The IBD interactome: an integrated view of aetiology, pathogenesis and therapy

Colon-targeted complement C5a1 receptor inhibition using pH-sensitive nanoparticles ameliorates experimental colitis

BACKGROUND AND PURPOSE

The complement system is associated with inflammatory bowel disease (IBD) pathology. Complement activation induces C5a production, which signals through the C5a1 receptor (C5aR1) to drive inflammatory responses that may underlie IBD.

EXPERIMENTAL APPROACH

We examined mucosal biopsies from ulcerative colitis patients and identified C5a1 receptor up-regulated in active lesions, supporting the C5a1 receptor as a target for therapeutic intervention. Cyclic peptide C5a1 receptor antagonists such as PMX205 are orally efficacious in preclinical colitis models; however, their clinical application may be limited by rapid metabolism. We therefore encapsulated PMX205 within pH-sensitive polymers to target drug for colon delivery following oral administration.

KEY RESULTS

PMX205 nanoparticles were non-toxic and released bioactive PMX205 in simulated colon fluid. In vivo imaging of Cy5-labelled nanoparticles demonstrated rapid entry and persistence in the mouse colon for up to 48 h. Next, we utilised the dextran sodium sulphate-induced colitis model to examine efficacy of the C5a1 receptor-antagonist formulation. We show that oral administration of PMX205 nanoparticles every 2 days from symptom onset significantly mitigated weight loss, clinical illness, colon length reduction and epithelial damage to a similar degree as C5a1 receptor-/- mice. Notably, unformulated PMX205 was markedly less effective in this dosing regimen.

CONCLUSION AND IMPLICATIONS

This novel colon-targeted formulation therefore offers a potent therapeutic strategy for translating C5a1 receptor antagonists for IBD conditions such as ulcerative colitis.

A Sequential Release Micro-nano System for Colitis Therapy via Gut Microbiota and Immune Regulation

Commencing with the breakdown of the intestinal barrier, various pathogenic factors, such as dysbiosis of the gut microbiota, harmful inflammatory cytokines, and immune system imbalance, collectively contribute to the development of colitis. Numerous interventions focusing on single factors have been developed to provide short-term therapeutic benefits, but the continued existence of unresolved pathogenic factors can lead to disease exacerbation. Here we have designed a multicomponent system-inulin microspheres encapsulating selenium-containing nanomicelles, aiming to tackle the multiple factors associated with colitis. This micro-nano drug delivery platform achieves sequential release of drugs in the inflamed colon, with each component of the system functioning independently and jointly. The outer layer of inulin supplies nutrients for probiotics. The inner core comprises selenocystamine and 3-oxolithocholic acid, which polarize macrophages towards an anti-inflammatory phenotype and regulate adaptive immunity by inhibiting TH17-cell differentiation, respectively. In an acute colitis mouse model, this therapeutic system ameliorates colonic inflammation, enhances the abundance of gut microbiota, and modulates the mucosal immune system, showing potential in preventing colitis.

Emerging Technologies in Inflammatory Bowel Disease: A Minireview on Future Treatment Modalities

Inflammatory bowel disease (IBD) can present as either Crohn's disease or ulcerative colitis. Both phenotypes are inflammatory conditions of the gastrointestinal tract. Despite scientific advances, the overall incidence and morbidity of IBD continues to increase worldwide. Fortunately, we continue to develop novel therapies, in hopes of providing safer, more effective treatment options. Such therapies include cell therapy, exosome therapy, hyperbaric oxygen therapy, and central nerve stimulation. The aim of this review is to briefly highlight each of these novel therapeutic interventions as they relate to the treatment of IBD.

Targeting the Endocannabinoidome: A Novel Approach to Managing Extraintestinal Complications in Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD) is a chronic inflammatory disorder marked by persistent gastrointestinal inflammation and a spectrum of systemic effects, including extraintestinal manifestations (EIMs) that impact the joints, skin, liver, and eyes. Conventional therapies primarily target intestinal inflammation, yet they frequently fail to ameliorate these systemic complications. Recent investigations have highlighted the complex interplay among the immune system, gut, and nervous system in IBD pathogenesis, thereby underscoring the need for innovative therapeutic approaches. Methods: We conducted a comprehensive literature search using databases such as PubMed, Scopus, Web of Science, Science Direct, and Google Scholar. Keywords including "cannabinoids", "endocannabinoid system", "endocannabinoidome", "inflammatory bowel disease", and "extraintestinal manifestations" were used to identify peer-reviewed original research and review articles that explore the role of the endocannabinoidome (eCBome) in IBD. Results: Emerging evidence suggests that eCBome-a network comprising lipid mediators, receptors (e.g., CB1, CB2, GPR55, GPR35, PPARα, TRPV1), and metabolic enzymes-plays a critical role in modulating immune responses, maintaining gut barrier integrity, and regulating systemic inflammation. Targeting eCBome not only improves intestinal inflammation but also appears to mitigate metabolic, neurological, and extraintestinal complications such as arthritis, liver dysfunction, and dermatological disorders. Conclusions: Modulation of eCBome represents a promising strategy for comprehensive IBD management by addressing both local and systemic disease components. These findings advocate for further mechanistic studies to develop targeted interventions that leverage eCBome as a novel therapeutic avenue in IBD.

Polyphenols-rich Portulaca oleracea L. (purslane) alleviates ulcerative colitis through restiring the intestinal barrier, gut microbiota and metabolites

Ulcerative colitis (UC) is a recurrent intestinal disease caused by a complex of factors, and there are serious adverse effects and tolerance problems associated with the current long-term use of therapeutic drugs. The development of natural food sources and multi-targeted drugs for the treatment of UC is imminent. Portulaca oleracea L. (PO), as a vegetable, has been shown in studies to have an anti-UC effects. However, the relationship between the abundant active ingredients contained in Portulaca oleracea L. and the improvement of intestinal barrier, gut microbiota and metabolites is unclear. In the present study, Portulaca oleracea L. which was found to be rich in phenolic acid-based active ingredients, were effective in alleviating dextran sulfate sodium (DSS)-induced body weight loss, disease activity index (DAI) score and colon length in mice. It also decreased C-reactive protein (CRP) and myeloperoxidase (MPO) responses, reduced the permeation of fluorescein isothiocyanate (FITC)-dextran, lipopolysaccharide (LPS) and evans blue (EB), and improved histopathological scores. Meanwhile, in vitro and in vivo validation revealed the protective effects of purslane on the intestinal barrier indicators ZO-1, Occludin and Claudin-1, and inhibited the expression of inflammation-associated iNOS and NLRP3 proteins through the NF-κB signaling pathway. In addition, purslane increased the diversity of the intestinal flora, enhancing the proportion of the genera Butyricoccus, Dorea and Bifidobacterium and decreasing the percentage of Bacteroides, Turicibacter and Parabacteroides. Serum metabolomics analysis showed that the imbalance of 39 metabolites was significantly reversed after PO deployment. Enrichment analysis showed that Pentose phosphate pathway and Pyruvate metabolism pathway were the key pathways of PO against UC. Overall, purslane effectively improved the intestinal barrier disruption and intestinal inflammation by inhibiting the NF-κB signaling pathway, and adjusted the disorder of gut microbiota and metabolites to exert anti-UC effects.

Microbiota-derived metabolites in inflammatory bowel disease

Understanding the role of the gut microbiota in the pathogenesis of inflammatory bowel diseases (IBD) has been an area of intense research over the past decades. Patients with IBD exhibit alterations in their microbial composition compared to healthy controls. However, studies focusing solely on taxonomic analyses have struggled to deliver replicable findings across cohorts regarding which microbial species drive the distinct patterns in IBD. The focus of research has therefore shifted to studying the functionality of gut microbes, especially by investigating their effector molecules involved in the immunomodulatory functions of the microbiota, namely metabolites. Metabolic profiles are altered in IBD, and several metabolites have been shown to play a causative role in shaping immune functions in animal models. Therefore, understanding the complex communication between the microbiota, metabolites, and the host bears great potential to unlock new biomarkers for diagnosis, disease course and therapy response as well as novel therapeutic options in the treatment of IBD. In this review, we primarily focus on promising classes of metabolites which are thought to exert beneficial effects and are generally decreased in IBD. Though results from human trials are promising, they have not so far provided a large-scale break-through in IBD-therapy improvement. We therefore propose tailored personalized supplementation of microbiota and metabolites based on multi-omics analysis which accounts for the individual microbial and metabolic profiles in IBD patients rather than one-size-fits-all approaches.

Neonatal microbiome in the multiomics era: development and its impact on long-term health

The neonatal microbiome has been the focus of considerable research over the past two decades and studies have added fascinating information in terms of early microbial patterns and how these relate to various disease processes. One difficulty with the interpretation of these relationships is that such data is associative and provides little in terms of proof of causality or the underpinning mechanisms. Integrating microbiome data with other omics such as the proteome, inflammatory mediators, and the metabolome is an emerging approach to address this gap. Here we discuss these omics, their integration, and how they can be applied to improve our understanding, treatment, and prevention of disease. IMPACT: This review introduces the concept of multiomics in neonatology and how emerging technologies can be integrated improve understanding, treatment, and prevention of disease. We highlight considerations for performing multiomic research in neonates and the need for validation in separate cohorts and/or relevant model systems. We summarise how the use of multiomics is expanding and lay out steps to bring this to the clinic to enable precision medicine.

