of colectomy was similar among children with ulcerative colitis in both age groups (hazard ratio, 0.71; 95% CI, 0.49-1.01).

CONCLUSIONS

Patterns of health services utilization are generally similar when comparing children diagnosed across age groups.

Inflammatory Bowel Disease and Skin Cancer: A Two-Sample Mendelian Randomization Analysis

Background: At present, numerous clinical studies suggest a correlation between inflammatory bowel disease (IBD) and skin cancer. However, some articles present differing views that IBD does not increase the risk of skin cancer. The presence of potential reverse causality and residual confounding is inherent in conventional observational studies. Thus, this study used a two-sample Mendelian randomization (MR) study design to estimate the causal effect of IBD on the risk of skin cancer, including cutaneous malignant melanoma (CMM, also named melanoma skin cancer) and nonmelanoma skin cancer (NMSC). Design: In this study, a two-sample MR analysis was used to estimate the causal effect of IBD on skin cancer outcomes. The inverse-variance weighted (IVW) method was used as the main MR analysis, with multiple sensitivity analyses conducted to assess the robustness of findings. Results: In examining the association between IBD and NMSC, all p-values of the IVW methods were found to be <0.05, providing evidence for a causal effect of IBD on an increased risk of NMSC. However, IVW for IBD on CMM yielded p-values >0.05, indicating no causal relationship between IBD and CMM. These findings were consistent across other MR methods, with no evidence of pleiotropy or heterogeneity. Sensitivity analyses confirmed the robustness of our results. Conclusion: Using MR analysis, we found evidence for a causal effect of genetic liability for IBD on an increased risk of NMSC. However, our study did not find sufficient evidence to support a significant impact of IBD on CMM outcomes.

Antagonizing interleukin-5 receptor ameliorates dextran sulfate sodium-induced experimental colitis in mice through reducing NLRP3 inflammasome activation

Inflammatory bowel disease (IBD) is a condition characterized by inflammation in the gastrointestinal tract. Reducing intestinal inflammation is a promising approach for treating IBD. The nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome, a critical component of the innate immune system, is implicated in the pathogenesis of IBD. Therefore, inhibiting NLRP3 inflammasome activation is a potential therapeutic strategy for IBD. In this study, we investigated the effects of the interleukin-5 (IL-5) receptor antagonist YM-90709 on dextran sulfate sodium-induced experimental colitis in mice. We found that YM-90709 reduced the expressions of IL-1β and caspase-1 p20 in the colon and ameliorated colitis. Furthermore, we identified YM-90709 as an effective agent for inhibiting NLRP3 inflammasome activation. Knockdown of IL-5 receptor or using an inhibitor of STAT5, a key transcription factor downstream of the IL-5/IL-5 receptor signal pathway, also reduced NLRP3 inflammasome-dependent IL-1β release and ASC speck formation. Our study is the first to demonstrate that the NLRP3 inflammasome may be a downstream signal of IL-5/IL-5 receptor and that YM-90709 protects against IBD by inhibiting IL-5 receptor. These findings suggest a new strategy for regulating intestinal inflammation and managing IBD.

Increased CpG methylation at the CDH1 locus in inflamed ileal mucosa of patients with Crohn disease

BACKGROUND

E-cadherin, a major actor of cell adhesion in the intestinal barrier, is encoded by the CDH1 gene associated with susceptibility to Crohn Disease (CD) and colorectal cancer. Since epigenetic mechanisms are suspected to contribute to the multifactorial pathogenesis of CD, we studied CpG methylation at the CDH1 locus. The methylation of the CpG island (CGI) and of the 1st enhancer, two critical regulatory positions, was quantified in surgical specimens of inflamed ileal mucosa and in peripheral blood mononuclear cells (PBMC) of 21 CD patients. Sixteen patients operated on for a non-inflammatory bowel disease, although not normal controls, provided a macroscopically normal ileal mucosa and PBMC for comparison.

RESULTS

In ileal mucosa, 19/21 (90%) CD patients vs 8/16 control patients (50%) (p < 0.01) had a methylated CDH1 promoter CGI. In PBMC, CD patients with methylated CGI were 11/21 (52%) vs 7/16 controls (44%), respectively. Methylation in the 1st enhancer of CDH1 was also higher in the CD group for each of the studied CpGs and for their average value (45 ± 17% in CD patients vs 36 ± 17% in controls; p < 0.001). Again, methylation was comparable in PBMC. Methylation of CGI and 1st enhancer were not correlated in mucosa or PBMC.

