Zach Bush M.D. Inroduction

An adult human typically has around 10 trillion human cells and about ten times as many non-human cells as human cells. The human microbiome also includes about100 trillion bacterial cells; and 1.5 billion Parasites; 124 trillion Fungi; 14 quadrillion Mitochondra cells; and uncountable numbers of viruses. The composition of human gut flora is continually changing and  immediate changes in the microbiota occur with our every breath.