Search Results (318)

Background/Objectives: Persistent gastrointestinal (GI) symptoms following oncologic treatment represent a major unmet need in survivorship care, often managed symptomatically without addressing underlying biological mechanisms. This study aimed to evaluate the clinical efficacy and biological correlates of an artificial intelligence (AI)-guided, personalized microbiome modulation strategy in oncology patients with chronic secondary GI dysfunction. Methods: We conducted a prospective, single-arm, open-label validation study including 29 adult female oncology patients with persistent GI symptoms lasting ≥3 months. Participants underwent baseline multidimensional assessment integrating shotgun metagenomic sequencing, inflammatory and nutritional biomarkers, and clinical symptom profiling. An AI-guided platform generated individualized dietary, supplement, and lifestyle recommendations. Outcomes were assessed at baseline and after a 3-month intervention, focusing on intra-individual changes in stool frequency (primary endpoint), self-reported energy, microbiome composition, and metabolic biomarkers. Paired statistical analyses, correlation testing, and multivariable regression were performed. Results: After three months, stool frequency significantly decreased (4.69 ± 2.41 to 2.07 ± 1.19 episodes/day; p < 0.0001), accompanied by a marked increase in energy levels (4.00 ± 1.04 to 7.24 ± 1.12; p < 0.0001). Microbiome analysis revealed consistent enrichment of butyrate-producing and barrier-supportive taxa, including Faecalibacterium prausnitzii, Eubacterium rectale, Roseburia intestinalis, Akkermansia muciniphila, and Bifidobacterium longum. Butyrate-related biomarkers and vitamin-associated parameters (B-complex, vitamin D) showed significant improvement, while lactate levels normalized. Changes in Bifidobacterium longum were independently associated with stool frequency reduction (β = −0.783, p = 0.0082). Conclusions: AI-guided personalized microbiome modulation was associated with significant clinical improvement and biologically coherent microbial and metabolic shifts in oncology patients with persistent GI symptoms. These findings support a precision supportive-care approach targeting microbiome restoration, warranting further validation in randomized controlled trials. Full article

A new selective fluorescent probe based on a vitamin B₆ derived hydrazone was synthesized and characterized for the detection of Al³⁺ and Ga³⁺ ions. The probe’s selectivity and sensitivity were evaluated using UV-Vis, fluorescence, and NMR spectroscopy in a buffered DMSO/water solution, complemented by density functional theory (DFT) calculations to elucidate the electronic structure and coordination modes of the resulting complexes. The probe exhibited a notable “turn-on” fluorescence response upon binding Al³⁺ and Ga³⁺, with emission maxima at 466 nm and 477 nm, respectively, and detection limits as low as 48 nM for Al³⁺ and 33 nM for Ga³⁺. The probe showed high selectivity for these ions over a wide range of competing cations and anions, forming stable 1:1 complexes with log β′ values of 5.98 for Al³⁺ and 6.28 for Ga³⁺. DFT calculations revealed a tridentate coordination mode via the phenolic oxygen, azomethine nitrogen, and carbonyl oxygen, with distinct electronic transitions for each complex, including a ligand-to-metal charge transfer character in the Ga³⁺ complex. The probe demonstrates reversibility and excellent solution stability, offering a simple and sensitive platform for the environmental and biological monitoring of aluminum(III) and gallium(III) ions. Full article

Background: Chronic stress is a major risk factor for cognitive decline and blood–brain barrier (BBB) disruption, yet the underlying molecular mechanisms remain elusive. This study aimed to investigate the specific role of the metabolic intermediate homocysteine (Hcy) in chronic stress-induced BBB dysfunction and cognitive impairment. Methods: We utilized a male Sprague-Dawley rat model of chronic unpredictable mild stress (CUMS) and administered vitamin B complex to lower Hcy levels in vivo. Regional Hcy accumulation, BBB permeability, and cognitive behaviors were assessed. In vitro, primary rat brain microvascular endothelial cells (BMECs) were exposed to Hcy to evaluate barrier-forming function, transcriptomic alterations, DNA methylation patterns, Cav1.2 expression, and reactive oxygen species (ROS) production. Results: CUMS selectively induced BBB hyperpermeability and significant Hcy accumulation predominantly within the rat hippocampus, which correlated intimately with cognitive deficits. Lowering Hcy levels via vitamin B supplementation successfully restored hippocampal BBB integrity and alleviated cognitive impairment. In addition, elevated Hcy severely impaired the barrier function of BMECs. Mechanistically, Hcy reduced global DNA methylation in BMECs and specifically induced targeted DNA hypomethylation at the intro region of Cacna1c. This epigenetic shift caused the transcriptional derepression and overexpression of the Cav1.2 calcium channel. Upregulated Cav1.2 subsequently triggered a robust ROS burst, leading to tight junction degradation. Conclusions: Our findings unveil a novel metabolic–epigenetic axis where Hcy-driven Cacna1c hypomethylation directly disrupts BMECs function to dismantle the hippocampal BBB. Lowering Hcy or targeting this Hcy-Cav1.2 pathway establishes a promising therapeutic strategy for mitigating stress-related neurovascular damage and cognitive disorders. Full article

