The Gut Microbiome in Health and Gastrointestinal Disease: From Dysbiosis to Therapeutic Targeting

This chapter provides a comprehensive appraisal of the human gut microbiome, examining its compositional dynamics across the lifespan and its mechanistic roles in intestinal homeostasis, mucosal immunity, and metabolic regulation. It critically evaluates the evidence linking microbial dysbiosis to the pathogenesis of inflammatory bowel disease, colorectal cancer, irritable bowel syndrome, and non-alcoholic fatty liver disease, while appraising emerging therapeutic strategies — including faecal microbiota transplantation, next-generation probiotics, and dietary modulation — aimed at restoring microbial equilibrium.