Antimicrobial peptide DP7 alleviates dextran sulfate sodium (DSS)-induced colitis via modifying gut microbiota and regulating intestinal barrier function

Inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), represent a growing global health concern. Restoring the balance of the gut microbiota, a crucial factor in intestinal health, offers potential for treating IBD. DP7, a novel antimicrobial peptide with potent antibacterial activity, was investigated for its anti-inflammatory effects in a dextran sulfate sodium (DSS)-induced UC mouse model. DP7 significantly ameliorated key disease parameters, including disease activity index, weight loss, and shortened colon length, while preserving colonic epithelial integrity and reducing inflammatory infiltration. Further analysis revealed potential targets of DP7, highlighting the significant role of Muribaculaceae bacteria during inflammatory states. To further explore the role of the gut microbiota in DP7's efficacy, fecal microbiota transplantation (FMT) was performed using feces from DP7-treated mice. FMT successfully ameliorated colitis in recipient mice, providing further evidence for the crucial role of the gut microbiome in IBD treatment and DP7's ability to modulate the gut microbiota for therapeutic benefit. Moreover, our findings suggest that DP7's modulation of the immune system is intricately linked to the complex microbial environment. Our findings demonstrate that DP7 effectively mitigates inflammation, attenuates barrier dysfunction, and shapes the gut microbiota, suggesting its potential as a therapeutic agent for UC.

MAPK signaling mediated intestinal inflammation induced by endoplasmic reticulum stress and NOD2

Endoplasmic reticulum (ER) stress is crucially involved in inflammatory bowel disease (IBD), but the mechanisms remain incompletely understood. This study aimed to elucidate how ER stress promotes inflammation in IBD. ER stress marker Grp78 and NOD2 in colon tissues of Crohn's disease (CD) patients and IBD model mice were detected by immunohistochemical analysis. THP-1 cells were exposed to ER stress and the expression of NOD2 and inflammatory cytokines was detected by PCR. We found that ER stress markers Grp78 and NOD2 were upregulated in intestinal tissues of CD patients and in THP-1 cells exposed to ER stress. ER stress inhibitor reduced Grp78 and NOD2 expression in colitis model mice and alleviated colitis. ER stress inducer cooperated with NOD2 ligand MDP to upregulate TNF-α, IL-8 and IL-1β, and activate MAPK signaling in THP-1 cells. Moreover, inhibitors of MAPK signaling led to the downregulation of IL-1β, IL-8 and TNF-α in THP-1 cells stimulated by ER stress inducer and MDP. In conclusion, ER stress upregulates NOD2 and promotes inflammation in IBD, at least partially due to the activation of MAPK pathway.

Targeting the Interleukin 23 Pathway in Inflammatory Bowel Disease

Interleukin (IL) 23, a member of the IL12 family of cytokines, maintains intestinal homeostasis, but is also implicated in the pathogenesis of inflammatory bowel diseases (IBDs). IL23 is a heterodimer composed of disulfide-linked p19 and p40 subunits. Humanized monoclonal antibodies selectively targeting the p19 subunit of IL23 are poised to become prominent drugs in IBDs. In this review, we discuss the pharmacodynamic and pharmacokinetic properties of the currently available IL23p19 inhibitors and discuss the mechanistic underpinnings of their therapeutic effects, including the mechanism of action, epitope affinity, potency, and downstream signaling. Furthermore, we address available data on the efficacy, safety, and tolerability of IL23p19 inhibitors in the treatment of IBDs and discuss important studies performed in other immune-mediated inflammatory diseases. Finally, we evaluate the potential for combining classes of biological therapies and provide future directions on the development of precision medicine-guided positioning of IL23p19 inhibitors in IBD.

Lipid Nanoparticles With Fine-Tuned Composition Show Enhanced Colon Targeting as a Platform for mRNA Therapeutics

Lipid Nanoparticles (LNPs) recently emerged as an invaluable RNA delivery platform. With many LNP-based therapeutics in the pre-clinical and clinical pipelines, there is extensive research dedicated to improving LNPs. These efforts focus mainly on the tolerability and transfectability of new ionizable lipids and RNAs, or modulating LNPs biodistribution with active targeting strategies. However, most formulations follow the well-established lipid proportions used in clinically approved products. Nevertheless, investigating the effects of LNPs composition on their biodistribution can expand the toolbox for particle design, leading to improved delivery strategies. Herein, a new LNPs (30-n-LNPs) formulation with increasing amounts of phospholipids is investigated as a possible mRNA delivery system for treating Inflammatory Bowel Diseases. Compared to LNPs with benchmark composition (b-LNPs), n-LNPs containing 30% distearoylphosphatidylcholine (DSPC) are well tolerated following intravenous administration and display natural targeting toward the inflamed colon in dextran sodium sulfate (DSS)-colitis bearing mice, while de-targeting clearing organs such as the liver and spleen. Using interleukin-10-encoding mRNA as therapeutic cargo, n-LNPs demonstrated a reduction of pathological burden in colitis-bearing mice. n-LNPs represent a starting point to further investigate the influence of LNPs composition on systemic biodistribution, ultimately opening new therapeutic modalities in different pathologies.

Lipopolysaccharide-regulated RNF31/NRF2 axis in colonic epithelial cells mediates homeostasis of the intestinal barrier in ulcerative colitis

BACKGROUND

Although previous studies have shown that the Ring Finger Protein 31 (RNF31) gene confers susceptibility to inflammatory disease and colorectal cancer, the exact function of this protein in ulcerative colitis (UC) has not been determined.

METHODS

A mouse dextran sulfate sodium (DSS)-induced experimental colitis model was used to study RNF31 and NRF2 in colitis. RNF31 silencing or overexpression in vitro was applied to address the role of RNF31 in colonic mucosal barrier damage. Immunohistochemistry and silico analysis was performed to investigate the expression of RNF31 via taking advantage of UC tissue samples and Gene Expression Omnibus (GEO) data, respectively. The cycloheximide (CHX)-chase experiment and Co-Immunoprecipitation (Co-IP) assays were conducted to explore the association of RNF31 protein with NRF2 and P62.

RESULTS

RNF31 is highly expressed in UC patients, in inflamed murine colon induced DSS and Lipopolysaccharide (LPS)-treated epithelial cells, while the express of NRF2 was Tabdecreased. RNF31-knockdown mice in the DSS-induced colitis model had a less severe phenotype, which was associated with a more integrated barrier of colon epithelial cells. While depletion of NRF2 in colitis model exacerbated intestinal inflammation. Mechanistically, RNF31 promoted the degradation of NRF2 by regulating its ubiquitination. Upon stimulation by RNF31, NRF2 is K63 ubiquitinated, which is associated with the C871 residue of RNF31. Moreover, downregulated NRF2 mediates inflammation by promoting the secretion of IL1β and IL18, leading to damage of the intestinal barrier. Upon LPS stimulation, the interaction of the PUB domain of RNF31 with the UBA domain of P62 increased, resulting in decreased degradation of the RNF31 protein via autophagy.

CONCLUSION

Overall, depletion of RNF31 effectively relieves DSS-induced colitis in mice by inhibiting NRF2 degradation, suggesting that RNF31 may be a potential therapy for human ulcerative colitis.

Peptostreptococcus Anaerobius enhances dextran sulfate sodium-induced colitis by promoting nf-κB-NLRP3-Dependent macrophage pyroptosis

Evidence indicates that gut microbiota is crucial in ulcerative colitis (UC) development. Increased Peptostreptococcus species abundance is linked to UC, but its role and mechanisms in intestinal inflammation are not well understood. This study used a dextran sulfate sodium (DSS)-induced colitis model in mice, and different bacterial strains were administered via gavage. We assessed clinical manifestations, colonic barrier function, gut microbiota composition, and levels of inflammatory cytokines, NOD-like receptor family pyrin domain-containing 3 (NLRP3) signaling molecules, and pyroptosis-related proteins. Mouse bone marrow-derived macrophages (BMDMs) were infected with Peptostreptococcus anaerobius at different time points and multiplicities of infection (MOI). Cell viability and the expression of NLRP3 signaling molecules and pyroptosis-associated proteins were assessed. The inhibitors C29, TAK-242, and MCC950 were employed for Toll-like receptor (TLR) and NLRP3 signaling pathways. It was observed that P. anaerobius exacerbated intestinal inflammation and barrier injury in DSS-induced colitis in mice. Additionally, P. anaerobius contributed to gut microbiota dysbiosis during colitis progression. P. anaerobius induced the expression of NLRP3 signaling molecules and pyroptosis-associated proteins in mouse colitis tissues. In vitro assays demonstrated that P. anaerobius activated NLRP3 inflammasome and evoked gasdermin D-mediated pyroptosis and interleukin (IL)-1β secretion in macrophages. Furthermore, TLR2 and TLR4 were identified as key mediators of P. anaerobius-induced macrophage pyroptosis via activation of the Nuclear Factor-kappa B (NF-κB)-NLRP3 pathway. In conclusion, P. anaerobius promotes macrophage pyroptosis and IL-1β secretion through the TLR2/4-NF-κB-NLRP3 signaling axis, thereby aggravating colitis. P. anaerobius may represent a potential risk factor for UC development.

