The Invisible Extinction.

The characterization of the human microbiome has opened a new chapter in understanding human biology and its relationship to health and disease. Yet we also have learned that our ancient coevolved microbiome has been changing across recent human generations; we have been losing a substantial amount of its diversity. This is especially concerning because the microbiota that we acquire early in life has important bearing on our developmental trajectory, especially with regard to metabolism, immunity, and cognition. Collectively, the early-life microbiota is a partner in our human developmental biology. We detail the medical, public health, and dietary phenomena bearing on the acquisition, maintenance, and loss of members of the microbiota and then consider the linkages between the altered microbiome and the diseases that have been emerging in recent years. Finally, we highlight ways to address and solve these problems associated with modernization.