Colitis Colon Research Articles

Can we improve the endoscopic resection of dysplastic lesions in colonic inflammatory bowel diseases?

Can we improve the endoscopic resection of dysplastic lesions in colonic inflammatory bowel diseases?

Characterisation of IBD heterogeneity using serum proteomics: A multicentre study.

Recent genetic and transcriptomic data highlight the need for improved molecular characterisation of inflammatory bowel disease (IBD). Proteomics may advance the delineation of IBD phenotypes since it accounts for post-transcriptional modifications. We aimed to assess the IBD spectrum based on inflammatory serum proteins and identify discriminative patterns of underlying biological subtypes across multiple European cohorts. Using proximity extension methodology, we measured 86 inflammation-related serum proteins in 1551 IBD patients and 312 healthy controls (HC). We screened for proteins exhibiting significantly different levels among IBD subtypes and between IBD and HC. Classification models for differentiating between Crohn's disease (CD) and ulcerative colitis (UC) were employed to explore the IBD spectrum based on estimated probability scores. Levels of multiple proteins, such as IL-17A, MMP-10, and FGF-19, differed (fold-change>1.2; FDR<0.05) between ileal vs colonic IBD. Using multivariable models, a protein signature reflecting the IBD spectrum was identified, positioning colonic CD between UC and ileal CD, which were at opposite ends of the spectrum. Based on area under the curve (AUC) estimates, classification models more accurately differentiated UC from ileal CD (median AUCs>0.73) than colonic CD (median AUCs<0.62). Models differentiating colonic CD from ileal CD demonstrated intermediate performance (median AUCs 0.67-0.69). Our findings in serum proteins support the presence of a continuous IBD spectrum rather than a clear separation of CD and UC. Within the spectrum, disease location may reflect a more similar disease than CD vs UC, as colonic CD resembled UC more closely than ileal CD.

Metabolomic insights into the beneficial effects of dietary purple potato on DSS-induced murine colon colitis

Inflammatory bowel disease (IBD) is characterized by disturbance in intestinal flora and metabolomic profiles. Building on previous findings that purple potato (PP) supplementation suppresses inflammation and restores intestinal barrier in dextran sulfate sodium (DSS)-treated mice, this study examined changes in the fecal metabolome in the same cohort. Mice were fed 0 % or 10 % PP for 7 weeks, with DSS administered in the fifth week of dietary treatment followed by one-week normal drinking water recovery. A total of 68 metabolites, including amino acids, fatty acids, organic acids, carbohydrates, and polyamines, were significantly altered across the groups. PP supplementation reversed changes in 13 of the 25 DSS-altered metabolites. Six microbial metabolites derived from PP polyphenols were identified and positively correlated with M2 macrophage polarization. Data suggest that dietary PP is effective in reducing inflammation and improves gut metabolites in DSS-induced colitis mice, offering a potential dietary therapy for managing IBD.

Exploring the relationship between ulcerative colitis, colorectal cancer, and prostate cancer.

Chronic systemic inflammation caused by diseases such as ulcerative colitis (UC) and Crohn's disease (CD) increases the risk of developing colorectal cancer (CRC). Recent evidence indicates that patients with UC are more susceptible to prostate cancer (PCa), and individuals with PCa may also be at a higher risk of developing CRC. However, these relationships are not well defined. A better understanding of this phenomenon could improve the identification of high-risk populations. In this study, we characterized these relationships with experiments using preclinical mouse models of dextran sulfate sodium (DSS)-induced colitis (DSS-UC) and DSS/azoxymethane (AOM)-induced CRC (DSS/AOM-CRC) in wild-type and conditional transgenic mice of PCa. We showed that DSS-induced UC was more severe in mice with PCa and resulted in the development of CRC in the absence of AOM. We further showed that PCa-free mice that developed DSS-induced UC also showed histological changes in the normal prostate that resembled proliferative inflammatory atrophy. Finally, we used immunohistochemical immune profiling to show that mice with PCa-induced chronic systemic inflammation accumulated Gr1+ myeloid cells in the normal colon and exposure to DSS further enriched these cells in active colitis regions and colon tumors. Our study provides evidence to support a link between systemic chronic inflammation and cancer.

