I think this is one of those ideas, that when you first hear about it you scratch your head thinking what on earth could that be useful for?, but then the more you think about it, actually these researchers have a point.
It would be silly to have large edible robots but what if the future is filled with trillions of tiny insect-sized robots? There are already drones being built this size. From that perspective, this makes more sense. For a start they are biodegradable. It gives them all sorts of uses in monitoring health and delivering medicine to animals. Suddenly you can have a whole layer of monitoring tiny robots in the environment and not have to worry about pollution when they come to the end of their useful life span. Not to mention this is a targeted way of delivering food to vulnerable species that may be affected by climate change emergencies.
The human intestine is 6 meters long. It can be useful to locate problems with millimeter precision as this approach claims to do.