Which Statement About the Relationship Between Bacteria and the Human

Question

Which statement about the relationship between bacteria and the human body is most accurate?
A) Although many tissues are kept bacteria-free, around 100 trillion bacteria live on or in us.
B) About one-tenth of our body weights are due to bacteria
C) Bacteria are found in the mouth, stomach, and intestines in about equal amounts.
D) Most bacteria are transient; that is, they come for brief periods and then are gone.

Accepted Answer

This statement is the most accurate as it reflects current scientific understanding that humans are colonized by a vast number of bacteria, with estimates suggesting that the number of bacterial cells in the human body is roughly equal to the number of human cells. While some tissues are generally kept bacteria-free, such as the bloodstream and certain internal organs, bacteria are found throughout the body, with the largest populations in areas like the gut, mouth, and skin. Option B is not accurate as it greatly exaggerates the contribution of bacteria to body weight. Option C is also not entirely accurate as bacteria populations vary widely between different parts of the digestive tract. Option D is also not accurate as many species of bacteria can establish more long-term or even permanent residence in the body.