Search Results (740)

Background: Ulcerative colitis (UC), characterized by chronic intestinal inflammation, epithelial barrier dysfunction, and immune imbalance demands novel ameliorative strategies beyond conventional approaches. Methods: In this study, the probiotic properties of Lactobacillus paracaseiL21 (L. paracaseiL21) and its ability to ameliorate colitis were evaluated using an in vitro lipopolysaccharide (LPS)-induced intestinal crypt epithelial cell (IEC-6) model and an in vivo dextran sulfate sodium (DSS)-induced UC mouse model. Results: In vitro, L. paracaseiL21 decreased levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-8) while increasing anti-inflammatory IL-10 levels (p < 0.05) in LPS-induced IEC-6 cells, significantly enhancing the expression of tight junction proteins (ZO-1, occludin, claudin-1), thereby restoring the intestinal barrier. In vivo, both viable L. paracaseiL21 and its heat-inactivated postbiotic (H-L21) mitigated weight loss, colon shortening, and disease activity indices, concurrently reducing serum LPS and proinflammatory mediators. Interventions inhibited NF-κB signaling while activating HIF1α/AhR pathways, increasing IL-22 and mucin MUC2 to restore goblet cell populations. Gut microbiota analysis showed that both interventions increased the abundance of beneficial gut bacteria (Lactobacillus, Dubococcus, and Akkermansia) and improved faecal propanoic acid and butyric acid levels. H-L21 uniquely exerted an anti-inflammatory effect, marked by the regulation of Dubosiella, while L. paracaseiL21 marked by the Akkermansia. Conclusions: These results highlight the potential of L. paracaseiL21 as a candidate for the development of both probiotic and postbiotic formulations. It is expected to provide a theoretical basis for the management of UC and to drive the development of the next generation of UC therapies. Full article

The production of water-in-water emulsion droplets, the coalescence of which is prevented by adding oil-in-water micrometric droplets, is reported. Hexadecane (O) and cetyl trimethyl ammonium bromide (CTAB) were added to a W/W emulsion made of dextran (Dex)-enriched droplets in a Polyethyleglycol (PEG)-enriched continuous phase, and the mixture was further sonicated. Using Nile red to label the oil droplets enabled the observation of their presence at the surface of Dex droplets (5 µm), allowing for stabilizing them, preventing coalescence of the W/W emulsion, and mimicking W/O/W double emulsions. The addition of sulfate derivative of Dextran (DexSulf) allowed for stable droplets of a slightly larger diameter. By contrast, the addition of carboxymethyl Dextran (CMDex) destabilized the initial aqueous double-like emulsion, yielding sequestration of the oil droplets within the Dex-rich phase. Interestingly, addition of DexSulf to that unstable emulsion re-yielded stable droplets. Similar findings (destabilization) were obtained when adding sodium dodecyl sulfate (SDS) to the initial double-like emulsion, which reformed stable droplets when adding positively charged Dextran (DEAEDex) derivatives. The use of fluorescently (FITC) labeled derivatives of Dextran (Dex, CMDex, DEAEDex, and DexSulf) allowed us to follow their position within, out of, or at the interface of droplets in the above-mentioned mixtures. These findings are expected to be of interest in the field of materials chemistry. Full article

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder associated with gut microbiota dysbiosis and impaired intestinal barrier function. Probiotic interventions have shown potential in alleviating intestinal inflammation and restoring microbial balance. This study explores the protective effects of Lacticaseibacillus paracasei (L. paracasei) E10 in mice. L. paracasei E10 demonstrated strong gastrointestinal transit tolerance, high mucosal adhesion, and probiotic properties such as hydrophobicity and aggregation ability (p < 0.05). The oral administration of L. paracasei E10 significantly alleviated colitis symptoms by reducing the disease activity index, preserving colonic architecture, increasing goblet cell density, and upregulating tight junction proteins, thereby enhancing intestinal barrier integrity. 16S rRNA sequencing revealed that L. paracasei E10 supplementation enriched microbial diversity, increased the abundance of Muribaculaceae, and modulated the Firmicutes/Bacteroidetes ratio, contributing to gut homeostasis. These findings indicate that L. paracasei E10 is a potential candidate for IBD management. Full article

