I'm afraid not. Itch.io could presumably add a feature to let you hide your profiles from search engines, but once you leave a comment on someone else's game, it's out of your hands.

At the end of the day, commenting on other games is public and everyone can see. To some extend, that information is available to everyone.

One way to prevent this, is to make a new account that is not tied to your main account, where you can interact with games publicly.

Keep in mind that it’s against the rules to interact with your creations from other accounts, but anything else is fine.