Background: Complex regional pain syndrome (CRPS) is a disabling post-traumatic pain condition that may occur after distal radius fracture (DRF), potentially impairing recovery and upper-limb function. Identifying effective preventive strategies after DRF is therefore clinically important. Objective: To synthesize and critically appraise interventions intended to prevent CRPS after DRF, including rehabilitation protocols and clinical prophylaxis strategies. Methods: This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses PRISMA and was registered in the International Prospective Register of Systematic Reviews PROSPERO (CRD42023408499). Five databases (PubMed, Web of Science, Scopus, ScienceDirect, and B-on) were searched for studies published from January 2013 to 22 September 2023 in English, Portuguese, or Spanish. The primary outcome was CRPS incidence after DRF. Findings were synthesized narratively due to heterogeneity in interventions and diagnostic criteria, and risk of bias was assessed using design-appropriate tools. Results: Nine studies were included (total N = 7075; CRPS cases n = 127). Interventions comprised vitamin C supplementation (2 studies), probiotics, aspirin, polarized/polychromatic light therapy plus conventional treatment, early rehabilitation/home-exercise programs, and general CRPS-prevention protocols after DRF. Probiotics and aspirin did not reduce CRPS incidence. Vitamin C showed mixed findings across the included studies and remains debated in the broader literature. Light therapy was associated with reduced CRPS occurrence in a single study, while early active home-exercise programs appeared promising but were supported by a limited number of studies. Study designs and CRPS diagnostic criteria varied, and risk of bias was moderate-to-serious in several non-randomized studies. Conclusions: Evidence remains insufficient to support a single standardized prevention protocol for CRPS after distal radius fracture. Early active rehabilitation and progressive mobilization appear promising, but the available evidence is still limited and heterogeneous. Adjunctive strategies such as vitamin C and light therapy should be interpreted with caution, as findings for vitamin C remain debated in the literature and the evidence for light therapy is currently based on a single study. Other approaches, including probiotics and aspirin, have shown inconclusive results. Full article

Background/Objectives: Bordetella bronchiseptica is a Gram-negative bacterium that, either acting alone or in concert with other bacterial or viral pathogens, is a major cause of the canine infectious respiratory disease (CIRD) complex in dogs. Most currently available vaccines are given intranasally or orally and, whilst providing satisfactory reduction in disease severity, can be difficult to use especially in aggressive or anxious dogs. Whilst a small number of injectable B. bronchiseptica vaccines have been developed, little is known about their characteristics with regard to the age at first vaccination, the onset of immunity, duration of immunity, induction of antibody responses, concurrent use with the core vaccines used in most dogs, efficacy in the face of maternally derived antibodies (MDAs) or existing immunity and safety in pregnant animals. Here we describe the development of a safe and efficacious injectable B. bronchiseptica vaccine that utilises a novel process to purify fimbriae. Methods: The fimbrial antigen was formulated with a vitamin E-based oil-in-water adjuvant known to be safe in dogs (Nobivac^® Respira Bb). To evaluate dose response, thirty-nine naïve 5–6-week-old Beagle puppies were allocated to four groups and vaccinated subcutaneously with Nobivac^® Respira Bb at 69 U, 25 U, and 7 U (with a booster at two weeks). All groups were challenged with B. bronchiseptica two weeks after the booster. To evaluate the onset of immunity at 5–6 weeks of age, twenty-one naïve Beagle dogs were split into two groups: group 1 received Nobivac Respira Bb (88 U/dose) plus Nobivac DHPPi and Nobivac L4; group 2 received DHPPi and L4 only. Both groups were challenged with B. bronchiseptica two weeks after the second vaccination. Safety in pregnancy was evaluated by vaccinating pregnant dams and monitoring whelping outcomes and puppy health. Protection in puppies with maternally derived antibodies (MDAs) was studied in 28 pups (11 MDA-negative and 17 MDA-positive from vaccinated and unvaccinated dams). Pups were vaccinated at 5–6 weeks; one group remained unvaccinated to monitor MDA kinetics. All puppies were challenged with B. bronchiseptica at 19 weeks, after MDAs became undetectable. Serology was monitored throughout; daily clinical observations and nasal swabs post-challenge assessed protection and bacterial shedding. Results: Nobivac Respira Bb (MSD Animal Health), was safe for use in 5–6-week-old puppies alongside other Nobivac core canine vaccines without vaccine interference. The vaccine has an onset of immunity of two weeks and significantly reduces both the clinical signs of B. bronchiseptica-induced disease and bacterial excretion into the environment. Furthermore, the vaccine is equally efficacious in puppies with maternally derived antibodies derived from vaccinated dams and can be used safely in pregnant bitches. Conclusions: This vaccine represents a convenient, safe and efficacious alternative to vaccines delivered via the oral or intranasal routes and is a positive addition to the range of vaccines targeted at reducing disease induced by B. bronchiseptica. Full article

