Where do we get enzymes?

I'm curious, could you elaborate on the sources from which we acquire enzymes? Are these biological molecules naturally occurring within our bodies, or do we also derive them from external sources? Are there specific foods that are rich in enzymes, or are there other methods of supplementation? Additionally, how does the process of enzyme acquisition differ in the context of industrial applications, such as in the production of biofuels or pharmaceuticals? I'm eager to understand the full scope of where and how enzymes are sourced.