Search Results (1,463)

Celiac disease (CeD) is a chronic immune-mediated enteropathy triggered by dietary gluten in genetically predisposed individuals which also entails intestinal dysbiosis. This hallmark microbial imbalance provides a rationale for exploring interventions that could modulate the gut ecosystem. Cocoa is a bioactive food rich in polyphenols, theobromine, and fiber, compounds known to have an influence on both immune function and gut microbiota composition. Here, we investigated the effects of cocoa supplementation on the gut microbial profile and predicted functionality in DQ8-D^d-villin-IL-15tg mice, genetically predisposed to CeD. Animals were assigned to a reference group receiving a gluten-free diet (GFD), a gluten-containing diet group (GLI), or the latter supplemented with defatted cocoa (GLI + COCOA) for 25 days. The cecal microbiota was analyzed via 16S rRNA sequencing, and functional pathways were inferred using PICRUSt2. Goblet cell counts and CeD-relevant autoantibodies were measured and correlated with microbial taxa. Cocoa supplementation partially attenuated gluten-induced dysbiosis, preserving beneficial taxa such as Akkermansia muciniphila and Lactobacillus species while reducing opportunistic and pro-inflammatory bacteria. Functional predictions suggested differences in the predicted microbial metabolic potential related to amino acid, vitamin, and phenolic compound metabolism. Cocoa also mitigated goblet cell loss and was inversely associated with anti-gliadin IgA levels. These findings suggest that cocoa, as an adjuvant to a GFD, could be of help in maintaining microbial homeostasis and intestinal health in CeD, supporting further studies to assess its translational potential. Full article

Background and Objectives: Clinically meaningful drug–drug interactions may be overlooked in oncology. Proton pump inhibitors (PPIs) may modulate outcomes with immune checkpoint inhibitors (ICIs) by altering the gut microbiome, altering the immune milieu, and affecting transporter interactions. We evaluated whether concomitant PPI use affects survival among patients with metastatic non-small cell lung cancer (NSCLC) treated with nivolumab. Materials and Methods: We retrospectively included patients with metastatic NSCLC who received second-line nivolumab across five oncology centers (January 2020–June 2023). Patients were grouped as concomitant PPI users vs. non-users. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan–Meier method and compared with the log-rank test; multivariable Cox models assessed independent associations. Results: A total of 194 patients were screened, of whom 30 were excluded according to predefined criteria. The final analysis included 164 patients—85 PPI users and 79 non-users. Median OS was 26.1 months (95% CI 15.5–36.7) in PPI users and 29.3 months (22.2–36.4) in non-users; this difference was not statistically significant (p = 0.54). Median PFS was 6.2 months (3.7–8.6) in PPI users vs. 10.2 months (7.1–13.2) in non-users (p = 0.04). In multivariable analysis, absence of concomitant PPI use (No vs. Yes) was independently associated with longer PFS (HR = 0.52, 95% CI 0.24–0.89, p = 0.03), whereas PPI use was not associated with OS (HR = 0.96, 95% CI 0.67–1.61, p = 0.83). Conclusions: Concomitant PPI use during nivolumab therapy was associated with significantly shorter PFS and a numerical reduction in OS in real-world metastatic NSCLC. Where clinically feasible, the need for PPIs should be re-evaluated before and during ICI therapy. Full article

Early life is a critical window for immune system development, during which the gut microbiome shapes innate immunity, antigen presentation, and adaptive immune maturation. Disruptions in microbial colonization—driven by factors such as cesarean delivery, antibiotic exposure, and formula feeding—deplete beneficial early-life taxa (e.g., Bifidobacterium, Bacteroides, and Enterococcus) and impair key microbial functions, including short-chain fatty acid (SCFA) production by these keystone species, alongside regulatory T cell induction. These dysbiosis patterns are associated with an increased risk of pediatric autoimmune diseases, notably type 1 diabetes, inflammatory bowel disease, celiac disease, and juvenile idiopathic arthritis. This review synthesizes current evidence on how the early-life microbiota influences immune maturation, with potential effects on the development of autoimmune diseases later in life. We specifically focus on human observational and intervention studies, where treatments with probiotics, synbiotics, vaginal microbial transfer, or maternal fecal microbiota transplantations have been shown to partially restore a disrupted microbiome. While restoration of the gut microbiome composition and function is the main reported outcome of these studies, to date, no reports have disclosed direct prevention of autoimmune disease development by targeting the early-life gut microbiome. In this regard, a better understanding of the early-life microbiome–immune axis is essential for developing targeted preventive strategies. Future research must prioritize longitudinal evaluation of autoimmune outcomes after microbiome modulation to reduce the burden of chronic immune-mediated diseases. Full article

