Search Results (77)

Background/Objectives: Aluminium is a widespread environmental element and food contaminant to which the general population is continuously exposed, primarily through diet and drinking water. Although gastrointestinal absorption is generally low, bioavailability varies according to chemical form, food matrix, and interactions with dietary components. Prolonged exposure can nevertheless result in gradual tissue accumulation. This review summarises current evidence on dietary aluminium exposure, factors influencing its bioavailability, toxicokinetics, biological effects, gut microbiota interactions, and population-level health risk. Methods: A comprehensive narrative literature review was conducted using publications retrieved from PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar. Original research articles, review papers, and reports issued by international organisations were critically evaluated with particular emphasis on dietary sources, drinking water, food additives, food contact materials, gastrointestinal absorption, toxicokinetics, biological mechanisms, gut microbiota, and health risk assessment. Results: Food represents the principal source of aluminium exposure in the general population, while drinking water usually contributes a smaller but continuous fraction of total oral intake. Dietary exposure varies substantially between populations and is influenced by food composition, processing practices, the use of aluminium-containing additives, and migration from food contact materials. Aluminium bioavailability is modified by chemical speciation and dietary constituents, including citrate, phosphates, silicates, phytates, polyphenols, and essential minerals. Despite limited absorption, prolonged exposure can lead to gradual aluminium accumulation, particularly in bone tissue and the central nervous system. Proposed biological mechanisms include oxidative stress, mitochondrial dysfunction, disruption of mineral homeostasis, and inflammatory signalling. Emerging evidence also indicates that aluminium may alter the gut microbiota, impair intestinal barrier integrity, and influence the gut–brain axis. Population exposure assessments show considerable regional variation, with some groups approaching or exceeding established tolerable weekly intake values. Conclusions: Dietary aluminium exposure represents a relevant issue in nutritional toxicology and food safety. Although current evidence does not establish that typical dietary exposure directly causes chronic disease, long-term exposure, differences in bioavailability, and the possibility of elevated intake in selected population groups justify continued monitoring and further prospective human studies. Future research should integrate dietary intake, aluminium speciation, nutritional status, biomarkers of internal exposure, and long-term health outcomes to improve risk assessment and support effective exposure-reduction strategies. Full article

Parturient paresis remains a major economic challenge in global ruminant production, causing acute periparturient hypocalcemia and predisposing high-yielding animals to a cluster of secondary pathologies. Traditional narratives often treat regulatory pathways in isolation, whereas this review synthesizes multi-organ endocrine networks to address the kinetic dyssynchrony between mammary calcium drain and homeostatic recruitment velocity. Beyond the classical parathyroid hormone–vitamin D axis, we integrate the mammary–gut–bone axis into a unified endocrine model, highlighting the critical role of the serotonin–parathyroid hormone-related protein rheostat for skeletal mineral mobilization and the fibroblast growth factor 23–Klotho axis in prepartum phosphorus-induced feedback suppression. We evaluate the molecular mechanisms underlying target-organ receptor resistance, driven by vitamin D receptor downregulation and epigenetic aging, which precipitate homeostatic feedback failure. Regarding clinical management, this synthesis contrasts reactive parenteral interventions with proactive nutritional priming strategies, such as negative dietary cation–anion difference acidification, zeolite-based gastrointestinal binders, and exogenous vitamin D or 5-hydroxytryptophan supplementation. Additionally, the role of microbiota-derived short-chain fatty acids in gut-bone communication and the potential of genomic selection to breed livestock with heritable metabolic resilience are explored. Ultimately, this comprehensive framework emphasizes a paradigm shift from emergency treatment to precision nutritional and genetic prophylaxis to mitigate PP across diverse ruminant species. Full article