CONCLUSIONS

Methylation of several CpGs at the CDH1 locus was increased in the inflamed ileal mucosa, not in the PBMC, of CD patients, suggesting the association of CDH1 methylation with ileal inflammation. Longitudinal studies will explore if this increased methylation is a risk marker for colorectal cancer.

Variation in the Care of Children with Inflammatory Bowel Disease Within and Across Canadian Provinces: A Multi-Province Population-Based Cohort Study

Purpose

The incidence of childhood-onset inflammatory bowel disease (IBD) is rising. We described variation in health services utilization and need for surgery among children with IBD between six and 60 months following IBD diagnosis across Canadian pediatric centers and evaluated the associations between care provided at diagnosis at each center and the variation in these outcomes.

Patients and Methods

Using population-based deterministically-linked health administrative data from four Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario) we identified children diagnosed with IBD <16 years of age using validated algorithms. Children were assigned to a pediatric center of care using a hierarchical approach based on where they received their initial care. Outcomes included IBD-related hospitalizations, emergency department (ED) visits, and IBD-related abdominal surgery occurring between 6 and sixty months after diagnosis. Mixed-effects meta-analysis was used to pool results and examine the association between center-level care provision and outcomes.

Results

We identified 3784 incident cases of pediatric IBD, of whom 2937 (77.6%) were treated at pediatric centers. Almost a third (31.4%) of children had ≥1 IBD-related hospitalization and there were 0.66 hospitalizations per person during follow-up. More than half (55.8%) of children had ≥1 ED visit and there were 1.64 ED visits per person. Between-center heterogeneity was high for both outcomes; centers where more children visited the ED at diagnosis had more IBD-related hospitalizations and more ED visits during follow-up. Between-center heterogeneity was high for intestinal resection in Crohn's disease but not colectomy in ulcerative colitis.

Conclusion

There is variation in health services utilization among children with IBD and risk of undergoing intestinal resection in those with Crohn's disease, but not colectomy among children with ulcerative colitis, across Canadian pediatric tertiary-care centers. Improvements in clinical care pathways are needed to ensure all children have equitable and timely access to high quality care.

The Human Gut Microbiota: A Dynamic Biologic Factory

The human body constitutes a living environment for trillions of microorganisms, which establish the microbiome and, the largest population among them, reside within the gastrointestinal tract, establishing the gut microbiota. The term "gut microbiota" refers to a set of many microorganisms [mainly bacteria], which live symbiotically within the human host. The term "microbiome" means the collective genomic content of these microorganisms. The number of bacterial cells within the gut microbiota exceeds the host's cells; collectively and their genes quantitatively surpass the host's genes. Immense scientific research into the nature and function of the gut microbiota is unraveling its roles in certain human health activities such as metabolic, physiology, and immune activities and also in pathologic states and diseases. Interestingly, the microbiota, a dynamic ecosystem, inhabits a particular environment such as the human mouth or gut. Human microbiota can evolve and even adapt to the host's unique features such as eating habits, genetic makeup, underlying diseases, and even personalized habits. In the past decade, biologists and bioinformaticians have concentrated their research effort on the potential roles of the gut microbiome in the development of human diseases, particularly immune-mediated diseases and colorectal cancer, and have initiated the assessment of the impact of the gut microbiome on the host genome. In the present chapter, we focus on the biological features of gut microbiota, its physiology as a biological factory, and its impacts on the host's health and disease status.

Current Approaches for Monitoring of Patients with Inflammatory Bowel Diseases: A Narrative Review

BACKGROUND

Patients with inflammatory bowel diseases (IBD) require proactive monitoring both during the active phase to evaluate therapeutic response and during the remission phase to evaluate relapse or colorectal cancer surveillance. However, monitoring may vary between patients with ulcerative colitis (UC) and Crohn's disease (CD), with distinct tools and intervals.

METHODS

This narrative review aims to focus on modern approaches to IBD monitoring, considering international guidelines and expert consensus.

RESULTS

The most recent European diagnostic guidelines advocate a combination of clinical, laboratory, endoscopic, and radiological parameters to evaluate the disease course of patients with IBD. Unfortunately, the conventional symptom-based therapeutic approach does not improve long-term outcomes and there is no single ideal biomarker available. Endoscopy plays a key role in evaluating response to therapy as well as monitoring disease activity. Recently, bedside intestinal ultrasound (IUS) has gained increasing interest and diffusion as it appears to offer several advantages including the monitoring of therapeutic response.

CONCLUSION

In light of growing clinical advances, we present a schematic evidence-based monitoring algorithm that can be easily applied in clinical practice which combines all major monitoring modalities, including noninvasive tools such as IUS and video-capsule endoscopy.

