Antibiotic pressure exerts profound effects on bacterial physiology, not limited to classical genetic resistance mechanisms. Increasing evidence highlights the ability of pathogens to undergo metabolic rewiring—an adaptive, reversible reorganization of core metabolic pathways that promotes survival under antimicrobial stress. This review provides a comprehensive analysis of antibiotic-induced metabolic adaptations, encompassing glycolysis, the tricarboxylic acid cycle, fermentation, redox balance, amino acid catabolism, and membrane biosynthesis. We critically examine how diverse antibiotic classes—including β-lactams, aminoglycosides, quinolones, glycopeptides, polymyxins, and antimetabolites—interact with bacterial metabolism to induce tolerance and persistence, often preceding stable resistance mutations. In parallel, we explore the ecological and host-derived signals—such as immunometabolites and quorum sensing—that modulate these metabolic responses. Therapeutically, targeting metabolic pathways offers promising strategies to potentiate antibiotic efficacy, including enzyme inhibition, metabolic adjuvants, and precision-guided therapy based on pathogen metabolic profiling. By framing metabolic plasticity as a dynamic and evolutionarily relevant phenomenon, this review proposes a unifying model linking transient tolerance to stable resistance. Integrating metabolic rewiring into antimicrobial research, clinical diagnostics, and therapeutic design represents a necessary paradigm shift in combating bacterial persistence and resistance.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as the leading cause of chronic liver disease worldwide, driven by the global epidemics of obesity, type 2 diabetes, and metabolic syndrome. In this evolving nosological landscape, alcohol consumption—traditionally excluded from the diagnostic criteria of non-alcoholic fatty liver disease (NAFLD)—has regained central clinical importance. The recently defined MetALD phenotype acknowledges the co-existence of metabolic dysfunction and a significant alcohol intake, highlighting the synergistic nature of their pathogenic interactions. This narrative review provides a comprehensive analysis of the biochemical, mitochondrial, immunometabolic, and nutritional mechanisms through which alcohol exacerbates liver injury in MASLD. Central to this interaction is cytochrome P450 2E1 (CYP2E1), whose induction by both ethanol and insulin resistance enhances oxidative stress, lipid peroxidation, and fibrogenesis. Alcohol also promotes mitochondrial dysfunction, intestinal barrier disruption, and micronutrient depletion, thereby aggravating metabolic and inflammatory derangements. Furthermore, alcohol contributes to sarcopenia and insulin resistance, establishing a bidirectional link between hepatic and muscular impairment. While some observational studies have suggested a cardiometabolic benefit of a moderate alcohol intake, emerging evidence challenges the safety of any threshold in patients with MASLD. Accordingly, current international guidelines recommend alcohol restriction or abstinence in all individuals with steatotic liver disease and metabolic risk. The review concludes by proposing an integrative clinical model and a visual cascade framework for the assessment and management of alcohol consumption in MASLD, integrating counseling, non-invasive fibrosis screening, and personalized lifestyle interventions. Future research should aim to define safe thresholds, validate MetALD-specific biomarkers, and explore the efficacy of multidisciplinary interventions targeting both metabolic and alcohol-related liver injury.

Over the past two decades, metabolic syndrome (MetS) and infections caused by multidrug-resistant (MDR) pathogens have emerged as converging global health challenges. Traditionally investigated as separate entities, accumulating evidence increasingly supports a bidirectional relationship between them, mediated by chronic inflammation, immune dysregulation, gut microbiota alterations, and antibiotic-driven expansion of the resistome. This narrative review examines the complex immunometabolic interplay linking MetS and MDR infections, focusing on molecular mechanisms, clinical implications, and prospective research directions. A systematic literature search was conducted using major databases, including PubMed and Scopus, targeting studies from the last 15 years that explore the interface between metabolic dysfunction and antimicrobial resistance. Particular attention is given to key immunometabolic pathways such as the IRS–PI3K–AKT–mTOR axis; the contribution of visceral adiposity and Toll-like receptor (TLR)-mediated inflammation; and the role of gut dysbiosis in augmenting both susceptibility to infections and metabolic derangements. Evidence is presented supporting the hypothesis that MetS increases host vulnerability to MDR pathogens, while chronic MDR infections may reciprocally induce systemic metabolic reprogramming. Viral infections with established metabolic sequelae (e.g., HIV, hepatitis C virus [HCV], and cytomegalovirus [CMV]) are also considered to broaden the conceptual framework. Although current data remain largely associative and fragmented, the emerging MetS–MDR syndemic model poses substantial challenges for translational research, antimicrobial stewardship, and personalized therapeutic strategies. Recognizing this reciprocal relationship is pivotal for refining infection risk stratification, optimizing treatment, and informing public health policies. Further investigations are warranted to elucidate the magnitude and directionality of this association and to identify predictive immunometabolic biomarkers that may guide targeted interventions in high-risk populations.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a highly prevalent liver-centred manifestation of systemic metabolic dysfunction. The gut–liver axis provides a biologically credible therapeutic rationale because intestinal dysbiosis, impaired barrier integrity, microbial metabolites, bile acid signalling, short-chain fatty acids, and trimethylamine N-oxide may influence hepatic steatosis, inflammation, and fibrogenesis. This narrative review critically evaluates dietary patterns, prebiotics, probiotics, synbiotics, postbiotics, and fecal microbiota transplantation (FMT) as microbiome-directed strategies in MASLD. The comparative framework prioritises disease-specific human evidence, clinically meaningful endpoints, trial duration and sample size, reproducibility, safety, and feasibility. Dietary optimisation remains the most clinically grounded intervention, whereas probiotics and synbiotics show modest and heterogeneous signals on biochemical or metabolic surrogate endpoints. Prebiotics are mechanistically coherent but supported by limited liver-centred trials. Postbiotics and microbiome-mediated bioactives remain early-stage and require stricter definitional boundaries. FMT is investigational and should not be extrapolated from its established role in recurrent Clostridioides difficile infection. Most available evidence across all intervention categories relies principally on surrogate endpoints—including aminotransferases, insulin resistance indices, lipid parameters, and microbiome compositional shifts—rather than on validated liver-centred outcomes such as histological improvement or quantitative liver fat assessment; this constrains the strength of conclusions that can currently be drawn. Across all categories, microbiome modulation does not by itself establish liver disease modification, and no microbiome-targeted nutritional intervention has yet demonstrated histological benefit in MASLD. Future trials in this field should prioritise validated hepatic endpoints, phenotype-stratified patient enrolment, adequate follow-up duration, and direct comparisons between intervention categories to determine which microbiome-directed strategies, if any, deliver measurable and reproducible hepatic benefit beyond surrogate markers.