Answer:
C. New studies suggest microbes in our bodies help us instead of hurting us.
Step-by-step explanation:
The main idea of the article "A Brief Study of Guts" is that there are some microbes present in our gastrointestinal tract that gives us benefits instead of harming. There are trillions of microbes about 90 % of which are bacteria present in our gastrointestinal tract. These bacteria performs important functions such as break down of food substances, produces vitamins for the body and keep our immune system active and healthy so we can conclude that these microbes provides benefits to our body instead of harming.