The interplay between the microbiota, diet and T regulatory cells in the preservation of the gut barrier in inflammatory bowel disease

Angiogenic Factors and Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is characterized by chronic intestinal inflammation and impaired epithelial barrier function. Emerging evidence highlights the critical role of vascular remodeling and angiogenesis in IBD pathogenesis. This review explores the intricate relationship between blood vessels and the intestinal epithelial barrier, emphasizing how aberrant vascularization contributes to barrier dysfunction and disease progression. In IBD, excessive angiogenesis is driven by hypoxia, immune cell infiltration, and pro-inflammatory cytokines, further perpetuating inflammation and tissue damage. Key angiogenic factors, such as vascular endothelial growth factor (VEGF), angiopoietins, and platelet-derived growth factor (PDGF), are upregulated in IBD, promoting pathological vessel formation. These newly formed vessels are often immature and hyperpermeable, exacerbating leukocyte recruitment and inflammatory responses. Given the pivotal role of angiogenesis in IBD, anti-angiogenic therapies have emerged as a potential therapeutic strategy. Preclinical and clinical studies targeting VEGF and other angiogenic pathways have shown promise in reducing inflammation and promoting mucosal healing. This review summarizes current knowledge on vascular-epithelial interactions in IBD, the mechanisms driving pathological angiogenesis, and the therapeutic potential of anti-angiogenic approaches, providing insights for future research and treatment development.

The Impact of Antibiotic Therapy on Intestinal Microbiota: Dysbiosis, Antibiotic Resistance, and Restoration Strategies

The human gut microbiota-an intricate and dynamic ecosystem-plays a pivotal role in metabolic regulation, immune modulation, and the maintenance of intestinal barrier integrity. Although antibiotic therapy is indispensable for managing bacterial infections, it profoundly disrupts gut microbial communities. Such dysbiosis is typified by diminished diversity and shifts in community structure, especially among beneficial bacterial genera (e.g., Bifidobacterium and Eubacterium), and fosters antibiotic-resistant strains and the horizontal transfer of resistance genes. These alterations compromise colonization resistance, increase intestinal permeability, and amplify susceptibility to opportunistic pathogens like Clostridioides difficile. Beyond gastrointestinal disorders, emerging evidence associates dysbiosis with systemic conditions, including chronic inflammation, metabolic syndrome, and neurodegenerative diseases, underscoring the relevance of the microbiota-gut-brain axis. The recovery of pre-existing gut communities post-antibiotic therapy is highly variable, influenced by drug spectrum, dosage, and treatment duration. Innovative interventions-such as fecal microbiota transplantation (FMT), probiotics, synbiotics, and precision microbiome therapeutics-have shown promise in counteracting dysbiosis and mitigating its adverse effects. These therapies align closely with antibiotic stewardship programs aimed at minimizing unnecessary antibiotic use to preserve microbial diversity and curtail the spread of multidrug-resistant organisms. This review emphasizes the pressing need for microbiota-centered strategies to optimize antibiotic administration, promote long-term health resilience, and alleviate the disease burden associated with antibiotic-induced dysbiosis.

A blood-based liquid biopsy analyzing soluble immune checkpoints and cytokines identifies distinct neuroendocrine tumors

BACKGROUND

Neuroendocrine neoplasms (NENs) comprise a group of rare tumors originating from neuroendocrine cells, which are present in both endocrine glands and scattered throughout the body. Due to their scarcity and absence of specific markers, diagnosing NENs remains a complex challenge. Therefore, new biomarkers are required, ideally, in easy-to-obtain blood samples.

METHODS

A panel of blood soluble immune checkpoints (sPD-L1, sPD-L2, sPD-1, sCD25, sTIM3, sLAG3, Galectin-9, sCD27, sB7.2 and sSIGLEC5) and cytokines (IL4, IL6, IP10 and MCP1) was quantified in a cohort of 139 NENs, including 29 pituitary NENs, 46 pheochromocytomas and paragangliomas, and 67 gastroenteropancreatic and pulmonary (GEPP) NENs, as well as in 64 healthy volunteers (HVs). The potential of these circulating immunological parameters to distinguish NENs from HVs, differentiate among various NENs subtypes, and predict their prognosis was evaluated using mathematical regression models. These immunological factors-based models generated scores that were evaluated by Receiver Operating Characteristic (ROC) and Area Under the Curve (AUC) analyses. Correlations between these scores and clinical data were performed. From these analyses, a minimal signature emerged, comprising the five shared immunological factors across the models: sCD25, sPD-L2, sTIM3, sLAG3, and Galectin-9. This refined signature was evaluated, validated, and checked for specificity against non-neuroendocrine tumors, demonstrating its potential as a clinically relevant tool for identifying distinct NENs.

