Homeostasis and dysbiosis of the gut microbiome in health and disease

ABSTRACT

The human gastrointestinal tract (GIT) harbors taxonomically and functionally complex microbial ecosystem. The composition of the microbial species in the GIT ecosystem varies among individuals and throughout development. Bothenvironmental factors as well as host genetics influence the composition and homeostasis of GIT microbiome. Intrinsic GITmicrobiome can be characterized in terms of diversity, richness, dynamics and resilience. In healthy individual, microbialcommunities maintain homeostatic equilibrium and are resistant against perturbations. The resilience and resistance toperturbations of the GIT microbial ecosystem are robust but not absolute. Several factors can affect the homeostaticequilibrium of GIT microbiome and lead to dysbiotic microbiome configuration. Taxonomic and/or functional dysbiosis inthe GIT microbiome is associated with numerous health disorders like inflammatory bowel disease (IBD), malnutrition,metabolic disorders, asthma and neurodegenerative diseases. In this review, we discuss our current understanding ofhomeostasis and dysbiosis of the microbial ecology in the human gut and health disorders that are associated with themicrobiome dysbiosis.