Answer:
Gut Microbiome
Explanation:
This is home base for the bacteria in your digestive tract. Here, they help you break down food and turn nutrients into things your body can use. They stop growing when they run out of food, so you'll only have what you need.
C) Hydrogen of water is separated from oxygen. DOES NOT OCCUR!
I am pretty sure that the medical condition you're looking for is Intussusception.
