Excess Dietary Sugar Alters Colonocyte Metabolism and Impairs the Proliferative Response to Damage

Modulation of intestinal signal transduction pathways: Implications on gut health and disease

The gastrointestinal (GI) tract is essential for nutrient absorption and protection against pathogens and toxins. Its epithelial lining undergoes continuous renewal every 3-5 days, driven by intestinal stem cells (ISCs). ISCs are primarily of two types: actively proliferating crypt base columnar cells (CBCs), marked by Lgr5 expression, and quiescent label-retaining cells (+4 LRCs), which act as reserves during stress or injury. Key signaling pathways, such as Wnt/β-catenin, Notch, bone morphogenetic proteins (BMPs), and epidermal growth factor (EGF), are crucial in maintaining epithelial homeostasis. These pathways regulate ISCs proliferation and their differentiation into specialized epithelial cells, including goblet cells, paneth cells, enteroendocrine cells, and enterocytes. Disruptions in ISCs signaling can arise from extrinsic factors (e.g., dietary additives, heavy metals, pathogens) or intrinsic factors (e.g., genetic mutations, metabolic changes). Such disruptions impair tight junction integrity, induce inflammation, and promote gut dysbiosis, often perpetuating a cycle of intestinal dysfunction. Chronic ISCs dysregulation is linked to severe intestinal disorders, including colorectal cancer (CRC) and inflammatory bowel disease (IBD). This review emphasizes the critical role of ISCs in maintaining epithelial renewal and how various factors disrupt their signaling pathways, jeopardizing intestinal health and contributing to diseases. It also underscores the importance of protecting ISCs function to mitigate the risk of inflammation-related disorders. It highlights how understanding these regulatory mechanisms could guide therapeutic strategies for preserving GI tract integrity and treating related conditions.

Nanoparticle Formulations for Intracellular Delivery in Colorectal Cancer Therapy

This study introduces advanced nanoparticle-based drug delivery systems (NDDS) designed for targeted colorectal cancer treatment. We developed and characterized three distinct formulations: Bevacizumab-loaded chitosan nanoparticles (BEV-CHI-NP), polymeric micelles (BEV-PM), and BEV-conjugated exosomes enriched with AS1411 and N1-methyladenosine (AP-BEV + M1A-EXO). Each formulation exhibited optimized physicochemical properties, with particle sizes between 150 and 250 nm and surface charges ranging from + 14.4 to + 43 mV, ensuring stability and targeted delivery. The AP-BEV + M1A-EXO formulation demonstrated targeted delivery to VEGF, a protein commonly overexpressed in colorectal cancer cells, as indicated by localized staining. This suggests a more precise delivery of the therapeutic agent to VEGF-enriched regions. In contrast, the BEV-CHI-NP formulation exhibited a broader pattern of tumor suppression, evidenced by reduced overall staining intensity. The BEV-PM group showed moderate effects, with a relatively uniform protein expression across tumor tissues. In vivo studies indicated that the AP-BEV + M1A-EXO formulation achieved a notable reduction in tumor volume (~ 65.4%) and decreased levels of tumor biomarkers, including CEA and CA 19-9, compared to conventional BEV-API treatment. In vitro experiments using human colon tumor organoids (HCTOs) further supported these findings, showing a significant reduction in cell viability following exposure to AP-BEV + M1A-EXO. These results suggest that combining aptamer specificity with exosome-based delivery systems could enhance the precision and effectiveness of colorectal cancer therapies, representing a potential advancement in treatment strategies. In vivo experiments further revealed that the AP-BEV + M1A-EXO formulation outperformed conventional BEV-API treatment, achieving a four-fold increase in tumor suppression. This formulation resulted in a 65.4% reduction in tumor volume and a significant decrease in tumor biomarkers, including CEA and CA 19-9. In vitro studies also demonstrated a significant reduction in cell viability in human colon tumor organoids exposed to AP-BEV + M1A-EXO. These findings highlight the potential of combining aptamer specificity with exosome-based delivery systems to enhance the precision and efficacy of colorectal cancer therapies, marking a promising step forward in cancer treatment innovation.

Health Benefits of Montmorency Tart Cherry Juice Supplementation in Adults with Mild to Moderate Ulcerative Colitis; A Placebo Randomized Controlled Trial

AIMS

Ulcerative colitis (UC) significantly impacts individuals' self-perception, body image, and overall quality of life, while also imposing considerable economic costs. These challenges highlight the necessity for complementary therapeutic strategies with reduced adverse effects to support conventional pharmacological treatments. Among natural interventions, Montmorency tart cherries, noted for their high anthocyanin content have emerged as a natural anti-inflammatory agent for UC. The current trial aimed to investigate the effects of Montmorency tart cherries compared to placebo in patients with mild to moderate UC.

