Human Gut microbiota Micro biome o the human gut microbiota is a complex ecosystem composed of approximately 1014 bacteria and archaea, as well as fungI and viruses >10 times larger than the human cell complement o The human gut microbiome is the collective genome capacity( genes) of the gut microbiota 150 times larger than the human gene complement with an estimated 3. 3 million microbial genesHuman Gut Microbiota & Microbiome  The human gut microbiota is  a complex ecosystem composed of approximately 1014 bacteria and archaea, as well as fungi and viruses  10 times larger than the human cell complement  The human gut microbiome is  the collective genome capacity (genes) of the gut microbiota  150 times larger than the human gene complement, with an estimated 3.3 million microbial genes