You are mistaken. Christ did not say the bread was His body.

"Take eat; this is my body" does not mean "This is not my body". Nor does it mean "This bread has become my body." Nor does it mean "This is my body but only in a spiritual sense." "Take eat; this is my body" means that Christ gives us His natural body to be eaten.

Luther would not have any fellowship, let alone communion, with Papists/Zwinglians/Calvinists. This intolerant attitude is held by all confessional Lutherans (Augsburg Confession, Formula of Concord, etc.). Do Zwinglians and Calvinists share fellowship and/or communion despite their differences?