What you think about the body, does it only consists of muscles, nerves, bones and all the other components? But sorry you missed one thing that is; our body is the house to hundreds of germs or micro-organisms. In which a few bacteria and yeast are essential for our body, at the same time their impact is very harmful.
Now, you will think of how you can get to know that your body has parasites which are harmful to health. Then you need to read this article: