When you hear this for the first time you might think, “why do people like bacon so much?” Apparently this idiom goes back to the 1600s where bacon meant a large piece of animal meat. In this sense, you can think of your body as bacon and someone helped to save your body from harm. But who knows, maybe people just really valued a good piece of bacon back then.
Definition
Save my bacon: To be helped out of a tricky situation
Save my bacon: わたしを窮地から救う
Examples
Example 1: Thanks for the help! You really saved my bacon.
私の危機を救ってくれてありがとう!