Progression Of Colitis Research Articles

Differential contributions of the gut microbiota and metabolome to pathomechanisms in ulcerative colitis: an in vitro analysis

ABSTRACT The gut microbiota has been implicated in onset and progression of ulcerative colitis (UC). Here, we assess potential causal involvement of the microbiota and -associated fecal water (FW) metabolome in altering key functional parameters of the colonic epithelium. Fecal samples were collected from N = 51 healthy controls (HC), N = 36 patients with active UC (UC-A), and N = 41 subjects in remission N = 41 (UC-R). Using in vitro incubation experiments, the FW metabolome’s impact on butyrate oxidation rates/gene expression and cell death (cytotoxicity) of HT-29 cells, cytokine production by PBMC, and barrier integrity of Caco2 monolayers was evaluated. The FW metabolome from patients and individuals hosting the Bacteroides 2 (Bact2) enterotype (69% of UC-A, 31% of UC-R, 3% of HC), characterized by lower levels of median- and short-chain fatty acids and furan compounds, left butyrate oxidation rates unaltered but affected associated gene expression profiles. UC patients/Bact2-carriers’ FW lowered PBMC IL-8 production and increased IL-1β production. Patients’ FW increased cytotoxicity, associated with sulfide compound levels. Bact2 carriers’ FW, displaying higher levels of bile acids, lowered barrier function upon incubation of monolayers. The FW metabolome of patients and individuals hosting a dysbiotic microbiota could contribute to the disruption of functional processes of the colonic epithelium as observed in UC.

Advances in research on the role of high carbohydrate diet in the process of inflammatory bowel disease (IBD)

Inflammatory bowel disease (IBD) is a chronic, systemic gastrointestinal disorder characterized by episodic inflammation that requires life-long management. Although the etiology of IBD is not fully understood, it is hypothesized to involve a multifaceted interplay among genetic susceptibility, the host immune response, and environmental factors. Previous studies have largely concluded that IBD is associated with this complex interplay; however, more recent evidence underscores the significant role of dietary habits as risk factors for the development of IBD. In this review, we review the molecular mechanisms of high-sugar and high-fat diets in the progression of IBD and specifically address the impacts of these diets on the gut microbiome, immune system regulation, and integrity of the intestinal barrier, thereby highlighting their roles in the pathogenesis and exacerbation of IBD.

Early subclinical stages of the inflammatory bowel diseases - insights from human and animal studies.

The inflammatory bowel diseases (IBD) occur in genetically susceptible individuals that mount inappropriate immune responses to their microbiota leading to chronic intestinal inflammation. The natural history of IBD progression begins with early subclinical stages of disease that occur before clinical diagnosis. Improved understanding of those early subclinical stages could lead to new or improved strategies for IBD diagnosis, prognostication or prevention. Here we review our current understanding of the early subclinical stages of IBD in humans including studies from first-degree relatives of IBD patients and members of the general population who go on to develop IBD. We also discuss representative mouse models of IBD that can be used to investigate disease dynamics and host-microbiota relationships during these early stages. In particular, we underscore how mouse models of IBD that develop disease later in life with variable penetrance may present valuable opportunities to discern early subclinical mechanisms of disease before histological inflammation and other severe symptoms become apparent.

Human gut commensal Alistipes timonensis modulates the host lipidome and delivers anti-inflammatory outer membrane vesicles to suppress colitis in an Il10 -deficient mouse model.

Correlative studies have linked human gut microbes to specific health conditions. Alistipes is one such microbial genus negatively linked to inflammatory bowel disease (IBD). However, the protective role of Alistipes in IBD has not been studied and the underlying molecular mechanisms also remain unknown. In this study, colonization of Il10 -deficient mice with Alistipes timonensis DSM 27924 delays the development of colitis. Colonization with Alistipes does not significantly alter the gut microbiome composition during colitis development, but instead shifts the host plasma lipidome, increasing phosphatidic acids while decreasing triglycerides. Outer membrane vesicles (OMVs) derived from Alistipes are also detected in the plasma of colonized mice, which carry metabolites with immunomodulatory potential into the host circulatory system. We further demonstrate that fractions of A. timonensis OMVs suppress LPS-induced Il6 , Il1b , and Tnfa expression in vitro in murine macrophages. We detect immunomodulatory sulfonolipids (SoLs) in the active fraction, which are also increased in the blood of A. timonensis -colonized mice; and we identify other putative bioactive lipids in the A. timonensis OMVs. Thus, A. timonensis OMVs represent a potential mechanism for Alistipes -mediated delay of colitis progression in Il10 -deficient mice through the delivery of immunomodulatory lipids, including SoLs, and modulation of the host plasma lipidome.