Oral creatine-modified selenium-based hyaluronic acid nanogel mediated mitochondrial energy recovery to drive the treatment of inflammatory bowel disease

The damnification of mitochondrion is often considered to be an important culprit of inflammatory bowel disease (IBD), however, there are fewer reports of mechanisms of mitochondria-mediated IBD treatment. Therefore, we first proposed to reboot mitochondrial energy metabolism to treat IBD by capturing the double-sided factor of ROS and creatine (Cr)-assisted energy adjustment. Herein, an oral Cr-modified selenium-based hyaluronic acid (HA) nanogel (HASe-Cr nanogel) was fabricated for treatment of IBD, through ROS elimination and energy metabolism upgradation. More concretely, due to IBD lesion-specific positive charge and the high expression of CD44, HASe-Cr nanogel exhibited dual targeted inflammatory bio-functions, and ROS-driven degradation properties in high-yield ROS levels in inflammation areas. As expected, multifunctional HASe-Cr nanogel could effectively ameliorate IBD-related symptoms, such as mitochondrial biological function restoration, inhibition of M1-like macrophage polarization, gut mucosal reconstruction, microbial ecological repair, etc., thus excellently treating IBD. Overall, the proposed strategy underlined that the great potentiality of HASe-Cr nanogel by restarting mitochondrial metabolic energy in colitis lesions, providing new a pavement of mitochondrion-mediated colitis treatment in clinical applications.

STARD7 maintains intestinal epithelial mitochondria architecture, barrier integrity, and protection from colitis

Susceptibility to inflammatory bowel diseases (IBDs), Crohn's disease (CD), and ulcerative colitis (UC) is linked with loss of intestinal epithelial barrier integrity and mitochondria dysfunction. Steroidogenic acute regulatory (StAR) protein-related lipid transfer (START) domain-containing protein 7 (STARD7) is a phosphatidylcholine-specific (PC-specific) lipid transfer protein that transports PC from the ER to the mitochondria, facilitating mitochondria membrane stabilization and respiration function. The aim of this study was to define the contribution of STARD7 in the regulation of the intestinal epithelial mitochondrial function and susceptibility to colitis. In silico analyses identified significantly reduced expression of STARD7 in patients with UC, which was associated with downregulation of metabolic function and a more severe disease phenotype. STARD7 was expressed in intestinal epithelial cells, and STARD7 knockdown resulted in deformed mitochondria and diminished aerobic respiration. Loss of mitochondria function was associated with reduced expression of tight junction proteins and loss of intestinal epithelial barrier integrity that could be recovered by AMPK activation. Stard7+/- mice were more susceptible to the development of DSS-induced and Il10-/- spontaneous models of colitis. STARD7 is critical for intestinal epithelial mitochondrial function and barrier integrity, and loss of STARD7 function increases susceptibility to IBD.

Probiotic Treatment of Ulcerative Colitis with Trichuris Suis Ova: A Randomised, Double-blinded, Placebo-controlled Clinical Trial [the PROCTO Trial]

BACKGROUND AND AIMS

To demonstrate that administration of 7500 Trichuris suis ova [TSO] every second week over 24 weeks would reduce the intestinal inflammation in moderate ulcerative colitis.

METHODS

A single-centre, randomised, double-blinded, placebo-controlled, phase 2b clinical trial of 7500 Trichuris suis ova every 2 weeks for 24 weeks compared with placebo in moderate activity of ulcerative colitis [Mayo score 6-10] were performed. Primary outcome: clinical remission; secondary outcomes: clinical response at 24 weeks, complete corticosteroid-free clinical remission, endoscopic remission, symptomatic remission at 12 and 24 weeks, and partial Mayo score over time.

RESULTS

In all, 119 patients were randomised to Trichuris suis ova [n = 60] or placebo [n = 59]. At Week 24, clinical remission was achieved in 30% of Trichuris suis ova-treated vs 34% of placebo-treated (risk ratio [RR] = 0.89; 95% confidence interval [CI]: 0.52-1.50; p = 0.80, intention to treat). No difference was found in clinical response in any of the clinical response subgroups. However, in patients who did not need treatment with corticosteroids during the trial, a temporary effect of TSO was seen in the analysis of symptomatic remission at Week 12 [p = 0.01] and the partial Mayo score at Week 14 and Week 18 [p < 0.05 and p = 0.02].

CONCLUSIONS

Compared with placebo, Trichuris suis ova administration was not superior in achieving clinical remission at Week 24 in ulcerative colitis or in achieving clinical Mayo score reduction, complete corticosteroid-free clinical remission, or endoscopic remission. However, Trichuris suis ova treatment induced symptomatic temporary remission at Week 12.

Serum electrolyte abnormalities in cats with chronic inflammatory enteropathy

BACKGROUND

Limited information is available on electrolyte abnormalities in cats with chronic inflammatory enteropathy (CIE).

HYPOTHESIS/OBJECTIVES

Report the prevalence of electrolyte abnormalities in cats with CIE compared to other gastrointestinal disorders, and determine their association with disease and outcome variables in cats with CIE.

ANIMALS

Three hundred twenty-eight client-owned cats from 2 referral hospitals: CIE (132), alimentary small cell lymphoma (29), acute gastroenteritis (48), and healthy controls (119).

METHODS

Retrospective study comparing serum electrolyte concentrations at time of diagnosis among the 4 groups of cats, and associations with clinical signs, intestinal mucosal fibrosis scores, treatment subclassification and outcome in CIE.

RESULTS

Cats with CIE had lower sodium and higher potassium concentrations and lower sodium: potassium ratios compared with healthy cats (P < .001, P = .01, and P < .001, respectively). Cats with CIE and a duodenal mucosal fibrosis score of 2 had lower sodium and lower total calcium concentrations compared with cats that had a score of 0 (P = .02 and P = .01). Cats with CIE and a colonic mucosal fibrosis score of 1 had higher potassium concentrations and lower sodium: potassium ratios compared with cats that had a score of 0 (P = .03 and P = .01). Cats with CIE that died as a result of their disease had higher potassium concentrations and lower sodium: potassium ratios compared to cats that were alive (P = .02 and P = .01).

CONCLUSIONS AND CLINICAL IMPORTANCE

Electrolyte abnormalities occur with CIE and, in particular, in cats with higher fibrosis scores and worse outcomes. Further research should aim to determine the pathogenesis of these findings and identify novel therapeutic targets for cats with CIE.

Analysis of global prevalence, DALY and trends of inflammatory bowel disease and their correlations with sociodemographic index: Data from 1990 to 2019

BACKGROUND

Inflammatory bowel disease (IBD) is a kind of chronic inflammatory disorders of the gastrointestinal tract with diverse prevalence rates and patterns globally. Accurate comprehension of the disease's epidemiological characteristics is imperative for disease control and prevention all over the world.

OBJECTIVE

To provide the most updated estimates on the global burden of IBD using the 2019 Global Burden of Disease (GBD) study data, to systematically analyze the IBD epidemiological characteristics at the global, regional, and national levels including the prevalence, incidence, and disability-adjusted life years (DALY) rates, and to analyze the correlations of the socioeconomic development level with IBD epidemiological characteristics.

METHODS

We conducted an overall analysis of the global, regional, and national burden of IBD from 1990 to 2019, data from the 2019 GBD study. The GBD's classification of the world into 21 regions and 204 countries and territories facilitated a thorough examination. Age-standardized estimated annual percentage changes (EAPCs) were computed to assess the temporal trends in IBD age-standardized rates (ASRs), with age standardization employed to mitigate potential confounding effects from age structure. The sociodemographic Index (SDI) was used to correlate the socioeconomic development level with the epidemiological characteristics of IBD.

RESULTS

From 1990 to 2019, the global age-standardized prevalence, incidence, and DALY rates of IBD remained high. There was a slight downward trend in the global age-standardized incidence and DALY rates of IBD and men exhibited higher DALY rates than women. In 2019, high-income North America recorded the highest age-standardized prevalence, incidence, and DALY rates, while Oceania had the lowest age-standardized prevalence and incidence rates. South Asia had the lowest age-standardized DALY rates. The age-standardized mortality and DALY rates decreased as SDI values increased and remained higher than the expected levels over the past three decades. A negative correlation was observed between age-standardized DALY rates and SDI at the national level.

CONCLUSIONS

This analysis of the GBD 2019 database demonstrates that the overall global burden of IBD is still high. Meanwhile, an increasing disease burden is observed in the middle and low SDI locations.

Human Amniotic Epithelial Stem Cells Promote Colonic Recovery in Experimental Colitis via Exosomal MiR-23a-TNFR1-NF-κB Signaling

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, manifests as chronic intestinal inflammation with debilitating symptoms, posing a significant burden on global healthcare. Moreover, current therapies primarily targeting inflammation can lead to immunosuppression-related complications. Human amniotic epithelial stem cells (hAESCs), which exhibit low immunogenicity and ethical acceptability, have gained attention as potential therapeutics. In this study, it is demonstrated that their encapsulation in a hydrogel and administration via anal injection enhanced the colonic mucosal barrier repair in a murine colitis model induced by dextran sodium sulfate during the recovery phase. The underlying mechanism involved the release of exosomes from hAESCs enriched with microRNA-23a-3p, which post-transcriptionally reduced tumor necrosis factor receptor 1 expression, suppressing the nuclear factor-κB pathway in colonic epithelial cells, thus played a key role in inflammation. The novel approach shows potential for IBD treatment by restoring intestinal epithelial homeostasis without the immunosuppressive therapy-associated risks. Furthermore, the approach provides an alternative strategy to target the key molecular pathways involved in inflammation and promotes intestinal barrier function using hAESCs and their secreted exosomes. Overall, this study provides key insights to effectively treat IBD, addresses the unmet needs of patients, and reduces related healthcare burden.