Objective: To investigate the effect of milk minerals on bone mineral density (BMD) and bone quality in growing rats and explore the underlying mechanisms related to calcium absorption, bone metabolism, and the gut–bone axis. Methods: Sixty healthy 4-week-old male Sprague-Dawley (SD) rats were randomly divided to five groups based on their body weight: Low-Calcium Control Group (Control), Low-Dose milk mineral Group (Low), Medium-Dose milk mineral Group (Medium), High-Dose milk mineral Group (High) and Calcium Carbonate Control Group (CaCO₃), which received the same dose level (elemental calcium) as the High group. The milk mineral dosage was set at 5, 10, and 15 times the human recommended intake of elemental calcium. After 12 weeks of intervention, femurs were collected for analysis of BMD, bone microstructure, and bone mechanical strength. Additionally, analyses included calcium levels in the femur, feces, and diet; serum bone metabolism biomarkers; tissue protein expression; as well as gut microbiota composition and short-chain fatty acid content. Result: Milk mineral exhibited non-inferior efficacy to CaCO₃ in increasing femoral calcium content, enhancing BMD, and improving bone microarchitecture. Notably, the Medium group achieved comparable bone-protective effects to the CaCO₃ group despite a 20.8% lower calcium content, which was accompanied by a relatively high calcium absorption rate (90.9% vs. 86.5%). With respect to serum markers, milk mineral maintained bone formation while suppressing bone resorption, resulting in a net anabolic state comparable to that of CaCO₃. Milk mineral significantly upregulated the protein expression of renal CYP27B1 and intestinal calcium ion transporters, and increased serum IGF-I levels. Furthermore, milk mineral promoted the enrichment of certain specific gut microbial genera, which showed a significant positive correlation with IGF-I, bone calcium content and BMD. Conclusions: Milk mineral supplementation appears to promote bone formation and mineralization in growing rats, accompanied by enhanced intestinal calcium absorption, enrichment of characteristic gut microbes and elevated microbial metabolite concentrations. Full article

Broodiness is a natural behavior whereby female birds stop laying eggs to sit on and hatch them. This behavior is regulated through genetic, hormonal, and environmental factors. The Taihe Black-Boned Silky Fowl (TBSF), a Chinese traditional domestic breed, exhibits a strong brooding tendency; however, the molecular mechanisms underlying this trait remain unclear. In this study, we performed an integrated multi-omics analysis to characterize differences between two groups of TBSF hens: 8 individuals undergoing 30 days of active brooding (BR30) and 8 individuals in the normal laying egg stage (NB), selected from a total group of 230 hens. We combined 16S rRNA sequencing, untargeted metabolomics, and hepatic transcriptome sequencing, with statistical analyses including QIIME 1.9.1, OPLS-DA (VIP > 1), Student’s t-test (p ≤ 0.05), and DESeq2 (|log₂FC| ≥ 1, FDR < 0.05) for differentially expressed genes (DEGs), respectively, and Pearson’s correlation analysis for multi-omics integration. Phenotypically, brooder hens showed significantly reduced feed intake, body weight, and main digestive tissue indices, alongside altered liver and blood biochemical parameters. Hepatic transcriptome analysis identified 1582 DEGs between groups, enriched in pathways related to fatty acid oxidation and the amino acid degradation pathway. In addition, 16S rRNA sequencing revealed distinct gut microbial community structures: the NB group was enriched in Bacilliota and Pseudomonadota, while the BR30 group was enriched in Spirochaetota and Synergistota. Metabolomic profiling identified a total of 143 differential metabolites, which were enriched in lipid and amino acid metabolites, including alpha-linolenic acid and pyruvate metabolites. Multi-omics correlation analysis revealed tight associations between gut microbial taxa, circulating metabolites, and hepatic gene expression. Specifically, beneficial lipid metabolites, including phospholipids, lysophosphatidylcholines, and sphingomyelins, were positively correlated with Synergistes and the Christensenellaceae R-7, as well as with key hepatic lipid metabolism genes FABP1, LPL, and FADS2. In summary, this study reveals that the gut–liver axis plays a critical part in the modulation of energy metabolism during broodiness, and further highlights new insights into metabolic targets that could optimize reproductive behavior and enhance poultry production. Full article