Metabolic syndrome (MetS) is a multifactorial cardiometabolic condition characterized by insulin resistance, visceral adiposity, dyslipidemia, hypertension, and chronic low-grade inflammation, collectively increasing the risk of type 2 diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular disease. Growing interest has focused on plant-derived dietary strategies capable of targeting multiple pathogenic pathways simultaneously. Opuntia ficus-indica fruits (OFIF) represent a complex food matrix containing betalains, polyphenols, carotenoids, soluble fiber, functional amino acids, vitamins, and minerals. Experimental evidence suggests that these constituents interact with key molecular networks implicated in MetS pathophysiology, including redox-sensitive pathways (NRF2), inflammatory signaling (NF-κB), energy-sensing regulators (AMPK), and lipid metabolism proliferator-activated receptor alpha (PPAR-α) dependent mechanisms. Preclinical studies consistently report associations with improvements in oxidative stress, inflammatory markers, hepatic steatosis, and glucose homeostasis following OFIF supplementation. However, human evidence remains limited by small sample size, short intervention duration, and variability in compositional standardization. This narrative review adopts a systems-level perspective to integrate mechanistic, preclinical, and early clinical evidence in the context of metabolic syndrome pathophysiology, while critically addressing translational gaps, compositional variability, and current limitations in human validation. Full article

Eating disorders (EDs), including anorexia nervosa (AN), bulimia nervosa (BN), and binge-eating disorder (BED), are complex psychiatric conditions characterized by high morbidity and mortality. Increasing evidence suggests that beyond disorder-specific symptomatology, shared transdiagnostic mechanisms contribute to their onset and persistence. This narrative review synthesizes current data on neurobiological and nutritional factors implicated in EDs, with particular emphasis on trait–state interactions and starvation-induced neuroadaptations. Predisposing vulnerabilities such as heightened anxiety, cognitive rigidity, and perfectionism appear to interact with state-dependent biological alterations induced by malnutrition. Chronic dietary restriction is associated with measurable alterations in serotonergic and dopaminergic systems, altered reward processing, and persistent activation of the hypothalamic–pituitary–adrenal (HPA) axis. Experimental studies suggest that acute tryptophan depletion may transiently reduce anxiety in individuals with anorexia nervosa, suggesting that, in some individuals, food restriction may function as a biologically reinforced strategy of affect regulation. Furthermore, disturbances in leptin and ghrelin signaling, along with widespread micronutrient deficiencies—including zinc, iron, selenium, and B vitamins—may exacerbate cognitive inflexibility, mood instability, and impaired decision-making. These metabolic and endocrine adaptations may contribute to a self-perpetuating cycle in which starvation-induced neurochemical changes reinforce restrictive or dysregulated eating behaviors. Importantly, several of these mechanisms extend beyond anorexia nervosa and may represent common transdiagnostic processes across eating disorders and related mental health conditions, including anxiety, depression, and addictive behaviors. Recognition of these biological and nutritional factors has significant implications for treatment. Nutritional rehabilitation should be conceptualized not solely as weight restoration, but as a neurobiological recalibration of stress regulation, reward sensitivity, and affective processing systems. An integrative treatment approach that combines behavioral stabilization with attention to underlying neurobiological and relational mechanisms may offer a more comprehensive framework for long-term recovery. Full article

