I promised not to post anymore links, so you'll have to research this on your own.
The colon is lined by special cells called colonocytes. They are special in that they get their energy from the bacteria which reside in your large intestine. Starved of substrate, they undergo autophagy and die. They do not get fed if you eat butyrate, only if you eat a resistant starch...not soluble or insoluble fiber, but resistant starch. This is where the claim that RS is protective of colon cancer comes from.
Protecting the gut and having a flourishing population of gut microflora is of utmost importance. That is not wild speculation by the Rice Crispy Corp.
Someone who needs to stay in ketosis for medical reasons, could still provide RS at 20-100g per day and stay in ketosis as RS is not turned into blood sugar and actually creates it's own SCFA, enhancing ketosis.
It is really, really bizarre to me that you guys find this line of thinking superfluous. Starch, meh. Resistant Starch, yeah!