Short stature is a common pediatric endocrine–metabolic disorder characterized by impaired linear growth and increased risks of adverse health outcomes. Although previous reviews have summarized associations between gut microbiota and childhood health, few have focused on the mechanistic links among microbial composition, microbial-derived metabolites, endocrine regulation, and skeletal growth in short stature. This review provides an integrated framework exploring the potential interactions among gut microbiota composition, microbial-derived metabolites, endocrine regulation, and skeletal development in short stature. We summarize the clinical characteristics and epidemiological features of major short stature subtypes and discuss emerging evidence demonstrating the involvement of gut microbiota alterations and metabolite dysregulation in growth regulation. Particular attention is given to the bidirectional interactions between the gut microbiota and the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis, as well as the potential role of the gut–liver–bone axis in skeletal growth. Furthermore, this review integrates evidence from metabolomics studies, experimental animal models, and microbiota-targeted interventions to provide mechanistic insights into microbiota-mediated growth regulation. Dietary factors, physical activity, sleep, antibiotic exposure, probiotic interventions, and current clinical treatments are also discussed from the perspective of microbiota modulation. Despite increasing interest in microbiota-based strategies, clinical translation remains limited by insufficient functional validation, unclear causal relationships, and a lack of well-designed intervention trials. Future integration of functional microbiology, multi-omics approaches, and human-based validation platforms may facilitate the development of microbiome-based precision interventions for improving growth outcomes in children with short stature, particularly those with ISS. Full article

Background: Osteoarthritis (OA) is the most common degenerative joint disease globally, with its pathogenesis yet to be fully elucidated. Accumulating evidence has redefined OA as a systemic low-grade inflammatory disorder. While the gut microbiota–joint axis is widely recognized as a key regulatory pathway in OA progression, a definitive causal and mechanistic framework linking microbiota-derived metabolites to OA pathology has not yet been established. Aim of Review: This review aims to comprehensively evaluate the roles of microbiota-derived metabolites in OA pathogenesis by integrating cutting-edge multi-omics data, causal evidence from Mendelian randomization studies, and advanced translational strategies. We propose a conceptual framework linking microbial dysbiosis to joint degeneration and discuss potential therapeutic targets for OA. Key Scientific Concepts of Review: Microbiota-derived signals, including lipopolysaccharides, peptidoglycans, short-chain fatty acids, bile acids, tryptophan metabolites, and hydrogen sulfide, are associated with mucosal barrier impairment, aberrant immune activation, and metabolic–endocrine dysfunction. These systemic host responses, in turn, may collectively contribute to the three core pathological hallmarks of OA: cartilage degeneration, synovial inflammation, and subchondral bone remodeling. We highlight novel regulatory pathways, including bile acid–glucagon-like peptide-1(GLP-1) signaling, aryl hydrocarbon receptor (AhR) modulation, and ferroptosis regulation, as potential critical mediators of OA. Causal evidence from multi-omics and Mendelian randomization analyses is synthesized to move beyond simple descriptive associations. Furthermore, we discuss translational strategies, such as metabolite-targeted interventions (GUDCA, IPA, HDCA) and engineered bacterial extracellular vesicle delivery systems, providing a potential framework for the precision theranostics of OA. Full article

Layer chickens have dual physiological demands for rapid growth and continuous egg production. The maintenance of skeletal homeostasis in layer chickens relies on the precise coordination among OCs, osteoblasts (OBs), and osteocytes. The imbalances in the supply of nutrients such as calcium (Ca) and phosphorus (P), as well as dysfunction of the “gut–bone” axis, can disrupt normal bone development in layer chickens, leading to bone diseases such as tibial dyschondroplasia (TD) and osteoporosis (OP), seriously damaging the production performance of layer chickens. This review systematically summarizes the knowledge background of the metabolic reprogramming of OCs in layer chickens, especially mitochondria-mediated biological processes, including oxidative phosphorylation (OXPHOS), glycolysis, reactive oxygen species (ROS) signaling, mitophagy, etc. Notably, the co-culture system of OCs derived from the bone marrow cavity of embryos in vitro has been established in laying chickens. However, there are few reports on the study of mitochondrial metabolism of OCs using this model. Therefore, this review particular focuses on the bone metabolism mediated by OCs in layer chickens and proposes future research priorities, including the application of gene editing and multi-omics methods to ultimately achieve targeted nutritional or pharmacological interventions for optimizing mitochondrial function and promoting bone health. Full article

