Gut microbiome and metabolic health: mechanisms and precision interventions

The gut microbiome is increasingly recognized as a fundamental regulator of metabolic health, shaping energy balance, insulin sensitivity, inflammatory tone, and inter-organ communication through a broad spectrum of microbial metabolites that engage host signaling pathways. In this review, we synthesize current mechanistic insights into how gut microbial communities shape metabolic function, with particular emphasis on short-chain fatty acids, secondary bile acid signaling, gut barrier integrity, immune modulation, and the microbiota-gut-brain-pancreas axis. We further summarize disease-associated alterations in microbial composition and function across obesity, type 2 diabetes, metabolic dysfunction-associated steatotic liver disease, and metabolic syndrome, highlighting key microbial and metabolic features that contribute to metabolic dysfunction. Evidence from germ-free models, fecal microbiota transplantation studies, and strain-level interventions suggests that shifts in microbial ecology may causally shape metabolic outcomes. We also critically evaluate emerging microbiome-centered therapeutic strategies, including targeted probiotics, prebiotics, dietary modulation, and fecal microbiota transplantation, while addressing factors that underlie inter-individual variability in treatment responses. In addition, we discuss the growing influence of multi-omics technologies, microbial metabolic modeling, and machine learning approaches in advancing precision microbiome medicine. To integrate these advances within a coherent framework, we outline a precision microbiome intervention pipeline linking multidimensional profiling to functional stratification and targeted therapeutic design. We also introduce a conceptual Precision Microbiome Intervention Triangle to mechanistically explain heterogeneity in responses to microbiome-targeted therapies. Collectively, these insights establish and position the gut microbiome as both a mechanistic driver and a modifiable therapeutic target in metabolic disease, and highlight key challenges and future directions for the development of personalized microbiome-based metabolic interventions.