Gut Microbiome as a Target of Intervention in Inflammatory Bowel Disease Pathogenesis and Therapy

Inflammatory bowel disease (IBD) is a chronic complicated inflammatory gut pathological disorder and is categorized into ulcerative colitis (UC) and Crohn’s disease (CD). Although the cause of IBD is unclear, dysbiosis of the gut microbiota is thought to be a key factor in the disease’s progression. The gut microbiome serves as a metabolic organ and promotes wellness by carrying out several biological activities. Any modification in the makeup of the gut microbiome leads to several pathological conditions, including IBD. In this review, we emphasize the key metabolic processes that control host–microbiome interaction and its impact on host health. We also discuss the association between microbiome dysbiosis (bacteriome, virome, and mycobiome) and the progression of IBD. Finally, we will highlight microbiome-based therapy as a novel and promising strategy to treat and manage IBD.

Advancements in the use of AI in the diagnosis and management of inflammatory bowel disease.

Inflammatory bowel disease (IBD) causes chronic inflammation of the colon and digestive tract, and it can be classified as Crohn's disease (CD) and Ulcerative colitis (UC). IBD is more prevalent in Europe and North America, however, since the beginning of the 21st century it has been increasing in South America, Asia, and Africa, leading to its consideration as a worldwide problem. Optical colonoscopy is one of the crucial tests in diagnosing and assessing the progression and prognosis of IBD, as it allows a real-time optical visualization of the colonic wall and ileum and allows for the collection of tissue samples. The accuracy of colonoscopy procedures depends on the expertise and ability of the endoscopists. Therefore, algorithms based on Deep Learning (DL) and Convolutional Neural Networks (CNN) for colonoscopy images and videos are growing in popularity, especially for the detection and classification of colorectal polyps. The performance of this system is dependent on the quality and quantity of the data used for training. There are several datasets publicly available for endoscopy images and videos, but most of them are solely specialized in polyps. The use of DL algorithms to detect IBD is still in its inception, most studies are based on assessing the severity of UC. As artificial intelligence (AI) grows in popularity there is a growing interest in the use of these algorithms for diagnosing and classifying the IBDs and managing their progression. To tackle this, more annotated colonoscopy images and videos will be required for the training of new and more reliable AI algorithms. This article discusses the current challenges in the early detection of IBD, focusing on the available AI algorithms, and databases, and the challenges ahead to improve the detection rate.

Inflammatory bowel disease uncovered in fecal immunochemical test positive patients in a Canadian provincial colon cancer screening program

Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition that usually affects younger adults but has a second incidence peak in the older population. Although diagnosis of IBD is driven by symptoms, some patients are asymptomatic and incidentally discovered while participating in colon screening program (CSP). We aimed to identify the incidence and outcome of IBD in fecal immunochemical test (FIT) positive patients in the British Columbia CSP. We conducted a retrospective chart review of patients who had colonoscopies for positive FIT and were found to have colitis based on endoscopic and histological assessment. Of 93,994 patients who underwent screening colonoscopy for positive FIT between 2009 and 2017, 608 (0.6%) were found to have colitis. From 11 CSP sites, 191 patients met the inclusion criteria. 58 patients (30.4%) were diagnosed with ulcerative colitis, 109 (57.1%) with Crohn’s disease (CD), and 24 (12.6%) with IBD unclassified. 124 patients (64.9%) received treatment, of which 34 (17.8%) received biologics and 4 (2.1%) required surgery. Our study demonstrated a clinically significant incidence of IBD, with novel finding of CD predominance, within a Canadian provincial CSP. Further research is needed to guide management of older patients with varying rates of IBD progression after incidental diagnosis.

