Search Results (838)

Background and Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is now widely acknowledged as belonging to the broader category of metabolic disorders, being closely associated with obesity, insulin resistance, and chronic systemic inflammation. Recent evidence indicates that in MASLD, alterations in the gut–liver axis—particularly increased intestinal permeability may serve as a crucial mechanistic link between metabolic dysfunction and hepatic steatosis. Zonulin, a physiological modulator of intestinal tight junctions, has been suggested as an indicator of compromised barrier integrity; however, its specific role in MASLD remains to be fully elucidated. Materials and Methods: We conducted a prospective observational study including 52 adult patients diagnosed with MASLD. Hepatic steatosis was evaluated using the SteatoTest (FibroMax panel), while fecal zonulin levels were measured by ELISA at baseline. Clinical, anthropometric, and metabolic parameters were assessed. We used ROC curve analysis to explore zonulin’s predictive value for moderate-to-severe steatosis (≥S2). Results: Elevated fecal zonulin (>107 ng/mL) occurred in 26.9% of participants. In a binary logistic model with SteatoTest ≥ S2 as outcome, zonulin was independently associated with clinically significant steatosis (OR per 1 ng/mL = 1.017; 95% CI 1.002–1.032; p = 0.029). Discrimination for ≥S2 was AUC = 0.680 (95% CI 0.535–0.825; p = 0.015). The Youden-optimal cut-off was 57.0 ng/mL (sensitivity 68.2%, specificity 63.3%) versus 40.9%/83.3% at the manufacturer’s 107 ng/mL threshold. Conclusions: Fecal zonulin shows modest discriminatory ability for steatosis and is best used as an adjunct to non-invasive assessment; cohort-specific calibration (57.0 ng/mL) outperformed the generic 107 ng/mL threshold. Full article

Type 2 diabetes (T2D) is a complex metabolic disease characterized by chronic hyperglycemia due to insulin resistance and inadequate insulin secretion. Beyond the classically implicated organs, emerging evidence highlights the gut as a central player in T2D pathophysiology through its interactions with metabolic organs. The gut hosts trillions of microbes and enteroendocrine cells that influence inflammation, energy homeostasis, and hormone regulation. Disruptions in gut homeostasis (dysbiosis and increased permeability) have been linked to obesity, insulin resistance, and β-cell dysfunction, suggesting multifaceted “Gut-X axes” contribute to T2D development. We aimed to comprehensively review the evidence for gut-mediated crosstalk with the pancreas, endocrine system, liver, and kidneys in T2D. Key molecular mechanisms (incretins, bile acids, short-chain fatty acids, endotoxins, etc.) were examined to construct an integrated model of how gut-derived signals modulate metabolic and inflammatory pathways across organs. We also discuss clinical implications of targeting Gut-X axes and identify knowledge gaps and future research directions. A literature search (2015–2025) was conducted in PubMed, Scopus, and Web of Science, following PRISMA guidelines (Preferred Reporting Items for Systematic Reviews). Over 150 high-impact publications (original research and review articles from Nature, Cell, Gut, Diabetologia, Lancet Diabetes & Endocrinology, etc.) were screened. Data on gut microbiota, enteroendocrine hormones, inflammatory mediators, and organ-specific outcomes in T2D were extracted. The GRADE framework was used informally to prioritize high-quality evidence (e.g., human trials and meta-analyses) in formulating conclusions. T2D involves perturbations in multiple Gut-X axes. This review first outlines gut homeostasis and T2D pathogenesis, then dissects each axis: (1) Gut–Pancreas Axis: how incretin hormones (GLP-1 and GIP) and microbial metabolites affect insulin/glucagon secretion and β-cell health; (2) Gut–Endocrine Axis: enteroendocrine signals (e.g., PYY and ghrelin) and neural pathways that link the gut with appetite regulation, adipose tissue, and systemic metabolism; (3) Gut–Liver Axis: the role of microbiota-modified bile acids (FXR/TGR5 pathways) and bacterial endotoxins in non-alcoholic fatty liver disease (NAFLD) and hepatic insulin resistance; (4) Gut–Kidney Axis: how gut-derived toxins and nutrient handling intersect with diabetic kidney disease and how incretin-based and SGLT2 inhibitor therapies leverage gut–kidney communication. Shared mechanisms (microbial SCFAs improving insulin sensitivity, LPS driving inflammation via TLR4, and aryl hydrocarbon receptor ligands modulating immunity) are synthesized into a unified model. An integrated understanding of Gut-X axes reveals new opportunities for treating and preventing T2D. Modulating the gut microbiome and its metabolites (through diet, pharmaceuticals, or microbiota therapies) can improve glycemic control and ameliorate complications by simultaneously influencing pancreatic islet function, hepatic metabolism, and systemic inflammation. However, translating these insights into clinical practice requires addressing gaps with robust human studies. This review provides a state-of-the-art synthesis for researchers and clinicians, underlining the gut as a nexus for multi-organ metabolic regulation in T2D and a fertile target for next-generation therapies. Full article