Considerations in Paediatric and Adolescent Inflammatory Bowel Disease

The incidence of inflammatory bowel disease [IBD] is rising most rapidly among children and adolescents. Paediatric-onset IBD is associated with a more extensive and severe disease course compared to adult-onset IBD. At a young age, screening for underlying genetic and immunological disorders is important and may impact treatment management. Early and effective treatment is crucial to reach disease remission and prevent complications of ongoing active disease. In children with Crohn's disease, exclusive enteral nutrition is an effective induction therapy. Other promising dietary therapies, such as the Crohn's disease exclusion diet, are emerging. Within paediatric IBD, anti-tumour necrosis factor therapy is the only approved biological thus far and additional treatment options are crucially needed. Other biological therapies, such as vedolizumab and ustekinumab, are currently prescribed off-label in this population. A specific challenge in paediatric IBD is the unacceptable and major delay in approval of drugs for children with IBD. A guided transfer period of paediatric patients to adult care is associated with improved disease outcomes and is required. Major knowledge gaps and challenges within paediatric IBD include the aetiology, diagnostics, and monitoring of disease, tailoring of treatment, and both understanding and coping with the physical and psychological consequences of living with IBD. Challenges and research gaps in paediatrics should be addressed without any delay in comparison with the adult field, in order to ensure a high quality of care for all patients with IBD, irrespective of the age of onset.

Toll-like receptor 7 protects against intestinal inflammation and restricts the development of colonic tissue-resident memory CD8+ T cells

Introduction

The maintenance of intestinal homeostasis depends on a complex interaction between the immune system, intestinal epithelial barrier, and microbiota. Alteration in one of these components could lead to the development of inflammatory bowel diseases (IBD). Variants within the autophagy gene ATG16L1 have been implicated in susceptibility and severity of Crohn's disease (CD). Individuals carrying the risk ATG16L1 T300A variant have higher caspase 3-dependent degradation of ATG16L1 resulting in impaired autophagy and increased cellular stress. ATG16L1-deficiency induces enhanced IL-1β secretion in dendritic cells in response to bacterial infection. Infection of ATG16L1-deficient mice with a persistent strain of murine norovirus renders these mice highly susceptible to dextran sulfate sodium colitis. Moreover, persistent norovirus infection leads to intestinal virus specific CD8+ T cells responses. Both Toll-like receptor 7 (TLR7), which recognizes single-stranded RNA viruses, and ATG16L1, which facilitates the delivery of viral nucleic acids to the autolysosome endosome, are required for anti-viral immune responses.

Results and discussion

However, the role of the enteric virome in IBD is still poorly understood. Here, we investigate the role of TLR7 and ATG16L1 in intestinal homeostasis and inflammation. At steady state, Tlr7-/- mice have a significant increase in large intestinal lamina propria (LP) granzyme B+ tissue-resident memory CD8+ T (TRM) cells compared to WT mice, reminiscent of persistent norovirus infection. Deletion of Atg16l1 in myeloid (Atg16l1ΔLyz2 ) or dendritic cells (Atg16l1ΔCd11c ) leads to a similar increase of LP TRM. Furthermore, Tlr7-/- and Atg16l1ΔCd11c mice were more susceptible to dextran sulfate sodium colitis with an increase in disease activity index, histoscore, and increased secretion of IFN-γ and TNF-α. Treatment of Atg16l1ΔCd11c mice with the TLR7 agonist Imiquimod attenuated colonic inflammation in these mice. Our data demonstrate that ATG16L1-deficiency in myeloid and dendritic cells leads to an increase in LP TRM and consequently to increased susceptibility to colitis by impairing the recognition of enteric viruses by TLR7.

Conclusion

In conclusion, the convergence of ATG16L1 and TLR7 signaling pathways plays an important role in the immune response to intestinal viruses. Our data suggest that activation of the TLR7 signaling pathway could be an attractive therapeutic target for CD patients with ATG16L1 risk variants.

Persistent Activation of the P2X7 Receptor Underlies Chronic Inflammation and Carcinogenic Changes in the Intestine

Aberrant signaling through damage-associated molecular patterns (DAMPs) has been linked to several health disorders, attracting considerable research interest over the last decade. Adenosine triphosphate (ATP), a key extracellular DAMP, activates the purinergic receptor P2X7, which acts as a danger sensor in immune cells and is implicated in distinct biological functions, including cell death, production of pro-inflammatory cytokines, and defense against microorganisms. In addition to driving inflammation mediated by immune and non-immune cells, the persistent release of endogenous DAMPs, including ATP, has been shown to result in epigenetic modifications. In intestinal diseases such as inflammatory bowel disease (IBD) and colorectal cancer (CRC), consequent amplification of the inflammatory response and the resulting epigenetic reprogramming may impact the development of pathological changes associated with specific disease phenotypes. P2X7 is overexpressed in the gut mucosa of patients with IBD, whereas the P2X7 blockade prevents the development of chemically induced experimental colitis. Recent data suggest a role for P2X7 in determining gut microbiota composition. Regulatory mechanisms downstream of the P2X7 receptor, combined with signals from dysbiotic microbiota, trigger intracellular signaling pathways and inflammasomes, intensify inflammation, and foster colitis-associated CRC development. Preliminary studies targeting the ATP-P2X7 pathway have shown favorable therapeutic effects in human IBD and experimental colitis.

Development of dual GPBAR1 agonist and RORγt inverse agonist for the treatment of inflammatory bowel diseases

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are chronic disorders characterized by dysregulated immune response and persistent inflammation. Recent studies suggest that bile acid receptors, particularly GPBAR1, and the transcription factor RORγt play critical roles in modulating intestinal inflammation. This study evaluates the therapeutic potential of PBT002, a dual GPBAR1 agonist and RORγt inverse agonist, in IBD models. The effects of PBT002 were assessed through in vitro and in vivo experiments. Macrophages and T lymphocytes obtained from the buffy coat were exposed to PBT002 to evaluate its immunomodulatory activity. The beneficial effects in vivo were evaluated in mouse models of colitis induced by TNBS, DSS or DSS + IL-23 using also a Gpbar1 knock-out male mice. PBT002 exhibited an EC50 of 1.2 µM for GPBAR1 and an IC50 of 2.8 µM for RORγt. In in vitro, PBT002 modulated macrophage polarization towards an anti-inflammatory M2 phenotype and reduced Th17 cell markers while increasing Treg markers. In the TNBS-induced colitis model, PBT002 reduced weight loss, CDAI, and colon damage, while it modulated cytokine gene expression towards an anti-inflammatory profile. In GPBAR1-/-, the anti-inflammatory effects of PBT002 were attenuated, indicating partial GPBAR1 dependence. RNA sequencing revealed significant modulation of inflammatory pathways by PBT002. In DSS+IL-23 induced colitis, PBT002 mitigated disease exacerbation, reducing pro-inflammatory cytokine levels and immune cell infiltration. In conclusion, PBT002, a GPBAR1 agonist and RORγt inverse agonist, modulates both the innate and adaptive immune responses to reduce inflammation and disease severity in models of IBD.

Deubiquitinase USP14 is upregulated in Crohn's disease and inhibits the NOD2 pathway mediated inflammatory response in vitro

The nucleotide binding oligomerization domain containing 2 (NOD2) protein and its ligand N-acetyl muramyl dipeptide (MDP) are crucially involved in Crohn's disease (CD). However, the mechanism by which NOD2 signaling is regulated in CD patients remains unclear. Ubiquitin specific protease (USP14) is a deubiquitylase that plays an important role in immunity. This study aimed to investigate the mechanism by which UPS14 regulates NOD2 induced inflammatory response in CD and inflammatory bowel diseases (IBD). Our results showed that USP14 protein and mRNA levels in intestinal tissues of CD patients were significantly higher than those in healthy controls. In addition, USP14 was upregulated in IBD mouse model. While treatment with MDP, TNF-α or the Toll-like receptor 1/2 agonist Pam3CSK4 all led to significantly higher mRNA levels of TNF-α, IL-8 and IL-1β in THP-1 cells, pretreatment with USP14 inhibitor IU1 could stimulate further upregulation of TNF-α, IL-8 and IL-1β. In particular, MDP promoted the activation of JNK, ERK1/2 and p38 as well as NF-kB in THP-1 cells, and IU1 significantly enhanced the MDP-induced activation of these proteins without effects on USP14 protein level. Furthermore, the JNK inhibitor sp600125, ERK1/2 inhibitor U0126 or P38 MAPK inhibitor PD169316 significantly decreased the mRNA levels of TNF-α, IL-8 and IL-1β in THP-1 cells stimulated by both IU1 and MDP. In conclusion, our findings suggest that USP14 could inhibit MDP-induced activation of MAPK signaling and the inflammation response involved in IBD, and that USP14 is a potential therapeutic target for IBD.