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease (IBD) that has been associated with overconsumption of calories and lipids, compared to the healthy population, and summer temperatures have been reported to be closely related to the prevalence of UC. To evaluate the effects of dietary and lifestyle factors on UC, a combination of 2.0% dextran sulfate sodium (DSS), a high-fat/high-sugar diet, and exposure to high temperature and humidity was used to construct mouse models of UC. Changes in body weight, disease activity index (DAI) scores, histopathological analysis, serum lipid levels, serum diamine oxidase (DAO), and D-Lactate (D-LA) levels, as well as the expression of inflammatory cytokines and tight junction proteins in colonic tissue, were all assessed to study the impacts of the high-fat/high-sugar diet and high-temperature/high-humidity exposure on the progression of UC. The symptoms observed in the UC mouse model induced by 2.0% DSS alone were similar to those seen in patients with UC, while the high-fat and high-sugar diet, along with humid and hot exposure, exacerbated DSS-induced UC in the mice. This included more severe histopathological damage to the colon tissue, increased expression of pro-inflammatory cytokines (IL-6, IL-17A, and IL-1β), and a more significantly compromised intestinal barrier, characterized by the destruction of ZO-1 and elevated levels of DAO and D-LA. Additionally, the high-fat/high-sugar diet and high-temperature/high-humidity exposure led to further disturbances in glucose and lipid metabolism in the mice, which were not observed in those treated with DSS alone. This study is the first to investigate the effects of a high-fat/high-sugar diet and high-temperature/high-humidity exposure on the progression of UC. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease driven by immune dysregulation, microbiota imbalance, and intestinal barrier dysfunction. Despite its global burden, effective therapies remain limited. This study explores the therapeutic potential of Agrocybe cylindracea polysaccharides (ACP) in a dextran sulfate sodium (DSS)-induced murine colitis model. High-performance liquid chromatography (HPLC)-characterized ACP was administered orally to BALB/c mice following colitis induction. ACP treatment significantly reduced Disease Activity Index (DAI) scores, preserved colon length, and restored intestinal barrier integrity by upregulating tight junction proteins. Mechanistically, ACP modulated immune homeostasis, suppressing pro-inflammatory cytokines (IL-17, IL-23, CRP) while enhancing anti-inflammatory mediators (IL-4, TGF-β). Furthermore, ACP inhibited hepatic TLR4/MyD88/NF-κB signaling, attenuated systemic inflammation, and reshaped gut microbiota composition by enriching beneficial taxa and reducing pathogenic Bacteroides. These findings demonstrate ACP multi-target efficacy in colitis, positioning it as a promising natural therapeutic for UC. Full article

Background: PTEN is a tumor suppressor that controls many pathophysiological pathways, including cell proliferation, differentiation, apoptosis and invasiveness. Although PTEN down-modulation is a critical event in neoplastic progression, it becomes apparent that transient and local inhibition of PTEN activity might be beneficial for the healing process. Methods: In the present study, we investigated the impact of PTEN invalidation in mouse intestinal epithelium under a physiological condition and after dextran sulfate sodium (DSS) treatment to induce experimental colitis. PTEN conditional knockout was induced in intestinal epithelial cells after crossing villin-Cre and PTEN^flox/flox mice. Results: PTEN invalidation alleviates experimental colitis induced by DSS, as evidenced by decreased weight loss during the acute phase, the lower expression of inflammation markers, including the proinflammatory cytokines IFN-γ, CXCL1 and CXCL2, reduced mucosal lesions, and faster recovery after resolution of inflammation. This protective effect might result in part from the sustained proliferation of colonic epithelium, leading to hyperplasia and increased colonic crypt depth under physiological conditions, which was further exacerbated in the vicinity of mucosal injury induced by DSS treatment. Furthermore, PTEN knockout decreased paracellular permeability, thereby enhancing the intestinal barrier function. This process was associated with the reinforcement of claudin-3 immunostaining, especially on the surface epithelium of villin-Cre PTEN^flox/flox mice. Conclusions: PTEN inactivation exerts a protective effect on the onset of colitis, and the transient and local down-modulation of PTEN might constitute an approach to drive recovery following acute intestinal inflammation. Full article

