what is the shelf life of wheat bran and oat bran?

Yesterday, I ate a whear/oat bran mixture that I bought from the store
about 2 weeks ago and ended up having problems sleeping the same
night. Was it because the bran went bad? Does anyone know the shelf
life of wheat/oat bran?
I am aware that the germ is removed from the wheat kernel to prevent
rancidity, but I thought the wheat bran outer hull was removed for
taste reasons. would it be correct to assume that the bran, like the
wheat germ, is removed for rancidity reasons also?