Nanotechnology for Targeted Inflammatory Bowel Disease Therapy: Challenges and Opportunities

Inflammatory bowel disease (IBD) is a complex and recurring inflammatory disorder that affects the gastrointestinal tract and is influenced by genetic predisposition, immune dysregulation, the gut microbiota, and environmental factors. Advanced therapies, such as biologics and small molecules, target diverse immune pathways to manage IBD. Nanoparticle (NP)-based drugs have emerged as effective tools, offering controlled drug release and targeted delivery. This review highlights NP modifications for anti-inflammatory purposes, utilizing changes such as those in size, charge, redox reactions, and ligand-receptor interactions in drug delivery systems. By using pathological and microenvironmental cues to guide NP design, precise targeting can be achieved. In IBD, a crucial aspect of NP intervention is targeting specific types of cells, such as immune and epithelial cells, to address compromised intestinal barrier function and reduce overactive immune responses. This review also addresses current challenges and future prospects, with the goal of advancing the development of NP-mediated strategies for IBD treatment.

Diagnostic delay in inflammatory bowel diseases in a German population

BACKGROUND

Early diagnosis is key to prevent bowel damage in inflammatory bowel disease (IBD). Risk factor analyses linked with delayed diagnosis in European IBD patients are scarce and no data in German IBD patients exists.

AIM

To identify risk factors leading to prolonged diagnostic time in a German IBD cohort.

METHODS

Between 2012 and 2022, 430 IBD patients from four Berlin hospitals were enrolled in a prospective study and asked to complete a 16-item questionnaire to determine features of the path leading to IBD diagnosis. Total diagnostic time was defined as the time from symptom onset to consulting a physician (patient waiting time) and from first consultation to IBD diagnosis (physician diagnostic time). Univariate and multivariate analyses were performed to identify risk factors for each time period.

RESULTS

The total diagnostic time was significantly longer in Crohn's disease (CD) compared to ulcerative colitis (UC) patients (12.0 vs 4.0 mo; P < 0.001), mainly due to increased physician diagnostic time (5.5 vs 1.0 mo; P < 0.001). In a multivariate analysis, the predominant symptoms diarrhea (P = 0.012) and skin lesions (P = 0.028) as well as performed gastroscopy (P = 0.042) were associated with longer physician diagnostic time in CD patients. In UC, fever was correlated (P = 0.020) with shorter physician diagnostic time, while fatigue (P = 0.011) and positive family history (P = 0.046) were correlated with longer physician diagnostic time.

CONCLUSION

We demonstrated that CD patients compared to UC are at risk of long diagnostic delay. Future efforts should focus on shortening the diagnostic delay for a better outcome in these patients.

Oral administration of RDP58 ameliorated DSS-induced colitis in intestinal microbiota dependent manner

BACKGROUND

Although the pathogenesis of inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), has not been fully elucidated, accumulating researches suggest that intestinal microbiota imbalance contributes to the development of IBD in patients and animal models. RDP58, a peptide-based computer-assisted rational design, has been demonstrated to be effective in protecting against a wide range of autoimmune and inflammatory diseases. However, the underlying mechanism by which RDP58 protects against IBD mediated by intestinal microbiota has yet to be elucidated.

METHODS

The colitis model was induced by continuously administering 2.5 % (wt/vol) dextran sodium sulfate (DSS) solution for 7 days. The manifestations of colon inflammation were assessed via daily weight changes, colon length, tumor necrosis factor-alpha (TNF-α) level, disease activity index (DAI) score, pathology score, and intestinal barrier permeability. Intestinal microbiota analysis was carried out by 16S-rRNA sequencing. Colonic short chain fatty acids (SCFAs) and regulatory T cells (Tregs) were also detected. To further confirm the protective effect of RDP58 on intestinal microbiota, broad-spectrum antibiotic cocktail (ABX) treatment and fecal microbial transplantation (FMT) experiment were performed.

RESULTS

Oral administration of RDP58 ameliorated DSS-induced mice colitis by altering the diversity and composition of intestinal microbiota. Notably, RDP58 significantly upregulated SCFAs-producing microbiota, thereby promoting the generation of Tregs. ABX and FMT were performed to verify the above mechanism.

CONCLUSIONS

RDP58 ameliorated DSS-induced colitis through altering intestinal microbiota and enhancing SCFAs and Tregs production in intestinal microbiota dependent manner, potentially provide a novel therapy for IBD.

Inhibition of Transmural Inflammation in Crohn's Disease by Orally Administered Tumor Necrosis Factor-Alpha Deoxyribozymes-Loaded Pyroptosis Nanoinhibitors

Crohn's disease (CD) is a refractory chronic inflammatory bowel disease (IBD) with unknown etiology. Transmural inflammation, involving the intestine and mesentery, represents a characteristic pathological feature of CD and serves as a critical contributor to its intractability. Here, this study describes an oral pyroptosis nanoinhibitor loaded with tumor necrosis factor-α (TNF-α) deoxyribozymes (DNAzymes) (DNAzymes@degradable silicon nanoparticles@Mannose, Dz@MDSN), which can target macrophages at the site of inflammation and respond to reactive oxygen species (ROS) to release drugs. Dz@MDSN can not only break the inflammatory cycle in macrophages by degrading TNF-α mRNA but also reduce the production of ROS mainly from macrophages. Moreover, Dz@MDSN inhibits excessive pyroptosis in epithelial cells through ROS clearance, thereby repairing the intestinal barrier and reducing the translocation of intestinal bacteria to the mesentery. Consequently, these combined actions synergistically contribute to the suppression of inflammation within both the intestine and the mesentery. This study likely represents the first successful attempt in the field of utilizing nanomaterials to achieve transmural healing for CD, which also provides a promising treatment strategy for CD patients.

The Role of Vitamin D and Vitamin D Receptor Gene Polymorphisms in the Course of Inflammatory Bowel Disease in Children

Background: The etiopathogenesis of inflammatory bowel disease (IBD) is still unclear. Prior studies suggest genetic components that may influence the incidence and severity of the disease. Additionally, it was shown that low levels of serum vitamin D may have an impact on the clinical course of the disease due to its effect on the immunological system. Methods: We aimed to investigate the correlation between the incidence of vitamin D receptor (VDR) gene polymorphisms (rs11568820, rs10735810, rs1544410, rs7975232, and rs731236, commonly described as Cdx2, FokI, Bsm, ApaI, and TaqI, respectively) and vitamin D concentration with the clinical course of IBD (disease activity, extent of the intestinal lesions). Data were obtained from 62 patients with IBD (34 with Crohn's disease, 28 with ulcerative colitis), aged 3-18 years, and compared with controls (N = 47), aged 8-18 years. Results: Although there was no difference in the incidence of individual genotypes between the study groups (IBD, C) in all the polymorphisms examined, we described a significant increase in the chance of developing IBD for heterozygotes of Cdx2 (OR: 2.3, 95% CI 0.88-6.18, p = 0.04) and BsmI (OR: 2.07, 95% CI 0.89-4.82, p = 0.048) polymorphisms. The mean serum 25OHD level in patients with IBD was significantly higher compared with the controls (19.87 ng/mL vs. 16.07 ng/mL; p = 0.03); however, it was still below optimal (>30 ng/mL). Furthermore, a significant correlation was found between vitamin D level and TaqI in patients with IBD (p = 0.025) and patients with CD (p = 0.03), as well as with the BsmI polymorphism in patients with IBD (p = 0.04) and patients with CD (p = 0.04). A significant correlation was described between the degree of disease activity and genotypes for the FokI polymorphism in patients with UC (p = 0.027) and between the category of endoscopic lesions and genotypes for the Cdx2 polymorphism also in patients with UC (p = 0.046). Conclusions: The results suggest a potential correlation of VDR gene polymorphism with the chance of developing IBD, and the clinical course of the disease requires further studies in larger group of patients. Vitamin D supplementation should be recommended in both children with inflammatory bowel disease and in healthy peers.

Alterations in tryptophan metabolism and de novo NAD+ biosynthesis within the microbiota-gut-brain axis in chronic intestinal inflammation

Background

Inflammatory bowel disease is an incurable and idiopathic disease characterized by recurrent gastrointestinal tract inflammation. Tryptophan metabolism in mammalian cells and some gut microbes comprise intricate chemical networks facilitated by catalytic enzymes that affect the downstream metabolic pathways of de novo nicotinamide adenine dinucleotide (NAD+) synthesis. It is hypothesized that a correlation exists between tryptophan de novo NAD+ synthesis and chronic intestinal inflammation.

Methods

Transcriptome analysis was performed using high-throughput sequencing of mRNA extracted from the distal colon and brain tissue of Winnie mice with spontaneous chronic colitis and C57BL/6 littermates. Metabolites were assessed using ultra-fast liquid chromatography to determine differences in concentrations of tryptophan metabolites. To evaluate the relative abundance of gut microbial genera involved in tryptophan and nicotinamide metabolism, we performed 16S rRNA gene amplicon sequencing of fecal samples from C57BL/6 and Winnie mice.

