Every person on earth has two genomes. The genome we inherit from our mom and dad is the one we are most familiar, and more or less stuck with for life. Our second genome, the one we initially acquire from mom as we pass through the birth canal, it is more dynamic and made up of trillions of bacteria that live on and in our body. Collectively known as our microbiome (our microbes and their genes). The evolutionary and ecological forces that are thought to have shaped our microbiome are governed not only by host genetics, but are profoundly conditioned by diet and lifestyle.