The effect of rs2910686 on ERAP2 expression in IBD and epithelial inflammatory response

BackgroundERAP2 is an aminopeptidase involved in antigen processing and presentation, and harbor genetic variants linked to several inflammatory diseases such as Inflammatory Bowel Disease (IBD). The lack of an ERAP2 gene homologue in mice has hampered functional studies, and most human studies have focused on cells of hematopoietic origin. Using an IBD biobank as vantage point, this study explores how genetic variation in ERAP2 affects gene expression in human-derived epithelial organoids upon proinflammatory stimulation.MethodsAn IBD patient cohort was genotyped with regards to two single nucleotide polymorphisms (SNP) (rs2910686/rs2248374) associated with ERAP2 expression levels, and we examined the correlation between colon gene expression and genotype, specifically aiming to establish a relationship with ERAP2 expression proficiency. Human-derived colon organoids (colonoids) with known ERAP2 genotype were established and used to explore differences in whole genome gene expression between ERAP2-deficient (n = 4) and -proficient (n = 4) donors upon pro-inflammatory encounter.ResultsWhen taking rs2910686 genotype into account, ERAP2 gene expression is upregulated in the inflamed colon of IBD patients. Colonoids upregulate ERAP2 upon IFNɣ stimulation, and ERAP2 expression proficiency is dependent on rs2910686 genotype. Colonoid genotyping confirms that mechanisms independent of the frequently studied SNP rs2248374 can cause ERAP2-deficiency. A total of 586 genes involved in various molecular mechanisms are differentially expressed between ERAP2 proficient- and deficient colonoids upon proinflammatory stimulation, including genes encoding proteins with the following molecular function: catalytic activity (AOC1, CPE, ANPEP and MEP1A), regulator activity (TNFSF9, MDK, GDF15, ILR6A, LGALS3 and FLNA), transmembrane transporter activity (SLC40A1 and SLC5A1), and extracellular matrix structural constituents (FGL2, HMCN2, and MUC17).ConclusionsERAP2 is upregulated in the inflamed IBD colon mucosa, and expression proficiency is highly correlated with genotype of rs2910686. While the SNP rs2248374 is commonly used to determine ERAP2 expressional proficiency, our data confirms that mechanisms independent of this SNP can lead to ERAP2 deficiency. Our data demonstrates that epithelial ERAP2 presence affects the inflammatory response in colonoids, suggesting a pleiotropic role of ERAP2 beyond MHC class I antigen processing.

Immune disease dialogue of chemokine-based cell communications as revealed by single-cell RNA sequencing meta-analysis.

Immune-mediated diseases are characterized by aberrant immune responses, posing significant challenges to global health. In both inflammatory and autoimmune diseases, dysregulated immune reactions mediated by tissue-residing immune and non-immune cells precipitate chronic inflammation and tissue damage that is amplified by peripheral immune cell extravasation into the tissue. Chemokine receptors are pivotal in orchestrating immune cell migration, yet deciphering the signaling code across cell types, diseases and tissues remains an open challenge. To delineate disease-specific cell-cell communications involved in immune cell migration, we conducted a meta-analysis of publicly available single-cell RNA sequencing (scRNA-seq) data across diverse immune diseases and tissues. Our comprehensive analysis spanned multiple immune disorders affecting major organs: atopic dermatitis and psoriasis (skin), chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis (lung), ulcerative colitis (colon), IgA nephropathy and lupus nephritis (kidney). By interrogating ligand-receptor (L-R) interactions, alterations in cell proportions, and differential gene expression, we unveiled intricate disease-specific and common immune cell chemoattraction and extravasation patterns. Our findings delineate disease-specific L-R networks and shed light on shared immune responses across tissues and diseases. Insights gleaned from this analysis hold promise for the development of targeted therapeutics aimed at modulating immune cell migration to mitigate inflammation and tissue damage. This nuanced understanding of immune cell dynamics at the single-cell resolution opens avenues for precision medicine in immune disease management.

Exploring the interactions of JAK inhibitor and S1P receptor modulator drugs with the human gut microbiome: Implications for colonic drug delivery and inflammatory bowel disease

The gut microbiota is a complex ecosystem, home to hundreds of bacterial species and a vast repository of enzymes capable of metabolising a wide range of pharmaceuticals. Several drugs have been shown to affect negatively the composition and function of the gut microbial ecosystem. Janus Kinase (JAK) inhibitors and Sphingosine-1-phosphate (S1P) receptor modulators are drugs recently approved for inflammatory bowel disease through an immediate release formulation and would potentially benefit from colonic targeted delivery to enhance the local drug concentration at the diseased site. However, their impact on the human gut microbiota and susceptibility to bacterial metabolism remain unexplored. With the use of calorimetric, optical density measurements, and metagenomics next-generation sequencing, we show that JAK inhibitors (tofacitinib citrate, baricitinib, filgotinib) have a minor impact on the composition of the human gut microbiota, while ozanimod exerts a significant antimicrobial effect, leading to a prevalence of the Enterococcus genus and a markedly different metabolic landscape when compared to the untreated microbiota. Moreover, ozanimod, unlike the JAK inhibitors, is the only drug subject to enzymatic degradation by the human gut microbiota sourced from six healthy donors. Overall, given the crucial role of the gut microbiome in health, screening assays to investigate the interaction of drugs with the microbiota should be encouraged for the pharmaceutical industry as a standard in the drug discovery and development process.

