For we being many are one bread, and one body: for we are all partakers of that one bread.
One bread - rather, 'loaf.' One loaf alone probably was used in each celebration.
(And) one body. Omit "and:" 'one loaf (that is), one body.' 'We, the many (communicants: so the Greek), are one bread (by partaking of the same loaf, which becomes assimilated to the substance of all; so we become), one body' (with Christ, 1 Corinthians 12:12, and with one another). Or, '(as there is) one bread (composed of many separate grains) (so) we the many are one body.'
We are all, х hoi (G3588) pantes (G3956)] - 'the whole of us.'