Soybean mosaic virus (SMV) is a major constraint on global soybean (Glycine max (L.) Merr.) production, causing substantial economic losses worldwide. Despite these losses, the potential of resistance genes as a solution remains largely unexplored. In this study, the COPPER CHAPERONE FOR SUPEROXIDE DISMUTASE (GmCCS) was initially employed as a bait to screen the soybean cDNA library, leading to the identification of a protein homologous to Arabidopsis thaliana COP9 signalosome complex subunit 5B (AtCSN5B), designated as GmCSN5B. Quantitative real-time PCR (qRT-PCR) analysis revealed differential expression of GmCSN5B in the SMV-resistant (Qihuang No.1, QH) and susceptible (Nannong 1138-2, NN) variety following SMV-SC3 strain inoculation. Knockdown of GmCSN5B via Bean pod mottle virus (BPMV)-induced gene silencing (VIGS) significantly enhanced SMV resistance compared to control plants. This work further demonstrated that GmCSN5B can interact with the downstream GmVTC1 protein, which was potentially associated with ascorbic acid (AsA; Vitamin C) synthesis. Moreover, GmVTC1 also responded to SMV infection, and its knockdown led to a reduction in endogenous AsA levels within the host, thereby compromising the plant’s resistance to SMV. Together, these findings suggest that the GmCCS-GmCSN5B-GmVTC1 pathway in soybean modulates host resistance to SMV through the regulation of AsA synthesis. Full article

Background and Aims: Autoimmune gastritis (AIG) is a chronic immune-mediated condition characterized by corpus-predominant atrophy, which can lead to vitamin B12 deficiency, achlorhydria, and an increased risk of gastric adenocarcinoma (GC) and neuroendocrine tumours. Diagnosis is often challenging due to a long asymptomatic phase and variable clinical presentation. This study aimed to assess the prevalence of gastric cancer and advanced premalignant lesions and to identify risk factors associated with a worse endoscopic outcome. Methods: This retrospective observational study involving AIG patients undergoing endoscopic surveillance (2006–2024) at the Hospital Clínic de Barcelona. Patients with AIG were identified based on the presence of anti-parietal cell antibodies and/or intrinsic factor antibodies and underwent endoscopic surveillance with histological assessment. Clinical, serological, endoscopic, and histological data were evaluated to estimate the prevalence of gastric lesions. Potential risk factors were evaluated using logistic regression. Results: A total of 70 patients met the inclusion criteria (median age 60 years; 60% female). Advanced premalignant findings (high- and low-grade dysplasia) were identified in 15.7% of the patients, while GC was found in 5.7%. Atrophy and intestinal metaplasia were present in 98.6% and 74.3% of patients, respectively. Female sex was independently associated with a lower risk of advanced neoplastic findings (OR = 0.24; 95% CI: 0.06–0.95; p = 0.044), whereas older age at diagnosis was associated with an increased risk (OR = 1.06; 95% CI: 1.00–1.11; p = 0.031). Conclusions: Given the high prevalence of premalignant lesions in AIG, endoscopic surveillance appears essential for early detection. The observed associations with female sex and older age, toward lower and higher probabilities of advanced neoplastic findings, respectively, may contribute to future risk stratification models. However, the limited identification of significant predictors underlines the complexity of AIG progression and supports the development of individualized follow-up protocols. Full article

Background: Obesity is commonly seen as a condition of overnutrition; however, it is paradoxically associated with micronutrient deficiencies. These deficiencies are clinically relevant and may contribute to the progression of obesity-related comorbidities through interconnected pathways, including chronic low-grade inflammation, oxidative stress, gut dysbiosis, and impaired nutrient absorption. Objectives: This narrative review aims to summarize current evidence regarding the prevalence, underlying mechanisms, and clinical consequences of micronutrient deficiencies in individuals with obesity, with particular emphasis on their metabolic implications and potential therapeutic strategies. Results: Among individuals with obesity, iron, zinc, magnesium, calcium, vitamin D, vitamin B12, and folate are the most frequently reported deficiencies. These deficiencies arise from multiple mechanisms, including poor diet quality, increased metabolic demands, and compromised gastrointestinal absorption. In addition, obesity-related alterations in pharmacokinetics may further interfere with micronutrient distribution and bioavailability. Together, these mechanisms may lead to various clinical outcomes, such as anemia, immune, metabolic, and cardiovascular dysfunctions, along with cognitive impairment. Although several studies suggest that correcting these deficiencies may improve clinical outcomes, findings remain inconsistent, highlighting the complex and multifactorial pathophysiology underlying micronutrient imbalance in obesity. Conclusions: Micronutrient deficiencies represent frequently overlooked contributors to metabolic dysregulation in obesity. Their identification and correction should be considered a central part of the obesity management strategy. A personalized supplementation approach, based on clinical, biological, and pathophysiological characteristics, may provide a complementary support for weight-management treatments. Full article

