Flip Me

Riddle: I am a sentence that can be flipped around yet still be the same. You may find me strange but here's a hint, I trade with something that brings allergies and a treat to a cat. What sentence am I?

Answer: A nut for a jar of tuna. Source: https://riddles.com/index.php/3375

I am a sentence that can be flipped around yet still be the same. You may find me strange but here's a hint, I trade with something that brings allergies and a treat to a cat. What sentence am I? — Flip me by L.K.KITTYCAT Riddle