Nothing that isn't already happening. There is magnetite in many foods already. Often as inexpensive iron fortification. Also, your cells are more robust to ex

Nothing that isn't already happening. There is magnetite in many foods already. Often as inexpensive iron fortification. Also, your cells are more robust to external reactive oxygen than bacteria. The catalysis occurs when hydrogen peroxide is "activated" by the magnetite to produce singlet oxygen, which then goes on to damage biofilms and bacterial walls. Your epithelial cells are basically expendable. Internal ROS isn't good, but that isn't the case here.