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🧬Human BodyHuman Biology20 sec read

Your Body Houses Roughly as Many Bacterial Cells as Human Cells

For decades, textbooks claimed bacteria outnumbered human cells 10 to 1, but a 2016 recalculation showed the true ratio is closer to 1.3 to 1.

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Approximately how many trillion bacterial cells live in an adult human body?

Your guess:0 trillions
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The colon contains orders of magnitude more bacteria than any other part of the human body.

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Why / How?

01

Scientific Mechanism

Researchers at the Weizmann Institute calculated that a 70 kg adult male has roughly 30 trillion human cells and 38 trillion bacteria. Nearly all of those microbes reside in the colon, weighing only about 200 grams in total.

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Why It Matters

The colon contains orders of magnitude more bacteria than any other part of the human body.

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Where do the vast majority of the body's 38 trillion bacteria reside?

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Approximately how many trillion bacterial cells live in an adult human body?

38 trillions

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Where do the vast majority of the body's 38 trillion bacteria reside?

In the colon (large intestine)

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