The human gut microbiota, comprising trillions of microorganisms, has emerged as a pivotal modulator of chronic disease pathogenesis, influencing metabolic, immune, and neurological pathways. This research article synthesizes recent evidence demonstrating that compositional and functional imbalances in gut microbial communities termed dysbiosis contribute significantly to type 2 diabetes mellitus, obesity, cardiovascular disease, cancer, autoimmune disorders, and mental health conditions. Key mechanisms include reduced short-chain fatty acid production, increased lipopolysaccharide-mediated inflammation, trimethylamine-N-oxide generation, and dysregulation of the microbiota-gut-brain axis. Human studies reveal distinct microbial signatures, such as elevated Fusobacterium nucleatum in colorectal cancer and reduced Faecalibacterium prausnitzii in diabetes. The Indian gut microbiome exhibits unique features, including Prevotella and Megasphaera enrichment, with urbanization driving compositional shifts that may influence non-communicable disease susceptibility. Therapeutic avenues encompassing dietary modification, probiotics, prebiotics, fecal microbiota transplantation, and postbiotics show promise but face challenges in standardization, safety, and personalized implementation. This article proposes a conceptual framework for microbiome research, critically evaluates therapeutic evidence, and recommends precision-based strategies to translate microbiome science into clinical practice, emphasizing the need for India-specific research and policy integration.