Tobacco smoke exposure in early childhood and later risk of inflammatory bowel disease: A Scandinavian birth cohort study

OBJECTIVES

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

METHODS

We followed 115,663 participants from the Norwegian Mother, Father and Child (MoBa) and All Babies in Southeast Sweden (ABIS) cohorts from birth (1997-2009) through 2021. IBD was identified through national patient registers. Validated questionnaire data defined maternal smoking during pregnancy, maternal environmental tobacco smoke (ETS) exposure during pregnancy, and child ETS exposure by age 12 and 36 months. Cox regression was used to estimate adjusted hazard ratios (aHRs) for sex, maternal age, education level, parental IBD and origin. Cohort-specific estimates were pooled using a random-effects model.

RESULTS

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

CONCLUSIONS

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

Predictors of Complicated Disease Course in Adults and Children With Crohn's Disease: A Nationwide Study from the epi-IIRN

BACKGROUND

Since data on predictors of complicated Crohn's disease (CD) from unselected populations are scarce, we aimed to utilize a large nationwide cohort, the epi-IIRN, to explore predictors of disease course in children and adults with CD.

METHODS

Data of patients with CD were retrieved from Israel's 4 health maintenance organizations, whose records cover 98% of the population (2005-2020). Time-to-event modeled a complicated disease course, defined as CD-related surgery, steroid-dependency, or the need for >1 class of biologics. Hierarchical clustering categorized disease severity at diagnosis based on available laboratory results.

RESULTS

A total of 16 659 patients (2999 [18%] pediatric-onset) with 121 695 person-years of follow-up were included; 3761 (23%) had a complicated course (750 [4.5%] switched to a second biologic class, 1547 [9.3%] steroid-dependency, 1463 [8.8%] CD-related surgery). Complicated disease was more common in pediatric- than adult-onset disease (26% vs 22%, odds ratio, 1.3; 95% confidence interval [CI], 1.2-1.4). In a Cox multivariate model, complicated disease was predicted by induction therapy with biologics (hazard ratio [HR], 2.1; 95% CI, 1.2-3.6) and severity of laboratory tests at diagnosis (HR, 1.7; 95% CI, 1.2-2.2), while high socioeconomic status was protective (HR, 0.94; 95% CI, 0.91-0.96). In children, laboratory tests predicted disease course (HR, 1.8; 95% CI, 1.2-2.5), as well as malnutrition (median BMI Z score -0.41; 95% CI, -1.42 to 0.43 in complicated disease vs -0.24; 95% CI, -1.23 to 0.63] in favorable disease; P < .001).

CONCLUSIONS

In this nationwide cohort, CD course was complicated in one-fourth of patients, predicted by laboratory tests, type of induction therapy, socioeconomic status, in addition to malnutrition in children.

TNF promoter hypomethylation is associated with mucosal inflammation in IBD and anti-TNF response

Background and aims

Inflammatory Bowel Diseases (IBD) are chronic inflammatory conditions influenced heavily by environmental factors. DNA methylation is a form of epigenetic regulation linking environmental stimuli to gene expression changes and inflammation. Here, we investigated how DNA methylation of the TNF promoter differs between inflamed and uninflamed mucosa of IBD patients, including anti-TNF responders and non-responders.

Methods

We obtained mucosal biopsies from 200 participants (133 IBD and 67 controls) and analyzed TNF promoter methylation using bisulfite sequencing, comparing inflamed with uninflamed segments, in addition to paired inflamed/uninflamed samples from individual patients. We conducted similar analyses on purified intestinal epithelial cells from bowel resections. We also compared TNF methylation levels of inflamed and uninflamed mucosa from a separate cohort of 15 anti-TNF responders and 17 non-responders. Finally, we sequenced DNA methyltransferase genes to identify rare variants in IBD patients and functionally tested them using rescue experiments in a zebrafish genetic model of DNA methylation deficiency.

Results

TNF promoter methylation levels were decreased in inflamed mucosa of IBD patients and correlated with disease severity. Isolated IECs from inflamed tissue showed proportional decreases in TNF methylation. Anti-TNF non-responders showed lower levels of TNF methylation than responders in uninflamed mucosa. Our sequencing analysis revealed two missense variants in DNMT1, one of which had reduced function in vivo.

Conclusions

Our study reveals an association of TNF promoter hypomethylation with mucosal inflammation, suggesting that IBD patients may be particularly sensitive to inflammatory environmental insults affecting DNA methylation. Together, our analyses indicate that TNF promoter methylation analysis may aid in the characterization of IBD status and evaluation of anti-TNF therapy response.

