Narutos bloodline will be something that is related to sasuke the other way round.
As you already see Naruto and Sasuke are Antagonists from the situation where Sasuke left Konoha with Orochimaru. Therefore Narutos's kekkei genkai must be something to knock out sharingan. This power might even come from Itachi (as he placed the bird in narutos mouth) but i doubt that
I think naruto's kekkei genkai is his will and his mind. Nobody has so good knowledge of knowing people by seeing them ones. Or he will be that fast as his father that even sharingan is not able to predict his movements.
Moreover it could be a kekkei genkai that he can control bijuu or can endure the chakra of the nine tails cause of the bloodline limit of his mother...
dont know
But these were MY thoughts

(moreover it can be that being able to get into sage mode is a kekkei genkai)