Bacteria vs. Human : Nature News

Scientists Bust Myth that Our Bodies Have More Bacteria than Human Cells

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A ‘reference man’ (one who is 70 kilograms, 20–30 years old and 1.7 metres tall) contains on average about 30 trillion human cells and 39 trillion bacteria, say Ron Milo and Ron Sender at the Weizmann Institute of Science in Rehovot, Israel, and Shai Fuchs at the Hospital for Sick Children in Toronto, Canada.

Those numbers are approximate — another person might have half as many or twice as many bacteria, for example — but far from the 10:1 ratio commonly assumed.

“The numbers are similar enough that each defecation event may flip the ratio to favour human cells over bacteria,” they delicately conclude in a manuscript posted to the preprint server bioRxiv1.

The 10:1 myth persisted from a 1972 estimate by microbiologist Thomas Luckey, which was “elegantly performed, yet was probably never meant to be widely quoted decades later”, say the paper’s authors. In 2014, molecular biologist Judah Rosner at the US National Institutes of Health at Bethesda, expressed his doubts about the 10:1 claim, noting that there were very few good estimates for the numbers of human and microbial cells in the body.

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About marypmadigan

Writer/photographer (profession), foreign policy wonk (hobby).
This entry was posted in Politics/Foreign correspondents, you learn something new every day. Bookmark the permalink.

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