Identification and Validation of Biomarkers to Predict Early Diagnosis of Inflammatory Bowel Disease and Its Progression to Colorectal Cancer.

Inflammatory bowel disease (IBD) has become a common global health problem as prevalence continues to rise. It is often associated with increased risk of colorectal cancer (CRC) development. Limitations in current IBD biomarker-based diagnosis hinder the accuracy of early detection of CRC progression. Therefore, in this study, we proposed the use of transcription factor (TF)-based biomarkers that can potentially detect the transition of IBD to CRC. Various bioinformatic analysis and online database validations, and RT-qPCR validations were performed to identify possible diagnostic TFs. RUNX1 was identified as a promising TF that regulates 106 IBD/CRC-related genes. The incorporation of RUNX1 in combination with currently known IBD biomarkers, FEV + NFKB1 + RELA, achieved a comparable sensitivity and specificity scores of 99% and 87%, respectively, while RUNX1 in combination with known CRC markers, CEA + TIMP1 + CA724 + CA199, achieved a sensitivity and specificity score of 97% and 99%, respectively. Furthermore, a small pilot RT-qPCR-based analysis confirmed a demarcated shift in expression profiles in CA724, CEA, RUNX1 and TIMP1 in IBD patients compared to CRC patients' tissue samples. Specifically, CA724 is noticeably elevated in IBD, while the levels of CEA, RUNX1 with TIMP1 are probable genes that may be employed in discerning IBD progression to CRC. Therefore, these preliminary results once validated in large patient cohorts could potentially have a significant impact on CRC disease stratification, resulting in a more precise prediction for treatment and treatment outcomes, especially in South African patients.

Cross-talk between macrophages and gut microbiota in inflammatory bowel disease: a dynamic interplay influencing pathogenesis and therapy.

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is a group of chronic immune-mediated gastrointestinal disorders. The etiology of IBD is multifactorial, involving genetic susceptibility, environmental factors, and a complex interplay between the gut microbiota and the host's immune system. Intestinal resident macrophages play an important role in the pathogenesis and progress of IBD, as well as in maintaining intestinal homeostasis and facilitating tissue repair. This review delves into the intricate relationship between intestinal macrophages and gut microbiota, highlighting their pivotal roles in IBD pathogenesis. We discuss the impact of macrophage dysregulation and the consequent polarization of different phenotypes on intestinal inflammation. Furthermore, we explore the compositional and functional alterations in gut microbiota associated with IBD, including the emerging significance of fungal and viral components. This review also examines the effects of current therapeutic strategies, such as 5-aminosalicylic acid (5-ASA), antibiotics, steroids, immunomodulators, and biologics, on gut microbiota and macrophage function. We underscore the potential of fecal microbiota transplantation (FMT) and probiotics as innovative approaches to modulate the gut microbiome in IBD. The aim is to provide insights into the development of novel therapies targeting the gut microbiota and macrophages to improve IBD management.

Construction of chlorogenic acid nanoparticles for effective alleviation of ulcerative colitis.

The onset and progression of ulcerative colitis (UC) are intricately linked to the worsening of intestinal inflammation, an imbalance in oxidative stress, and impairment of the intestinal mucosal barrier. Although chlorogenic acid (CA) shows potential in effectively alleviating the symptoms of UC, its clinical application is hindered by its poor bioavailability, stability, rapid metabolism, and quick excretion. This study utilized a one-step enzyme-catalyzed polymerization technique to create chlorogenic acid nanoparticles (CA NPs), aiming to improve the bioavailability and stability of CA. The CA NPs exhibited an optimal nanosize (106.65 ± 4.12 nm) and showed increased cellular uptake over time. Importantly, CA NPs significantly prolonged retention time in inflamed colonic tissues, enhancing accumulation and providing a targeted therapy for UC. Animal studies confirmed the substantial benefits of CA NPs, including reduced weight loss, lessened reduction in colon length, and a lowered disease activity index (DAI) score in DSS-induced UC mice. Moreover, CA NPs effectively reduced oxidative stress and levels of inflammatory factors in the colonic tissues of UC mice, thus mitigating tissue damage and restoring the integrity of the intestinal mucosal barrier. In conclusion, our research proposes a novel approach to increase the bioavailability and stability of CA, offering a promising avenue for its effective application in preventing UC.

