Donald Trump on Thursday blamed a “young intern” for retweeting a jab at Iowa voters on his Twitter account and said the intern has apologized for it.

Earlier on Thursday, the GOP front-runner reposted a tweet from a follower who blamed Trump’s slide in an Iowa poll on genetically modified corn that “creates issues in the brain.”

The tweet, which referenced Monsanto, a pioneer in genetically modified organism (GMO) farming, has since been deleted.

A poll released by Quinnipiac University on Thursday shows Trump trailing in the first-in-the-nation Iowa caucus. Retired neurosurgeon Ben Carson leads the real-estate mogul 28 percent to 20 percent margin among likely caucus-goers in the state.

GMO farming produces larger crops and uses fewer resources, but critics say genetically modified food is not safe for consumption.

Monsanto has become the poster child for the anti-GMO movement, spurring a "March Against Monsanto" movement.

The Food and Drug Administration has said food made with GMOs is safe.