I see no particuliar reason to ingest diatomaceous earth.
It is a highly absorbant substance used to stabilize nitroglycerine to form dynamite.
It's the skeletal remains from fossilized water plants, algae-like plants it may be used as a barrier to control adult flea beetles and just about all insects. I used it as a filter medium for my swimming pool when used as a powder you must wear a dust mask. It also comes in food grade for parasites.