The Potential Benefits of Exercise in Managing Inflammatory Bowel Disease: A Systematic Review.

Adults with inflammatory bowel disease (IBD) experience a significant decline in quality of life due to various symptoms. Exercise has emerged as a potential therapeutic approach to improve IBD management, but its effectiveness requires further investigation. This systematic review, adhering to PRISMA 2020 guidelines, explored the effects of exercise on IBD progression and its potential as a treatment in adults. A comprehensive search strategy was conducted across three databases and two registries from May 12, 2024, to May 22, 2024. Methodological rigor and potential bias were minimized through quality assessment using the Cochrane risk-of-bias tool 2 (RoB 2) for randomized controlled trials (RCTs), the Newcastle-Ottawa Scale (NOS) for cohort studies, and the Joanna Briggs Institute (JBI) critical appraisal checklist for studies evaluating the effectiveness of non-randomized interventions. This process yielded 12 high-quality studies for analysis. The review identified positive evidence from both RCTs and observational studies. Exercise interventions demonstrated improvements in cardiorespiratory fitness, disease activity, quality of life, and mental health in adults with IBD. Studies explored various modalities, including aerobic exercise, resistance training, and mind-body interventions. However, further research is needed to optimize exercise prescription and elucidate the underlying mechanisms of action. This review strengthens the evidence for exercise as a beneficial intervention for IBD patients. Personalized exercise programs based on individual needs hold promise for improved IBD management and patient outcomes. However, limitations exist due to study design variations and the need for long-term follow-up studies.

The Role of Claudins in the Pathogenesis of Dextran Sulfate Sodium-Induced Experimental Colitis: The Effects of Nobiletin.

The pathogenesis of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease is not well understood. This study investigated the roles and regulation of the claudin-1, -2, -3, and -4 isoforms in the pathogenesis of ulcerative colitis, and the potential therapeutic effects of nobiletin. Colitis was induced in rats by administering dextran sulfate sodium [DSS] in drinking water for seven days. Animals were treated daily with nobiletin [oral, 60 mg/Kg body weight] and studied in four groups, C [non-colitis control], D [DSS-induced colitis], CN [nobiletin-treated non-colitis control], and DN [nobiletin-treated DSS-induced colitis]. On day seven, the animals were sacrificed, and colonic tissues were collected and analyzed. Both macroscopic and microscopic findings suggest the progression of colitis. In the inflamed colon, claudin-1 and -4 proteins were decreased, claudin-2 increased, while the claudin-3 protein remained unchanged. Except for claudin-1, these changes were not paralleled by mRNA expression, indicating a complex regulatory mechanism. Uniform β-actin expression along with consistent quality and yield of total RNA indicated selectivity of these changes. Nobiletin treatment reversed these changes. Altered expression of the claudin isoforms -1, -2, and -4 disrupts tight junctions, exposing the lamina propria to microflora, leading to electrolyte disturbance and the development of ulcerative colitis. Nobiletin with its anti-inflammatory properties may be useful in IBD.

Oxidative Stress Regulator NRF2 Controls Inflammatory T-helper 1 (Th1) Subset Differentiation by Modulating Glycolysis and Protects against Colitis Progression in Mice

Oxidative Stress Regulator NRF2 Controls Inflammatory T-helper 1 (Th1) Subset Differentiation by Modulating Glycolysis and Protects against Colitis Progression in Mice

Targeting STING oligomerization with licochalcone D ameliorates STING-driven inflammatory diseases.

