Search Results (2,178)

Background: The early-life gut microbiota plays a critical role in programming intestinal barrier function and immune homeostasis, with profound implications for long-term host health. However, the effects of early-life compound probiotic intervention on the maturation of intestinal barrier function and the underlying molecular mechanisms remain incompletely understood, particularly in large-animal models relevant to human physiology. Methods: In this preclinical study, 3627 neonatal piglets—a well-established translational model for human infant gut development—were orally administered a novel compound probiotic formulation comprising Bifidobacterium longum subsp. infantis BZ, Lactobacillus plantarum LZ, and Pediococcus acidilactici PZ during early life. A total of 1512 fecal samples collected at seven time points from birth to day 180 were analyzed by 16S rRNA sequencing, and 525 samples from three developmental windows (days 10, 25, and 70) were subjected to LC-MS-based metabolomics. The candidate metabolite indole-3-lactic acid (ILA) was further mechanistically validated in a DSS-induced colitis mouse model and in IPEC-J2 cells. Results: Early-life probiotic intervention significantly enhanced intestinal barrier integrity, as evidenced by improved intestinal morphology and upregulated expression of tight junction proteins—zonula occludens-1 (ZO-1), occludin (OCLN), and Claudin-1 (CLDN1)—in the jejunum (p < 0.05). Notably, intervention at birth was more effective than post-weaning administration, and two administrations (birth + weaning) yielded superior outcomes compared with a single administration (p < 0.05). Microbiome analysis revealed enhanced microbial diversity and enrichment of beneficial genera during the juvenile-to-adult transition (p < 0.05). Metabolomic profiling identified ILA as a signature metabolite consistently elevated by probiotic supplementation. Conclusions: These findings provide evidence that early-life compound probiotic intervention is associated with improved intestinal barrier maturation, with ILA identified as a key candidate metabolite that may mediate this effect, as supported by functional validation in murine and cellular models. This provides a mechanistic rationale for probiotic-based strategies to support intestinal health in human infants during critical developmental windows. Full article

This study evaluated the effects of oligomeric ultrafine-nano hydrogen water (OUHW) on production performance, egg quality, egg nutrient deposition, systemic metabolism, intestinal barrier function, and reproductive status in late-laying hens. Unlike conventional hydrogen-rich water, which primarily delivers molecular hydrogen dissolved in water, OUHW integrates oligomeric water with ultrafine-nano-sized hydrogen bubbles, providing a distinct physicochemical form of hydrogen-water intervention. A total of 288 healthy 67-week-old Jingfen No. 8 laying hens were assigned to 2 treatments with 6 independent replicates per treatment (24 hens per replicate) and provided with either tap water or OUHW for 11 weeks. Compared with the control, OUHW reduced the feed conversion ratio and the rates of manure-spotting while increasing the laying rate, qualified egg rate, and total egg number during weeks 5–8 (p < 0.05). These productive and egg quality improvements were phase-specific effects observed in the late laying stage during the 11-week trial. At week 4, OUHW significantly increased egg weight (p < 0.05). At week 8, OUHW also improved eggshell compressive elastic deformation, eggshell thickness, albumen height, and Haugh unit (p < 0.05). At week 6, eggs from OUHW-treated hens had higher concentrations of glutamate, glycine, alanine, C18:0, C18:1n9c, C20:4n6, and C22:6n3 (p < 0.05). Serum metabolomics showed that 25 differential metabolites from the OUHW treatment group were predominantly enriched in glycerophospholipid, sphingolipid, branched-chain amino acid, histidine, and tryptophan metabolism. In the cecum, OUHW decreased p-cresol and increased isovaleric acid and acetic acid (p < 0.05). Notably, the overall community structures of the cecal and oviductal microbiota exhibited no significant treatment-related alterations, indicating limited structural changes in the microbial communities in response to the OUHW intervention. OUHW also reduced interleukin-2 and tumor necrosis factor-α, increased interleukin-10 in the jejunum and oviductal isthmus (p < 0.05), and upregulated the mRNA expression of ovarian steroidogenic acute regulatory protein and intestinal Occludin, Claudin-1, and Mucin-2 (p < 0.05). These findings indicate that OUHW improved laying performance, egg quality, and egg nutrient deposition, possibly through modulation of the metabolism, intestinal barrier function, ovarian function, and oviductal inflammation. Full article

