Foods high in starch won’t help your constipation or your gut flora, but they’ll benefit candida and pathogenic bacteria. There are plenty of vegetables that are better than potatoes, and bread isn’t hard to give up. If you’re eating that kind of stuff, you’ll probably be stuck in limbo not progressing past a certain point and not enjoying the tastiest foods you really want, so what’s the point? You might as well go for it 100% if you’re going to at all. It’s a big adjustment at first, but really, it’s not that much of a big deal when you’re a few weeks into it. It’s just food after all.