Search Results (153)

Kawasaki disease (KD) represents the foremost cause of acquired pediatric heart disease, with coronary artery injury being the principal factor contributing to adverse prognoses. A significant clinical challenge is that 20–30% of patients demonstrate resistance to intravenous immunoglobulin (IVIG), which markedly elevates the risk of coronary artery lesions and long-term cardiovascular sequelae. Consequently, there is an urgent need to investigate novel pathogenic mechanisms beyond the conventional cytokine storm theory and to identify effective therapeutic targets. This review systematically summarizes the key role of the autophagy–inflammation axis in KD vasculopathy. Current evidence indicates that defective mitophagy and lysosomal dysfunction induce mitochondrial DNA release, resulting in overactivation of the NLRP3 inflammasome and cGAS-STING pathways, which amplify inflammatory responses and aggravate endothelial damage. The regulation of this axis is dynamic during both the acute and recovery phases and is influenced by metabolic reprogramming and epigenetic modifications, which may partially explain the lack of response to IVIG. Pharmacological agents, such as rapamycin and metformin, as well as natural compounds, such as resveratrol and urolithin A, have demonstrated beneficial anti-inflammatory effects in preclinical studies. Targeting the autophagy–inflammation axis represents a significant research direction with the potential to evolve into a promising therapeutic strategy. Mechanistically, restoring the balance of the autophagy–inflammation axis holds promise for mitigating coronary complications and improving long-term cardiovascular outcomes in children with KD; however, this prospect requires validation through prospective clinical studies. Full article

Polyphenols act in humans through authentic metabolites, including regio-isomeric glucuronides/sulphates, O-methylated forms, and microbiota products (urolithins, γ-valerolactones, equol), that reach targets by spatiotemporally gated exposure. Vectorial transport (MRP2/BCRP/P-gp), enterohepatic cycling, and β-glucuronidase hubs create early, surface-proximal microbursts of aglycone/catechol, whereas microbiota metabolites arrive systemically 6–24 h later. Signalling emerges from a continuum of weak noncovalent modulation, conditionally gated electrophile/redox relays (catechol → o-quinone, reversible Michael adduction plus signalling-range H₂O₂), and PTM cascades (phosphorylation → acylation → proteostasis) that reprogram NRF2/Keap1, NF-κB/IKK, AMPK/MAPK/PI3K-Akt, SIRT1/HDACs, PPARγ, AhR, and TFEB according to where and when metabolites appear. We provide methods and standards to dose isomer-resolved metabolites at physiological free concentrations (nM-low µM) in transport-competent systems, with PK-informed sampling across seconds–minutes, 15/60/240 min, and 6–24 h, and we outline a research agenda (reference panels, spatial exposure atlases, metabotype-stratified trials, safety windows). Framed this way, polyphenols shift from vague “antioxidants” to programmable dietary signals that enable precision nutrition targeting transcription-factor and proteostasis programmes in vivo. Full article

Circadian desynchronization is increasingly linked to metabolic, immune, neurocognitive, and oncological disease, but integrated clinical phenotyping across endocrine, microbiome, metabolic, and neuroimaging domains remains limited. We conducted a prospective, single-centre, observational study in 179 symptomatic patients referred for chronic multisystem features consistent with circadian dysregulation and 107 practically healthy controls. Circadian melatonin status was assessed using fractionated 24 h urinary 6-sulfatoxymelatonin (aMT6s) and standardized dim-light plasma sampling at daytime (14:00–16:00) and nocturnal (02:00–04:00) windows. Microbiome composition was assessed by 16S rRNA sequencing, urolithin A by targeted metabolomics, and putative glymphatic/perivascular clearance by MRI-derived DTI-ALPS index, perivascular space scoring, and white-matter-hyperintensity (WMH) volumetry. Patients showed markedly reduced nocturnal melatonin output and loss of day–night contrast (night aMT6s 10.2 vs. 40.6 ng/mL; urinary aMT6s day/night ratio 0.81 vs. 0.14; plasma nocturnal melatonin 12.7 vs. 54.4 pg/mL; all p < 0.0001), accompanied by altered cortisol day–night patterning. Patients also showed reduced microbiome diversity, depletion of Gordonibacter and Ellagibacter, lower plasma urolithin A, higher WMH volume and perivascular space scores, and a lower DTI-ALPS index. Age distributions broadly overlapped in the individual-level dataset, and key biomarkers were not significantly correlated with chronological age within the patient cohort; however, this finding is interpreted as an exploratory absence of detectable age gradient within the symptomatic cohort, not as proof of biological age-independence. Overall, the data support a coherent cross-sectional association among blunted nocturnal melatonin rhythmicity, dysbiosis/urolithin depletion, and MRI markers compatible with impaired perivascular clearance. The MGM axis framework should be regarded as hypothesis-generating; causal direction, melatonin receptor involvement, and AQP4-related mechanisms require longitudinal and mechanistic validation. Full article