2-Butanol is a promising biofuel due to its favorable properties and lower microbial toxicity compared to other butanol isomers. However, microbial production remains challenging due to the absence of a native biochemical pathway for directly converting sugars into 2-butanol. To achieve this goal, glucose should be directed through the 2,3-butanediol (2,3-BD) pathway, involving α-acetolactate synthase, α-acetolactate decarboxylase, and butanediol dehydrogenase for the formation of meso-2,3-BD, followed by diol dehydratase-catalyzed conversion of meso-2,3-BD to butanone and alcohol dehydrogenase-mediated reduction in butanone to 2-butanol. In this study, we report the development of six new recombinant strains based on Klebsiella pneumoniae G31, in which the metabolic pathway for converting glucose to meso-2,3-BD was extended to 2-butanol. All engineered strains harbored the vitamin B₁₂-dependent diol dehydratase complex (pduCDEGH) from Lentilactobacillus diolivorans DSM 14421 under its native promoter control. In addition, pduQ from the same strain, and adh from Clostridium beijerinckii DSM 51 encoding alcohol dehydrogenases were expressed under native, T7, or Ptac promoters. The highest yield of 2-butanol from glucose was achieved by K. pneumoniae K6 carrying the adh gene under the control of the T7 promoter—437 mg/L. Using 2-butanone as a substrate, K6 again produced the highest titer of 2-butanol (3.9 g/L), followed by the recombinant K8 (with adh under the Ptac promoter), and notably, by the native K. pneumoniae strains. Therefore, although pduQ encodes a key alcohol dehydrogenase in L. diolivorans, it has weaker properties than adh for the K. pneumoniae host in all promoter configurations. As the high expression levels of adh under T7 promoter control were driven by the native bacterial RNA polymerase, this promoter–host combination appears particularly suitable for developing other strains of industrial relevance. Full article

Marine byproducts generated from seafood processing represent valuable reservoirs of structurally and functionally distinct biomolecules, whose composition reflects species, habitat, and processing history. This systematic review identified which marine byproducts have been most extensively studied between 2020 and 2025, with emphasis on their composition, valorisation, and suitability for tracing their geographic origin. Following the PRISMA protocol, 6443 publications were initially retrieved, of which 96 peer-reviewed studies were included for data extraction and analysis. The five most frequently investigated byproducts—skin, bones, scales, shells, and roe—were identified as rich sources of proteins (collagen and gelatin), minerals (hydroxyapatite and calcium carbonate), polysaccharides (chitin), lipids (notably polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)), and vitamin B12. Collagen properties, particularly imino acid content, hydroxylation degree, crosslinking density, and thermal stability, correlate more strongly with environmental temperature than taxonomy, supporting their potential as markers for tracing geographic origin. The mineral fractions, dominated by hydroxyapatite in bones and scales, or calcium carbonate in shells, provided complementary inorganic fingerprints based on calcium-to-phosphorus ratios, carbonate substitution, trace element composition, and thermal analyses. While the lipid profile alone could not completely discriminate fish roe, proteomic techniques, such as MALDI-TOF MS, make it possible to reliably identify species. Collectively, these byproducts offer complementary organic and inorganic markers that support integrated strategies that allow tracing their origin and fostering their sustainable valorisation, overcoming a key technical bottleneck for their use. However, their large-scale conversion into market-ready products remains limited by technical complexity, process variability, and cost-related constraints. Full article