MATERIALS AND METHODS

Thirty-five patients with UC were randomly assigned to receive either placebo or Montmorency tart cherry juice, of which they drank 60 mL per day for 6 weeks. The primary outcomes and health-related quality of life, measured via the Inflammatory Bowel Disease Quality of Life Questionnaire (IBDQ), and the secondary measures, including other health-related questionnaires, blood biomarkers, and faecal samples, were measured before and after the intervention. Linear mixed-effects models were adopted to contrast the changes from baseline to 6 weeks between trial arms. Effect sizes were calculated using Cohen's d.

RESULTS

There were significantly greater improvements in the IBDQ (22.61 (95% CI = 5.24 to 39.99) d = 0.90) and simple clinical colitis activity index (-3.98 (95% CI = -6.69 to -1.28) d = -1.01) in the tart cherry trial arm compared to placebo. In addition, reductions in faecal calprotectin levels were significantly greater in the tart cherry trial arm compared to placebo (-136.17 µg/g (95% CI = -258.06 to -4.28) d = -1.14). Loss to follow-up (N = 1) and adverse events (N = 1) were low and compliance was very high in the tart cherry (95.8%) trial arm.

CONCLUSIONS

Given the profoundly negative effects of UC on health-related quality of life and its fiscal implications for global healthcare systems, this trial indicates that twice-daily tart cherry supplementation can improve IBD-related quality of life as well as the severity of symptoms and therefore may be important in the management of UC.

Intestinal stem cell niche: An upcoming area of immense importance in gastrointestinal disorders

The intestinal stem cell (ISC) niche is vital for maintaining the integrity and function of the intestinal epithelium. ISC populations, characterized by their high proliferation and multipotency, reside within a specialized microenvironment at the base of crypts. Crypt base columnar (CBC) cells at the deepest part of crypts serve as replicating ISCs, while position 4 label-retaining cells (LRCs) located higher up in the crypts are also important for ISC maintenance during experiments. The interplay between CBCs, position 4 LRCs, transient amplifying (TA) cells and other niche components, including the pericrypt stromal cells, ensures a continuous supply of differentiated epithelial cells. Recent advancements in ISC biomarker studies have provided valuable insights into their molecular signatures, regulatory pathways and roles in the pathogenesis of intestinal disorders. Understanding the ISC niche has significant therapeutic implications, as manipulating ISC behaviors and regenerating damaged or diseased intestinal tissue show promise for novel therapeutic approaches. ISC organoids have also provided a platform for studying intestinal diseases and testing personalized therapies. This comprehensive review covers the anatomical composition, physiological regulation, ISC biomarker studies, contribution to intestinal disorder pathogenesis and potential therapeutic implications of the ISC niche.

Eicosapentaenoic acid enhances intestinal stem cell-mediated colonic epithelial regeneration by activating the LSD1-WNT signaling pathway

INTRODUCTION

Inflammatory bowel disease (IBD) is often associated with impaired proliferation and differentiation of intestinal stem cells (ISCs). Eicosapentaenoic acid (EPA), which is predominantly found in fish oil, has been recognized for its intestinal health benefits, although the potential mechanisms are not well understood.

OBJECTIVES

This study aimed to investigate the regulatory role and mechanism of EPA in colonic epithelial regeneration, specifically from the perspective of ISCs.

METHODS

Wild-type mice whose diet was supplemented with 5% EPA-enriched fish oil were subjected to dextran sulfate sodium (DSS) to induce colitis. We utilized intestinal organoids, ISC-specific lysine-specific demethylase 1 (LSD1) knockout mice, and WNT inhibitor-treated mice to explore how EPA influences ISC proliferation and differentiation. ISC proliferation, differentiation and apoptosis were assessed using tdTomato and propidium iodide tracer testing, histological analyses, and immunofluorescence staining.