The gut microbiota is increasingly recognized as a dynamic endocrine-like microbial network that exerts systemic effects far beyond the gastrointestinal tract. Emerging evidence supports the existence of a “gut-bone marrow axis” through which gut-derived signals orchestrate hematopoietic homeostasis. However, shifting from correlative observations to causal mechanisms remains a major challenge in defining precise microbial impacts on hematopoietic outcomes. In this review, we systematically synthesize current knowledge on the molecular mechanisms by which microbial products—specifically short-chain fatty acids (SCFAs) and bile acids—translocate into the systemic circulation to modulate hematopoietic stem cell (HSC) function, lineage commitment, and the bone marrow microenvironment. Furthermore, we discuss how gut dysbiosis acts as a driver of hematopoietic dysfunction, contributing to the pathogenesis of anemia, bone marrow failure, and hematologic malignancies such as leukemia. Beyond mechanistic insights, this review critically evaluates the therapeutic promise of emerging microbiota-targeted interventions, including precision probiotics, prebiotics, and FMT, which hold the potential to modulate hematopoietic function and support recovery. Although preclinical evidence is accumulating, these approaches are underpinned by limited yet mechanistically informative clinical evidence. Thus, these emerging interventions require rigorous mechanistic validation and well-designed clinical trials. Herein, by integrating multi-systemic perspectives, we provide a comprehensive framework for future research and clinical strategies aimed at leveraging the microbiota to treat hematologic disorders. Full article

Clonal hematopoiesis of indeterminate potential (CHIP) and the gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) are both linked to NLRP3-mediated cardiovascular inflammation, but their interaction has not previously been explored. This work proposes the CHIDT axis (clonal hematopoiesis–dysbiosis–TMAO), a feed-forward mechanism in which TET2 loss-of-function CHIP- and TMAO-generating Gram-negative gut dysbiosis mutually enhance cardiovascular risk. The model proceeds in three nodes. CHIP-associated intestinal immune dysregulation promotes luminal expansion of Gammaproteobacteria, which produce both trimethylamine via CntA/CntB-mediated L-carnitine oxidation and ADP-heptose as an obligate LPS biosynthetic intermediate. TMAO amplifies NLRP3 inflammasome activation through the SIRT3 → SOD2 → mtROS pathway. The evidence base of the CHIDT model is strongest for TET2-CHIP; the proposed extension to DNMT3A-CHIP rests on indirect, associative data and requires dedicated experimental confirmation before it can be considered established. TXNIP cascade, with predicted disproportionate potency in macrophages epigenetically primed by TET2 haploinsufficiency. High concentrations of TMAO have also been shown to suppress TET2 expression in endothelial cells through CYTB promoter hypermethylation, inducing NLRP3–GSDMD-dependent pyroptosis, although it remains unclear whether physiological TMAO levels can trigger this effect. Concurrently, ADP-heptose activates the ALPK1–TIFA–NF-κB pathway in bone marrow progenitors, favoring the expansion of mutant hematopoietic stem and progenitor cells. The model identifies three potential therapeutic strategies: NLRP3 inhibition, microbial TMA lyase inhibition, and microbiome-targeted reduction in Gram-negative bacteria. None has been tested in CHIP carriers stratified by plasma TMAO. Further studies in preclinical models and human cohorts integrating CHIP genotyping and TMAO quantification are needed to validate the CHIDT axis as a target for precision cardiovascular prevention. Full article

