Chapter 6: The Gut Microbiota and Its Role in Nutraceuticals and Functional Foods Check Access

The human gastrointestinal (GI) tract harbours trillions of microorganisms, collectively known as gut microbiota, which have specific functions in nutrient metabolism, energy supply, xenobiotic and drug metabolism, maintenance of structural integrity of the gut mucosal barrier, immunomodulation, and protection against pathogens. There are direct or indirect interactions between the gut microbiota and the host, constructing a complex and dynamic micro-ecosystem that is closely related to human nutrition and health. The imbalance of gut microbial communities has been identified as the core defect that leads to a number of chronic diseases ranging from gastrointestinal inflammatory and metabolic conditions to neurological, cardiovascular, and respiratory illnesses. Extensive research studies have demonstrated that diet is one of the key modulators of the gut microbiota and plays an important role in promotion/modulation of human health. The long-term diet, as well as a short-term macronutrient change, can rapidly and reversibly alter the genomic composition and metabolic activities of microbiota in the human gut. However, the changes in the gut microbiota are distinct in response to different dietary components. This chapter summarises current knowledge of the development and composition of the microbiota in human GI, and how diet, especially some nutraceuticals and functional foods, affects human health through modulation of the gut microbiota.