What is the human microbiome?

To organize this text, the author divides it into sections with subheadings. What contrast does the author make in the section with the subheading "Look, Ma, No Cavities!"?

Some species of bacteria benefit humans. What information in the text supports this statement?

Bacteria that are helpful in one place may be harmful in another. What information in the text supports this statement?

What is the main idea of this text?

Read these sentences from the text. "perhaps not surprisingly, skin-our interface with the world-supports a large number of the body's most diverse populations of bacteria. There are at least 1,000 different species of skin bacteria, along with dozens of fungi and other microbes. Most aren't harmful, and many protect us." Based on this information, what does the word "diverse" probably mean?

Read this sentence from the text. "In fact, the microbiome is so important that it is like an additional organ-a part of the body that serves a vital function, like the skin or kidney's." What word or phrase could replace the second "like" in this sentence without changing the sentence's meaning?