Results

Tryptophan and nicotinamide metabolism-associated gene expression was altered in distal colons and brains of Winnie mice with chronic intestinal inflammation. Changes in these metabolic pathways were reflected by increases in colon tryptophan metabolites and decreases in brain tryptophan metabolites in Winnie mice. Furthermore, dysbiosis of gut microbiota involved in tryptophan and nicotinamide metabolism was evident in fecal samples from Winnie mice. Our findings shed light on the physiological alterations in tryptophan metabolism, specifically, its diversion from the serotonergic pathway toward the kynurenine pathway and consequential effects on de novo NAD+ synthesis in chronic intestinal inflammation.

Conclusion

The results of this study reveal differential expression of tryptophan and nicotinamide metabolism-associated genes in the distal colon and brain in Winnie mice with chronic intestinal inflammation. These data provide evidence supporting the role of tryptophan metabolism and de novo NAD+ synthesis in IBD pathophysiology.

Navigating the complexities of drug development for inflammatory bowel disease

Inflammatory bowel disease (IBD) - consisting of ulcerative colitis and Crohn's disease - is a complex, heterogeneous, immune-mediated inflammatory condition with a multifactorial aetiopathogenesis. Despite therapeutic advances in this arena, a ceiling effect has been reached with both single-agent monoclonal antibodies and advanced small molecules. Therefore, there is a need to identify novel targets, and the development of companion biomarkers to select responders is vital. In this Perspective, we examine how advances in machine learning and tissue engineering could be used at the preclinical stage where attrition rates are high. For novel agents reaching clinical trials, we explore factors decelerating progression, particularly the decline in IBD trial recruitment, and assess how innovative approaches such as reconfiguring trial designs, harmonizing end points and incorporating digital technologies into clinical trials can address this. Harnessing opportunities at each stage of the drug development process may allow for incremental gains towards more effective therapies.

Prevotella histicola ameliorates DSS-induced colitis by inhibiting IRE1α-JNK pathway of ER stress and NF-κB signaling

Inflammatory bowel disease (IBD) is a chronic and recurrent gastrointestinal inflammation regulated by intricate mechanisms. Recently, prebiotics is considered as promising nutritional strategy for the prevention and treatment of IBD. Prevotella histicola (P. histicola), an emerging probiotic, possesses apparently anti-inflammatory bioactivity. However, the role and underlying mechanism of P. histicola on IBD remain unclear. Hence, we probe into the effect of P. histicola on dextran sulfate sodium (DSS)-induced colitis and clarified the potential mechanism. Our results revealed that DSS-induced colonic inflammatory response and damaged epithelial barrier in mice were attenuated by oral administration of P. histicola. Moreover, supplementary P. histicola significantly enriched short-chain fatty acid (SCFA)-producing bacteria (Lactobacillus, and Bacillus) and reduced pathogenic bacteria (Erysipelotrichaceae, Clostridium, Bacteroides) in DSS-induced colitis. Notably, In DSS-treated mice, endoplasmic reticulum stress (ERS) was persistently activated in colonic tissue. Conversely, P. histicola gavage suppressed expansion of endoplasmic reticulum, downregulated PERK-ATF4-CHOP and IRE1α-JNK pathway. In vitro, the P. histicola supernatant eliminated LPS-induced higher production of pro-inflammatory cytokines regulated by NF-κB and impairment of epithelial barrier by inhibiting IRE1α-JNK signaling in Caco-2 cell. In summary, our study indicated that P. histicola mitigated DSS-induced chronic colitis via inhibiting IRE1α-JNK pathway and NF-κB signaling. These findings provide the new insights into the promotion of gut homeostasis and the application potential of P. histicola as a prebiotic for IBD in the future.

ROS-responsive nano-medicine for navigating autophagy to enhance targeted therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder characterized by immune dysregulation and intestinal inflammation. Rapamycin (Ra), an mTORC1 pathway inhibitor, has shown promise for autophagy induction in IBD therapy but is associated with off-target effects and toxicity. To address these issues, we developed an oral liposome responsive to reactive oxygen species (ROS) using lipids and amphiphilic materials. We combined ketone thiol (TK) for ROS responsive and hyaluronic acid (HA) with high affinity for CD44 receptors to prepare rapamycin-loaded nanoparticle (Ra@TH). Owing to its ROS responsive characteristic, Ra@TH can achieve inflammatory colonic targeting. Additionally, Ra@TH can induce autophagy by inhibiting the mTORC1 pathway, leading to the clearance of damaged organelles, pathogenic microorganisms and oxidative stress products. Simultaneously, it also collaboratively inhibits the NF-κB pathway suppressed by the removal of ROS resulting from TK cleavage, thereby mediating the expression of inflammatory factors. Furthermore, Ra@TH enhances the expression of typical tight junction proteins, synergistically restoring intestinal barrier function. Our research not only expands the understanding of autophagy in IBD treatment but also introduces a promising therapeutic approach for IBD patients.

Baseline Data and Measurement Instruments Reported in Observational Studies in Inflammatory Bowel Disease: Results from a Systematic Review

BACKGROUND

Heterogeneity in demographic and outcomes data with corresponding measurement instruments [MIs] creates barriers to data pooling and analysis. Several core outcome sets have been developed in inflammatory bowel disease [IBD] to homogenize outcomes data. A parallel Minimum Data Set [MDS] for baseline characteristics is lacking. We conducted a systematic review to develop the first MDS.

METHODS

A systematic review was made of observational studies from three databases [2000-2021]. Titles and abstracts were screened, full-text articles were reviewed, and data were extracted by two reviewers. Baseline data were grouped into ten domains: demographics, clinical features, disease behaviour/complications, biomarkers, endoscopy, histology, radiology, healthcare utilization and patient-reported data. Frequency of baseline data and MIs within respective domains are reported.

RESULTS

From 315 included studies [600 552 subjects], most originated from Europe [196; 62%] and North America [59; 19%], and were published between 2011 and 2021 [251; 80%]. The most frequent domains were demographics [311; 98.7%] and clinical [289; 91.7%]; 224 [71.1%] studies reported on the triad of sex [306; 97.1%], age [289; 91.7%], and disease phenotype [231; 73.3%]. Few included baseline data for radiology [19; 6%], healthcare utilization [19; 6%], and histology [17; 5.4%]. Ethnicity [19; 6%], race [17; 5.4%], and alcohol/drug consumption [6; 1.9%] were the least reported demographics. From 25 MIs for clinical disease activity, the Harvey-Bradshaw Index [n = 53] and Mayo score [n = 37] were most frequently used.

CONCLUSIONS

Substantial variability exists in baseline population data reporting. These findings will inform a future consensus for MDS in IBD to enhance data harmonization and credibility of real-world evidence.

Environmental and Microbial Factors in Inflammatory Bowel Disease Model Establishment: A Review Partly through Mendelian Randomization

Inflammatory bowel disease (IBD) is a complex condition resulting from environmental, microbial, immunologic, and genetic factors. With the advancement of Mendelian randomization research in IBD, we have gained new insights into the relationship between these factors and IBD. Many animal models of IBD have been developed using different methods, but few studies have attempted to model IBD by combining environmental factors and microbial factors. In this review, we examine how environmental factors and microbial factors affect the development and progression of IBD, and how they interact with each other and with the intestinal microbiota. We also summarize the current methods for creating animal models of IBD and compare their advantages and disadvantages. Based on the latest findings from Mendelian randomization studies on the role of environmental factors in IBD, we discuss which environmental and microbial factors could be used to construct a more realistic and reliable IBD experimental model. We propose that animal models of IBD should consider both environmental and microbial factors to better mimic human IBD pathogenesis and to reveal the underlying mechanisms of IBD at the immune and genetic levels. We highlight the importance of environmental and microbial factors in IBD pathogenesis and offer new perspectives and suggestions for improving experimental animal modeling. Our goal is to create a model that closely resembles the clinical picture of IBD.

Peripheral and intestinal T lymphocyte subsets in dogs with chronic inflammatory enteropathy

BACKGROUND

Dysregulated T lymphocyte response is thought to play a key role in chronic intestinal inflammation (CIE).

OBJECTIVES

To evaluate the presence of changes in peripheral and intestinal T lymphocyte subsets and to describe potential immune and inflammatory biomarkers in dogs with CIE.

ANIMALS

Sixteen healthy dogs and 26 dogs were diagnosed with CIE.

METHODS

Prospective case-control study evaluating peripheral and intestinal T lymphocytes using flow cytometry and inflammatory markers obtained from complete blood cell counts.

RESULTS

Dogs with CIE had higher peripheral activated T helper (Th) lymphocytes (87/μL [18-273] CIE, 44/μL [16-162] healthy control (HC, P = .013) and regulatory T cells (Treg; 108/μL [2-257] CIE, 34/μL [1-114] HC, P = .004). In the intestinal epithelium, CIE dogs presented lower percentages of Th (4.55% [1.75-18.67] CIE, 8.77% [3.79-25.03] HC, P = .002), activated Th cells (0.16% [0.02-0.83] CIE, 0.33% [0.05-0.57] HC, P = .03) and CD4/CD8 ratio (0.08 [0.02-0.39] CIE, 0.21 [0.07-0.85] HC, P = .003). Conversely, higher percentage of activated T cytotoxic cells (20.24% [3.12-77.12] CIE, 12.32% [1.21-39.22] HC, P = .04) and interferon-gamma (IFN-γ) producing T lymphocytes (7.36% [0.63-55.83] CIE, 1.44% [0.00-10.56] HC, P = .01) within the epithelium was observed. In the lamina propria the percentage of Treg lymphocytes was higher (6.02% [1.00-21.48] CIE, 3.52% [0.18-10.52] HC, P = .02).