Hydrogel-forming viscous liquid in response to ROS restores the gut mucosal barrier of colitis mice via regulating oxidative redox homeostasis

The disrupted oxidative redox homeostasis plays a critical role in the progress of ulcerative colitis (UC). Herein, hydrogel-forming viscous liquid (HSD) composed of cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) has been designed for UC. When the viscous HSD liquid was infused into colitis colon, SOD would convert the pathological superoxide (O2·−) to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion toward colitis colon. H2O2-treated HSD presented the higher storage modulus and stronger adhesion force toward porcine colon than the untreated HSD. Besides, H2O2-treated HSD presented the slower erosion profile in the colitis-mimicking medium (pH 3-5), while its rapid degradation was displayed in physiologic condition (pH7.4). The combination of pH-resistant erosion and ROS-responsive adhesion for HSD rendered it with the specifical retention on the inflamed colonic mucosa of DSS-induced colitis mice. Rectally administrating HSD could effectively hinder the body weight loss, reduce the disease activity index and improve the colonic shorting of DSS-induced colitis mice. Moreover, the pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) were substantially decreased, the colonic epitheliums were well rearranged and the tight junction proteins were greatly recovered after HSD treatment. Besides, HSD also modulated the gut flora, markedly augmenting the abundance of Firmicutes, Barnesiella and Lachnospiraceae. Moreover, HSD treatment could regulate oxidative redox homeostasis via activating Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH). Collectively, HSD might be a promising therapy for UC treatments. Statement of significanceHerein, a hydrogel-forming viscous liquid (HSD) was designed by cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) for UC treatments. When the viscous HSD liquid was infused into a colitis colon, SOD would convert the pathological superoxide to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion to the colitis colon. The colonic epitheliums of DSS-induced colitis mice were well rearranged and the tight junction proteins (Zonula-1 and Claudin-5) were greatly recovered after the HSD treatment. Moreover, the HSD treatment could regulate oxidative redox homeostasis via activating the Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH).

Clinical and diagnostic value of transrectal ultrasound in assessing the severity of ulcerative colitis

Background. Endoscopic and histological studies play a decisive role in the diagnosis of inflammatory bowel diseases, as they allow confirming the diagnosis, determining the degree of inflammatory activity, the extent of intestinal damage, and monitoring the course of disease and the effectiveness of therapy. Howe­ver, it is not possible to assess the state of all intestinal layers with colonoscopy. Modern non-invasive methods such as ultrasound, computed tomography, and magnetic resonance imaging cope best with this purpose. With their help, you can assess the state of the intestinal wall and obtain a cross-sectional image of the intestine, evaluate extraintestinal structures (lymph nodes, vessels, fatty tissue). It can be said that endoscopy and ultrasound search for the same type of information but look at different things. Deepening the knowledge about the role of ultrasound of the distal parts of the colon in ulcerative colitis (UC) will contribute to the improvement of diagnosis, development of methods for determining the activity of UC, control of therapy, which will allow optimizing the choice of adequate treatment measures. The goal of the work: to improve the diagnosis of ulcerative colitis based on the study of ultrasonographic parameters of the rectum. Materials and methods. Transrectal ultrasound was performed on an expert-class SonoScape S60 ultrasound scanner using a low-frequency convex probe of 3.5 MHz and a rectovaginal convex probe of 6 MHz. Transperineal and transrectal approaches were used. Results. Wall thickness and submucosal thickness differed significantly in moderate and severe UC. Analysis of transrectal ultrasound indicators depending on the endoscopic activity of the UC revealed no significant differences in the rectal wall thickness. But there was a tendency to increase in the thickness of the mucous layer and the coefficient of deformation with increasing endoscopic activity. Most patients had an increase in the degree of blood flow density, which depended on the disease severity. During the regression analysis, a relationship was found between the intestinal wall thickness (r = 0.44; p = 0.0121) and submucosal layer thickness (r = 0.86; p = 0.006) with the Mayo index. A correlation was revealed between the thickness of the colon wall and the frequency of bowel movements (r = 0.37; p = 0.018), leukocytosis (r = 0.38; p = 0.016) and erythrocyte sedimentation rate (r = 0.35; p = 0.027). The blood flow density in the intestinal wall positively correlated with the presence of edema (r = 0.32; р = 0.045), the severity of the vascular pattern (r = 0.42; р = 0.008), the presence of erosions (r = 0.4; р = 0.011) and bleeding of the mucous membrane (r = 0.50; p = 0.001). The coefficient of deformation positively correlated with the presence of flatulence (r = 0.35; р = 0.048). Conclusions. Endoscopic exa­mination in patients with UC should be supplemented with transrectal ultrasound. A correlation was found between the intestinal wall thickness and the thickness of the submucosal layer in patients with UC and the Mayo index. A tendency to increase in the thickness of the mucous layer and the coefficient of deformation with increasing endoscopic activity was determined. Relationships between endoscopic and ultrasound parameters can be used to assess disease activity.