Gut-derived indole metabolites are implicated in the gut–kidney axis, but the factors controlling the intestinal conversion of indole-3-acetic acid (IAA) to skatole remain incompletely defined. We developed a deterministic, hypothesis-generating framework that represents this conversion as a finite-pool allocation process governed by $\mathrm{pH}$-dependent ecological permissiveness, terminal-conversion capacity, precursor availability, spatial progression, and competing loss. The model separates the available-pool scale from a dimensionless integrated conversion exposure, $\Psi$. Across 5400 loss-free scenarios spanning 10 pH profiles and graded metabolic and host-associated constraints, the distal endpoint normalized to the available pool followed the analytically derived relationship $1-\exp \left(-\Psi \right)$. Thus, distinct combinations of mechanistically relevant parameters produced the same normalized distal endpoint, demonstrating that this endpoint alone cannot uniquely identify the underlying mechanism. Competing loss further separated absolute, total-pool-normalized, and conditional outputs, showing that mechanistic interpretation depends on endpoint normalization. Analytical and numerical checks supported internal consistency. The framework was not fitted to biological data, and concentration values were used only as technical scaling references. This biologically unvalidated model generates experimentally testable hypotheses regarding the roles of $\mathrm{pH}$, terminal-conversion capacity, precursor availability, and competing loss in intestinal IAA-to-skatole metabolism; it is not intended to provide physiological or clinical predictions. Full article

Aflatoxin B1 (AFB1) is a potent foodborne mycotoxin classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC) and is widely recognized for its causal role in hepatocellular carcinoma (HCC). Beyond its well-established hepatotoxicity, increasing evidence indicates that AFB1 also disrupts intestinal homeostasis by impairing epithelial barrier integrity, reducing mucus production, altering gut microbial composition, and disturbing microbial metabolism. These changes promote increased intestinal permeability, facilitating the translocation of bacteria and microbial products and contributing to chronic inflammation through the gut–liver axis. Recent experimental studies further suggest that alterations in short-chain fatty acid (SCFA) production and microbiota-dependent signaling pathways may actively mediate AFB1-induced intestinal and hepatic injury. Although direct evidence linking AFB1-induced dysbiosis to extrahepatic carcinogenesis remains limited, growing evidence indicates that persistent barrier dysfunction, microbial imbalance, and chronic inflammation may create a microenvironment favorable for tumor initiation and progression in tissues beyond the liver. This review critically summarizes current evidence regarding the effects of AFB1 on intestinal barrier function, gut microbiota dysbiosis, bacterial translocation, microbial metabolites, and the gut–liver axis while evaluating the mechanistic evidence supporting these interactions and highlighting the major knowledge gaps that should be addressed in future research. Full article

Background: Hyperlipidemia is a major risk factor for cardiometabolic disorders, including non-alcoholic fatty liver disease (NAFLD), and is closely associated with oxidative stress. Opuntia ficus-indica (OFI) cladodes are recognized as a rich source of bioactive phytochemicals; however, the molecular mechanisms underlying their metabolic benefits remain incompletely understood. Objectives: This study aimed to comprehensively evaluate the hypolipidemic and hepatoprotective potential of a polyphenol-rich O. ficus-indica cladode extract (OCE) using an integrated approach combining in vivo evaluation, untargeted metabolomics (UHPLC-Orbitrap-MS/MS), molecular docking, and ADMET prediction. Methods: Hyperlipidemic mice fed a high-fat diet (HFD) were treated with OCE, while molecular docking was performed on ten major annotated phytochemicals against twelve key proteins involved in lipid metabolism and cholesterol homeostasis, including HMGCR, FAS, PPARα, PCSK9, and NPC1L1, using simvastatin as the reference compound. Results: OCE treatment significantly improved plasma and hepatic lipid profiles, improved glucose homeostasis, and markedly reduced hepatic malondialdehyde (MDA) levels, indicating attenuation of oxidative stress. Histopathological analysis further supported a pronounced hepatoprotective effect, with a substantial reduction in hepatic steatosis. Untargeted metabolomics enabled the annotation of 102 metabolites, putatively identifying piscidic acid as the predominant phenolic constituent together with a diverse profile of flavonoids and phenolic acids. Molecular docking supported the potential contribution of these phytochemicals to the regulation of lipid metabolism through favorable interactions with multiple therapeutic targets, while ADMET prediction suggested an overall favorable pharmacokinetic and toxicity profile despite the lower intestinal permeability predicted for glycosylated derivatives. Conclusions: Overall, these findings support O. ficus-indica cladodes as a promising source of dietary bioactive compounds with potential applications in the nutritional management and prevention of hyperlipidemia and related cardiometabolic disorders. Full article