The gut microbiota and its metabolites, as components of the gut–bone axis, play a pivotal role in regulating skeletal homeostasis through the bidirectional communication network. In this systematic review, evidence was collected from mainstream databases following standardized inclusion/exclusion criteria for screening, to comprehensively retrieve and screen eligible studies from multiple mainstream databases according to standardized inclusion and exclusion criteria, and systematically summarize current research progress on plant-derived bioactive compounds targeting the gut–bone axis for skeletal health regulation. This review systematically explores the underlying mechanisms of the gut–bone axis and critically evaluates the regulatory effects and therapeutic potential of plant-derived bioactive compounds. Particular attention is given to targeted interventions involving prebiotics, probiotics, synbiotics, and plant-rich diets or functional foods. Among these interventions, synbiotics represent the most successful strategy and show the most prominent therapeutic possibilities in bone-related disorders. Different from single prebiotics (only nourish endogenous intestinal microbes), individual probiotics (easy to be degraded in gastrointestinal tract with poor colonization) and ordinary plant-rich diets (unfixed effective dosage and weak targeting property), synbiotics combine prebiotic carriers and viable probiotic strains to produce complementary advantages, which is the core reason for its outstanding therapeutic prospect against bone diseases. Synbiotics exert synergistic effects on gut microecology, mineral absorption, and immune regulation, leading to more robust and consistent improvements in bone health than single prebiotics, probiotics, or general plant-rich diets. They have been verified in preclinical and clinical studies to ameliorate osteoporosis and related skeletal diseases via the gut–bone axis. These strategies offer novel insights into the prevention and treatment of bone metabolic disorders, such as osteoporosis, by targeting the gut–bone axis with phytochemicals. Key outcomes of this review include that synbiotics, soy isoflavones, naringin, curcumin, and resveratrol effectively improve bone mineral density, restore gut microbiota balance, and inhibit pathological bone resorption via the gut–bone axis. Collectively, the above bioactive substances realize bone protection mainly by reshaping gut flora, elevating mineral uptake and suppressing excessive osteoclast activity. Representative cases include soy isoflavones mitigating estrogen-deficient bone loss in OVX models, naringin improving the trabecular microarchitecture, and probiotic BL-11 promoting longitudinal bone growth in children. Future directions will focus on clarifying dose–response relationships, developing standardized synbiotic formulations, constructing microbiome-guided precision diets, and conducting large-sample randomized controlled trials to translate plant-derived compounds into clinical therapies. Full article

Down syndrome (DS), caused by trisomy 21, is associated with a wide spectrum of endocrine and gastrointestinal disorders that often arise early in life and significantly impact long-term health. This narrative review examines the pathophysiological mechanisms underlying these conditions, with a particular focus on their bidirectional interactions. Endocrine abnormalities in DS, including thyroid dysfunction, type 1 diabetes mellitus, growth impairment, and altered bone metabolism, occur at higher rates than in the general population and are largely driven by immune dysregulation, chronic inflammation, and gene dosage effects. Similarly, gastrointestinal disorders—ranging from congenital malformations to autoimmune conditions such as celiac disease—are highly prevalent and often present with atypical clinical features. Emerging evidence highlights the central role of gut dysbiosis, characterized by reduced microbial diversity and increased pro-inflammatory taxa, in modulating immune and metabolic pathways. This altered gut environment contributes to a chronic inflammatory state and may promote autoimmunity and endocrine dysfunction through the gut–endocrine–immune axis. Nutritional deficiencies and epigenetic factors, including microRNA dysregulation, further influence disease expression. Understanding this complex cross-talk is essential for improving clinical management. Integrated, multidisciplinary approaches and early screening strategies are crucial to optimize outcomes and guide future research in DS. Full article

Background: Natto, a well-known fermented soybean product beneficial for bone health, remains unclear in its mechanism. Methods: This study investigated its effect on secondary osteoporosis (OP) in mice. Results: Natto significantly inhibited weight loss, bone quality deterioration, and bone morphological damage, and regulated OPG/RANKL pathway protein expression (p < 0.05) in OP mice. Analysis of 16S rRNA revealed that natto increased gut microbiota α-diversity and the abundance of Sutterella, Roseburia, and Coprococcus, while reducing harmful bacteria such as Streptococcus, Shigella, and Helicobacter. These microbial changes positively correlated with body weight, bone size, and serum osteogenic metabolism in OP mice. Serum metabolomics showed differential metabolites of the natto group enriched in PPAR signaling and primary bile acid biosynthesis. Verification by mRNA and ELISA indicated that the upregulated liver and circulating PPARα by natto may regulate downstream bile acid pathways, linking gut microbiota to multi-organ metabolic functions. Conclusions: In summary, natto may act on gut microbiota to alleviate bone loss via the “gut microbiota–bile acid–OPG/RANKL” network, targeting multiple organs including gut, liver, and bone. This provides a theoretical basis for natto dietary intervention in osteoporosis prevention through the gut–bone axis. Full article

