Buckwheat don’t convince me at all, at least the whole grain. I have done enemas where I can see buckwheat grains totally undigested and surrounded by mucus. It means they were fermenting in the colon.
The carbs that are probably better are those that are digested and absorbed in the upper intestinal part. The secret to win this infection is to target the colon. It is there where the biggest fungal presence is.