D239Y germline variant of NTHL1 glycosylase increases susceptibility to colorectal cancer in mice

Introduction: Persistent genotoxic stress leads to spontaneous DNA damage, which occurs on the order of 104−105 events per cell per day. The base excision repair is the first responder in the repair mechanisms after DNA damage, with DNA glycosylase being the first step in the repair process by binding to the DNA, cleaving the N-glycosidic bond and removing the oxidized pyrimidine DNA lesions. NTHL1 is a pivotal bifunctional DNA glycosylase enzyme involved in base excision repair mechanism. NTHL1 tumor syndrome is characterized by an increased lifetime risk for colorectal cancer (CRC), breast cancer, and colorectal polyposis. A rare rs3087468 polymorphism (D239Y) exhibits no glycosylase activity and may act as a dominant-negative mutation. Hypothesis: NTHL1-D239Y variant conforms susceptibility to inflammation-associated colorectal cancer. Methods: 6-8 weeks/old male and female C57BL/6 wild-type (WT, NTHL1WT/WT), heterozygous (NTHL1WT/D239Y), or homozygous (NTHL1D239Y/D239Y) knock-in mice were injected with 7.5mg/kg azoxymethane (AOM) followed by three cycles of alternating 2.5% dextran sulfate sodium (DSS, 5 days) and normal drinking water (14 days). We monitored body weight, collected fecal samples for microbial 16S rRNA amplicon sequencing, and analyzed colon length and number/size of polyps at euthanasia. The histology score was assessed by an unbiased pathologist to evaluate inflammation and tumor development. Blood samples were used to evaluate micronuclei formation. Results: NTHL1WT/D239Y and NTHL1D239Y/D239Y mice showed more pronounced weight loss starting from the 2nd DSS cycle. The number and size of polyps in the distal colon of NTHL1WT/D239Y and NTHL1D239Y/D239Y male mice were increased compared to WT littermates. NTHL1D239Y/D239Y females, but not males, showed increased polyp number compared to NTHL1WT/D239Y mice. No statistical difference was observed in the polyps’ size. Tumors extending into the proximal colon were observed uniquely in NTHL1D239Y/D239Y females. On the other hand, only NTHL1WT/D239Y males developed high adenomas in the distal colon compared to WT males. Interestingly, only NTHL1D239Y/D239Y males showed statistical difference in micronucleated normochromatic erythrocytes compared to WT mice. NTHL1 genotype did not significantly affect fecal microbial α- or β-diversity or colitis score and colon length in either gender. Conclusion: Our data suggest that NTHL1-D239Y variant confers a complex, zygosity- and sex-dependent susceptibility risk for inflammation-associated colorectal cancer that may be intrinsic and independent of changes in the gut microbiota. In females, it promotes more proximal tumor location, while in males, it promotes the size and tumor progression. 5P30CA023074 (JBS), Phoenix Women's Board of the Steele Children's Research Center (FKG). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effects of alimentary-derived bacterial metabolites on energy metabolism in colonic epithelial cells and inflammatory bowel diseases

In this review, we present the main luminal fuels that are responsible for energy production in colonocytes, namely the bacterial metabolites short-chain fatty acids and lactate, which are produced from undigestible polysaccharides and proteins, and hydrogen sulfide that is mainly produced from undigested proteins. In addition to these luminal fuels, colonocytes can use glutamine, and to a lower extent glucose, as energy substrates provided by arterial capillaries. The effects of excessive concentrations of bacterial metabolites within the colonic luminal fluid (including butyrate, hydrogen sulfide, p-cresol, indole derivatives, ammonia, 4-hydroxyphenylacetic acid, and acetaldehyde) on the mitochondrial energy metabolism in colonic epithelial cells and the consequences of altered ATP production on the colonic epithelium renewal and barrier function are detailed, as well as consequences for water and electrolyte absorption. The relationships between modifications of these latter processes and development of colitis are then discussed. Finally, several mechanisms that are considered as adaptive against deleterious effects of bacterial metabolites on colonic epithelial cell energy metabolism are presented.