Patients with ulcerative colitis exhibit an increased risk for supraventricular arrhythmia during the active disease phase of the disease and show signs of atrial electrophysiological remodeling in remission. The goal of this study was to determine the basis for colitis-induced changes in atrial excitability. In a mouse model (C57BL/6; 3 months) of dextran sulfate sodium (DSS)-induced active colitis (3.5% weight/volume, 7 days), electrocardiograms (ECG) revealed altered atrial electrophysiological properties with a prolonged P-wave duration and PR interval. ECG changes coincided with a decreased atrial conduction velocity in Langendorff perfused hearts. Action potentials (AP) recorded from isolated atrial myocytes displayed an attenuated maximal upstroke velocity and amplitude during active colitis, as well as a prolonged AP duration (APD). Voltage clamp analysis revealed a colitis-induced shift in the voltage-dependent activation of the Na-current (I_Na) to more depolarizing voltages. In addition, protein levels of Na_v1.5 protein and connexin isoform Cx43 were reduced. APD prolongation depended on a reduction in the transient outward K-current (I_to) mostly generated by K_v4.2 channels. The changes in ECG, atrial conductance, and APD were reversible upon remission. The change in conduction velocity predominantly depended on the reversibility of the reduced Cx43 and Na_v1.5 expression. Treatment of mice with inhibitors of Angiotensin-converting enzyme (ACE) or Angiotensin II (AngII) receptor type 1 (AT1R) prevented the colitis-induced atrial electrophysiological remodeling. Our data support a colitis-induced increase in AngII signaling that promotes atrial electrophysiological remodeling and puts colitis patients at an increased risk for atrial arrhythmia. Full article

Background/Objectives: The establishment of early gut microbiota is crucial for host health. Lactoferrin (LF), which is present in breast milk, positively impacts gut microbiota composition. However, the effect of lactation LF on the establishment and composition of early gut microbiota in different disease models in adulthood remains unclear. Methods: Lactation-LF-deficient mice were established using systemically LF–knocked-out maternal mice. This study assessed the maturity of the gut microbiota in LF feeding-deficient mice in relation to age and changes in the gut microbiota in adult high-fat diet (HFD)-induced obesity, dextran sodium sulfate (DSS)-induced acute colitis, and chronic unpredictable mild stress (CUMS)-induced depression models. Results: Compared to LF intake during lactation, LF deficiency during lactation increased the abundance of potentially pathogenic bacteria in the gut, resulting in abnormal microbial maturation. LF intake during lactation aggravated gut microbiota dysbiosis induced via HFD, DSS, and CUMS in adulthood and may change the function of Enterorhabdus, GCA-900066575, Peptococcus, Tuzzerella, Akkermansia, and Desulfovibrio. Comparing the different models revealed that bacteria that were jointly upregulated via HFD and DSS exhibited increased levels of inflammation and oxidation. LF deficiency during lactation may weaken the association between an HFD and inflammatory bowel disease (IBD). The changing trends in many gut microbes caused by DSS and HFD were opposite to those that changed with age. Conclusions: Lactoferrin deficiency increases the abundance of potential pathogens and disrupts microbial maturation. This lack of LF exacerbates dysbiosis in models of obesity, colitis, and depression. Regulating the gut microbiota according to the rules of microbial succession during the maturation process of gut microbiota may improve gut microbiota dysbiosis in patients with obesity and IBD. Full article

This study investigated the therapeutic potential of Bacillus thuringiensis extracellular polysaccharide BPS-2 in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) murine models. BPS-2 demonstrated significant efficacy in ameliorating UC-associated pathologies through three principal mechanisms: (1) attenuating histopathological damage while preserving colon epithelial integrity, (2) modulating immune marker expression patterns in colon tissues, and (3) restoring gut microbiota homeostasis. BPS-2 exhibited multi-faceted protective effects on the gut by mitigating oxidative stress responses and enhancing short-chain fatty acid biosynthesis, leading to an improved gut microbial community structure. Molecular docking analysis displayed strong binding affinity (ΔG = −7.8 kcal/mol) between the BPS-2U fragment and the Nuclear Factor κB (NF-κB) p50/p65 heterodimer, suggesting the potential disruption of NF-κB signaling pathways. Complementary molecular dynamics simulations revealed exceptional conformational stability in the p65-BPS-2U complex. These findings establish BPS-2 as a natural food additive that modulates the microbiota-barrier–inflammation axis through dietary intervention, offering a novel strategy to alleviate UC. Full article

