“Researchers at the Technical University of Denmark (DTU) and Lund University, Sweden, have used enzymes produced by a common gut bacteria to remove the A and B antigens from red blood cells, bringing them one step closer to creating universal donor blood.”
Probably not very when it comes to blood itself since they would be able to accept blood that’s been exposed to the enzymes from other people. But the enzymes might interact with other things in the body.