Paul speaks of how all of us are drawn together by our all receiving the same Christ as Holy Communion.
I don’t think one could give a magnetic charge to a loaf of bread, but to grasp the point Paul makes here, let’s pretend that a loaf of bread could be magnetized. Next, imagine that the priest pulling a switch de-magnetizes the loaf: after which, he breaks the loaf into many bite-sized pieces which he has us consume like Holy Communion.
Next, imagine him pulling the switch back on again, returning the charge to all the scattered bits of bread, so that they are magnetically drawn to reassemble themselves as the loaf.
That is one way of picturing what Paul meant when he said:
“The bread that we break, is it not a participation in the Body of Christ? Because the loaf of bead is one, we though many, are one Body, for we all partake of the one loaf.”
The same Christ whom we have all received into our hearts, wanting to reassemble himself as the loaf, pulls our hears together.