RESULTS

Most of the immunological factors analyzed showed specific expression patterns among different NENs. Scores based on signatures of these factors identified NENs with high efficiency, showing AUCs ranging between 0.948 and 0.993 depending on the comparison, and accuracies between 92.52% and 95.74%. These scores illustrated biological features of NENs including the similarity between pheochromocytomas and paragangliomas, the divergence between gastrointestinal and pulmonary NENs, and correlated with clinical features. Furthermore, the models demonstrated strong performance in distinguishing metastatic and exitus GEPP NENs, achieving sensitivities and specificities ranging from 80.95% to 88.89%. Additionally, an easy-to-implement minimal signature successfully identified all analyzed NENs with AUC values exceeding 0.900, and accuracies between 84.11% and 93.12%, which was internally validated by a discovery and validation randomization strategy. These findings highlight the effectiveness of the models and minimal signature in accurately diagnosing and differentiating NENs.

CONCLUSIONS

The analysis of soluble immunological factors in blood presents a promising liquid biopsy approach for identifying NENs, delivering critical insights for both prognosis and diagnosis. This study serves as a proof-of-concept for an innovative clinical tool that holds the potential to transform the management of these rare malignancies, providing a non-invasive and effective method for early detection and disease monitoring.

Eurotium-Cristatum fermented black tea alleviates ulcerative colitis through the PPARγ-NF-κB signaling axis

Ulcerative colitis (UC) is a chronic inflammatory bowel condition that significantly impairs patient quality of life and remains incurable. Effective dietary management is crucial for both prevention and treatment. This study investigates the effects and mechanisms of Eurotium cristatum-fermented black tea (FBT) in a dextran sulfate sodium (DSS)-induced UC mouse model using transcriptome sequencing, immunofluorescence, and flow cytometry. Our results demonstrate that FBT significantly protects intestinal integrity by suppressing NF-κB-dependent inflammatory genes through the activation of peroxisome proliferator-activated receptor gamma (PPARγ) and modulation of the NF-κB signaling pathway. FBT enhances intestinal barrier integrity by limiting microbial penetration and metabolite translocation into systemic circulation, thereby reducing systemic inflammation risk. Additionally, FBT promotes intestinal mucosa repair and maintains microecological homeostasis by regulating intestinal flora and enhancing the biosynthesis of short-chain fatty acids and amino acids. These findings suggest that FBT has promising prophylactic potential for preventing and alleviating UC by modulating multiple biological pathways, including reducing inflammation, mitigating oxidative stress, and strengthening intestinal barrier integrity. This study lays the groundwork for future research on dietary interventions for UC prevention and management.

Comparative analysis of the effects of cyclophosphamide and dexamethasone on intestinal immunity and microbiota in delayed hypersensitivity mice

BACKGROUND

The T cell-mediated delayed-type hypersensitivity (DTH) response is critical for elucidating cellular immune mechanisms, especially the role of memory T cells upon antigen re-exposure. This study aimed to investigate the specific effects of the immunosuppressive drugs Cyclophosphamide (CY) and Dexamethasone (DEX) on intestinal immunity and microbiota in a DTH mouse model, contributing to a more nuanced understanding of their immunomodulatory mechanisms.

METHODS

Female BALB/c mice were sensitized to 2,4-dinitrofluorobenzene (DNFB) and randomly allocated into control, CY, and DEX groups. The impact of CY and DEX on immune function was assessed through measurement of thymus and spleen indices, lymphocyte proliferation in mesenteric lymph nodes (MLNs) using MTT assay, and flow cytometric analysis of T cell subsets and TCR expression. Intestinal secretory IgA (sIgA) was quantified by ELISA, and gut microbiota diversity was evaluated using 16S rRNA gene sequencing.

RESULTS

CY and DEX significantly reduced the immune function in DNFB-induced sensitized mice, as indicated by decreased thymus and spleen indices, MLN enlargement, intestinal sIgA content, and ear swelling degree. Flow cytometry revealed that CY increased the proportion of total CD3+ T cells but reduced CD3+CD69+ activated T cells and CD3+TCRγ/δ+ T cells, while DEX increased CD3+CD4+ helper T cells. Both drugs induced distinct changes in gut microbiota diversity and structure, with CY enhancing α diversity and DEX reducing it.

CONCLUSIONS

The study demonstrates that CY and DEX have distinct regulatory effects on the immune organ index, distribution of T cell subsets, and diversity and structure of gut microbiota on DTH-induced immune responses mice, suggesting their differential influence on intestinal mucosal immunity. These findings have implications for the development of targeted immunotherapies and understanding the interplay between immunosuppressive drugs and gut microbiota.

The emerging role of the gut microbiota and its application in inflammatory bowel disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a complex disorder with an unknown cause. However, the dysbiosis of the gut microbiome has been found to play a role in IBD etiology, including exacerbated immune responses and defective intestinal barrier integrity. The gut microbiome can also be a potential biomarker for several diseases, including IBD. Currently, conventional treatments targeting pro-inflammatory cytokines and pathways in IBD-associated dysbiosis do not yield effective results. Other therapies that directly target the dysbiotic microbiome for effective outcomes are emerging. We review the role of the gut microbiome in health and IBD and its potential as a diagnostic, prognostic, and therapeutic target for IBD. This review also explores emerging therapeutic advancements that target gut microbiome-associated alterations in IBD, such as nanoparticle or encapsulation delivery, fecal microbiota transplantation, nutritional therapies, microbiome/probiotic engineering, phage therapy, mesenchymal stem cells (MSCs), gut proteins, and herbal formulas.