Berberine alleviates inflammation and suppresses PLA2-COX-2-PGE2-EP2 pathway through targeting gut microbiota in DSS-induced ulcerative colitis

Berberine, isolated from Coptis chinensis and Phellodendron amurense, can attenuate colonic injury and modulate gut microbiota disorders in ulcerative colitis (UC). However, the mechanism and causal relationship between gut microbiota and the efficacy of Berberine on UC are still unclear, which were investigated by pseudo-germ-free (PGF) mice, 16S rRNA gene analysis and transcriptome analysis in this study. The results demonstrated that Berberine improved gut microbiota disorders, colon damage, tight-junction proteins, inflammatory and anti-inflammatory cytokines in DSS-induced colitis mice with intact gut microbiota but not in PGF mice. Besides, immune-related and inflammation-related pathways were closely related to the efficacy that Berberine alleviated colitis by regulating gut microbiota. Furthermore, Berberine reduced PGE2, PLA2, COX-2, Ptges, EP2 and p-Stat3 only in colitis mice with intact gut microbiota. In summary, our study confirms that Berberine inhibits PLA2-COX-2-PGE2-EP2 pathway in UC through gut microbiota, leading to the alleviation of inflammation in colon, which further elucidates the underlying mechanism and promotes the application of Berberine in UC.

Mycobacterium avium ssp. paratuberculosis and Crohn's Disease-Diagnostic Microbiological Investigations Can Inform New Therapeutic Approaches

Mycobacterium avium ssp. paratuberculosis (MAP) is the cause of Johne's disease (JD), which is a chronic infectious gastrointestinal disease of ruminants and is often fatal. In humans, MAP has been associated with Crohn's disease (CD) for over a century, without conclusive evidence of pathogenicity. Numerous researchers have contributed to the subject, but there is still a need for evidence of the causation of CD by MAP. An infectious aetiology in CD that is attributable to MAP can only be proven by bacteriological investigations. There is an urgency in resolving this question due to the rising global incidence rates of CD. Recent papers have indicated the "therapeutic ceiling" may be close in the development of new biologics. Clinical trial outcomes have demonstrated mild or inconsistent improvements in therapeutic interventions over the last decades when compared with placebo. The necessity to revisit therapeutic options for CD is becoming more urgent and a renewed focus on causation is essential for progress in identifying new treatment options. This manuscript discusses newer interventions, such as vaccination, FMT, dietary remediation and gut microbiome regulation, that will become more relevant as existing therapeutic options expire. Revisiting the MAP theory as a potential infectious cause of CD, rather than the prevailing concept of an "aberrant immune response" will require expanding the current therapeutic programme to include potential new alternatives, and combinations of existing treatments. To advance research on MAP in humans, it is essential for microbiologists and medical scientists to microscopically detect CWDM and to biologically amplify the growth by directed culture.

Adalimumab Biosimilar in Pediatric Inflammatory Bowel Disease: A Retrospective Study from the Sicilian Network for Inflammatory Bowel Disease (SN-IBD)

BACKGROUND

The utilization of anti-tumor necrosis factor-α (anti-TNF-α) biosimilars in inflammatory bowel disease (IBD) is constantly increasing. However, pediatric data are limited. This study aimed to assess the effectiveness and safety of adalimumab biosimilar (ADL-BioS) in pediatric IBD patients.

METHODS

All consecutive pediatric IBD patients from the Sicilian Network for Inflammatory Bowel Disease cohort treated with ADL-BioS from 2019 to 2021 were recruited. Remission at weeks 14 and 52, treatment persistence, and adverse events were the endpoints of this study. Factors associated with clinical remission and treatment persistence were examined.

RESULTS

There were 41 patients in total. Nine (22%) patients were switched from the reference product to ADL-BioS. Two patients had multiple switches. Eleven months was the median follow-up period. Clinical remission was attained by 70.7% and 72.0% of patients on weeks 14 and 52, respectively. Four (9.8%) adverse events occurred (10.1/100 person-year). Treatment persistence was 85.4% at 1 and 2 years. Patients with a longer duration of disease had a higher probability of stopping their treatment (p = 0.036).

CONCLUSIONS

This is the first real-world study that particularly addresses the use of ADL-BioS in pediatric IBD. With high rates of treatment persistence and a low frequency of non-serious side effects, ADL-BioS seems to be effective.

