AudioSuite in Pro Tools is destructive signal processing. Using it, though, does not actually destroy anything. You will not lose any audio. It is called destructive because it writes (renders in Avidspeak) a new file with the processing added, and inserts the new file in the time line, at the proper place replacing the original audio.
The original audio will always be available in the Clips folder, if you need it.
Actually, this makes AudioSuite very valuable for sound effects creation. Select an AudioSuite plugin to process the file with, hit Render, and you now have a new file that has your processing permanently included. This file can then be exported and kept in your personal library, for use on future projects.
This is an example of when creating a new file with the processing “baked in” is a better option than real-time DSP.