For we being many are one bread, and one body: for we are all partakers of that one bread.

People's New Testament

10:17 For we being many are one bread. One loaf. There being one loaf implies that we Christians, though many, are all one body, and joint participators of the one body of Christ. Paul had no conception of a divided church.

Wesley's Notes

10:17 For it is this communion which makes us all one. We being many are yet, as it were, but different parts of one and the same broken bread, which we receive to unite us in one body.

Jamieson-Fausset-Brown Bible Commentary

17. one bread-rather, "loaf." One loaf alone seems to have been used in each celebration.

and one body-Omit "and"; "one loaf [that is], one body." "We, the many (namely, believers assembled; so the Greek), are one bread (by our partaking of the same loaf, which becomes assimilated to the substance of all our bodies; and so we become), one body" (with Christ, and so with one another).

we . all-Greek, "the whole of us."

Matthew Henry's Concise Commentary

10:15-22 Did not the joining in the Lord's supper show a profession of faith in Christ crucified, and of adoring gratitude to him for his salvation ? Christians, by this ordinance, and the faith therein professed, were united as the grains of wheat in one loaf of bread, or as the members in the human body, seeing they were all united to Christ, and had fellowship with him and one another. This is confirmed from the Jewish worship and customs in sacrifice. The apostle applies this to feasting with idolaters. Eating food as part of a heathen sacrifice, was worshipping the idol to whom it was made, and having fellowship or communion with it; just as he who eats the Lord's supper, is accounted to partake in the Christian sacrifice, or as they who ate the Jewish sacrifices partook of what was offered on their altar. It was denying Christianity; for communion with Christ, and communion with devils, could never be had at once. If Christians venture into places, and join in sacrifices to the lust of the flesh, the lust of the eye, and the pride of life, they will provoke God.