The thing you should be asking yourself with these flours is “how will they benefit me?”
There’s only one prebiotic flour out of all of these and its the artichoke flour. Prebiotics feed the beneficial bacteria in the gut.
Another thing to consider is the glycemic load of each of these. For instance, amaranth flour is rather high in the glycemic index while oat bran is rather low.
Another factor is its inflammatory rating. Yams are rather inflammatory for instance. Chestnuts are off the charts in the inflammatory rating:
The lotus flour might be OK too, but I have never heard of it.