Final answer:
Commensal bacteria are the approximate parent of all bacteria that are harmless and can even be beneficial to humans. They live in or on the human body without causing harm and can provide benefits such as aiding in digestion, producing vitamins, and preventing harmful bacteria from colonizing certain areas.
Step-by-step explanation:
The approximate parent of all bacteria that are harmless and can even be beneficial to humans are called "commensal bacteria."
These bacteria live in or on the human body without causing harm and can provide benefits such as aiding in digestion, producing vitamins, and preventing harmful bacteria from colonizing certain areas.
For example, the bacteria in our gut, such as Lactobacillus and Bifidobacterium, help break down food and produce vitamins like vitamin K.