Background/Objectives: Chronic low-grade inflammation, underpinned by persistent activation of the NLRP3 inflammasome, is a central pathological mechanism in non-communicable diseases including cardiovascular disease, type 2 diabetes, inflammatory bowel disease, and neurodegeneration. Dietary polyphenols have been consistently associated with reduced inflammatory burden; however, the mechanisms underlying these effects remain incompletely understood. This review aims to characterize the gut microbiota–polyphenol–NLRP3 inflammasome axis as a central regulatory network through which diet modulates innate immune signaling and chronic inflammatory tone. Methods: A comprehensive narrative review of the available literature was conducted, integrating evidence from mechanistic studies in cell culture and animal models, microbiome research, metabolomics, and human epidemiological and interventional data. Results: The gut microbiota emerges as a critical biochemical intermediary that transforms dietary polyphenols into bioactive metabolites, including urolithins, phenyl-γ-valerolactones, protocatechuic acid, and short-chain fatty acids, with enhanced bioavailability and potent inflammasome-modulating properties. These compounds suppress NLRP3 activation through multiple converging mechanisms, including inhibition of NF-κB-dependent priming, mitochondrial quality control via mitophagy, Nrf2-mediated antioxidant responses, and HDAC inhibition. Evidence across cardiovascular, metabolic, neurological, and respiratory disease models supports the translational relevance of this axis. Conclusions: The microbiota–polyphenol–NLRP3 axis functions as an integrated, self-regulated network in which each component simultaneously shapes and is shaped by the others: dysbiosis primes NLRP3 and depletes protective metabolites, while inflammasome hyperactivation further destabilises microbial ecology; polyphenol biotransformation by specific taxa interrupts this feed-forward loop at multiple nodes, restoring homeostasis. Full article

Aging is a multifactorial biological process characterized by progressive functional decline and increased susceptibility to chronic diseases. Targeting the molecular mechanisms underlying aging has therefore emerged as an important strategy for promoting healthy aging. Natural polyphenols, widely present in fruits, vegetables, tea, and medical and aromatic plants, have attracted considerable attention due to their geroprotective properties. This review examines current evidence on the ability of major dietary polyphenols, including resveratrol, epigallocatechin gallate (EGCG), curcumin, and quercetin, to modulate the hallmarks of aging, with particular emphasis on mitochondrial quality control as a central regulatory mechanism. Evidence indicates that polyphenols regulate key signaling pathways involved in aging biology, including AMP-activated protein kinase (AMPK), sirtuins (SIRT), mechanistic target of rapamycin (mTOR), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor-κB (NF-κB). Through coordinated modulation of these pathways, polyphenols influence mitochondrial biogenesis, mitophagy, redox homeostasis, cellular senescence, and chronic inflammation. In addition, interactions between dietary polyphenols and the gut microbiome generate bioactive metabolites, such as urolithin A, which further contribute to mitochondrial regulation. Overall, polyphenols represent promising modulators of aging-associated pathways and may support strategies aimed at improving healthspan and reducing age-related disease risk. Full article