Nickel allergy remains the most prevalent cause of allergic contact dermatitis worldwide, imposing a substantial socio-epidemiological and economic burden. Beyond its classical cutaneous presentation, systemic nickel allergy syndrome highlights the systemic dimension of Nickel hypersensitivity, wherein dietary nickel intake may provoke both gastrointestinal and cutaneous symptoms through mechanisms involving gut barrier impairment and mucosal immune priming. Recent evidence highlights the contribution of angiogenesis and lymph-angiogenesis to Nickel-induced allergic contact dermatitis, through crosstalk among keratinocytes, mast cells, endothelial cells, and pro-angiogenic mediators such as vascular endothelial growth factor. Against this background, we propose to revisit palmitoylethanolamide, an endogenous ALIAmide with well-documented anti-inflammatory, anti-angiogenic, and anti-allergic properties. Already studied in pain and inflammatory disorders and employed in veterinary dermatology, palmitoylethanolamide down-modulates mast cell degranulation, suppresses VEGF expression via PPAR-α/Akt/mTOR signaling, and enhances intestinal barrier integrity, acting as a promising “gatekeeper” molecule that reduces gut hyperpermeability characterizing systemic nickel allergy as well as other gut disorders with systemic consequences. This paper is presented as a viewpoint intended to highlight the untapped therapeutic potential of palmitoylethanolamide, suitable for both oral and topical administration, as a candidate to address the multifactorial pathophysiology of Nickel allergic contact dermatitis and systemic nickel allergy. Our purpose is not to provide definitive answers, but to stimulate scientific debate on its rational use within emerging gut–skin therapeutic strategies. We thus encourage future experimental and clinical studies to explore its potential integration within emerging gut–skin therapeutic paradigms. Full article

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by abdominal pain, altered motility, and visceral hypersensitivity. Emerging evidence implicates G protein-coupled receptors (GPCRs) as key integrators of microbial, immune, endocrine, and neural signals in IBS pathophysiology. This review summarizes recent advances in understanding how GPCRs mediate gut immune regulation, microbiota–host crosstalk, metabolic signaling, and pain processing in IBS. Recent studies show that microbial metabolites (e.g., short-chain fatty acids, biogenic amines, and lipid mediators) signal through GPCRs on immune cells, epithelia, and neurons to influence intestinal homeostasis. On immune cells and neurons, GPCRs also mediate signals from external substances (such as fats, sugars, histamine, etc.) to regulate immune and neural functions. And there are challenges and future directions in targeting GPCRs for IBS, including patient heterogeneity and the complexity of host–microbiome interactions. This review provides a mechanistic framework for GPCR-based therapies in IBS. Full article

