Ratio between number of microbial cells and number of animal cells in body

Range 10 (outdated, updated value is 1.3, see comments section) unitless
Organism Human Homo sapiens
Reference Savage DC. Microbial ecology of the gastrointestinal tract. Annu Rev Microbiol. 1977 31: 107-33. p.107 top paragraphPubMed ID334036
Method Division of 1e+14 (BNID 102392) by 1e+13 (BNID 102390), both values from p.107 top paragraph in ref
Comments There are 1e+13 mammalian cells in the human body (BNID 102390) and 1e+14 microbial cells (BNID 102392). This is also the ratio between number of bacteria on the skin and the number of skin cells (see BNID 101734, 105712). See Gravitz 2012 PMID 22616099 p.S12 left column bottom paragraph: "The average human gut is home to trillions of bacteria. They outnumber the cells of their human host by a factor of ten to one, and collectively their genes outnumber human genes one hundred-fold." For updated values please see 3.8e+13bacteria/human body (BNID 113000) and 3.0e+13human cells/human body (BNID 113006) thus a ratio of 1.3 bacterial/human cells
Entered by Uri M
ID 102391