The gut microbiota is recognized as one of the extrinsic factors that modulate the clinical outcomes of immune checkpoint inhibitors (ICIs), such as inhibitors targeting programmed cell death protein 1 (PD-1), in cancer patients. However, the link between intestinal barrier, which mutually interacts with the gut microbiota, and therapeutic effects has not been extensively studied so far. Therefore, the primary goal of this study was to investigate the relationship between intestinal barrier functionality and clinical outcomes of anti-PD-1 therapy in patients with advanced melanoma. Fecal samples were collected from 64 patients before and during anti-PD-1 therapy. The levels of zonulin, calprotectin, and secretory immunoglobulin A (SIgA), which reflect intestinal permeability, inflammation, and immunity, respectively, were measured in fecal samples (n = 115) using an Enzyme-Linked Immunosorbent Assay (ELISA). Moreover, the composition of the immunoglobulin (Ig)-bound (n = 108) and total stool microbiota (n = 117) was determined by the V3–V4 region of 16S rRNA gene sequencing. ELISA indicated a higher baseline concentration of fecal SIgA in patients with favorable clinical outcomes than those with unfavorable ones. Moreover, high baseline concentrations of intestinal barrier state biomarkers correlated with survival outcomes. In the cases of fecal zonulin and fecal SIgA, there was a positive correlation, while in the case of fecal calprotectin, there was a negative correlation. Furthermore, there were differences in the microbial profiles of the Ig-bound stool microbiota between patients with favorable and unfavorable clinical outcomes and their changes during treatment. Collectively, these findings indicate an association between intestinal barrier functionality and clinical outcomes of anti-PD-1 therapy in advanced melanoma patients. Full article

Microbial metabolites offer a multitude of mechanisms for alleviating diabetes, particularly type 2 diabetes (T2D). However, the metabolites of yeasts recognised as safe remain under-explored and are receiving less attention in the treatment of T2D. In addition to the recognised probiotic status of certain yeasts, their genetic feature is responsible for many of the effects observed. Branched and non-branched short-chain fatty acids, bioactive peptides, carotenoids, and polysaccharides (β-glucans, mannans, and peptides derived from them) have vital properties that modulate intestinal permeability, soothe inflammation, and directly influence insulin sensitivity. Their action mechanism ranges from hepatic lipogenesis via the induction of hormone-sensitive lipase and the inhibition of α-glucosidase or DPP-IV to promoting the secretion of GLP-1 (Glucagon-Like Peptide-1) and GIP (Gastric Inhibitory Polypeptide), orchestrating immune modulation, and nourishing the gut microbiota. The richness of the yeast metabolome suggests that a concentrated fermentate could be developed to potentiate the functional effects in vitro in the treatment of T2D. The purpose of this review is to take stock of the current state of knowledge of probiotic yeast metabolites and outline their potential for the treatment of diabetes via the development of food supplements or nutraceuticals. Full article