Berberine (BBR), a protoberberine alkaloid with a long history of medicinal use, has consistently demonstrated benefits in glucose–lipid metabolism and inflammatory balance across both preclinical and human studies. These diverse effects are not mediated by a single molecular target but by BBR’s capacity to restore network coordination among metabolic, immune, and microbial systems. At the core of this regulation is an AMP-activated Protein Kinase (AMPK)-centered mechanistic hub, integrating signals from insulin and nutrient sensing, Sirtuin 1/3 (SIRT1/3)-mediated mitochondrial adaptation, and inflammatory pathways such as nuclear Factor Kappa-light-chain-enhancer of Activated B cells (NF-κB) and NOD-, LRR- and Pyrin Domain-containing Protein 3 (NLRP3). This hub is dynamically regulated by system-level inputs from the gut, mitochondria, and epigenome, which in turn strengthen intestinal barrier function, reshape microbial and bile-acid metabolites, improve redox balance, and potentially reverse the epigenetic imprint of metabolic stress. These interactions propagate through multi-organ axes, linking the gut, liver, adipose, and vascular systems, thus aligning local metabolic adjustments with systemic homeostasis. Within this framework, BBR functions as a negentropic modulator, reducing metabolic entropy by fostering a coordinated balance among these interconnected systems, thereby restoring physiological order. Combination strategies, such as pairing BBR with metformin, Sodium-Glucose Cotransporter 2 (SGLT2) inhibitors, and agents targeting the microbiome or inflammation, have shown enhanced efficacy and substantial translational potential. Berberine ursodeoxycholate (HTD1801), an ionic-salt derivative of BBR currently in Phase III trials and directly compared with dapagliflozin, exemplifies the therapeutic promise of such approaches. Within the hub–axis paradigm, BBR emerges as a systems-level modulator that recouples energy, immune, and microbial circuits to drive multi-organ remodeling. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a continuum of hepatic pathological manifestations of the metabolic syndrome. Pathogenesis is not clearly understood despite recent progress, but Kupffer cells and bone marrow-derived macrophages (BMDMs) have a fundamental role. In this review, the multiple pathophysiological aspects of MASLD are presented, including genetics, insulin resistance, lipotoxicity, and inflammation. The participation of innate and adaptive immunity, as well as the implications of the recently described trained immunity, is presented. The interplay of the liver with the gut microbiota is also analyzed. A recent adipocentric theory and the various mechanisms of hepatocyte death are also described. The fundamental role of Kupffer cells and other liver macrophages is discussed in detail, including their extreme phenotypic plasticity in both the normal and the MASLD liver. The functional differentiation between pro-inflammatory and anti-inflammatory subpopulations and their protective or detrimental involvement is further described, including the participation of Kupffer cells and BMDMs in all aspects of MASLD pathogenesis. The role of macrophages in the development of advanced MASLD, including fibrosis and hepatocellular carcinoma, is analyzed and the lack of explanation for the transition from MASLD to MASH is recognized. Finally, current modalities of drug treatment are briefly presented and the effects of different drugs on macrophage polarization and functions are discussed. Full article

Background: Gut barrier dysfunction and altered gut microbial metabolism are emerging signatures of chronic gut disorders. Considering growing interest in combining structurally and mechanistically distinct bioactives, we investigated the individual and combined effects of serum-derived bovine immunoglobulin (SBI) and N-acetylglucosamine (NAG) on the gut microbiome and barrier integrity. Methods: The validated ex vivo SIFR^® (Systemic Intestinal Fermentation Research) technology, using microbiota from healthy adults (n = 6), was combined with a co-culture of epithelial/immune (Caco-2/THP-1) cells. Results: While SBI and NAG already significantly improved gut barrier integrity (TEER, transepithelial electrical resistance, +21% and +29%, respectively), the strongest effect was observed for SBI_NAG (+36%). This potent combined effect related to the observation that SBI and NAG each induced distinct, complementary shifts in microbial composition and metabolite output. SBI most selectively increased propionate (~Bacteroidota families) and health-associated indole derivatives (e.g., indole-3-propionic acid), while NAG most specifically boosted acetate and butyrate (~Bifidobacteriaceae, Ruminococcaceae, and Lachnospiraceae). The combination of SBI_NAG displayed effects of the individual ingredients, thus, for instance, enhancing all three short-chain fatty acids (SCFA) and elevating microbial diversity (CMS, community modulation score). Conclusions: Overall, SBI and NAG exert complementary, metabolically balanced effects on the gut microbiota, supporting combined use, particularly in individuals with gut barrier impairment or dysbiosis linked to lifestyle or early-stage gastrointestinal disorders. Full article

The enteric nervous system (ENS) constitutes a highly organized and intricate neuronal network comprising two principal plexuses: myenteric and submucosal. These plexuses consist of neurons and enteric glial cells (EGCs). Neurons ensure innervation throughout the intestinal wall, whereas EGCs, distributed within the mucosa, contribute to epithelial barrier integrity and modulation of local inflammatory responses. The ENS orchestrates essential gastrointestinal functions, including motility, secretion, absorption, vascular regulation, and immune interactions with gut microbiota. Under physiological conditions, intestinal homeostasis involves moderate generation of reactive oxygen species (ROS) through endogenous processes such as mitochondrial oxidative phosphorylation. Cellular antioxidant systems maintain redox equilibrium; however, excessive ROS production induces oxidative stress, promoting EGCs activation toward a reactive phenotype characterized by pro-inflammatory cytokine release. This disrupts neuron–glia communication, predisposing to enteric neuroinflammation and neurodegeneration. Obesity, associated with hyperglycemia, hyperlipidemia, and micronutrient deficiencies, enhances ROS generation and inflammatory cascades, thereby impairing ENS integrity. Nevertheless, non-pharmacological strategies—including synthetic and natural antioxidants, bioactive dietary compounds, probiotics, and prebiotics—attenuate oxidative and inflammatory damage. This review summarizes preclinical and clinical evidence elucidating the interplay among the ENS, obesity-induced oxidative stress, inflammation, and the modulatory effects of antioxidant interventions. Full article