Abstract 1406: Plk1 attenuates colon inflammation and tumorigenesis

Abstract Inflammation-associated colon cancer, linked with long-standing colon inflammation, is often seen in patients with inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis. Typically, these patients are diagnosed at a younger age compared to those with sporadic colon cancer. Despite some advancements, the detailed molecular mechanisms driving cancer development in IBD remain unclear. Polo-like kinase 1 (Plk1), a serine/threonine kinase and cell cycle regulator, is recognized as an oncogene in various cancers. Intriguingly, higher Plk1 expression correlates with better survival rates in colon cancer patients. Besides, Plk1 also elevates in IBD cases, suggesting its significant role in both colitis and colon cancer. Our study explores Plk1's role in IBD-associated colon cancer using the azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model, revealing Plk1's suppressive impact on both colitis and related colon cancer. Citation Format: Xinyi Wang, Dang he, Fengyi Mao, Yifan Kong, Chaohao Li, Sai Wu, Jia Peng, Chi Wang, Zhiguo Li, Xiaoqi Liu. Plk1 attenuates colon inflammation and tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1406.

Sophora japonica Extract Inhibits Ulcerative Colitis and Colitis-Associated Colon Cancer via Regulation of Lipid Metabolism

Inflammation is a well-known risk factor for tumor development. Intervening in chronic inflammation may be an effective approach to inhibit the progression of ulcerative colitis (UC) to colitis-associated colon cancer (CAC). Sophora japonica is a medicinal and food plant commonly used to treat hemorrhoids, bleeding, and inflammation, symptoms that coincide with those of patients with CAC. However, studies on using Sophora japonica to treat CAC are scarce. Therefore, this study aimed to investigate the anti-inflammatory and antitumor effects of Sophora japonica extract (SJE) using dextran sodium sulfate (DSS)-induced UC and azoxymethane (AOM)/DSS-induced CAC models. Furthermore, we employed ultraperformance liquid chromatography–quadrupole time-of-flight–tandem mass spectrometry (UPLC–QTOF–MS/MS) technology to explore the metabolomics mechanism through which SJE inhibited the progression of UC to CAC. The results demonstrated that SJE significantly inhibited UC and CAC and alleviated symptoms such as bloody stools, colon shortening, inflammation, and intestinal tissue damage in model mice. Further, 57 differential metabolites were identified by UPLC–QTOF–MS/MS, which were composed mainly of lipids (fatty acids, glycerophospholipids, sterol lipids, pregnenolone lipids, etc.) and peptides (amino acids). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested that SJE might inhibit the progression of UC to CAC by regulating lipid metabolic pathways such as arachidonic acid metabolism, primary bile acid biosynthesis, and linoleic acid metabolism. This study, for the first time, substantiated the inhibitory effect of SJE on CAC. Employing metabolomics techniques, the research delved into the potential pathways through which SJE may exert its inhibitory effects on CAC by suppressing the progression of UC. These findings contribute scientific evidence to the application of Sophora japonica in functional foods and the development of natural drugs for the prevention and treatment of UC and CAC.

Dynamic Prediction of Advanced Colorectal Neoplasia in Inflammatory Bowel Disease

Colonoscopic surveillance is recommended in patients with colonic inflammatory bowel disease (IBD) given their increased risk of colorectal cancer (CRC). We aimed to develop and validate a dynamic prediction model for the occurrence of advanced colorectal neoplasia (aCRN, including high-grade dysplasia and CRC) in IBD. We pooled data from six existing cohort studies from Canada, the Netherlands, the UK, and the USA. Patients with IBD and an indication for CRC surveillance were included if they underwent at least one follow-up procedure. Exclusion criteria included prior aCRN, prior colectomy, or an unclear indication for surveillance. Predictor variables were selected based on literature. A dynamic prediction model was developed using a landmarking approach based on Cox proportional hazard modelling. Model performance was assessed with Harrell's concordance-statistic (discrimination) and by calibration curves. Generalizability across surveillance cohorts was evaluated by internal-external cross-validation. The surveillance cohorts comprised 3,731 patients, enrolled and followed-up in the time period 1973-2021, with a median follow-up of 5.7 years (26,336 patient-years of follow-up); 146 individuals were diagnosed with aCRN. The model contained eight predictors, with a cross-validation median c-statistic of 0.74 and 0.75 for a 5- and 10-year prediction window, respectively. Calibration plots showed good calibration. Internal-external cross-validation results showed medium discrimination and reasonable to good calibration. The new prediction model showed good discrimination and calibration, however, generalizability results varied. Future research should focus on formal external validation and relate predicted aCRN risks to surveillance intervals prior to clinical application.

