Probiotics can help - but I think DA has a probiotic in it already, right? You could always try supplementing what's already there with soy yogurt. If DA doesn't contain probiotics, then that's certainly something you can try.
Other than that, my best advice is to eat safely, drink plenty, get lots of rest, and therefore try to avoid *other* potential triggers.
Honestly, I've been on antibiotics a couple times, and it really hasn't been that bad at all. Whatever you do, don't worry, because you're twice as likely to upset your guts by worrying!