ABSTRACT
This chapter discusses the concept of the holobiont, the mutual relationship between human cells and microbial cells. The global human microbiome has experienced a bacterial depauperation with the human adaptation to a modern lifestyle, particularly, since the western diet pattern became established in western societies, while the microbiome of people in rural populations are significantly richer and more diverse. This chapter discusses whether a less diverse and the “global microbial diversity crisis” is a risk factor for cancer and chronic disease development in modern societies.