Background/Objectives: The gut microbiome influences melanoma biology and response to immune checkpoint inhibitors. Dietary fiber is a key modifiable factor that shapes the microbial composition and metabolite production. This review summarizes mechanistic, preclinical, and clinical evidence describing how fiber and fiber-responsive taxa may affect melanoma immunity and treatment outcomes. Methods: A literature search of MEDLINE, Embase, and Scopus identified studies published within the past five years examining dietary fiber, gut microbiome interactions, immune modulation, or melanoma outcomes. After screening 491 unique records, 49 peer-reviewed mechanistic, preclinical, observational, and interventional studies were synthesized qualitatively in this narrative review. Results: Fiber fermentation produces short-chain fatty acids that regulate dendritic cell activation, T-cell priming, and cytokine signaling. Preclinical melanoma models show that fibers such as inulin and β-glucan enhance IFN-γ-driven antitumor immunity, increase CD8⁺ infiltration, and improve checkpoint blockade efficacy in a microbiota-dependent manner. In humans, fiber-rich diets and enrichment of taxa such as Bifidobacterium, Faecalibacterium, and Akkermansia are associated with improved PD-1 inhibitor responses, longer progression-free survival, and possible reductions in ICI-related colitis. Although epidemiologic studies suggest no clear association between fiber intake and melanoma incidence, dietary fiber intake appears to correlate strongly with treatment-related outcomes. Conclusions: Dietary fiber represents a potentially safe and plausible adjunct to melanoma immunotherapy. However, study variability and emerging counterevidence highlight the need for controlled trials to clarify causality and define optimal fiber-based interventions. Full article

The intestinal barrier is essential for gastrointestinal and systemic homeostasis by enabling nutrient absorption while limiting the translocation of pathogens and toxins. When barrier function is impaired, bacterial components such as lipopolysaccharides (LPSs) may cross the epithelium and promote inflammatory signaling. In dogs, chronic inflammatory enteropathies are frequent disorders associated with barrier dysfunction, dysbiosis, and immune dysregulation, and may progress to protein-losing enteropathy or systemic inflammation. Humic substances, particularly humic acid (HA), are natural organic compounds with reported antioxidative, immunomodulatory, and barrier-supporting effects; however, the cellular mechanisms underlying these effects in intestinal and immune models remain insufficiently characterized. This study evaluated the effects of a commercially available HA-based supplement on epithelial barrier integrity and inflammatory responses using an in vitro system combining IPEC-J2 intestinal epithelial cells and primary canine peripheral blood mononuclear cells (PBMCs). Epithelial barrier integrity (FD4 paracellular flux), reactive oxygen species, and cytokine production (TNF-α, IL-6) were assessed under basal and LPS-stimulated conditions. HA treatment preserved epithelial barrier function and reduced LPS-induced pro-inflammatory cytokine production, supporting further investigation of HA as a nutraceutical adjunct for gut health support in dogs with chronic enteropathies. Full article

Repeat-in-toxin (RTX) toxins are calcium-dependent exoproteins secreted by diverse Gram-negative bacteria and play central roles in cytotoxicity, immune modulation, and tissue colonization. While their structure and secretion mechanisms are well-characterized, the regulation of RTX toxin expression remains complex and species-specific. This review provides a comprehensive overview of the regulatory networks governing RTX gene expression, highlighting both conserved mechanisms and niche-specific adaptations. RTX genes are controlled by multilayered regulatory systems that integrate global transcriptional control, metabolic regulation, and environmental sensing. Expression is further shaped by host-derived signals, physical contact with host cells, and population-dependent cues. Quorum sensing, post-transcriptional regulation by small RNAs, and post-translational activation mechanisms contribute additional layers of control to ensure precise regulation of toxin production. We also explore how RTX regulation varies across anatomical niches, including the gut, lung, bloodstream, and biofilms, and how it is co-regulated with broader bacterial virulence. Finally, we discuss emerging insights from omics-based approaches and the potential of anti-virulence strategies targeting RTX regulatory pathways. Together, these topics underscore RTX regulation as a model for adaptive virulence control in bacterial pathogens. Full article