Hepatocellular carcinoma (HCC) remains a major global health challenge and one of the leading causes of cancer-related mortality, with advanced disease continuing to be associated with limited therapeutic options and substantial heterogeneity in response to systemic treatment. Recent evidence has established the gut microbiota, through the gut–liver axis, as a critical determinant of immunotherapy efficacy, while also influencing antitumor immunity and liver carcinogenesis. Microbial dysbiosis may promote chronic inflammation, intestinal barrier disruption, bacterial translocation, and immune dysfunction, thereby contributing to hepatocarcinogenesis. Moreover, gut microbial composition and microbial-derived metabolites, including bile acids, short-chain fatty acids (SCFAs), and inosine, have been associated with modulation of antitumor immune responses and differential outcomes to immune checkpoint inhibitors (ICIs). Emerging clinical evidence in HCC has identified distinct gut microbial signatures associated with response to nivolumab, pembrolizumab, and atezolizumab-based regimens, including enrichment of Akkermansia muciniphila and SCFA-producing taxa such as Ruminococcaceae, Roseburia, and Prevotella in responders. However, these findings remain inconsistent across studies, with no reproducible microbial signature identified because of small cohort sizes, heterogeneous patient populations, geographic variation, cirrhosis-related confounding factors, and methodological differences in microbiome analysis. This review summarizes the current understanding of microbiome–immune interactions in HCC, examines mechanistic pathways linking the microbiota to immunotherapy response, critically evaluates available clinical evidence, and discusses current limitations and future therapeutic strategies, including fecal microbiota transplantation, probiotics, dietary modulation, and engineered bacterial platforms. Collectively, microbiome-based approaches may contribute to the development of personalized immunotherapeutic strategies in HCC, although larger standardized prospective studies are required before microbiome-derived biomarkers can be implemented in routine clinical practice. Full article

Piglets’ early weaning frequently encounters intestinal dysfunction and diarrhea that results in growth retardation and even mortality. We previously found Cortex Phellodendri extract (CPE) could relieve post-weaning piglets’ diarrhea whereas the underlying mechanism remains unclear. Here, to explore the mechanism, 126 piglets were allotted into three groups of seven replicates fed with basal diet, or basal diet + 0.04% CPE, or basal diet + 0.08% CPE. We found 0.04% CPE supplementation effectively decreased piglets’ fecal scores on d7 and d14 post-weaning. In addition, CPE supplementation improved growth performance of early weaning piglets during days 8–14. Further analysis showed CPE supplementation improved the jejunum morphology and increased antioxidant indices, whereas it reduced oxidative metabolites in jejunum tissue. Meanwhile, CPE supplementation increased the mRNA levels of antioxidant indices and anti-inflammatory cytokines but decreased the mRNA levels of inflammatory cytokines. CPE supplementation shifted gut microbiota and increased alpha diversity indices, namely the Observed species and Abundance-Based Coverage Estimator indices. CPE supplementation increased the relative abundances of Proteobacteria, SMB53, Flexispira, and Ruminococcus_gnavus, but decreased the relative abundances of Parabacteroides and Sutterella. The gut microbiota shifted by CPE supplementation has a significant correlation with the early weaning-related indices. Overall, CPE supplementation alleviated intestinal oxidative stress, inflammation, and microbiota dysbiosis in early weaning piglets. Full article