Research Progress of Interleukin-27 in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) can be identified as an inflammatory disorder in the intestine, being characterized by maladjusted immune responses and chronic inflammation of the intestinal tract. However, as the etiology and pathogenesis are still unclear, more effective therapeutic approaches are needed. Recent studies have discovered a new cytokine, interleukin-27 (IL-27), which belongs to the superfamily of IL-6 and IL-12, demonstrating multiple functions in many infectious diseases, autoimmune diseases, and cancers. Interleukin-27 is mainly produced by antigen presentation cells (APCs) such as dendritic cells and mononuclear macrophages, playing a dual regulatory role in immunological response. Therefore, this updated review aims to summarize the new progress of the regulatory role of IL-27 in IBD and focus more on the interaction between IL-27 and immune cells, hoping to provide more evidence for the potential IBD treatment mediated by IL-27.

Adjusting for genetic confounders in transcriptome-wide association studies improves discovery of risk genes of complex traits

Many methods have been developed to leverage expression quantitative trait loci (eQTL) data to nominate candidate genes from genome-wide association studies. These methods, including colocalization, transcriptome-wide association studies (TWAS) and Mendelian randomization-based methods; however, all suffer from a key problem-when assessing the role of a gene in a trait using its eQTLs, nearby variants and genetic components of other genes' expression may be correlated with these eQTLs and have direct effects on the trait, acting as potential confounders. Our extensive simulations showed that existing methods fail to account for these 'genetic confounders', resulting in severe inflation of false positives. Our new method, causal-TWAS (cTWAS), borrows ideas from statistical fine-mapping and allows us to adjust all genetic confounders. cTWAS showed calibrated false discovery rates in simulations, and its application on several common traits discovered new candidate genes. In conclusion, cTWAS provides a robust statistical framework for gene discovery.

Bacteroides thetaiotaomicron and its inactivated bacteria ameliorate colitis by inhibiting macrophage activation

BACKGROUND

Studies have demonstrated that Bacteroides thetaiotaomicron (BT) has protective effect against colon inflammation in murine models. Macrophages play an important role in gut immunity. However, the specific mechanisms of BT on macrophage are still unelucidated. Thus, our study investigates the anti-inflammatory effect of BT and its heat-treated inactivated bacteria on experimental colitis and macrophages.

METHODS

A dextran sulfate sodium (DSS)-induced acute colitis model with male C57BL/6 mice, BT (ATCC29148) strain, THP1 cell lines were used in this study. Live and heat-treated inactivated BT (IBT) solution (1 × 10^9cfu/ml) were intragastrically gavaged daily for 14 days. Colonic inflammation was determined by the disease activity index (DAI) score, colon length, histological score, and inflammatory factors. THP1 cells were induced towards M1, then treated with different concentrations of inactivated BT solution and p38 inhibitor. Western blotting, immunohistochemistry, immunofluorescence and qRT-PCR were performed to assess the levels of inflammatory cytokines and molecules of MAPK pathway including IL-6, TNF-α, IL-1β, IL-22, p38 and phosphor-p38 expressions. Moreover, 16S rRNA sequencing of colitis murine fecal samples was applied to investigate the influence of supplementation of BT to the gut microbiota homeostasis.

RESULTS

Both live and heat-treated inactivated BT decreased the DAI and histological scores as well as levels of inflammatory factors, particularly IL-6 while increasing IL-22 of DSS-induced colitis murine models. The cell experiments showed that inactivated BT downregulates IL-6 expression in THP1 via inhibiting p38 phosphorylation and affecting M1 polarization. Moreover, the 16S rRNA sequencing results showed that BT and IBT gavage could increase beta-diversity of gut flora in DSS-induced colitis mice. Furthermore, the significance test for differences between the groups showed that BT could increase Faecalebaculum, Lactobacillus and Bacteroides, while decreasing Akkermansia.

CONCLUSION

In summary, our findings imply that BT and its heat-treated inactivated bacteria exert a protective effect by suppressing macrophage-induced IL-6 through the inhibition of p38 MAPK pathway and ameliorating intestinal gut dysbiosis in experimental colitis.

Natural history and impact of irritable bowel syndrome-type symptoms in inflammatory bowel disease during 12 months of longitudinal follow-up

BACKGROUND

Little is known about the natural history and impact of irritable bowel syndrome (IBS)-type symptoms on psychological health and quality of life in inflammatory bowel disease (IBD). We aimed to address this in a 12-month longitudinal follow-up study of secondary care patients.

METHODS

We collected demographic, Rome III IBS-type symptom, psychological, and quality of life data, with questionnaires at 3-month intervals, over 12 months of follow-up in patients with IBD in clinical remission at baseline. We assessed the natural history of Rome III IBS-type symptoms over the 12 months of the study and compared psychological and quality of life data between those reporting Rome III IBS-type symptoms at each of the points of follow-up with those not reporting such symptoms.