Emerging evidence suggests a critical role of the gut microbiome in modulating systemic immune responses, with increasing relevance in dermatological diseases. Chronic spontaneous urticaria (CSU), traditionally viewed as an isolated cutaneous disorder, is now recognized as a systemic immune condition involving complex interactions between innate and adaptive immunity, mast cell dysregulation, and non-IgE-mediated pathways. This review explores the gut–skin axis as a unifying concept linking intestinal dysbiosis to inflammatory skin diseases, including atopic dermatitis, psoriasis, rosacea, and acne. Special emphasis is placed on CSU, where altered gut microbial composition, characterized by reduced diversity, depletion of short-chain fatty acid-producing bacteria, and expansion of Proteobacteria, may contribute to increased intestinal permeability, systemic immune activation via toll-like receptors, and heightened mast cell sensitivity. We discuss findings from animal models demonstrating that gut microbiota modulation can attenuate mast cell hyperreactivity and reduce urticarial symptoms. In parallel, we examine clinical evidence supporting the potential role of probiotics, prebiotics, dietary interventions, and fecal microbiota transplantation as adjunctive strategies in CSU management. Despite promising findings, challenges remain in translating microbiome research into effective therapies due to interindividual variability, the complexity of host–microbiome interactions, and a lack of standardized protocols. Future research should focus on identifying predictive microbial patterns and developing personalized microbiome-targeted interventions. Understanding the bidirectional gut–skin relationship may open new therapeutic avenues beyond symptomatic treatment, positioning the microbiome as a novel target in CSU and related inflammatory dermatoses. Full article

Background/Objectives: Gut microbial dysbiosis, leaky gut, and increased transepithelial translocation of commensal bacteria have been documented in multiple sclerosis (MS). Intrathecal IgGs specific for Akkermansia muciniphila, a gut bacterium, are increased in patients with MS and associated with clinical disability. Our objective here was to explore the putative involvement of intrathecal anti-A. muciniphila IgG in MS pathogenesis by characterizing patients with different anti-A. muciniphila IgG indices. Methods: Serum and intrathecal IgG specific for A. muciniphila and other gut bacteria, as well as routine cerebrospinal fluid (CSF) parameters, were measured in 61 patients with MS. Examination of these patients included immunophenotyping of CSF-infiltrating and paired circulating lymphocytes, intrathecal markers of neurodegeneration and inflammation, and a detailed characterization of demographic, clinical, and magnetic resonance imaging (MRI) features. Results: Plasma blasts (p < 0.01), B cells (p < 0.01), and Th2 cells (p < 0.01), which might be involved in antibody production, were increased in the CSF of these patients, as well as blood pro-inflammatory Th17 cells (p < 0.05). Anti-A. muciniphila IgG indices were negatively associated with blood-brain barrier (BBB) permeability and circulating monocytes (p < 0.001), and positively with brain lesion load (p < 0.01). Conclusions: The differences between patients with low and high anti-A. muciniphila IgG indexes regarding BBB permeability, CSF cell infiltrates, and pro-inflammatory peripheral immune cells, as well as imaging features, support a role of anti-A. muciniphila immune response in MS pathogenesis. Full article

Obesity, type 2 diabetes mellitus (T2DM) and steatohepatitis associated with metabolic dysfunction (MASLD) are on the rise and pose serious health challenges worldwide. In recent years, researchers have gained a better understanding of the important role of the gut microbiota in the development and progression of these diseases. Intestinal dysbiosis can contribute to the occurrence of increased intestinal permeability, inflammation and reduced numbers of commensal bacteria. In obesity, these changes contribute to chronic low-grade inflammation and deregulated metabolism. In MASLD, gut microbiota dysbiosis can promote liver fibrosis and impair bile acid metabolism, while in T2DM, they are associated with impaired glycemic control and insulin resistance. Regular physical activity has a positive effect on the composition of the gut microbiota, increasing its diversity, modulating its metabolic functions, strengthening the intestinal barrier and reducing inflammation. These findings suggest that exercise and microbiota-targeted interventions may play an important role in the prevention and treatment of metabolic diseases. Full article