The development of STING inhibitors for the treatment of STING-related inflammatory diseases continues to encounter significant challenges. The activation of STING is a multi-step process that includes binding with cGAMP, self-oligomerization, and translocation from the endoplasmic reticulum to the Golgi apparatus, ultimately inducing the expression of IRF3 and NF-κB-mediated interferons and inflammatory cytokines. It has been demonstrated that disruption of any of these steps can effectively inhibit STING activation. Traditional structure-based drug screening methodologies generally focus on specific binding sites. In this study, a TransformerCPI model based on protein primary sequences and independent of binding sites is employed to identify compounds capable of binding to the STING protein. The natural product Licochalcone D (LicoD) is identified as a potent and selective STING inhibitor. LicoD does not bind to the classical ligand-binding pocket; instead, it covalently modifies the Cys148 residue of STING. This modification inhibits STING oligomerization, consequently suppressing the recruitment of TBK1 and the nuclear translocation of IRF3 and NF-κB. LicoD treatment ameliorates the inflammatory phenotype in Trex1-1- mice and inhibits the progression of DSS-induced colitis and AOM/DSS-induced colitis-associated colon cancer (CAC). In summary, this study reveals the potential of LicoD in treating STING-driven inflammatory diseases. It also demonstrates the utility of the TransformerCPI model in discovering allosteric compounds beyond the conventional binding pockets.

Amelioration effects of chlorogenic acid on mice colitis: Anti-inflammatory and regulation of gut flora

This research endeavors to investigate the potential preventive and protective effects of chlorogenic acid (CGA), a bioactive component found in various foods, in the context of dextran sodium sulfate (DSS)-induced colitis in mice. The study reveals that CGA administration, at dosages of 150 and 300 mg/kg, significantly retards the progression of colitis. This is substantiated by observable enhancements in colon length, reduction in the disease activity index, and mitigation of colon tissue damage. Meanwhile, CGA acts as an antioxidant by reducing the oxidative stress associated with colitis inflammation and increasing the activity of antioxidant enzymes. Furthermore, CGA demonstrates anti-inflammatory properties by inhibiting the inflammatory response associated with colitis and regulating the excessive expression of cytokines. Notably, CGA contributes to the restoration of intestinal barrier function by augmenting the levels of claudin-1 and ZO-1. Moreover, the investigation uncovers CGA's capacity to modulate the gut microbiota composition in colitic mice, fostering the proliferation of beneficial bacteria, notably Lactobacillus, while concurrently impeding the growth of detrimental bacteria like Bacteroides, Enterobacteriaceae, and Escherichia_Shigella. To conclude, these findings substantiate the viability of CGA for diverse applications in the realms of food and medicine, thereby bolstering its potential as a therapeutic strategy within dietary interventions.

Exploring causal association between malnutrition, nutrients intake and inflammatory bowel disease: a Mendelian randomization analysis.

Malnutrition has emerged as main side effects of inflammatory bowel disease (IBD) which might also affect the prognosis of IBD. However, whether these associations are causal remains unclear. We aimed to identify the causality of IBD on malnutrition and explore the causal relationship of malnutrition and nutrients intake on IBD by using Mendelian randomization (MR). Single nucleotide polymorphisms associated with IBD, malnutrition and nutrients intake were obtained from previous researches of genome-wide association studies (GWAS) (p < 0.00000005). MR analysis was conducted to evaluate the causality with different methods based on OR and their 95% CIs. Meanwhile, heterogeneity, pleiotropy and MR-PRESSO were used for instrumental variables evaluation. The results of MR analysis revealed that IBD, both Crohn disease (CD) and ulcerative colitis (UC), could directly impact the incidence of malnutrition (p-value <0.01). CD is directly related to nutrients such as sugar, fat, VA, VC, VD and zinc, while UC is correlated with carbohydrate, fat, VB12, VC, VD, VE, iron, zinc and magnesium. However, our results suggested that malnutrition could not affect the risk of IBD directly (p > 0.05). Further analysis showed similar results that nutrients intake had no direct effect on IBD, neither CD or UC. Our results indicated that IBD increases the risk of malnutrition, however, malnutrition and nutrients intake might not directly affect the progression of IBD.

