I've not read anything specifically about vegetable protein maintaining the digestive enzymes, but I guess it could happen. But I was in my organic grocery last week and the deli guy mentioned that too much soy protein can cause problems, too.
I wouldn't worry about it. Listen to your body (and I don't mean that gurgling noise). Moderation in all things (including moderation).
Maybe you should look forward to getting doubled-over sick, it might help fight off those favorite restaurant cravings next time
But seriously, a month is nothing. I think we're talking years here (unless you're naturally prone, which is genetic).
And remember, you need protein of some sort regularly. It's not healthy to go for a month without protein, one way or the other.