This review introduces a novel integrative framework linking gut dysbiosis, systemic inflammation, and cardiovascular risk in patients with inflammatory bowel disease (IBD). We highlight emerging biomarkers, including short-chain fatty acids (SCFAs), calprotectin, and zonulin, that reflect alterations in the gut microbiome and increased intestinal permeability, which contribute to cardiovascular pathology. Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality worldwide, and recent evidence identifies IBD, encompassing ulcerative colitis (UC) and Crohn’s disease (CD), as a significant non-traditional risk factor for CVD. This review synthesizes current knowledge on how dysbiosis-driven inflammation in IBD patients exacerbates endothelial dysfunction, hypercoagulability, and atherosclerosis, even in the absence of traditional risk factors. Additionally, we discuss how commonly used IBD therapies may modulate cardiovascular risk. Understanding these multifactorial mechanisms and validating reliable biomarkers are essential for improving cardiovascular risk stratification and guiding targeted prevention strategies in this vulnerable population. Full article

Suckling is crucial for piglet intestinal development and gut health, as it improves resilience during the challenging weaning phase and promotes subsequent growth. IPS, comprising Na⁺/K⁺ ions, whey protein, and glucose, has been shown to have positive effects on animal growth and intestinal health. The objectives of this study were to assess the impact of IPS consumption on the growth performance, immunity, intestinal growth and development, and microbiota structure of suckling piglets. A total of 160 newborn piglets were randomly divided into control and IPS groups, with IPS supplementation starting from 2 to 8 days after birth and continuing until 3 days before weaning. The findings revealed that IPS boosted the body weight at 24 days by 3.6% (p < 0.05) and improved the body weight gain from 16 to 24 days by 15.7% (p < 0.05). Additionally, the jejunal villus height and villus height to crypt depth ratio in the IPS group were notably increased to 1.08 and 1.31 times (p < 0.05), respectively, compared to the control group. Furthermore, IPS elevated the plasma levels of IgA and IgM, reduced the plasma levels of blood urea nitrogen (BUN), and enhanced the content of secretory immunoglobulin A (SIgA) in the jejunal mucosa of suckling piglets. Furthermore, IPS upregulated the mRNA expression of tight junction proteins GLP-2, ZO-1, and Claudin-1 in jejunal tissue, while downregulating the regulatory genes in the Toll-like pathway, including MyD88 and TLR-4 (p < 0.05). The analysis of gut microbiota indicated that IPS altered the relative abundance of gut microbes, with an increase in beneficial bacteria like Alloprevotella and Bacteroides. In conclusion, this study demonstrates that IPS supplementation enhances weaning weight, growth performance, immune function, and intestinal development in piglets, supporting the integration of IPS supplementation in the management of pre-weaning piglets. Full article

Background/Objectives: Autism spectrum disorder (ASD) encompasses several neurodevelopmental disorders, whose onset is correlated to genetic and environmental factors. Although the etiopathogenesis is not entirely clear, the involvement of inflammatory processes, the endocannabinoid system, and alterations in the permeability and composition of the intestinal microbiota are known to occur. Methods: This review systematically explores the literature available to date on the most widely used murine models for the study of ASD, the main biomarkers investigated for the diagnosis of ASD, and the therapeutic potential of probiotics, with a particular focus on the use of strains of Lactiplantibacillus (Lpb.) plantarum in in vivo models and clinical trials for ASD. Results: Several studies have demonstrated that targeting multifactorial biomarkers in animal models and patients contributes to a more comprehensive understanding of the complex mechanisms underlying ASD. Moreover, accumulating evidence supports the beneficial effect of probiotics, including Lpb. plantarum, as a promising alternative therapeutic strategy, capable of modulating gut–brain axis communication. Conclusions: Probiotic supplementation, particularly with selected Lpb. plantarum strains, is emerging as a potential complementary approach for ameliorating ASD-related gastrointestinal and behavioral symptoms. However, further large-scale clinical studies are essential to validate their efficacy and determine optimal treatment protocols and dietary strategies. Full article