Therapeutic effects of epigallocatechin-3-gallate for inflammatory bowel disease: A preclinical meta-analysis

BackgroundEpigallocatechin-3-gallate (EGCG), the primary active compound in green tea, is recognized for its significant anti-inflammatory properties and potential pharmacological effects on inflammatory bowel disease (IBD). However, comprehensive preclinical evidence supporting the use of EGCG in treating IBD is currently insufficient. PurposeTo evaluate the efficacy of EGCG in animal models of IBD and explore potential underlying mechanisms, serving as a groundwork for future clinical investigations. MethodsA systematic review of pertinent preclinical studies published until September 1, 2023, in databases such as PubMed, Embase, Web of Science, and Cochrane Library was conducted, adhering to stringent quality criteria. The potential mechanisms via which EGCG may address IBD were summarized. STATA v16.0 was used to perform a meta-analysis to assess IBD pathology, inflammation, and indicators of oxidative stress. Additionally, dose-response analysis and machine learning models were utilized to evaluate the dose-effect relationship and determine the optimal dosage of EGCG for IBD treatment. ResultsThe analysis included 19 studies involving 309 animals. The findings suggest that EGCG can ameliorate IBD-related pathology in animals, with a reduction in inflammatory and oxidative stress indicators. These effects were observed through significant changes in histological scores, Disease Activity Index, Colitis Macroscopic Damage Index and colon length; a decrease in markers such as interleukin (IL)-1β, IL-6 and interferon-γ; and alterations in malondialdehyde, superoxide dismutase, glutathione, and catalase levels. Subgroup analysis indicated that the oral administration route of EGCG exhibited superior efficacy over other administration routes. Dose-response analysis and machine learning outcomes highlighted an optimal EGCG dosage range of 32–62 mg/kg/day, with an intervention duration of 4.8–13.6 days. ConclusionsEGCG exhibits positive effects on IBD, particularly when administered at the dose range of 32 – 62 mg/kg/day, primarily attributed to its ability to regulate inflammation and oxidative stress levels.

THE MODULATORY EFFECT OF PREBIOTIC INULIN-TYPE FRUCTANS ON THE MICROBIOME PROFILE OF CHILDREN WITH INFLAMMATORY BOWEL DISEASE: A DOUBLE-BLIND RANDOMIZED CONTROLLED TRIAL

Abstract OBJECTIVE The intestinal microbiota plays a pivotal role in the inflammation associated with inflammatory bowel disease (IBD) through their interaction with the mucosal immune system. Prebiotic interventions using inulin-type fructans increase faecal and mucosal bifidobacteria as well as butyrate producing bacteria in healthy volunteers. The aim of this study was to assess the effect of a two-month oligofructose-enriched inulin (OI) supplementation on the microbiome composition, metabolome of children with IBD with subclinical disease activity. DESIGN We performed a single-center, double-blind, placebo-controlled trial at the Children’s Hospital of Philadelphia. Participants included children, 6–21 years old, with subclinical active colonic IBD as defined by a fecal calprotectin level between 50 and 500 μg/g and clinical remission. Participants were randomly assigned 1:1 to consume prebiotic OI or maltodextrin placebo for 8 weeks. Fecal and rectal swabs samples were collected at baseline, week 4, 8 and 16 for fecal calprotectin, microbiome profiling (shotgun metagenomic sequencing) and matching metabolomics (liquid chromatography tandem mass spectrometry). RESULTS The study randomized 68 patients, and 59 were included in the efficacy analyses. The global fecal and mucosal microbiome composition was significantly altered by prebiotic intake and specific inulin-induced increase in relative abundance of Bifidobacterium and Anaerostipes in the fecal samples were identified at week 4 (Figure 1). Two months after discontinuation of OI, the microbial composition of both groups returned to baseline levels. Fecal metabolite profiles were not altered during the 8-week intervention. A negative correlation was observed between calprotectin levels and the relative abundance of Bifidobacterium [q=0.08] and butyrate producer Anaerostipes [q=0.017] (Figure 2). Outcome analysis of inulin-induced change in calprotectin level during the intervention is pending. CONCLUSIONS Dietary intervention with prebiotic OI causes short term alterations in the microbiome of children with IBD characterized by an enrichment of Bifidobacterium and butyrate producer Anaerostipes. These results open new perspectives for development of microbiome-targeted dietary interventions in pediatric IBD. JB received the Crohn’s and Colitis Foundation Career Development Award # 693867 for this study. Figure 1 Selective effect of prebiotic supplementation on microbiome composition Figure 2 Correlation between calprotectin level and inulin-induced microbiome shift A negative correlation between fecal calprotectin level and inulin-induced change in relative abundance of Bifidobacterium [q= 0.08] and Anaerostipes [q=0.017] was observed during the 8-week intervention.