Since there is currently no cure for Parkinson’s disease, pharmacobiotic approaches based on gut microbiota—capable of producing pharmacologically active compounds—are under development. In this study, we propose LfU21, derived from the strain Limosilactobacillus fermentum U-21, as a candidate pharmacobiotic. To evaluate its efficacy, a combined LPS- and lactacystin (LAC)-induced Parkinson’s disease model was established in Wistar rats. Effects were assessed using behavioral, biochemical, immunomodulatory, and transcriptomic biomarkers. LfU21 administration reduced α-synuclein levels, altered motor performance in the “Rung ladder” test, and modulated bdnf gene expression in the right and left striata. Under LPS exposure, LfU21 prevented alterations in immune response markers, GSH levels, drd2 and bdnf gene expression, and intestinal goblet cell counts. In LAC and LAC + LPS groups, LfU21 mitigated the rise in α-synuclein, the decline in bdnf expression, and behavioral deficits in the “Open Field” and “Rung ladder” tests, respectively. The multifunctional activity of LfU21 in a combined Parkinson’s disease model underscores its therapeutic potential and helps identify a target patient cohort for future clinical trials. Full article

Gliomas, particularly glioblastoma multiforme, remain among the most lethal brain tumours despite multimodal therapy. Increasing evidence indicates that systemic factors, including the gut microbiota, may influence glioma progression through immune, metabolic, and neurochemical pathways. We conducted a comprehensive systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines to synthesize recent evidence on the role of gut and intratumoral microbiota in glioma biology. Peer-reviewed studies published within the last five years were identified through structured searches of major biomedical databases, and original studies using human cohorts, animal models, or Mendelian randomization approaches were included. The 17 studies met the eligibility criteria. Glioma was consistently associated with gut dysbiosis characterized by a reduced Firmicutes:Bacteroidetes ratio and enrichment of Verrucomicrobia, particularly Akkermansia, alongside decreased short-chain fatty acids and altered neurotransmitter profiles, contributing to neuroinflammation, immune suppression, and blood–brain barrier dysfunction. Antigenic mimicry by Bacteroidetes-derived peptides may impair antitumour T-cell responses, while intratumoral Fusobacteriota and Proteobacteria appear to promote angiogenesis and pro-inflammatory chemokine expression. In contrast, SCFA-producing taxa such as Ruminococcaceae and probiotic genera including Lactobacillus and Bifidobacterium show protective associations. Evidence is limited by small cohorts and methodological heterogeneity. Standardized humanized models and integrated multi-omics approaches are required to clarify causal mechanisms and support microbiome-targeted therapies in glioma. Full article

Vaccination is a tool to control Lawsonia intracellularis (LI) in pigs. However, pigs may have co-infections that worsen clinical signs and lesions. The aim of this study was to characterize systemic and gut-mediated humoral and cell-mediated immune (CMI) responses in pigs vaccinated with a killed intramuscular LI vaccine and to analyze the impact of co-infection with Brachyspira hyodysenteriae (Bhyo) on the immune response. The study included eighty pigs and five study groups: V-CO (LI-vaccinated and co-infected with LI + Bhyo, n = 21), P-CO (placebo and co-infected with LI + Bhyo, n = 18), V-LI (LI-vaccinated and infected with LI, n = 21), P-LI (placebo and infected with LI, n = 12), and NC (negative control, placebo and non-challenged, n = 8). Parameters analyzed: fecal score and pathogen shedding), gross intestinal lesions, LI intestinal colonization (IHC), serum IgG, LI-specific IFN-γ production (ELISPOT), and immune cell subsets (flow cytometry) in blood, mesenteric lymph nodes, Peyer’s patches, and intestinal epithelium. LI vaccination significantly reduced LI fecal shedding, intestinal colonization, and macroscopic lesions—even under Bhyo co-infection. Vaccinated pigs had earlier and stronger serum IgG and IFN-γ responses. B cells seem to play an important role in the local immune response, and T regulatory cells apparently do not have a significant role in immunomodulation. This study contributes to a better understanding of LI immune response and can provide subtract for further research in the control of LI. Full article