Systemic antibiotics are among the most widely prescribed therapeutic agents worldwide, and their effects on host–microbe equilibrium extend well beyond the infection for which they are intended. Periodontitis is conventionally framed as a biofilm-initiated, host-mediated inflammatory disease, although recent work has shifted this framework toward microbial homeostasis as a regulator of periodontal stability. We hypothesize that antibiotics are not direct etiologic agents of periodontitis but instead act as risk-modifying factors that lower the threshold at which plaque-mediated inflammation progresses to destructive disease. We propose that this effect may operate through several mechanisms: broad-spectrum or repeated exposure could deplete protective commensals and narrow microbial diversity, creating ecological space for opportunistic and pathogenic taxa; antibiotics may also alter host neutrophil function, cytokine profiles, and antimicrobial peptide regulation and may interfere with the osteoblastic and osteoclastic dynamics governing alveolar bone remodelling; and antibiotic-induced gut dysbiosis may propagate systemic inflammatory signals that further modulate periodontal susceptibility. To evaluate this hypothesis, we synthesize the available clinical, epidemiological, and experimental data across four converging axes—oral microbial ecology, immune regulation, alveolar bone remodelling, and the gut–oral axis—and identify the predictions the hypothesis generates and the evidence gaps it exposes. We emphasize that no clinical study has yet demonstrated a causal link between antibiotic exposure and periodontitis; the framework advanced here is therefore intended to inform antimicrobial stewardship in dentistry and to define a research agenda for determining whether antibiotic exposure constitutes a clinically meaningful modifier of periodontal disease susceptibility. Full article

Osteoporosis arises from disrupted bone remodeling, and growing evidence shows that gut microbiota and their metabolites have a major influence on skeletal health through the gut-bone and gut–brain–bone axes. In this systematic review, we synthesize findings from 932 studies to identify key microbial taxa, metabolites, and signaling pathways that modulate osteoblast and osteoclast activities. Short-chain fatty acids (SCFA), tryptophan-derived metabolites, and β-D-glucuronidase-related estrogen regulation emerge as central microbial mechanisms affecting bone formation and resorption. By integrating these data with the Phylobone extracellular matrix proteins database, we highlight Osteopontin and Cathepsin K as important downstream mediators linking microbial signals to bone matrix turnover. Probiotic strains (particularly Lactobacillus rhamnosus GG and L. reuteri) show potential to improve bone health through metabolic, immune, and endocrine pathways. Together, these findings outline a mechanistic framework connecting gut function to skeletal biology and identify promising microbiome-based targets for osteoporosis interventions. Full article

The gut microbiota regulates host physiology and drives extraintestinal diseases through the gut–X axis. Bile acids (BAs) function as key mediators of this interorgan crosstalk by activating nuclear and membrane receptors (FXR, TGR5, PXR, VDR). Traditional Chinese Medicine (TCM) demonstrates efficacy across multiple organ systems through multi-component formulations. This narrative review synthesizes evidence from preclinical and clinical studies supporting that TCM exerts systemic protection via strategic modulation of the microbiota–BA–host receptor axis, which functions as a core regulatory circuit within a larger network of microbial metabolites. Mechanistically, representative TCM formulas remodel gut microbial ecology and reinforce intestinal barrier integrity, leading to optimized BA profiles. These favorable BA signatures engage tissue-specific receptor signaling to resolve inflammation, mitigate fibrosis, and restore metabolic homeostasis across the gut–heart, gut–kidney, gut–liver, gut–bone, and gut–endocrine axes. Support for this causal relationship is provided by microbiota depletion, fecal transplantation, and multi-omics studies, collectively suggesting that TCM’s benefits are microbiota-dependent and at least partially BA-mediated. Moreover, context-dependent modulation of BA receptors, such as differential regulation of FXR, enables TCM to achieve pathology-specific outcomes. Current evidence is derived predominantly from preclinical models, and clinical data remain lacking. Nonetheless, the microbiota–BA–organ axis thus provides a potential framework for understanding TCM’s systemic actions and establishes a molecular basis for developing microbiome-informed precision therapeutics. Future directions include patient stratification and precision intervention design inspired by TCM’s ecological modulation strategies. Full article