microbial biomass Human Microbiota http://mpkb.org/home/pathogenesis/microbiota scientists are beginning to discover composed of microorganisms Microbes in the human body (MPKB) http://mpkb.org/home/pathogenesis/microbiota http://mpkb.org/home/pathogenesis/microbiota only a small percentage of the millions of non-human genes microbial biomass composed of microorganisms per a 2007 study Human Microbiota microbial biomass microbial biomass 100 trillion bacteria