KEY RESULTS

Among 206 patients with IBD in clinical remission at baseline (104 [50.5%] women, mean age 56.9 years [range 18-83 years], 79 [38.3%] Crohn's disease), 33 (16.0%) reported Rome III IBS-type symptoms at baseline and 72 (35.0%) reported Rome III IBS-type symptoms at one or more time points. Among the 33 patients with Rome III IBS-type symptoms at baseline, symptoms resolved in 6 (18.2%) patients, were present throughout in 6 (18.2%) patients, and fluctuated in the remaining 21 (63.6%) patients. Among the 39 patients with new onset of Rome III IBS-type symptoms after baseline, 24 (65.1%) had symptoms at one point in time only, 10 (25.6%) at two points, four (10.3%) at three points, and one (2.6%) at four points. At each point in time, reporting IBS-type symptoms was associated with significantly higher anxiety, depression, or somatoform symptom-reporting scores, and/or lower quality of life scores.

CONCLUSIONS & INFERENCES

In this 12-month follow-up study, one-third of patients with IBD reported presence of Rome III IBS-type symptoms at any point in time. Reporting such symptoms was associated with significant impacts on psychological health and/or quality of life.

Factors that influence infliximab biosimilar trough levels in the pediatric inflammatory bowel disease population

BACKGROUND

The pharmacokinetics and pharmacodynamics of biosimilar infliximab (IFX-BioS) in pediatric inflammatory bowel disease (IBD) are poorly investigated. The aim of this study was to investigate factors predicting IFX-BioS trough levels (TLs).

RESEARCH DESIGN AND METHODS

IBD children with an indication to start IFX-BioS were included in this prospective observational study (January 2021-June 2022). TLs were measured at the 4th and 6th infusions and correlated with several covariates.

RESULTS

A total of 110 TLs in 55 children were included. The multivariate linear regression model at the 4th infusion found a positive correlation between TLs and age at diagnosis (B:1.950, 95% CI: [0.019, 3.882], p = 0.048) and IFX-BioS dose/kg (B:1.962, 95% CI: [0.238, 3.687], p = 0.029), and a negative correlation with clinical scores (B:-0.401, 95% CI: [-0.738, -0.064], p = 0.023). At the 6th infusion, female gender (B:6.887, 95% CI: [0.861, 12.913], p = 0.029), hemoglobin (B:1.853, 95% CI: [0.501, 3.204], p = 0.011), and IFX-BioS dose/kg (B:1.792, 95% CI: [0.979, 2.605], p < 0.001) were found to be positively correlated to TLs. No association between combined clinical and biochemical remission and TLs was found.

CONCLUSIONS

This study discovered some predictors for IFX-BioS TLs in IBD children. Knowledge of predictive factors could help physicians choose the best dosing regimen.

Implication of Inflammatory Bowel Disease Diagnosed Before the Age of 18 for Achieving an Upper Secondary Education: A Nationwide Population-Based Cohort Study

BACKGROUND

Educational achievement may be adversely affected by chronic conditions in childhood and adolescence. This study aimed to examine the effect of being diagnosed with IBD on achievement of an upper secondary education and the influence of disease severity and psychiatric comorbidity.

METHODS

This cohort study was based on nationwide Danish administrative registries. We compared a cohort of patients with IBD with a matched population-based cohort. The IBD cohort included patients born between 1970 and 1994 who were diagnosed with IBD (age <18 years). The outcome was achieving an upper secondary education and was analyzed using Cox regression. The impact of disease severity (expressed by surgery or corticosteroid prescriptions) or psychiatric comorbidity within the IBD cohort was assessed using Poisson regression.

RESULTS

We identified 3178 patients with IBD (Crohn's disease [CD] n = 1344, ulcerative colitis [UC] n = 1834) and matched them with 28 204 references. The hazard ratio of achieving an upper secondary education was 1.14 (95% confidence interval, 1.07-1.21) for CD and 1.16 (95% confidence interval, 1.10-1.23) for UC. In the IBD cohort, having surgery, a steroid prescription, or a comorbid psychiatric condition was associated with a lower chance of achieving an upper secondary education.

CONCLUSION

Being diagnosed with IBD before 18 years of age increased the chance of achieving an upper secondary education. However, patients with more severe disease or psychiatric comorbidity were at higher risk of not achieving an upper secondary education than patients with milder disease.