OP15 High-definition white light endoscopy with segmental re-inspection is non-inferior compared to dye-based chromoendoscopy in Inflammatory Bowel Disease: the randomized controlled HELIOS trial

Abstract Background Patients with colonic inflammatory bowel disease (IBD) undergo endoscopic surveillance to detect and remove colorectal neoplasia (CRN). Although high-definition dye-based chromo-endoscopy (HD-CE) is the recommended modality in guidelines, high-definition white light endoscopy (HD-WLE) with matched procedural time may yield similar neoplasia detection rates. We designed a non-blinded, randomized controlled trial in four academic hospitals aiming to compare three endoscopic surveillance techniques in IBD patients for the outcome of CRN detection rate. Methods Eligible patients were aged ≥18 years and scheduled for colitis-associated CRN surveillance according to Dutch IBD surveillance guidelines. Patients were excluded in case of insufficient bowel cleansing, active colitis, or if &amp;gt;50% of the colon was resected. Patients were randomly assigned (2:2:1) to undergo HD-WLE with segmental re-inspection (SR), HD-CE, or single pass HD-WLE. The primary outcome was CRN detection rate, defined as the proportion of procedures in which macroscopic CRN was detected. Secondary outcomes included the number of CRN and withdrawal time. To demonstrate non-inferiority of HD-WLE with SR compared to HD-CE (one-sided testing, α=0.05, 1−β=0.8, non-inferiority (NI) margin -10%), and superiority compared to single-pass HD-WLE (two-sided testing, estimated CRN detection rate of 24% and 12%, respectively1) with Mantel-Haenszel analyses, a total of 566 patients were needed. Results In total, 666 patients were randomized, 563 fulfilled all study criteria and were analysed per protocol (table 1). Of these, 51.8% were male, with a median age of 51 years (interquartile range 35-63). CRN detection rates were 9.8% for HD-WLE with SR, 13.1% for HD-CE, and 6.1% for single pass HD-WLE. HD-WLE with SR was non-inferior compared to HD-CE (Δ-3.1%, lower boundary of the 95% confidence interval (CI) -8.1 not exceeding the NI margin of -10%, p&amp;lt;.05). HD-WLE with SR was not superior compared to single-pass HD-WLE (Δ3.7%, 95% CI -2.5:9.1%, p=0.31). A significant difference was found between arms for the number of detected CRN (n=29 vs n=36 vs n=8 for HD-WLE with SR, HD-CE and single-pass HD-WLE, respectively (p=.04)) and withdrawal time (p=.03, table 1). One advanced lesion was detected (high-grade dysplasia in the HD-CE arm). Conclusion In this large, randomized controlled trial, HD-WLE with SR was non-inferior compared to HD-CE for CRN detection in IBD patients. HD-WLE with SR was not superior to single-pass HD-WLE, although this may have resulted from lower than expected neoplasia yields and subsequent lower power. These results suggest that HD-WLE with SR may provide a feasible alternative to HD-CE in clinical practice (NCT04291976). 1Imperatore et al. JCC 2019;13(6):714-24

P224 JAK-STAT-Driven Tryptophan Degradation Fuels Mucosal Inflammation through QPRT Suppression-Induced Quinolinic Acid Overflow

Abstract Background Inflammatory bowel disease is characterized by disturbed metabolism, including disrupted tryptophan (TRP) metabolism along the kynurenine pathway (KP). However, the molecular mechanism how this fuels inflammation is not understood. Here, we unravel rewiring of TRP metabolism in IBD by combining murine DSS colitis with multi-omics of longitudinal IBD cohorts. Methods Serum metabolites were associated with CRP, e/pMayo, SESCD and CDAI (n=83 UC, n=51 CD). Mucosal IDO1 and QPRT expression (both KP enzymes; indoleamine2,3-dioxygenase1, quinolinate phosphoribosyltransferase; n=273 UC) was correlated with Nancy index and eMayo. Murine enterocytes were treated with Qprt siRNA, LPS or IFNγ and cytokines measured by RT-qPCR. Tissue and serum of DSS colitis (C57BL/6, 2.5%, 5 days) and human PBMC or colon organoids (hOG) treated with IFNγ or Tofacitinib (Tofa) were analysed by LC-MS. Blood and biopsies for metabolomics and transcriptomics were obtained over 14 weeks from IBD patients (n=62) first introduced to biologics. Mucosal IDO1/QPRT expression was assessed at week 0, 8 and 16 in Tofa-treated UC (n=15). Results In longitudinal IBD therapy intervention cohorts, restoration of serum TRP metabolism was associated with 12-month disease control. Quinolinic acid (QUIN) levels relative to other TRP derivatives positively correlated with several disease activity metrics. Increased mucosal IDO1 and decreased QPRT expression upon proceeding disease severity suggested unbalanced QUIN levels as a joint result of augmented TRP turnover by IDO1 and blocked QUIN conversion by QPRT in active disease. In-vitro, QUIN overflow exaggerated pro-inflammatory cytokine responses. Accumulation of colonic QUIN was reproduced in DSS colitis and resulted in NAD+ (nicotinamide adenine dinucleotide) exhaustion, suggesting a local KP roadblock due to QPRT suppression. Integrated metabolomics and transcriptomics of IBD blood and biopsies confirmed TRP hyper-degradation at the inflammation site and revealed common JAK/STAT pathway upregulation in blood and mucosa. As IDO1 exerts the KP via JAK/STAT, IFNγ-induced KP-activation was rescued by JAK inhibition (JAKi) in human PBMC and hOG. Ultimately, we found mucosal QPRT and IDO1 expression to be significantly associated with therapy response to Tofa in UC, suggesting their baseline expression as an a priori predictor of JAKi therapy response. Conclusion TRP wasting in IBD appears to fuel mucosal inflammation due to QPRT suppression and subsequent QUIN overflow. Whether this mechanism is unique to IBD remains to be shown. Obvious future applications may include diagnostic patient classification and targeting therapeutic interventions in the TRP pathway.