Enterotoxigenic Bacteroides fragilis (ETBF) promotes colitis-associated cancer through the Bacteroides fragilis toxin (BFT), which induces colonic inflammation that can be exacerbated by external stimuli. We found that BALB/c mice infected with ETBF and treated with azoxymethane and dextran sodium sulfate (DSS) developed numerous distal colon polyps more rapidly than B6 mice, suggesting strain differences in ETBF-induced tumorigenicity. Using a bft gene-deficient ETBF strain, we confirmed BFT’s crucial role in ETBF-promoted tumorigenesis and inflammation. While both 1% and 2% DSS induced comparable polyp formation, 1% DSS minimized mortality, proving sufficient for maximizing polyp development. Mechanistically, BFT-mediated tumorigenesis involves NF-κB/CXCL1 signaling in colonic epithelial cells exposed to BFT and DSS, a pathway known to be critical for inflammation and cancer progression. This model provides a valuable platform for dissecting ETBF’s colitis-associated cancer-promoting mechanisms, particularly those involving BFT, and for evaluating BFT-targeted therapeutic interventions. Full article

Polyphenols are compounds derived from plant-based food possessing numerous biological activities, including inhibiting oxidative stress, suppressing inflammation, and regulating gut microbiota. In this study, we investigated the effects of quinic acid, a phenolic acid from millet, on the regulation of gut microbiota and intestinal inflammation and further discussed the possible mechanism. The results showed that quinic acid could improve the microbiota composition of the feces of patients with inflammatory bowel disease (IBD) by in vitro anaerobic fermentation by increasing the abundance of beneficial genera including Bifidobacterium, Weissella, etc., and decreasing that of harmful genera like Escherichia-Shigella. Quinic acid treatment could alleviate the symptoms of dextran sodium sulfate (DSS)-induced colitis in mice, maintain the intestinal barrier, down-regulate the expression of inflammatory factors such as IL-1β and TNF-α, and inhibit the activation of the MyD88/NF-κB signaling pathway. In addition, quinic acid also improved the diversity of gut microbiota in mice with colitis. Furthermore, pseudo-germ-free colitis mice proved that the effect of quinic acid on intestinal inflammation was diminished after removing most gut microbiota by antibiotic treatment, suggesting that gut microbiota play important roles during the regulation of colitis by quinic acid. In a word, our study verified the regulatory effects of quinic acid on intestinal inflammation, depending on gut microbiota regulation and NF-κB signaling suppression. Full article

Background: Intestinal epithelial barrier (IEB) dysfunction is related to multiple gastrointestinal disorders, notably inflammatory bowel disease (IBD). Betulinic acid (BA), a compound derived from birch bark, has demonstrated potential therapeutic benefits in IBD. Nevertheless, the impact of BA on IEB function has not been fully elucidated. Methods: The current study aimed to explore the potential underlying mechanisms of BA in dextran sodium sulfate (DSS)-induced IBD in mice and co-culture models involving Caco-2/HT29-MTX-E12 cell monolayers or mouse intestinal organoids (IOs) in conjunction with macrophages stimulated by lipopolysaccharide (LPS). Results: In vivo, BA treatment significantly improved body weight and colon length, alleviated disease activity index (DAI) scores, and reduced colonic histopathological injury in IBD mice. In vitro, BA reduced the flux of FITC-dextran; increased the TEER; and decreased the production of IL-6, IL-1β, and TNF-α while increasing IL-10 mRNA levels. Additionally, BA enhanced IEB formation by upregulating ZO-1, occludin (OCLN), and claudin-1 (CLDN1). Molecular docking studies revealed significant docking scores and interactions between BA and PPAR-γ. Moreover, BA significantly upregulated PPAR-γ protein expression, decreased NF-κB and MLC2 phosphorylation, and reduced MLCK protein expression. However, this effect was reversed by GW9662, an effective PPAR-γ antagonist. Conclusions: The findings reveal that BA mitigates IBD by safeguarding the intestinal barrier against dysfunction. This effect may be attributed to its ability to suppress inflammation and enhance the expression of tight junction proteins by modulating the PPAR-γ/NF-κB signaling pathway. Full article