The intestinal epithelium is a dynamic tissue renewed by intestinal stem cells (ISCs) within the crypt niche. ISC behavior is regulated not only by intrinsic genetic programs but also by dietary composition, nutrient availability, microbial metabolites, and feeding rhythms. This narrative review synthesizes mechanisms through which diet influences ISC self-renewal, proliferation, differentiation, metabolic programming, and regenerative capacity. Dietary patterns exert context-dependent effects: caloric restriction, fasting, and structured feeding–fasting cycles may enhance epithelial regeneration through nutrient-sensing pathways, mitochondrial adaptation, and circadian regulation, whereas Western-type and high-fat diets may promote niche remodeling, inflammation, metabolic reprogramming, and tumorigenic risk. Macronutrients regulate ISC fate through carbohydrate metabolism, amino acid sensing, fatty acid oxidation, and lipid-derived signaling molecules. Micronutrients, including vitamins A, D, and B and minerals such as iron, zinc, selenium, and magnesium, contribute to epithelial differentiation, redox balance, and barrier integrity. Phytochemicals may modulate ISC function through Wnt/β-catenin, Nrf2, SIRT1, and epigenetic pathways or by stabilizing the epithelial microenvironment. The gut microbiota mediates diet–ISC interactions via short-chain fatty acids, bile acids, indole derivatives, and other metabolites. However, human evidence remains limited, and studies integrating human organoids, single-cell analyses, metabolomics, and chrononutrition are needed to inform personalized nutritional strategies for intestinal health. Full article

Quercetin is one of the most abundant plant flavonoids and an intensively studied bioactive compound belonging to the class of functional heterocyclic compounds with outstanding biological activities, due to its numerous biological, pharmacological and therapeutic effects. This paper presents the main information on the chemical structure, dietary sources, absorption, metabolism and bioavailability of quercetin, highlighting the role of the intestinal microbiota in the formation of metabolites responsible for an important part of its effects. The limitations related to stability and bioavailability are analyzed as well as modern formulation strategies and advanced delivery systems aimed at improving the efficacy of the compound. The major biological activities of quercetin are also summarized, including antioxidant, anti-inflammatory, immunomodulatory, antiviral, cardioprotective, neuroprotective, metabolic and anticancer effects. Unlike previous reviews, which have generally addressed these topics separately, the present work integrates the gut-microbiota-mediated metabolism, cellular senescence, advanced delivery systems, combined therapies, and safety and regulatory considerations within a unified translational framework. Overall, this review emphasizes the need to relate the multifunctional biological potential of quercetin to its pharmacokinetic limitations, formulation performance and clinically achievable exposure while highlighting the need for standardized formulations and further clinical studies to validate its therapeutic benefits. Full article

Depression is defined by clinical symptoms, but its biology varies considerably among patients. In this review, dietary tryptophan allocation describes the routes taken by tryptophan after intestinal absorption. Some is incorporated into proteins. Some enters serotonin and melatonin synthesis or the kynurenine pathway, while gut bacteria convert another fraction into indole compounds. Brain availability also depends on the circulating free pool and competition with other large neutral amino acids. This term does not imply a new biochemical pathway. It allows these known processes to be considered in relation to inflammation, metabolism, the gut microbiota, medication use, and current disease state. Recent meta-analyses indicate that peripheral tryptophan is lower in depression. They do not show a consistent increase in the kynurenine-to-tryptophan ratio, and findings from cerebrospinal fluid vary between studies. Human multiomics studies have associated microbial and metabolite profiles with cognition and response to treatment, although the evidence remains largely correlational. Changes in kynurenine, 3-hydroxykynurenine, and quinolinic acid are more apparent in inflammatory subgroups than in unselected samples. Modern evidence for L-tryptophan monotherapy is sparse. Trials of 5-hydroxytryptophan and interventions directed at the gut microbiota have also produced mixed results. Studies should characterize participants and sampling conditions more carefully. Diet and competition among amino acids need to be recorded. Albumin concentration, medication exposure, and disease state also affect interpretation. Considering these variables together may improve biomarker analyses and support trials in more biologically homogeneous groups. Dietary tryptophan allocation is proposed for these research purposes, not for clinical diagnosis or routine supplementation. Full article

