ABSTRACT
A vast majority of microorganisms colonize the human body, including mucosal, skin, and gut environments, while bacteria are the biggest players among them. Humans also host single-celled organisms known as archaea, fungi, viruses, and other microbes. Interest in the role of the microbiome in human health and disease has flourished over the past decade owing to the advent of high-throughput sequencing technology and humanized gnotobiotic model for interrogating complex microbial communities. Recent research suggests that human health is affected by the gut microbiome. Clinical meta-omic approaches, i.e. phylogenetic marker-based microbiome profiling, metagenomics, metatranscriptomics, and metabolomics, have shown specific microbial functions that robustly stratify diseased individuals from healthy controls. Many of these functions are associated with multiple diseases, suggesting a role in host health, while others are specific to a particular disease and may indicate disease-specific etiology. This chapter aims to understand the human gut–microbiome interaction and provides an overview of how gut microbiome plays a role in host metabolism, nutrition, and disease. We further elucidate how imbalance or dysbiosis in the microbiome contributes to a broad spectrum of diseases, e.g. obesity, Crohn’s disease, type 2 diabetes, and irritable bowel disease, and their current advancement. In addition, microbiome-based novel therapy, such as fecal microbiome transplantation, prebiotics, and probiotics, is emerging diagnosis to ameliorate human gut microbiome dysbiosis.
