Zipping Up Multiple Public_html Folders From Shell

OK so I'm on the shell and looking at the contents of my home/ directory which has all the various accounts. In each account directory are subdirs such as mail, logs, tmp, etc, and public_html. Is there a way (or a ZIP command) to be in the home directory and create a massive ZIP file containing all the account directories, each containing ONLY the respective public_html subdir for that account?

Using the command "zip -r Backups.zip ./" seems to include all those extra folders (such as mail, etc.) that aren't needed.