But before you say congratulations, it wasn’t a stellar grade on a report card or end-of-year project. It’s my blood type, according to an at-home DIY blood typing kit I bought on Amazon—the Eldoncard ...

The key to changing blood types may be in the gut. Enzymes made by bacteria in the human digestive tract can strip the sugars that determine blood type from the surface of red blood cells in the lab, ...