I'm talking about what fiber really does. Feeds bacteria, which leads to more excretion of said bacteria. Hey if you like fiberous foods or cold potato then go for it! But, the problem that we have is the black swans. We have societies NOT eating tons of this who are healthy. Just saying, sure we can mark and measure various changes to the gut biome with more or less RS, but you cannot explicitly link those changes to an improved human condition. Not when there are so many instances of healthy humans that don't fit that model.
You might be able to explain it as a sort of prescription for post antibiotic use or some other neolithic item that would require special consideration. There is always that way of looking at utilizing it, but I'm not sure.