CONCLUSIONS AND CLINICAL IMPORTANCE

Systemic and intestinal immune alterations occur in dogs with CIE suggesting that blood IFN-γ producing T lymphocytes and the systemic immune-inflamation index (SII) could potentially serve as biomarkers for the disease.

Single-cell transcriptomics reveals activation of endothelial cell and identifies LHPP as a potential target in ulcerative colitis

This study delves into Ulcerative colitis (UC), a persistent gastrointestinal disorder marked by inflammation and ulcers, significantly elevating colorectal cancer risk. The emergence of single-cell RNA sequencing (scRNA-seq) technology has opened new avenues for dissecting the intricate cellular dynamics and molecular mechanisms at play in UC pathology. By analyzing scRNA-seq data from individuals with UC, our study has revealed a consistent enhancement of inflammatory response pathways throughout the course of the disease, alongside detailing the characteristics of endothelial cell damage within colitis environments. A noteworthy finding is the downregulation of Phospholysine Phosphohistidine Inorganic Pyrophosphate Phosphatase (LHPP), which exhibited a inversely correlate with STAT3 expression levels. The markedly reduced expression of LHPP in both the tissues and plasma of UC patients positions LHPP as a compelling target for therapeutic intervention. Our findings highlight the pivotal role LHPP could play in moderating inflammation, spotlighting its potential as a crucial molecular target in the quest to understand and treat UC.

DHX9 maintains epithelial homeostasis by restraining R-loop-mediated genomic instability in intestinal stem cells

Epithelial barrier dysfunction and crypt destruction are hallmarks of inflammatory bowel disease (IBD). Intestinal stem cells (ISCs) residing in the crypts play a crucial role in the continuous self-renewal and rapid recovery of intestinal epithelial cells (IECs). However, how ISCs are dysregulated in IBD remains poorly understood. Here, we observe reduced DHX9 protein levels in IBD patients, and mice with conditional DHX9 depletion in the intestinal epithelium (Dhx9ΔIEC) exhibit an increased susceptibility to experimental colitis. Notably, Dhx9ΔIEC mice display a significant reduction in the numbers of ISCs and Paneth cells. Further investigation using ISC-specific or Paneth cell-specific Dhx9-deficient mice demonstrates the involvement of ISC-expressed DHX9 in maintaining epithelial homeostasis. Mechanistically, DHX9 deficiency leads to abnormal R-loop accumulation, resulting in genomic instability and the cGAS-STING-mediated inflammatory response, which together impair ISC function and contribute to the pathogenesis of IBD. Collectively, our findings highlight R-loop-mediated genomic instability in ISCs as a risk factor in IBD.

Prebiotics for induction and maintenance of remission in ulcerative colitis

BACKGROUND

People affected by ulcerative colitis (UC) are interested in dietary therapies as treatments that can improve their health and quality of life. Prebiotics are a category of food ingredients theorised to have health benefits for the gastrointestinal system through their effect on the growth and activity of intestinal bacteria and probiotics.

OBJECTIVES

To assess the efficacy and safety of prebiotics for the induction and maintenance of remission in people with active UC.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and WHO ICTRP on 24 June 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) on people with UC. We considered any type of standalone or combination prebiotic intervention, except those prebiotics combined with probiotics (known as synbiotics), compared to any control intervention. We considered interventions of any dose and duration.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We included 9 RCTs involving a total of 445 participants. Study duration ranged from 14 days to 2 to 3 months for induction and 1 to 6 months for maintenance of remission. All studies were on adults. Five studies were on people with mild to moderate active disease, three in remission or mild activity, and one did not mention. We judged only one study as at low risk of bias in all areas. Two studies compared prebiotics with placebo for induction of remission. We cannot draw any conclusions about clinical remission (70% versus 67%; risk ratio (RR) 1.05, 95% confidence interval (CI) 0.57 to 1.94); clinical improvement (mean Rachmilewitz score on day 14 of 4.1 versus 4.5; mean difference (MD) -0.40, 95% CI -2.67 to 1.87); faecal calprotectin levels (mean faecal calprotectin on day 14 of 1211 μg/mL versus 3740 μg/mL; MD -2529.00, 95% CI -6925.38 to 1867.38); interleukin-8 (IL-8) levels (mean IL-8 on day 7 of 2.9 pg/mL versus 5.0 pg/mL; MD -2.10, 95% CI -4.93 to 0.73); prostaglandin E2 (PGE-2) levels (mean PGE-2 on day 7 of 7.1 ng/mL versus 11.5 ng/mL; MD -4.40, 95% CI -20.25 to 11.45); or withdrawals due to adverse events (21% versus 8%; RR 2.73, 95% CI 0.51 to 14.55). All evidence was of very low certainty. No other outcomes were reported. Two studies compared inulin and oligofructose 15 g with inulin and oligofructose 7.5 g for induction of remission. We cannot draw any conclusions about clinical remission (53% versus 12.5%; RR 4.27, 95% CI 1.07 to 16.96); clinical improvement (67% versus 25%; RR 2.67, 95% CI 1.06 to 6.70); total adverse events (53.5% versus 31%; RR 1.71, 95% CI 0.72 to 4.06); or withdrawals due to adverse events (13% versus 25%; RR 0.53, 95% CI 0.11 to 2.50). All evidence was of very low certainty. No other outcomes were reported. One study compared prebiotics and anti-inflammatory therapy with anti-inflammatory therapy alone for induction of remission. We cannot draw any conclusions about clinical improvement (mean Lichtiger score at 4 weeks of 6.2 versus 10.3; MD -4.10, 95% CI -8.14 to -0.06) or serum C-reactive protein (CRP) levels (mean CRP levels at 4 weeks 0.55 ng/mL versus 0.50 ng/mL; MD 0.05, 95% CI -0.37 to 0.47). All evidence was of very low certainty. No other outcomes were reported. Three studies compared prebiotics with placebo for maintenance of remission. There may be no difference between groups in rate of clinical relapse (44% versus 33%; RR 1.36, 95% CI 0.79 to 2.31), and prebiotics may lead to more total adverse events than placebo (77% versus 46%; RR 1.68, 95% CI 1.18 to 2.40). The evidence was of low certainty. We cannot draw any conclusions about clinical improvement (mean partial Mayo score at day 60 of 0.428 versus 1.625; MD -1.20, 95% CI -2.17 to -0.22); faecal calprotectin levels (mean faecal calprotectin level at day 60 of 214 μg/mL versus 304 μg/mL; MD -89.79, 95% CI -221.30 to 41.72); quality of life (mean Inflammatory Bowel Disease Questionnaire (IBDQ) score at day 60 of 193.5 versus 188.0; MD 5.50, 95% CI -8.94 to 19.94); or withdrawals due to adverse events (28.5% versus 11%; RR 2.57, 95% CI 1.15 to 5.73). The evidence for these outcomes was of very low certainty. No other outcomes were reported. One study compared prebiotics with synbiotics for maintenance of remission. We cannot draw any conclusions about quality of life (mean IBDQ score at 4 weeks 182.4 versus 176.1; MD 6.30, 95% CI -6.61 to 19.21) or withdrawals due to adverse events (23% versus 20%; RR 1.13, 95% CI 0.48 to 2.62). All evidence was of very low certainty. No other outcomes were reported. One study compared prebiotics with probiotics for maintenance of remission. We cannot draw any conclusions about quality of life (mean IBDQ score at 4 weeks 182.4 versus 168.6; MD 13.60, 95% CI 1.22 to 25.98) or withdrawals due to adverse events (22.5% versus 22.5%; RR 1.00, 95% CI 0.44 to 2.26). All evidence was of very low certainty. No other outcomes were reported.

AUTHORS' CONCLUSIONS

There may be no difference in occurrence of clinical relapse when adjuvant treatment with prebiotics is compared with adjuvant treatment with placebo for maintenance of remission in UC. Adjuvant treatment with prebiotics may result in more total adverse events when compared to adjuvant treatment with placebo for maintenance of remission. We could draw no conclusions for any of the other outcomes in this comparison due to the very low certainty of the evidence. The evidence for all other comparisons and outcomes was also of very low certainty, precluding any conclusions. It is difficult to make any clear recommendations for future research based on the findings of this review given the clinical and methodological heterogeneity among studies. It is recommended that a consensus is reached on these issues prior to any further research.