RESULTS

EPA treatment significantly mitigated the symptoms of DSS-induced acute colitis, as evidenced by lower body weight loss and decreased disease activity index, histological scores and proinflammatory cytokine levels. Additionally, EPA increased the numbers of proliferative cells, absorptive cells, goblet cells, and enteroendocrine cells, which enhanced the regeneration of intestinal epithelium. Pretreatment with EPA increased ISC proliferation and differentiation, and protected against TNF-α-induced cell death in intestinal organoids. Mechanistically, EPA upregulated G protein-coupled receptor 120 (GPR120) to induce LSD1 expression, which facilitated ISC proliferation and differentiation in organoids. ISC-specific ablation of LSD1 negated the protective effect of EPA on DSS-induced colitis in mice. Moreover, EPA administration activated the WNT signaling pathway downstream of LSD1 in ISCs, while inhibiting WNT signaling abolished the beneficial effects of EPA.

CONCLUSIONS

These findings demonstrate that EPA promotes ISC proliferation and differentiation, thereby enhancing colonic epithelial regeneration through the activation of LSD1-WNT signaling. Consequently, dietary supplementation with EPA represents a promising alternative therapeutic strategy for managing IBD.

Metabolomics reveals soluble epoxide hydrolase as a therapeutic target for high-sucrose diet-mediated gut barrier dysfunction

Highsucrose diet (HSD) was reported as a causative factor for multiorgan injuries. The underlying mechanisms and therapeutic strategies remain largely uncharted. In the present study, by using a metabolomics approach, we identified the soluble epoxide hydrolase (sEH) as a therapeutic target for HSD-mediated gut barrier dysfunction. Specifically, 16-week feeding on an HSD caused gut barrier dysfunction, such as colon inflammation and tight junction impairment in a murine model. A metabolomics analysis of mouse colon tissue showed a decrease in the 5(6)-epoxyeicosatrienoic acid [5(6)-EET] level and an increase in soluble epoxide hydrolase, which is related to HSD-mediated injuries to the gut barrier. The mice treated with a chemical inhibitor of sEH and the mice with genetic intervention by intestinal-specific knockout of the sEH gene significantly attenuated HSD-caused intestinal injuries by reducing HSD-mediated colon inflammation and improving the impaired tight junction caused by an HSD. Further, in vitro studies showed that treatment with 5(6)-EET, but not its hydrolytic product 5,6-dihydroxyeicosatrienoic acid (5,6-DiHET), significantly ablated high sucrose-caused intestinal epithelial inflammation and impaired tight junction. Additionally, 5(6)-EET is anti-inflammatory and improves gut epithelial tight junction while 5,6-DiHET cannot do so. This study presents an underlying mechanism of and a therapeutic strategy for the gut barrier dysfunction caused by an HSD.

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

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

Host-diet-microbiota interplay in intestinal nutrition and health

The intestine is populated by a complex and dynamic assortment of microbes, collectively called gut microbiota, that interact with the host and contribute to its metabolism and physiology. Diet is considered a key regulator of intestinal microbiota, as ingested nutrients interact with and shape the resident microbiota composition. Furthermore, recent studies underscore the interplay of dietary and microbiota-derived nutrients, which directly impinge on intestinal stem cells regulating their turnover to ensure a healthy gut barrier. Although advanced sequencing methodologies have allowed the characterization of the human gut microbiome, mechanistic studies assessing diet-microbiota-host interactions depend on the use of genetically tractable models, such as Drosophila melanogaster. In this review, we first discuss the similarities between the human and fly intestines and then we focus on the effects of diet and microbiota on nutrient-sensing signaling cascades controlling intestinal stem cell self-renewal and differentiation, as well as disease. Finally, we underline the use of the Drosophila model in assessing the role of microbiota in gut-related pathologies and in understanding the mechanisms that mediate different whole-body manifestations of gut dysfunction.

Nutrigenomic underpinnings of intestinal stem cells in inflammatory bowel disease and colorectal cancer development

Food-gene interaction has been identified as a leading risk factor for inflammatory bowel disease (IBD) and colorectal cancer (CRC). Accordingly, nutrigenomics emerges as a new approach to identify biomarkers and therapeutic targets for these two strongly associated gastrointestinal diseases. Recent studies in stem cell biology have further shown that diet and nutrition signal to intestinal stem cells (ISC) by altering nutrient-sensing transcriptional activities, thereby influencing barrier integrity and susceptibility to inflammation and tumorigenesis. This review recognizes the dietary factors related to both CRC and IBD and investigates their impact on the overlapping transcription factors governing stem cell activities in homeostasis and post-injury responses. Our objective is to provide a framework to study the food-gene regulatory network of disease-contributing cells and inspire new nutrigenomic approaches for detecting and treating diet-related IBD and CRC.