Fecal microbiota and metabolites in the pathogenesis and precision medicine for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract, and its pathogenesis is believed to be associated with an imbalance between commensal organisms and the intestinal immune system. This imbalance is significantly influenced by the intestinal microbiota and metabolites and plays a critical role in maintaining intestinal mucosal homeostasis. However, disturbances in the intestinal microbiota cause dysregulated immune responses and consequently induce intestinal inflammation. Recent studies have illustrated the roles of the intestinal microbiota in the pathogenesis of IBD and underscored the potential of precision diagnosis and therapy. This work summarises recent progress in this field and particularly focuses on the application of the intestinal microbiota and metabolites in the precision diagnosis, prognosis assessment, treatment effectiveness evaluation, and therapeutic management of IBD.

Immunomodulatory Effects of a Probiotic Mixture: Alleviating Colitis in a Mouse Model through Modulation of Cell Activation Markers and the Gut Microbiota

Ulcerative colitis (UC) is a persistent inflammatory intestinal disease that consistently affects the colon and rectum. Its exact cause remains unknown. UC causes a considerable challenge in healthcare, prompting research for novel therapeutic strategies. Although probiotics have gained popularity as possible candidates for managing UC, studies are still ongoing to identify the best probiotics or probiotic mixtures for clinical applications. This study aimed to determine the efficacy of a multi-strain probiotic mixture in mitigating intestinal inflammation in a colitis mouse model induced by dextran sulfate sodium. Specifically, a multi-strain probiotic mixture consisting of Tetragenococcus halophilus and Eubacterium rectale was used to study its impact on colitis symptoms. Anti-inflammatory effects were evaluated using ELISA and flow cytometry. The configuration of gut microbial communities was determined using 16S rRNA metagenomic analysis. According to this study, colitis mice treated with the probiotic mixture experienced reduced weight loss and significantly less colonic shortening compared to untreated mice. Additionally, the treated mice exhibited increased levels of forkhead box P3 (Foxp3) and interleukin 10, along with decreased expression of dendritic cell activation markers, such as CD40+, CD80+, and CD83+, in peripheral blood leukocytes and intraepithelial lymphocytes. Furthermore, there was a significant decrease in the frequencies of CD8+N.K1.1+ cells and CD11b+Ly6G+ cells. In terms of the gut microbiota, probiotic-mixture treatment of colitis mice significantly increased the abundance of the phyla Actinobacteria and Verrucomicrobia (p < 0.05). These results provide valuable insights into the therapeutic promise of multi-strain probiotics, shedding light on their potential to alleviate colitis symptoms. This research contributes to the ongoing exploration of effective probiotic interventions for managing inflammatory bowel disease.

Enteric Nervous System Alterations in Inflammatory Bowel Disease: Perspectives and Implications

The enteric nervous system (ENS), consisting of neurons and glial cells, is situated along the gastrointestinal (GI) tract's wall and plays a crucial role in coordinating digestive processes. Recent research suggests that the optimal functioning of the GI system relies on intricate connections between the ENS, the intestinal epithelium, the immune system, the intestinal microbiome, and the central nervous system (CNS). Inflammatory bowel disease (IBD) encompasses a group of chronic inflammatory disorders, such as Crohn's disease (CD) and ulcerative colitis (UC), characterized by recurring inflammation and damage to the GI tract. This review explores emerging research in the dynamic field of IBD and sheds light on the potential role of ENS alterations in both the etiology and management of IBD. Specifically, we delve into IBD-induced enteric glial cell (EGC) activation and its implications for persistent enteric gliosis, elucidating how this activation disrupts GI function through alterations in the gut-brain axis (GBA). Additionally, we examine IBD-associated ENS alterations, focusing on EGC senescence and the acquisition of the senescence-associated secretory phenotype (SASP). We highlight the pivotal role of these changes in persistent GI inflammation and the recurrence of IBD. Finally, we discuss potential therapeutic interventions involving senotherapeutic agents, providing insights into potential avenues for managing IBD by targeting ENS-related mechanisms. This approach might represent a potential alternative to managing IBD and advance treatment of this multifaceted disease.

Extracellular Vesicles: Novel Potential Therapeutic Agents in Inflammatory Bowel Diseases

Patients affected by inflammatory bowel diseases (IBD) can nowadays benefit from a growing number of pharmacological options. However, in moderate-to-severe cases, the therapeutic response is still far from optimal, and treatment changes and optimizations are often required. Thus, researchers in this field are strongly engaged in studies aiming to identify new potential therapeutic targets. Extracellular vesicles (EVs) are tiny subcellular bodies with a phospholipid bilayer envelope containing bioactive molecules, which are released from different cells and are involved in intercellular communication. Recent pre-clinical data show their emerging role in the pathogenesis and treatment of IBD. In our review, we summarize current evidence about the function of EVs as active therapeutic agents in ulcerative colitis and Crohn's disease, analyzing the properties of EVs derived from different cellular sources and the mechanisms through which they may improve intestinal inflammation.