A novel causative role of imbalanced kynurenine pathway in ulcerative colitis: Upregulation of KMO and KYNU promotes intestinal inflammation

The kynurenine pathway (KP) is the principal metabolic route for the essential amino acid tryptophan (TRP). Recent advances have highlighted a pivotal role for several KP metabolites in inflammatory diseases, including ulcerative colitis (UC). However, the alterations of KP enzymes and their functional impact in UC remain poorly defined. Here, we focused on kynurenine 3-monooxygenase (KMO) and kynureninase (KYNU), which serve as critical branching enzymes in the KP. We observed that dextran sodium sulfate (DSS)-induced colitis mice exhibited disturbed TRP metabolism along with KMO and KYNU upregulated. In patients with active UC, both the expression of KMO and KYNU were positively correlated with inflammatory factors TNF-α and IL-1β. Pharmacological blockade of KMO or genetic silencing of KYNU suppressed IL-1β-triggered proinflammatory cytokines expression in intestinal epithelial cells. Furthermore, blockage of KMO by selective inhibitor Ro 61-8048 alleviated the symptoms of DSS-induced colitis in mice, accompanied by an expanded NAD+ pool and redox balance restoration. The protective role of Ro 61-8048 may be partly due to its effect on KP regulation, particularly in enhancing kynurenic acid production. In summary, our study provides new evidence for the proinflammatory property of KMO and KYNU in intestinal inflammation, hinting at a promising therapeutic approach in UC through targeting these enzymes.

B cell-mediated CD4 T-cell costimulation via CD86 exacerbates pro-inflammatory cytokine production during autoimmune intestinal inflammation

Dysregulated B cell responses have been described in inflammatory bowel disease (IBD) patients; however, the role of B cells in IBD pathology remained incompletely understood. We here provide evidence for the detrimental role of activated B cells during the onset of autoimmune intestinal inflammation. Using Wiskott-Aldrich Syndrome interacting protein deficient (Wipf1-/-) mice as a mouse model of chronic colitis, we identified clusters of differentiation (CD)86 expression on activated B cells as a crucial factor exacerbating pro-inflammatory cytokine production of intestinal CD4 T cells. Depleting B cells through anti-CD20 antibody treatment or blocking costimulatory signals mediated by CD86 through cytotoxic T lymphocyte antigen-4-immunoglobulin (CTLA-4-Ig) diminished intestinal inflammation in our mouse model of chronic IBD at the onset of disease. This was due to a reduction in aberrant humoral immune responses and reduced CD4 T cell pro-inflammatory cytokine production, especially interferon-g (IFN-g) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Interestingly, in addition to B cells isolated from the inflamed colon of Wipf1-/- mice, we also found CD86 mRNA and protein expression upregulated on activated B cells isolated from inflamed tissue of human patients with IBD. B cell activation and CD86 expression were boosted by soluble CD40L in vitro, which we found in the serum of mice and human patients with IBD. In summary, our data provides detailed insight into the contribution of B cells to intestinal inflammation, with implications for the treatment of IBD.

Knowledge Levels About Inflammatory Bowel Disease Vary Between Healthcare Professional Groups

BACKGROUND

Inflammatory Bowel Disease (IBD) is one of the most serious chronic diseases affecting the global population. Clinical team members involved in the care of individuals with IBD should have sufficient knowledge about IBD.

AIMS

The study aim was to assess IBD knowledge among four health care professional groups in New Zealand: nurses, medical students, dietitians, and pharmacists.

METHODS

All four groups completed surveys on demographics, work experience, and contact with patients with IBD. All completed a validated IBD knowledge assessment questionnaire (IBD-KID2), and percentage scores with standard deviation (SD) for each group calculated and compared.

RESULTS

Participants included 200 nurses, 196 medical students, 45 dietitians, and 28 pharmacists. Mean IBD-KID2 percentage scores were nurses 69.7% (SD 14.7), medical students 77.6% (SD 14.5), dietitians 87.4% (SD 8.3), and pharmacists 83.4% (SD 10.1). Nurses scored lower than other HCP (P < 0.001). Independent variables were associated (P < 0.05) with higher scores for nurses having first degree relative with IBD, access to IBD guidelines, worked with children with IBD; medical students in their clinical years of study; and dietitians with IBD-specific education. Specific items scored poorly: growth, food triggers, heritability of IBD, and nutrient absorption.

CONCLUSIONS

Knowledge gaps exist among HCP that may be addressed with targeted education. Improvements in the knowledge of those caring for people with IBD may optimize patient outcomes.

Gut microbiota signatures in inflammatory bowel disease

BACKGROUND

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), affect millions of people worldwide with increasing incidence.

OBJECTIVES

Several studies have shown a link between gut microbiota composition and IBD, but results are often limited by small sample sizes. We aimed to re-analyze publicly available fecal microbiota data from IBD patients.

