my gut tells me
According to my instincts or intuition. I don't know, Tom—my gut tells me it was the path to the right that will lead us back to camp. My gut told me that he was the one to arrest, and I was right.
my gut tells me (that)
my instincts tell me that. (This refers to one's gut reaction or gut response.) My gut tells me that her idea is a sound one. This looks good on paper, but my gut tells me that it is all wrong.