Gut Microbiota and Its Importance in Health and Disease

The relationship between gut microbiota and human health is being increasingly recognized. It is now well established that a healthy gut flora is mainly responsible for the host’s overall health. The normal human gut microbiota comprises two significant phyla: Bacteroidetes and Firmicutes. Several factors shape the normal gut microbiota, such as the mode of delivery, diet, use of antibiotics, or antibiotic-like molecules derived from the environment or the gut commensal community. The microbial communities are symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases, including cardiovascular diseases, cancers, respiratory diseases, dementia, etc. This chapter discusses the current knowledge of how microbiota links to host health or pathogenesis.