METHODS

We extracted original fecal 16S rRNA amplicon sequencing data from 45 cohorts of IBD patients and healthy individuals using the BioProject database at the National Center for Biotechnology Information. Unlike previous meta-analyses, we merged all study cohorts into a single dataset, including sex, age, geography, and disease information, based on which microbiota signatures were analyzed, while accounting for varying technical platforms.

RESULTS

Among 2518 individuals in the combined dataset, we discovered a hitherto unseen number of genera associated with IBD. A total of 77 genera associated with CD, of which 38 were novel associations, and a total of 64 genera associated with UC, of which 28 represented novel associations. Signatures were robust across different technical platforms and geographic locations. Reduced alpha diversity in IBD compared to healthy individuals, in CD compared to UC, and altered microbiota composition (beta diversity) in UC and especially in CD as compared to healthy individuals were found.

CONCLUSIONS

Combining original microbiota data from 45 cohorts, we identified a hitherto unseen large number of genera associated with IBD. Identification of microbiota features robustly associated with CD and UC may pave the way for the identification of new treatment targets.

Lnc-ing RNA to intestinal homeostasis and inflammation

Long noncoding RNAs (lncRNAs) play important roles in numerous biological processes, including the immune system. Initial research in this area focused on cell-based studies, but recent advances underscore the profound significance of lncRNAs at the organismal level, providing invaluable insights into their roles in inflammatory diseases. In this rapidly evolving field, lncRNAs have been described with pivotal roles in the intestinal tract where they regulate intestinal homeostasis and inflammation by influencing processes such as immune cell development, inflammatory signaling pathways, epithelial barrier function, and cellular metabolism. Understanding the regulation and function of lncRNAs in this tissue may position lncRNAs not only as potential disease biomarkers but also as promising targets for therapeutic intervention in inflammatory bowel disease and related diseases.

Precision nutrition in pediatric IBD: A position paper from the ESPGHAN special interest group for basic science and translational research, the IBD Porto group, and allied health professionals

Stratified and precision nutrition refers to disease management or prevention of disease onset, based on dietary interventions tailored to a person's characteristics, biology, gut microbiome, and environmental exposures. Such treatment models may lead to more effective management of inflammatory bowel disease (IBD) and reduce risk of disease development. This societal position paper aimed to report advances made in stratified and precision nutritional therapy in IBD. Following a structured literature search, limited to human studies, we identified four relevant themes: (a) nutritional epidemiology for risk prediction of IBD development, (b) food-based dietary interventions in IBD, (c) exclusive enteral nutrition (EEN) for Crohn's disease (CD) management, and (d) pre- and probiotics for IBD management. There is scarce literature upon which we can make recommendations for precision or stratified dietary therapy for IBD, both for risk of disease development and disease management. Certain single-nucleotide polymorphisms related to polyunsaturated fatty acid (PUFA) metabolism may modify the effect dietary PUFA have in increasing the risk of IBD development. Non-colonic CD, mild-to-moderate CD, and high microbiota richness may predict success of EEN and may be used both for prediction of treatment continuation, but also for early cessation in nonresponders. There is currently insufficient evidence to make recommendations for precision or stratified dietary therapy for patients with established IBD. Despite the great interest in stratified and precision nutrition, we currently lack data to support conclusive recommendations. Replication of early findings by independent research groups and within structured clinical interventions is required.

The Role of Gut Microbiome in the Pathogenesis and the Treatment of Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, is a chronic condition characterized by inflammation of the gastrointestinal tract. Its exact cause is unknown, but it's thought to result from a dysregulated immune response influenced by various factors, including changes in the intestinal microbiota, diet, lifestyle, and genetics. The gut microbiome, consisting of diverse microorganisms, plays a crucial role in maintaining physiological balance, with its disruption leading to inflammatory responses typical of IBD. Treatments primarily aim at symptom control, employing immunomodulators, corticosteroids, and newer approaches like probiotics, prebiotics, fecal transplants, and dietary modifications, all focusing on leveraging the microbiota's potential in disease management. These strategies aim to restore the delicate balance of the gut microbiome, typically altered in IBD, marked by a decrease in beneficial bacteria and an increase in harmful pathogens. This review underscores the importance of the gut microbiome in the pathogenesis and treatment of IBD, highlighting the shift towards personalized medicine and the necessity for further research in understanding the complex interactions between the gut microbiota, immune system, and genetics in IBD. It points to the potential of emerging treatments and the importance of a multifaceted approach in managing this complex and challenging disease.