Accurate in vitro models of intestinal permeability are essential for predicting oral drug absorption. Standard models like Caco-2 cells have well-known limitations, including lack of segment-specific physiology, but are widely used. Emerging models such as organoid-derived monolayers and microphysiological systems (MPS) offer enhanced physiological relevance but require comparative validation. We performed a head-to-head evaluation of Caco-2 cells, human jejunal (J2) and duodenal (D109) enteroid-derived cells, and EpiIntestinal^TM tissues cultured on either static Transwell and flow-based MPS platforms. We assessed tissue morphology, barrier function (TEER, dextran leakage), and permeability of three model small molecules (caffeine, propranolol, and indomethacin), integrating the data into a physiologically based gut absorption model (PECAT) to predict human oral bioavailability. J2 and D109 cells demonstrated more physiologically relevant morphology and higher TEER than Caco-2 cells, while the EpiIntestinal^TM model exhibited thicker and more uneven tissue structures with lower TEER and higher passive permeability. MPS cultures offered modest improvements in epithelial architecture but introduced greater variability, especially with enteroid-derived cells. Predictions of human fraction absorbed (F_abs) were most accurate when using static Caco-2 data with segment-specific corrections based on enteroid-derived values, highlighting the utility of combining traditional and advanced in vitro gut models to optimize predictive performance for F_abs. While MPS and enteroid-based systems provide physiological advantages, standard static models remain robust and predictive when used with in silico modeling. Our findings support the need for further refinement of enteroid-MPS integration and advocate for standardized benchmarking across gut model systems to improve translational relevance in drug development and regulatory reviews. Full article

The balance between physiological, psychological, and environmental factors often shapes human experience. In recent years, research has drawn attention to the gut microbiota as a significant contributor to brain function and emotional regulation. This narrative review examines how changes in gut microbiota may relate to depression. We selected studies that explore the link between intestinal dysbiosis and mood, focusing on mechanisms such as inflammation, vagus nerve signaling, HPA axis activation, gut permeability, and neurotransmitter balance. Most of the available data come from animal models, but findings from human studies suggest similar patterns. Findings are somewhat difficult to compare due to differences in measurement procedures and patient groups. However, several microbial shifts have been observed in people with depressive symptoms, and trials with probiotics or fecal microbiota transplant show potential. These results remain limited. We argue that these interventions deserve more attention, especially in cases of treatment-resistant or inflammation-driven depression. Understanding how the gut and brain interact could help define clearer subtypes of depression and guide new treatment approaches. Full article

The intestinal barrier governs organismal health through nutrient absorption, microbial homeostasis, and immune surveillance. While calorie restriction (CR) enhances metabolic health, the molecular mechanisms underlying its beneficial effects on gut integrity remain unclear. Here, we demonstrate that the aryl hydrocarbon receptor (AHR), a conserved xenobiotic sensor and metabolic regulator, is essential for CR-mediated improvements in intestinal function. Using Caenorhabditis elegans (C. elegans), we subjected wild-type (N2) and AHR-deficient strains (CZ2485 and ZG24) to ad libitum feeding (AL), intermittent fasting (IF), or complete food deprivation (FD). In wild-type animals, intermittent fasting markedly reduced intestinal permeability and bacterial burden while enhancing mitochondrial function and reducing reactive oxygen species. Complete food deprivation conferred modest benefits. Remarkably, these protective effects were severely compromised in AHR mutants, which exhibited increased gut leakage, bacterial colonization, and mitochondrial oxidative stress under fasting conditions. These findings establish AHR as a critical mediator of fasting-induced intestinal resilience, revealing a previously unrecognized regulatory axis linking metabolic sensing to gut barrier homeostasis. Our work illuminates fundamental mechanisms through which calorie restriction promotes gastrointestinal health and identifies AHR-dependent pathways as promising therapeutic targets for metabolic and inflammatory distress affecting the gut–systemic interface. Full article