Blocking GPR15 Counteracts Integrin-dependent T Cell Gut Homing in Vivo.

The G protein coupled receptor GPR15 is expressed on and functionally important for T cells homing to the large intestine. However, the precise mechanisms by which GPR15 controls gut homing have been unclear. Thus, we aimed to elucidate these mechanisms as well as to explore the potential of targeting GPR15 for interfering with T cell recruitment to the colon in inflammatory bowel disease [IBD]. We used dynamic adhesion and transmigration assays, as well as a humanised in vivo model of intestinal cell trafficking, to study GPR15-dependent effects on gut homing. Moreover, we analysed GPR15 and integrin expression in patients with and without IBD, cross-sectionally and longitudinally. GPR15 controlled T cell adhesion to MAdCAM-1 and VCAM-1 upstream of α4β7 and α4β1 integrin, respectively. Consistently, high co-expression of these integrins with GPR15 was found on T cells from patients with IBD, and GPR15 also promoted T cell recruitment to the colon in humanised mice. Anti-GPR15 antibodies effectively blocked T cell gut homing in vitro and in vivo. In vitro data, as well as observations in a cohort of patients treated with vedolizumab, suggest that this might be more effective than inhibiting α4β7. GPR15 seems to have a broad, but organ-selective, impact on T cell trafficking and is therefore a promising target for future therapy of IBD. Further studies are needed.

Unraveling the gut health puzzle: exploring the mechanisms of butyrate and the potential of High-Amylose Maize Starch Butyrate (HAMSB) in alleviating colorectal disturbances.

Colorectal disturbances encompass a variety of disorders that impact the colon and rectum, such as colitis and colon cancer. Butyrate, a short-chain fatty acid, plays a pivotal role in supporting gut health by nourishing colonocytes, promoting barrier function, modulating inflammation, and fostering a balanced microbiome. Increasing colorectal butyrate concentration may serve as a critical strategy to improve colon function and reduce the risk of colorectal disturbances. Butyrylated high-amylose maize starch (HAMSB) is an edible ingredient that efficiently delivers butyrate to the colon. HAMSB is developed by esterifying a high-amylose starch backbone with butyric anhydride. With a degree of substitution of 0.25, each hydroxy group of HAMSB is substituted by a butyryl group in every four D-glucopyranosyl units. In humans, the digestibility of HAMSB is 68% (w/w), and 60% butyrate molecules attached to the starch backbone is absorbed by the colon. One clinical trial yielded two publications, which showed that HAMSB significantly reduced rectal O6-methyl-guanine adducts and epithelial proliferation induced by the high protein diet. Fecal microbial profiles were assessed in three clinical trials, showing that HAMSB supplementation was consistently linked to increased abundance of Parabacteroides distasonis. In animal studies, HAMSB was effective in reducing the risk of diet- or AOM-induced colon cancer by reducing genetic damage, but the mechanisms differed. HAMSB functioned through affecting cecal ammonia levels by modulating colon pH in diet-induced cancer, while it ameliorated chemical-induced colon cancer through downregulating miR19b and miR92a expressions and subsequently activating the caspase-dependent apoptosis. Furthermore, animal studies showed that HAMSB improved colitis via regulating the gut immune modulation by inhibiting histone deacetylase and activating G protein-coupled receptors, but its role in bacteria-induced colon colitis requires further investigation. In conclusion, HAMSB is a food ingredient that may deliver butyrate to the colon to support colon health. Further clinical trials are warranted to validate earlier findings and determine the minimum effective dose of HAMSB.