Reproductive efficiency in cattle is critically dependent on embryo quantity and quality, particularly in assisted reproductive technology (ART) programs such as superovulation, embryo transfer, and embryo production. Nutrition is a key determinant of embryo yield through its regulatory effects on metabolic signaling, ovarian function, oocyte competence, and early embryogenesis. This review synthesizes the current evidence describing mechanistic links between nutritional status and embryo production in dairy and beef cattle across both in vivo and in vitro systems. Energy balance, protein supply, micronutrients, and fatty acids influence metabolic hormones including insulin, insulin-like growth factor-1, and leptin, which regulate hypothalamic–pituitary–gonadal axis activity, follicular recruitment, and steroidogenesis. Negative energy balance disrupts endocrine signaling, elevates circulating non-esterified fatty acids, increases oxidative stress, and impairs oocyte mitochondrial function, resulting in reduced embryo yield, compromised blastocyst quality, and diminished cryotolerance. Targeted micronutrients such as selenium, zinc, vitamins A and E, B-complex vitamins, and omega-3 fatty acids enhance antioxidant capacity, membrane integrity, and epigenetic regulation, thereby supporting embryo viability and post-transfer survival. Furthermore, early-life nutrition programs long-term reproductive capacity by influencing ovarian reserve establishment and oocyte epigenetic competence. Strategic nutritional management is therefore essential to optimize ART outcomes and promote sustainable genetic progress in cattle production systems. Full article

The development of functional cereal-based products with enhanced nutritional and biological value is a priority in modern food science, as single-grain cereals often exhibit limitations in amino acid balance and micronutrient composition. This study aimed to develop, optimize, and evaluate a multicomponent cereal-based food mixture with improved functional and nutritional properties. A mixture composed of rice, buckwheat, oats, and corn was formulated using computer-based modeling to optimize essential amino acid composition and energy value in accordance with WHO recommendations. The technological process included cleaning, sorting, hydrothermal treatment, dehulling, drying, cooling, grinding, and subsequent blending of the cereal components. Standard methods were used to assess organoleptic properties, chemical composition, mineral and vitamin content, microbiological safety, and shelf life at a moisture content of 13–14%. The developed mixture demonstrated favorable sensory characteristics and a balanced chemical composition, with a protein content of 14.43 g/100 g, carbohydrates of 59.92 g/100 g, fat of 4.48 g/100 g, and an energy value of 322.74 kcal (1351 kJ) per 100 g. The product was rich in essential macro- and microelements and B-complex vitamins, met all microbiological safety requirements, and exhibited a shelf life of 4–5 months. These findings indicate that the proposed multicomponent cereal mixture is nutritionally balanced, safe, and suitable for functional and health-oriented food applications. Full article

Background and Purpose: The effects of B-vitamin combinations on the prevention of cardiovascular diseases, such as myocardial infarction (MI) and stroke, remain controversial. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) over three decades to evaluate the association between B-vitamin combinations and mortality and arterial thrombotic outcomes. Methods: PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched for RCTs with minimal duration over 24 months published between January 1996 and November 2025. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Cochrane Risk of Bias 2.0 tool. Random-effects models were used in this meta-analysis to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs). Results: Thirteen randomized trials enrolling 68,363 participants across both primary and secondary prevention populations were included. B-vitamin combinations were associated with a nonsignificant reduction in stroke and 3-point major adverse cardiovascular events (MACE) (stroke: RR 0.91, 95% CI 0.81–1.04; MACE: RR 0.93, 95% CI 0.86–1.01). No significant effects were observed for all-cause mortality (RR 1.01, 95% CI 0.96–1.06), cardiovascular mortality (RR 0.97, 95% CI 0.88–1.07), or MI (RR 0.97, 95% CI 0.91–1.03). In primary prevention populations, B-vitamin combinations were associated with significant reductions in stroke (RR 0.79, 95% CI 0.68–0.93) and MACE (RR 0.80, 95% CI 0.69–0.92). A modest reduction in MACE was also observed in secondary prevention populations (RR 0.91, 95% CI 0.83–0.99). Between-study heterogeneity was minimal to low for ischemic outcomes, supporting the robustness of these estimates, whereas substantial heterogeneity was observed for mortality outcomes in secondary prevention populations. Conclusions: The evidence is limited by heterogeneity in trial populations, vitamin formulations and doses, and outcome definitions, with substantial between-study inconsistency for mortality outcomes and imprecision in subgroup estimates derived from a small number of contributing trials. Overall, B-vitamin combinations do not confer consistent benefit for major cardiovascular outcomes but may reduce stroke and MACE in selected primary prevention populations, suggesting that baseline cardiovascular risk and regional folic acid fortification modify treatment effects and should guide future trial design and clinical use. Full article