The idea that advanced super-intelligent aliens would want to eat earthlings or consume Earth is nonsense. Why would such an entity travel across huge distances for such a small meal? The energy needed to get to Earth from even the closest star-system would be on the order of the mass of Jupiter. Any entity that can harness energy on that scale, can do anything it wants really. I assume that any super-intelligence worthy of the name would be able to synthesize any tasty morsel it wanted. They would have access to vast and rich sources for raw materials and even water almost anywhere in the distances between their home star-system and our Solar System.
However, it is possible that a clumsy or lazy super-intelligence might bring lower-level parasites and other pesky hitchhikers that might be harmful to earthlings.