Although the underlying mechanisms are not yet fully understood, vitamin D has been proven to be associated with the pathogenesis of inflammatory bowel disease, participating in immune response and regulating gut microbiota composition. In this study, we established a dextran sodium sulfate-induced colitis model and intervened with vitamin D. Subsequently, colonic histopathology, serum biochemistry, transcription of inflammatory cytokines, gut microbiota, and key signaling pathways were examined. Our research demonstrated that intervention with vitamin D reduced the disease activity index of DSS-induced colitis and improved histopathological changes, protecting tight junction protein ZO-1 and intestinal glands from damage induced by DSS. Analysis of gut microbiota revealed alterations in both α diversity and β diversity in DSS-induced colitis, whereas interventions with active vitamin D corrected the changes in certain bacterial abundance and improved the composition of gut microbiota. The transcription levels of inflammatory cytokines, including IL-23, IL-1β, IFN-γ, IL-6, IL-17, and STING, were elevated in the DSS-induced colitis model. However, intervention with active vitamin D effectively suppressed the transcription of these factors. Finally, immunohistochemistry and Western blotting revealed that the intervention with vitamin D suppressed the expression of proteins associated with the STING pathway, including GATA1, STING, IRF3, and IKBα, leading to inhibition of downstream IFN-β production. Vitamin D administration can ameliorate the severity of DSS-induced colitis by preserving intestinal barrier integrity, modulating gut microbiota composition through suppression of the STING pathway. Full article

A growing body of evidence suggests the potent anti-inflammatory properties of the newly discovered arm of the renin–angiotensin–aldosterone system, ACE2/Ang-(1–7)/MasR, in various disease conditions. Our group was the first to report the anti-inflammatory properties of the Ang-(1–7) polypeptide in the murine dextran sulfate sodium (DSS) colitis model. Both its short half-life and high degradation rate limit the clinical use of Ang-(1–7). One way to compensate for these limitations is through the use of the non-peptide MasR agonist AVE0991. Herein, we aimed to study the anti-inflammatory effects of AVE0991 using the DSS model and the possible synergistic effects with other clinically available medications. Colitis severity was determined using both prophylactic and treatment approaches by gross anatomical and histological assessments and daily weight changes. The colonic expression level/activity of various pro-inflammatory and adhesion molecules was determined by western blotting, immunofluorescence, and proteomic profiling. We showed that AVE0991 treatment significantly reduced colitis severity more effectively with the prophylactic than the treatment approach. An additive anti-inflammatory effect was observed in the combination regimen with AVE0991 plus azathioprine, which was mediated through an increased colonic expression level of mucins and focal adhesion kinase, decreased colonic activity of p38 MAPK and Akt, and decreased colonic expression level of various pro-inflammatory mediators. In conclusion, these data suggest a promising potential for the non-peptide MasR agonist AVE0991 in the treatment of inflammatory bowel disease. Full article

Saccharomyces boulardii (S. boulardii) has attracted widespread attention due to its antimicrobial and anti-inflammatory properties. In this study, we prepared postbiotics from the heat-inactivated cells (HIC) and cell-free supernatant (CFS) of S. boulardii, with the important component L-arginine (Arg) from the metabolic products included as one of the experimental groups. The results showed that in LPS-stimulated Caco-2 cells, HIC, CFS, and Arg protect intestinal epithelial barrier integrity by inhibiting the expression of TNF-α, IL-1β, and IL-6 while enhancing the expression of occludin and ZO-1 proteins. In dextran sulfate sodium (DSS)-induced colitis mice, HIC, CFS, and Arg alleviate symptoms such as weight loss and colonic damage while suppressing the upregulation of pro-inflammatory factors and the downregulation of tight junction proteins. Moreover, these postbiotics help restore the gut microbiota composition and functionality in colitis mice, with potentially superior regulatory effects compared to sulfasalazine (SASP). Overall, HIC and CFS protect the intestinal barrier function and improve DSS-induced colitis, supporting the development of functional food supplements. Full article