WTAP promotes the progression of ulcerative colitis by silencing the expression of CES2 through m6A modification

ObjectiveThis study will explore the function of WTAP, the critical segment of m6A methyltransferase complex, in UC and its regulation on immune response. MethodsThe expression levels of key proteins were detected in colon tissues which were derived from UC patients and mice. Macrophage polarization and CD4+ T cell infiltration were detected by flow cytometry and IF staining. ELISA assay was utilized to analyze the level of the inflammatory cytokines. m6A-RIP-PCR, actinomycin D test, and RIP assays were utilized to detect the m6A level, stability, and bound proteins of CES2 mRNA. A dual luciferase reporter assay was conducted to confirm the transcriptional interactions between genes. A co-culture system of intestinal epithelium-like organs was constructed to detect the primary mouse intestinal epithelial cells (PMIEC) differentiation. The interaction between proteins was detected via Co-IP assay. ResultsThe expression of WTAP and CES2 in UC tissues was increased and decreased, respectively. Knockdown of WTAP inhibited the progression of UC in mice by inhibiting M1 macrophage polarization and CD4+ T cell infiltration. WTAP combined YTHDF2 to promote the m6A modification of CES2 mRNA and inhibited its expression. CES2 co-expressed with EPHX2 and overexpression of CES2 promoted the differentiation of PMIEC. The inhibitory effect of WTAP knockdown on the progress of UC was partially abrogated by CES2 knockdown. ConclusionWTAP/YTHDF2 silences CES2 by promoting its m6A modification and then promotes the progression of UC. WTAP could be a promoting therapy target of UC.

Sensing of Liver-Derived Nicotinamide by Intestinal Group 2 Innate Lymphoid Cells Links Liver Cirrhosis and Ulcerative Colitis Susceptibility.

The correlation between liver disease and the progression of ulcerative colitis (UC) has remained elusive. In this study, it demonstrates that liver injury is intricately linked to the heightened severity of UC in patients, and causes more profound intestinal damage during DSS-induced colitis in mice. Metabolomics analysis of plasma from liver cirrhosis patients shows liver injury compromising nicotinamide supply for NAD+ biosynthesis in the intestine. Subsequent investigation identifies intestinal group 2 innate lymphoid cells (ILC2s) are responsible for liver injury-exacerbated colitis. Reconstitution of ILC2s or the restoration of NAD+ metabolism proves effective in relieving liver injury-aggravated experimental colitis. Mechanistically, the NAD+ salvage pathway regulates gut ILC2s in a cell-intrinsic manner by supporting the generation of succinate, which fuels the electron transport chain to sustaining ILC2s function. This research deepens the understanding of cellular and molecular mechanisms in liver disease-UC interplay, identifying a metabolic target for innovative treatments in liver injury-complicated colitis.

Sustained release of 5-aminosalicylic acid from azoreductase-responsive polymeric prodrugs for prolonged colon-targeted colitis therapy

Ulcerative colitis (UC) is a challenging inflammatory gastrointestinal disorder, whose therapies encounter limitations in overcoming insufficient colonic retention and rapid systemic clearance. In this study, we report an innovative polymeric prodrug nanoformulation for targeted UC treatment through sustained 5-aminosalicylic acid (5-ASA) delivery. Amphiphilic polymer-based 13.5 nm micelles were engineered to incorporate azo-linked 5-ASA prodrug motifs, enabling cleavage via colonic azoreductases. In vitro, micelles exhibited excellent stability under gastric/intestinal conditions while demonstrating controlled 5-ASA release over 24 h in colonic fluids. Orally administered micelles revealed prolonged 24-h retention and a high accumulation within inflamed murine colonic tissue. At an approximately 60% dose reduction from those most advanced recent studies, the platform halted DSS colitis progression and outperformed standard 5-ASA therapy through a 77–97% suppression of inflammatory markers. Histological analysis confirmed intact colon morphology and restored barrier protein expression. This integrated prodrug nanoformulation addresses limitations in colon-targeted UC therapy through localized bioactivation and tailored pharmacokinetics, suggesting the potential of nanotechnology-guided precision delivery to transform disease management.

Cooperative progression of colitis and leukemia modulated by clonal hematopoiesis via PTX3/IL-1β pro-inflammatory signaling

Cooperative progression of colitis and leukemia modulated by clonal hematopoiesis via PTX3/IL-1β pro-inflammatory signaling