Dear Bubbles (Stavros)
Swallowing chewing gum is certainly not recommended.
Your body can't process chewing gum so it gets passed through unchanged. But there is a potential there for it to form the basis of a blockage. So it's not recommended.
For instance, I read a few years ago of a girl who developed a habit of chewing bits of paper and then swallowing them. The paper ended up forming a blockage in her intestinal track. It killed her.