Punica granatum L. is a nutritionally relevant fruit with a complex phytochemical profile that varies across its anatomical fractions, including peel, arils, juice, seeds, and seed oil. Although pomegranate is widely recognized for its health-promoting potential, the nutritional significance of its matrix-dependent composition, bioavailability, and gut microbiota-mediated metabolism remains insufficiently integrated. This review aimed to critically evaluate the phytochemical diversity of pomegranate and its nutrition-related multi-target biological functions, with particular emphasis on food matrices, bioaccessibility, and translational relevance. A structured review of peer-reviewed studies indexed in major scientific databases from 2000 to January 2026 was conducted. Eligible reports included analytical, preclinical, and clinical studies addressing the composition of pomegranate-derived materials and their biological effects, with attention to extraction matrix, processing, bioavailability, microbial biotransformation, and mechanisms of action. Pomegranate exhibits marked matrix-specific phytochemical diversity. Peel is particularly rich in ellagitannins, especially punicalagin and punicalin; arils and juices are enriched in anthocyanins and flavonols; and seed oil contains high levels of punicic acid. Reported biological activities include antioxidant, anti-inflammatory, antimicrobial, metabolic, anti-aging, and anticancer effects. These actions appear to result from synergistic interactions among multiple bioactive compounds rather than from a single dominant constituent. Importantly, gut microbiota-driven conversion of ellagitannins and ellagic acid into urolithins is a major determinant of systemic bioactivity and may contribute to interindividual variability in response. The health effects of pomegranate should be interpreted within a nutrition-focused, matrix-dependent framework integrating composition, processing, bioavailability, and microbiota-derived metabolism. Full article

Nutraceuticals are emerging as promising agents for the prevention and treatment of atherosclerosis, particularly in light of the limitations associated with current pharmacotherapies. Pomegranate-derived polyphenols, especially punicalagin (PC), possess multiple cardioprotective properties. However, their direct biological effects are constrained by poor absorption and low bioavailability. Instead, many of their actions are mediated by gut microbiota-derived metabolites known as urolithins. Despite this, the roles of PC and its metabolites in atherosclerosis remain inadequately defined. The objective of this study was to investigate the anti-atherogenic effects and underlying mechanisms of PC and its major metabolites—ellagic acid and urolithins A, B, C, and D—using in vitro and in vivo approaches. In vitro, these compounds broadly inhibited key pro-atherogenic processes in macrophages and endothelial cells, including reactive oxygen species production and inflammatory gene expression, with notable metabolite-specific differences. Urolithin A (UA), identified as the most effective compound, was further evaluated in LDL receptor-deficient mice fed a high-fat diet. UA supplementation improved peripheral blood immune cell profile, reduced atherosclerotic plaque burden and inflammation, and enhanced markers of plaque stability. RNA sequencing of the thoracic aorta revealed key molecular pathways underlying the protective actions of UA. Collectively, these findings highlight the therapeutic potential of PC-derived metabolites, particularly UA, in combating atherosclerosis and support the need for future human clinical studies. Full article

Polyphenols are a diverse class of bioactive phytochemicals increasingly recognized for their ability to modulate human physiology through extensive interactions with the gut microbiota. This review provides a comprehensive and updated synthesis of the bidirectional polyphenol–microbiota relationship, emphasizing how dietary polyphenols reshape microbial community structure while intestinal microorganisms metabolize polyphenols into smaller, more bioavailable derivatives. These microbial metabolites—such as urolithins, phenolic acids, and dihydroresveratrol—exert amplified biological activities compared to their parent molecules, acting on key molecular pathways linked to oxidative stress, inflammation, energy homeostasis, and metabolic regulation. Through integration of mechanistic studies, multi-omics analyses, and emerging clinical evidence, this review outlines the potential of the polyphenol–microbiota–metabolite axis as a target for precision nutrition and microbiota-informed therapeutic interventions. The manuscript highlights ongoing challenges, including inter-individual variability in polyphenol metabolism, and proposes future research directions to advance the field of personalized nutrition. Full article

