Both the bread and the cup are necessary parts of the communion service as commanded by Christ.Odd that Rome, who wants to take John 6:55 literally, departs from other literal commands.
Leviticus 6:30 But no sin offering shall be eaten from which any blood is brought into the tent of meeting to make atonement in the Holy Place; it shall be burned up with fire.
Sin offerings are NOT to be eaten. Period.
And this..... Leviticus 7:26-27 26 Moreover, you shall eat no blood whatever, whether of fowl or of animal, in any of your dwelling places. 27 Whoever eats any blood, that person shall be cut off from his people.”