Stroke remains one of the leading causes of death and long-term neurological disability worldwide, while currently available therapeutic strategies are limited by narrow treatment windows and incomplete neuroprotection. In this context, plant-derived polyphenols have attracted increasing attention as potential adjunctive agents because of their multimodal biological activity. This review focuses on resveratrol and curcumin, two of the most extensively investigated polyphenols, and evaluates their potential role in the prevention and treatment of ischaemic and haemorrhagic stroke. Evidence from in vitro studies, animal models, and early clinical trials indicates that both compounds may attenuate key mechanisms involved in stroke-related brain injury, including oxidative stress, neuroinflammation, mitochondrial dysfunction, apoptosis, autophagy dysregulation, blood–brain barrier disruption, and microglial activation. Emerging evidence further suggests that interactions with the gut microbiota and modulation of the gut–brain axis may contribute to their biological effects by influencing intestinal barrier integrity, microbial metabolite production, systemic inflammation, and vascular risk. Preclinical studies show that resveratrol and curcumin can reduce infarct volume, limit cerebral oedema, preserve neuronal viability, promote angiogenesis and neurogenesis, and improve neurological and cognitive outcomes. Their beneficial effects have been reported both when administered before stroke onset and after cerebral injury, suggesting potential relevance for both prevention and post-stroke therapy. However, interpretation of these findings requires consideration of the translational limitations of experimental stroke models, which do not fully reproduce the heterogeneity, comorbidities, age profile, and variable reperfusion patterns characteristic of human stroke. Although commonly used models such as middle cerebral artery occlusion provide important mechanistic and therapeutic insights, preclinical efficacy should therefore not be regarded as a direct predictor of clinical benefit. Resveratrol and curcumin may also complement established and emerging treatment strategies, including thrombolysis, endovascular interventions, antihypertensive therapy, and stem cell-based approaches. Nevertheless, their clinical translation remains limited by poor solubility, low bioavailability, rapid metabolism, and insufficient clinical evidence. Novel formulations, including nanoparticles, exosome-based delivery systems, and structurally modified analogues, may help overcome these barriers by improving brain targeting and therapeutic efficacy. Overall, resveratrol and curcumin represent promising but still investigational candidates for adjunctive stroke therapy, requiring further well-designed clinical trials to define their optimal dosing, timing, safety, and clinical value. Full article

Diarrhea-predominant irritable bowel syndrome (IBS-D) frequently occurs alongside depression, greatly impairing patients’ life quality, with limited targeted treatments. Low-molecular-weight peptides (LMWPs) from Musca domestica larvae exert gut-protective bioactivities, but their efficacy and molecular mechanisms for comorbid IBS-D and depression remain unelucidated. A chronic–acute combined stress (CACS)-induced rat model of IBS-D complicated with depression was established and treated with LMWPs. The study evaluated intestinal and depressive behavioral phenotypes, and integrated 16S rRNA sequencing, untargeted serum metabolomics and quantitative detection of fecal SCFAs for multi-omics correlation analysis. 1. CACS triggered typical comorbid symptoms, which LMWPs alleviated with effects similar to trimebutine maleate. 2. LMWP treatment was associated with reshaped gut microbiota, restored metabolic pathways, altered levels of 27 disease-associated serum metabolites, and increased fecal SCFA levels. 3. Multi-omics correlation analyses suggested that the therapeutic benefits may involve crosstalk among gut microbiota, SCFAs, and tryptophan metabolites. Larva-derived LMWP relieves IBS-D combined with depression by modulating gut microecology, SCFA generation and serum metabolic balance through the gut–brain axis, which can serve as a novel promising therapeutic candidate. Full article

Global poultry consumption continues to rise, while worldwide bans on in-feed antibiotic growth promoters raise an urgent requirement for eco-friendly alternatives to guarantee production efficiency and food safety. Probiotics, live beneficial microorganisms that improve host intestinal health, are reviewed. We elaborate four core functional pathways of probiotics: competitive exclusion of pathogens, enhancement of intestinal barrier integrity, immune modulation and regulation of microbial metabolites such as short-chain fatty acids. Their mitigating effects against heat stress, suboptimal rearing environments, mycotoxin contamination, heavy metal exposure and immune stress are analyzed. We further evaluate the capacity of single and compound probiotics to control major poultry diseases. Early-life intervention strategies and innovative preparations (multistrain probiotics, synbiotics, postbiotics) are systematically summarized. Critical bottlenecks restricting industrial translation are highlighted, including empirical strain combination, non-standardized administration protocols, divergent evaluation indicators and single-factor laboratory challenge models inconsistent with actual farm conditions. Finally, we propose future research directions covering multi-omics-assisted strain screening, optimized delivery technology, unified industrial quality control standards and field verification under compound stress. This review offers integrated references for mechanistic research, strain development and precise industrial application of probiotics in sustainable antibiotic-free poultry breeding. Full article

