Bread loaded with beta-carotene, the stuff that makes carrots orange and helps prevent blindness, could improve the health of millions of people, thanks to a strain of genetically enhanced yeast developed by undergraduate students.

“It looks exactly like normal bread,” Arjun Khakhar, a junior biomedical engineering student at Johns Hopkins University, told me Monday. “There’s no orange color or anything because the yeast only makes up a very small part of the bread.”