Emerging evidence suggests a bidirectional relationship between gut microbiota, melatonin synthesis, and breast cancer (BC) development in hormone receptor-positive patients (HR+HER2+ and HR+HER2-). This study investigated alterations in gut microbiota composition, the serum serotonin–N-acetylserotonin (NAS)–melatonin axis, fecal short-chain fatty acids (SCFAs) and beta-glucuronidase (βGD) activity, and serum zonulin in HR+ BC patients compared to healthy controls. Blood and fecal samples were analyzed using mass spectrometry for serotonin, NAS, melatonin, and SCFAs; ELISA for AANAT, ASMT, 14-3-3 protein, and zonulin; fluorometric assay for βGD activity; and 16S rRNA sequencing for gut microbiota composition. HR+ BC patients exhibited gut dysbiosis with reduced Bifidobacterium longum and increased Bacteroides eggerthii, alongside elevated fecal βGD activity, SCFA levels (e.g., isovaleric acid), and serum zonulin, indicating increased intestinal permeability. Serum serotonin and N-acetylserotonin (NAS) levels were elevated, while melatonin levels were reduced, with a higher NAS/melatonin ratio in BC patients. AANAT levels were increased, and ASMT levels were decreased, suggesting disrupted melatonin synthesis. Bifidobacterium longum positively correlated with melatonin and negatively with βGD activity, while Bacteroides eggerthii showed a positive correlation with βGD activity. These findings suggested that gut microbiota alterations, disrupted melatonin synthesis, microbial metabolism, and intestinal permeability may contribute to BC pathophysiology. The NAS/melatonin ratio could represent a potential biomarker, necessitating further mechanistic studies to confirm causality and explore therapeutic interventions. Full article

Background/Objectives: Colitis is a chronic condition affecting millions worldwide. Purple muscadine wine polyphenols have a unique composition and possible disease-preventive properties. This study aims to determine how dealcoholized muscadine wine (DMW) affects the development of colitis and gut microbiome in IL-10^−/− mice, compared to wild types (WT). Methods: Six-week-old male IL-10^−/− and WT C57BL/6 mice were fed either a DMW-supplemented diet (4.8% v/w) or a control diet based on AIN-93M for 154 days. Colitis severity was evaluated by disease activity, intestinal permeability, gene expression of cytokines and tight junction proteins in the colon, and inflammatory cytokines in the serum. Fecal samples were collected for gut microbiome profiling via 16S rRNA gene sequencing. Results: DMW contained predominantly anthocyanins and a significant amount of ellagic acid. IL-10^−/− mice developed mild colitis as indicated by the disease activity index. DMW × gene interactions decreased intestinal permeability, colonic mRNA levels of IL-1β, and serum TNF-α in the IL-10^−/− mice. DMW suppressed the colonic mRNA levels of IL-6, enhanced the gene expression of ZO-1, but did not influence the mRNA level of TNF-α or occludin. While DMW did not alter α-diversity of the gut microbiome, it significantly influenced β-diversity in the WT mice. DMW significantly reduced the relative abundances of Akkermansia in the IL-10^−/− and WT mice. DMW and DMW×gene interaction decreased the relative abundance of Parasutterella only in IL-10^−/− mice. Conclusions: These results suggested that polyphenols from DMW interacted with genes to moderately alleviate the development of colitis in IL-10^−/− mice and could be a useful dietary strategy for IBD prevention. Full article