Multiple sclerosis (MS) is characterized by progressive mitochondrial dysfunction affecting complexes I, III, and IV of the electron transport chain, contributing to axonal energy failure and neurodegeneration. This review examines the potential of combining β-hydroxybutyrate (βHB), epigallocatechin-3-gallate (EGCG), and ellagic acid (EA) as a multi-target therapeutic strategy to restore mitochondrial function in patients with MS. Experimental and clinical studies demonstrate that each compound exerts complementary mechanisms. Ketone bodies provide an alternative energy substrate and restore complex I activity via sirtuin-dependent pathways. EGCG acts predominantly at the peripheral level by reducing systemic inflammation and oxidative stress. EA-derived urolithins effectively cross the blood–brain barrier to directly enhance mitochondrial biogenesis and respiratory chain function in the central nervous system. Clinical trials have reported improvements in fatigue, cognition, mood, and muscle function following supplementation with these compounds. The convergence of their actions on energy restoration, reactive oxygen species reduction, and epigenetic modulation of protective pathways suggests their synergistic potential. Optimized delivery strategies, including exogenous ketone salts, liposomal EGCG, and microencapsulated EA, may overcome bioavailability limitations and interindividual variability in the gut microbiota metabolism. Full article

Background: Antibiotics are essential for treating infections; however, they disrupt the microbiome and key microbiome-dependent functions. Clinical evidence is mixed for probiotic supplementation following antibiotics due to product heterogeneity and inconsistencies in evaluating biological mechanisms that drive clinical consequences. Accordingly, this study investigates the effects of a multi-species synbiotic on gut microbiome composition and function, and gut barrier integrity, during and following antibiotics. Methods: In a randomized, placebo-controlled trial designed to assess proof-of-mechanism, healthy adult participants received a daily synbiotic (53.6 billion AFU multi-species probiotic and 400 mg Indian pomegranate extract; DS-01) or matching placebo for 91 days. All participants also received ciprofloxacin (500 mg orally twice daily) and metronidazole (500 mg orally three times daily) for the first 7 days. Samples were collected at baseline and Days 7, 14, 49, and 91. Endpoints included fecal microbiome composition, fecal acetate and butyrate levels, urinary Urolithin A (UroA), serum p-cresol sulfate (pCS), gut barrier integrity, and safety. Results: The multi-species synbiotic significantly increased the alpha-diversity of Bifidobacterium and Lactobacillus at all timepoints compared to placebo, including short-term (Day 7, p < 0.0001) and end-of-study (Day 91, p < 0.001). The multi-species synbiotic enhanced recovery of native beneficial microbes, including butyrate-producing species and a novel Oscillospiraceae species (UMGS1312 sp900550625, p < 0.001). Beneficial microbiome-dependent metabolites increased, including fecal butyrate (119%, p < 0.05), fecal acetate (62%, p < 0.01), and UroA (13,008%, p < 0.05), whereas detrimental metabolite pCS decreased (68%, p < 0.05) compared to placebo. Functionally, the multi-species synbiotic improved gut barrier integrity rapidly (Day 7; 305%, p < 0.05) and over the long-term (Day 91; 161%, p < 0.05) compared to placebo. Conclusions: During and after antibiotics, this multi-species synbiotic promotes recovery of gut microbiome diversity and native beneficial microbes, microbiome metabolite recovery, and gut barrier function, all of which underpin antibiotic-associated gastrointestinal symptoms. Full article

Cellular senescence, mitochondrial dysfunction, and cumulative oxidative stress (OS) are the main causes of the progressive decreases in oocyte and sperm quality that define reproductive age. There is growing evidence that these processes are controlled by systemic variables, such as metabolites produced from the gut microbiome and extracellular vesicle (EV)-mediated intercellular communication, rather than being exclusively regulated at the tissue level. Antioxidant enzymes, regulatory microRNAs, and bioactive lipids that regulate mitochondrial redox balance, mitophagy, and inflammatory signaling are transported by EVs derived from reproductive organs, stem cells, immune cells, and the gut microbiota. Concurrently, microbiome-derived metabolites such as urolithin A, short-chain fatty acids, and polyphenol derivatives enhance mitochondrial quality control, activate antioxidant pathways, and suppress senescence-associated secretory phenotypes. This narrative review integrates the most recent research on the relationship between redox homeostasis, mitochondrial function, gut microbiota activity, and EV signaling in the context of male and female reproductive aging. We propose an emerging gut–EV–mitochondria axis as a unified framework through which systemic metabolic and antioxidant signals affect gamete competence, reproductive tissue function, and fertility longevity. Finally, we discuss therapeutic implications, including microbiome modulation, EV-based interventions, and senotherapeutic strategies, highlighting key knowledge gaps and future research directions necessary for clinical translation. Full article

Punicalagin, the major polyphenol in pomegranate peel, shows broad bioactivity but suffers from poor oral bioavailability. Whether hepatic or intestinal first-pass processes dominate this limitation remains unresolved. We developed a quantitative UPLC-MS/MS workflow to dissect punicalagin’s first-pass disposition and elimination in rats. Sprague–Dawley rats received punicalagin by intravenous, portal vein, oral, or intraduodenal dosing; plasma exposure was quantified by UPLC-MS/MS and analyzed noncompartmentally. We also profiled urinary and fecal excretion of punicalagin and key metabolites (punicalin, ellagic acid, urolithin C and urolithin A) to define biotransformation and clearance. Punicalagin displayed an absolute oral bioavailability of ~3.49%. First-pass analysis revealed modest hepatic extraction (~13.94%) but near-complete intestinal extraction (95.95%), identifying intestinal first-pass metabolism as the dominant barrier to systemic exposure. Consistently, parent and metabolites were eliminated mainly in feces, whereas urine contained only trace conjugated urolithin A. Collectively, these findings demonstrate that the poor oral bioavailability of punicalagin is driven primarily by extensive intestinal first-pass metabolism rather than hepatic clearance, and that its feces-dominant elimination is compatible with widespread hydrolysis and microbiota-mediated conversion within the gut. This work provides a pharmacokinetic framework to guide strategies aimed at improving oral delivery and systemic exposure of punicalagin. Full article

Over the past decade, research on urolithins has expanded significantly due to their role as mediators between polyphenol-rich diets and human health. Understanding the relationships between ellagitannin intake, gut microbiota composition, and urolithin production is essential for evaluating their biological effects and nutraceutical potential. The primary objective of this review is to critically summarise current knowledge on urolithins, bioactive metabolites derived from ellagitannins in plant-based foods, with a focus on their biosynthesis, bioavailability, protein interactions, and potential therapeutic applications. A comprehensive literature search was conducted using PubMed, Scopus, and Google Scholar to identify studies on urolithin biosynthesis, absorption, transport mechanisms, protein binding, and incorporation into extracellular vesicles. Relevant articles were critically analysed to synthesise current evidence and highlight emerging concepts. Key findings indicate that after absorption, urolithins bind to serum albumin, which facilitates their transport to target tissues, exerting anti-inflammatory and antioxidant actions. Recent evidence also shows that urolithins can be packaged into extracellular vesicles, suggesting novel mechanisms for intracellular transport and potential therapeutic applications. This review highlights gaps in current knowledge and proposes directions for future research to optimise their therapeutic potential. Full article

Urolithin A (UA), a metabolite of dietary ellagitannins produced by the gut microbiome, is a potential dual-purpose bioactive compound that may interfere with the shared pathogenic pathways linking colorectal cancer (CRC) and type 2 diabetes mellitus (T2DM). This review summarizes recent preclinical and clinical data on UA’s mechanisms, therapeutic potential, and translational challenges. In CRC models, UA promotes G2/M cell cycle arrest, triggers both intrinsic and extrinsic caspase-mediated apoptosis, enhances CD8+ T-cell mitophagy and memory functions, suppresses Wnt/β-catenin signaling, and reduces chemoresistance, especially to 5-FU. For T2DM, UA enhances autophagic flux, mitophagy, insulin signaling, and GLUT4-mediated glucose uptake through the AMPK and PI3K/AKT pathways, reduces fasting glucose and insulin resistance in animal studies, and promotes adipose tissue browning and mitochondrial beta-oxidation. Human biomarker research is limited but indicates positive changes following interventions that increase UA. Future priorities include biomarker-driven, dose-finding trials stratified by metabotype, developing colon-targeted vs. systemic formulations, and testing combinations with chemotherapy and immunotherapy to determine safety and effectiveness. Full article