I think the theory of candida is really interesting, but I saw a 'red flag' when it promised to solve so many health problems.
I remember trying the candida diet several years ago, and I stuck to it pretty well. Having done that, I have to say I felt quite a bit better, but I think it was mostly from eliminating sugar and any junk food. While I don't buy totally into the candida overgrowth theory, I will say it points everyone towards better eating and just taking better care of our bodies. It sure doesn't hurt to eliminate sugar, and it's also helpful to know there are many hidden sugars in foods these days.
My doctor gets very irritated by theories such as this and claims it just promotes greed among scammers claiming to have cures. While that's often true, again, I do think there are still some "pros" for following such a diet. These days, though, I do allow a tiny amount of sugar in my diet daily, but I've really cut back from my more careless eating a few years ago.
ETA: Just wondering if this topic should be in the special thread for diet and food discussions? I just thought of that--too early in the morning, I guess!