In this chapter, we explore how the rapidly burgeoning scientific understanding of the gut microbiome can be applied in order to develop dietary strategies that optimize the composition and function of this bacterial community for better health and well-being. We review the many factors in the Western lifestyle that affect the integrity and ecological balance of the gut microbiome, and how dietary approaches can be used as a basic strategy to counteract their negative effects. To take maximum advantage of this strategy, it is important to understand the precise chemical composition of the foods we consume, in order to better understand how food components interact with the gut microbiome. This should facilitate the rational use of specific foods and food supplements to shape the microbiome in well-defined directions. In addition, food can also be supplemented with live microorganisms that fulfill or enable important functions within the gut microbiome. Overall, these dietary approaches have great potential for promoting well-being and for contributing to the prevention or treatment of the many diseases now known to be related to gut microbiome imbalances.