I don't even eat gluten

A: Hey, give me that. I don’t know what tricks you have up those new sleeves of yours.
B: You think I poisoned both drinks? That’s not my style. I don’t even eat gluten.

I saw the dialogue from the movie , and don’t know the meaning of the last line, “I don’t even eat gluten” means.
Is it something “between the lines”?

Thank you!!!

B is joking.
B makes the assumption that A suspects him to have something in the B’s sleeves, like assassins could have a knife or a poison.
Then he denies his own assumption, saying “That’s not my style”. Because from the context B must have poisoned either both or none of the drinks, but obviously B wasn’t going to die.
Moreover, B cares of his health to the point that B “doesn’t even eat gluten”.