An Inflammatory Bowel Diseases Integrated Resources Portal (IBDIRP)

IBD, including ulcerative colitis and Crohn's disease, is a chronic and debilitating gastrointestinal disorder that affects millions of people worldwide. Research on IBD has generated massive amounts of data, including literature, metagenomics, metabolomics, bioresources and databases. We aim to create an IBD Integrated Resources Portal (IBDIRP) that provides the most comprehensive resources for IBD. An integrated platform was developed that provides information on different aspects of IBD research resources, such as single-nucleotide polymorphisms (SNPs), genes, transcriptome, microbiota, metabolomics, single cells and other resources. Valuable and comprehensive IBD-related data were collected from PubMed, Google, GMrepo, gutMega, gutMDisorder, Single Cell Portal and other sources. Then, the data were systematically sorted, and these resources were manually curated. We systematically sorted and cataloged more than 320 unique risk SNPs associated with IBD in the SNP section. We presented over 289 IBD-related genes based on the database collection in the gene section. We also obtained 153 manually curated IBD transcriptomics data, including 12 388 samples, on the Gene Expression Omnibus database. The sorted IBD-related microbiota data from three primary microbiome databases (GMrepo, gutMega and gutMDisorder) were available for download. We selected 23 149 IBD-related taxonomic records from these databases. Additionally, we collected 24 IBD metabolomics studies with 2896 participants in the metabolomics section. We introduced two interactive single-cell data plug-in units that provided data visualization based on cells and genes. Finally, we listed 18 significant IBD web resources, such as the official European Crohn's and Colitis Organisation and International Organization for the Study of IBD websites, IBD scoring tools, IBD genetic and multi-omics resources, IBD biobanks and other useful research resources. The IBDIRP website is the first integrated resource for global IBD researchers. This portal will help researchers by providing comprehensive knowledge and enabling them to reinforce the multidimensional impression of IBD. The IBDIRP website is accessible via www.ibdirp.com Database URL: www.ibdirp.com.

Effects of polyphenolic maqui (Aristotelia chilensis) extract on the inhibition of NLRP3 inflammasome and activation of mast cells in a mouse model of Crohn's disease-like colitis

Introduction

Crohn's disease (CD) involves activation of mast cells (MC) and NF-кB in parallel with the PPAR-α/NLRP3 inflammasome/IL-1β pathway in the inflamed colon. Whether polyphenols from maqui (Aristotelia chilensis) represent a natural alternative treatment for CD is unclear. Therefore, we used an animal model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced CD-like colitis to investigate protective effects of maqui extract through monitoring NLRP3 inflammasome and MC activation in colon tissue.

Methods

Maqui extract was administered via orogastric route to mice after (post-Treatment group) or prior (pre-Treatment group) to TNBS-induction. Colon pathology was characterized by histoarchitectural imaging, disease activity index (DAI), and assessing NF-кB, p-NF-кB, PPAR-α/NLRP3 expression and IL-1β levels.

Results

Compared to mice treated with TNBS alone administration of anthocyanin-rich maqui extract improved the DAI, colon histoarchitecture and reduced both colon wet-weight and transmural inflammation. Induction with TNBS significantly increased colonic NLPR3 inflammasome activation, while co-treatment with maqui extract (either post- or pre-Treatment) significantly downregulated NLRP3, ASC and caspase-1 levels, which manifested as reduced colonic IL-1β levels. Supplemented maqui extract marginally diminished NF-кB activity in epithelial cells but reached statistical significance in immune cells (as judged by decreased NF-кB phosphorylation). PPAR-α signaling was largely unaffected by Maqui whereas MC infiltration into the colon mucosa and submucosa decreased and their level of degranulation was suppressed.

Conclusion

These outcomes show the post- and pre- Treatment effect of a polyphenolic extract rich in anthocyanins from maqui the acute phase of TNBS- induced CD-like colitis is linked to suppression of the NLRP3 inflammasome and reduced MC responses. These data indicate that maqui extract represents a potential nutraceutical for the treatment of inflammatory bowel disease (IBD).

Bile acid profiling as an effective biomarker for staging in pediatric inflammatory bowel disease

Rapid and accurate clinical staging of pediatric patients with inflammatory bowel disease (IBD) is crucial to determine the appropriate therapeutic approach. This study aimed to identify effective, convenient biomarkers for staging IBD in pediatric patients. We recruited cohorts of pediatric patients with varying severities of IBD to compare the features of the intestinal microbiota and metabolites between the active and remitting disease stages. Metabolites with potential for staging were targeted for further assessment in both patients and colitis model mice. The performance of these markers was determined using machine learning and was validated in a separate patient cohort. Pediatric patients with IBD exhibited distinct gut microbiota structures at different stages of disease activity. The enterotypes of patients with remitting and active disease were Bacteroides-dominant and Escherichia-Shigella-dominant, respectively. The bile secretion pathway showed the most significant differences between the two stages. Fecal and serum bile acid (BA) levels were strongly related to disease activity in both children and mice. The ratio of primary BAs to secondary BAs in serum was developed as a novel comprehensive index, showing excellent diagnostic performance in stratifying IBD activity (0.84 area under the receiver operating characteristic curve in the primary cohort; 77% accuracy in the validation cohort). In conclusion, we report profound insights into the interactions between the gut microbiota and metabolites in pediatric IBD. Serum BAs have potential as biomarkers for classifying disease activity, and may facilitate the personalization of treatment for IBD.

Integrative analysis with microbial modelling and machine learning uncovers potential alleviators for ulcerative colitis

Ulcerative colitis (UC) is a challenging form of inflammatory bowel disease, and its etiology is intricately linked to disturbances in the gut microbiome. To identify the potential alleviators of UC, we employed an integrative analysis combining microbial community modeling with advanced machine learning techniques. Using metagenomics data sourced from the Integrated Human Microbiome Project, we constructed individualized microbiome community models for each participant. Our analysis highlighted a significant decline in both α and β-diversity of strain-level microbial populations in UC subjects compared to controls. Distinct differences were also observed in the predicted fecal metabolite profiles and strain-to-metabolite contributions between the two groups. Using tree-based machine learning models, we successfully identified specific microbial strains and their associated metabolites as potential alleviators of UC. Notably, our experimental validation using a dextran sulfate sodium-induced UC mouse model demonstrated that the administration of Parabacteroides merdae ATCC 43,184 and N-acetyl-D-mannosamine provided notable relief from colitis symptoms. In summary, our study underscores the potential of an integrative approach to identify novel therapeutic avenues for UC, paving the way for future targeted interventions.

Inhibition of FABP5 attenuates inflammatory bowel disease by modulating macrophage alternative activation

Fatty acid binding protein 5 (FABP5) is an intracellular chaperone of fatty acid molecules that regulates lipid metabolism and cell growth. However, its role in intestinal inflammation remains enigmatic. Through examination of human tissue samples and single-cell data, we observed a significant upregulation of FABP5 within the mucosa of patients afflicted with ulcerative colitis (UC) and Crohn's disease (CD), predominantly localized in intestinal macrophages. Herein, we investigate the regulation of FABP5-IN-1, a FABP5 inhibitor, on various cells of the gut in an inflammatory environment. Our investigations confirmed that FABP5 ameliorates DSS-induced colitis in mice by impeding the differentiation of macrophages into M1 macrophages in vitro and in vivo. Furthermore, following FABP5-IN-1 intervention, we observed a notable restoration of intestinal goblet cells and tuft cells, even under inflammatory conditions. Additionally, FABP5-IN-1 exhibits a protective effect against DSS-induced colitis by promoting the polarization of macrophages towards the M2 phenotype in vivo. In summary, FABP5-IN-1 confers protection against DSS-induced acute colitis through a multifaceted approach, encompassing the reduction of inflammatory macrophage infiltration, macrophage polarization, regulating Th17/Treg cells to play an anti-inflammatory role in IBD. The implications for IBD are underscored by the comprehensive in vivo and in vitro experiments presented in this article, thereby positioning FABP5 as a promising and novel therapeutic target for the treatment of IBD.

Factors influencing the quality of life in inflammatory bowel disease: A comprehensive review

Inflammatory bowel disease (IBD) is a group of chronic relapsing disorders, including Crohn's disease (CD) and ulcerative colitis (UC), which affects an increasing number of people worldwide. In the last few decades, the scientific world has witnessed many developments in IBD management by controlling debilitating symptoms and remaining in remission for more protracted periods. Even so, we still have a large population suffering from active IBD. An individual's quality of life (QoL) can be severely affected by IBD, like any other chronic illness. In this article, we have reviewed factors influencing the QoL in IBD patients, including chronic pain, diet, physical activity, and psychological factors like depression, anxiety, and stress symptoms. We also discussed the mechanisms of diet-microbial-immune system interaction, currently available dietary therapies for active CD and UC, and early psycho-social interventions that can reduce the disease burden and improve QoL in IBD patients.

Impact of artificial intelligence on prognosis, shared decision-making, and precision medicine for patients with inflammatory bowel disease: a perspective and expert opinion

INTRODUCTION

Artificial intelligence (AI) is expected to impact all facets of inflammatory bowel disease (IBD) management, including disease assessment, treatment decisions, discovery and development of new biomarkers and therapeutics, as well as clinician-patient communication.

AREAS COVERED

This perspective paper provides an overview of the application of AI in the clinical management of IBD through a review of the currently available AI models that could be potential tools for prognosis, shared decision-making, and precision medicine. This overview covers models that measure treatment response based on statistical or machine-learning methods, or a combination of the two. We briefly discuss a computational model that allows integration of immune/biological system knowledge with mathematical modeling and also involves a 'digital twin', which allows measurement of temporal trends in mucosal inflammatory activity for predicting treatment response. A viewpoint on AI-enabled wearables and nearables and their use to improve IBD management is also included.

EXPERT OPINION

Although challenges regarding data quality, privacy, and security; ethical concerns; technical limitations; and regulatory barriers remain to be fully addressed, a growing body of evidence suggests a tremendous potential for integration of AI into daily clinical practice to enable precision medicine and shared decision-making.