Background/Objectives: Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder influenced by environmental factors including cold stress. While cold exposure exacerbates intestinal inflammation, the specific microbial metabolites linking environmental stress to colitis remain unclear. 3-Hydroxypropionate (3-HPA) is a gut microbial metabolite elevated following cold exposure, but its pathogenic role in intestinal inflammation has not been investigated. This study aimed to determine whether 3-HPA contributes to colitis progression and to characterize its effects on gut microbiota and intestinal epithelial function. Methods: We employed a dextran sulfate sodium (DSS)-induced colitis mouse model to assess the impact of cold exposure and exogenous 3-HPA administration. Paired shotgun metagenomic and metabolomic analyses were performed to evaluate gut microbial composition and metabolic outputs. Mechanistic studies using NCM460 intestinal epithelial cells were conducted to examine mitochondrial respiration and tight junction integrity under nutrient-limited conditions. Results: Cold exposure increased fecal 3-HPA levels and aggravated DSS-induced colitis, characterized by enhanced weight loss, histological damage, and immune cell infiltration. Direct 3-HPA supplementation alone was sufficient to worsen colitis severity. Multi-omics profiling revealed that 3-HPA reshaped gut microbiota composition, depleted short-chain fatty acids (SCFAs), and disrupted microbial tryptophan and bile acid metabolism. In vitro, 3-HPA impaired mitochondrial oxidative phosphorylation, reduced ATP production, and compromised tight junction organization in intestinal epithelial cells. Conclusions: These findings identify 3-HPA as a gut microbial metabolite elevated by cold exposure that contributes to colitis progression by disrupting beneficial microbial metabolism while also impairing epithelial mitochondrial function and barrier integrity. Modulating 3-HPA production or its downstream epithelial effects may represent a potential therapeutic approach for IBD exacerbated by environmental stress. Full article

Background: Microbiome-based mechanisms have emerged as a key area of investigation in epilepsy, given the growing recognition that gut microbial communities can modulate central nervous system (CNS) function through the gut–brain axis. Epilepsy is a common chronic neurological disorder affecting more than 65 million people worldwide, and despite the availability of anti-seizure medications (ASMs), approximately 30% of patients develop drug-resistant epilepsy. Current ASMs primarily suppress seizures rather than prevent disease progression, highlighting the need for alternative therapeutic strategies. In this context, increasing evidence supports a role for microbiota-dependent pathways in modulating seizure activity and treatment responsiveness. However, the mechanistic basis of these interactions remains incompletely understood. Methods: This narrative review synthesizes findings from the existing literature to examine the role of microbiota-derived metabolites, including neurotransmitters, vitamins, and the polyphenol metabolite S-equol, in gut–brain communication relevant to epilepsy. Evidence was drawn from both preclinical animal models and clinical studies to provide an integrated, mechanistic perspective on how these pathways may influence central nervous system function and seizure susceptibility. Emphasis was placed on studies describing molecular, metabolic, and signaling mechanisms linking the gut microbiome to epileptogenesis and treatment response. Results: Current evidence indicates that communication between the gut and CNS occurs through neural pathways, such as the vagus nerve, as well as through circulating microbial metabolites. These metabolites can cross the intestinal barrier and, in some cases, the blood–brain barrier (BBB), serving as key mediators of host–microbiota signaling. Emerging studies suggest that while some microbial metabolites may directly influence neuronal hyperexcitability and seizure susceptibility, others likely exert secondary or modulatory effects through broader metabolic and immune pathways. However, the precise mechanisms underlying these interactions remain incompletely understood. Conclusions: Some microbial-derived metabolites may serve as promising biomarkers and mechanistic mediators of epilepsy; however, further investigation is needed to define the molecular and cellular pathways through which these metabolites influence seizure susceptibility and epileptogenesis. Full article