Introduction to the Gut Microbiome and Its Impact on Health and Disease

Diet, environmental exposures, lifestyle, disease processes, and treatment modalities influence the gut microbiome. Optimal gut health and the onset and progression of numerous diseases are modulated by the stability and diversity of the gut microbiome. These diseases include gastrointestinal diseases, such as irritable bowel syndrome and Crohn's disease, and chronic diseases, such as obesity, type 2 diabetes mellitus, and cardiovascular disease. This review provides an introductory overview to the gut microbiome, basic definitions and distinctions, microorganisms contributing to the gut microbiome, their core functions and prevalence, factors that impact their composition, and their significant role in human health and disease.