The term "communion of saints" therefore has two closely linked meanings: communion in holy things (sancta)" and "among holy persons (sancti).
"Sancta sancti's! ("God's holy gifts for God's holy people") is proclaimed by the celebrant in most Eastern liturgies during the elevation of the holy Gifts before the distribution of communion. The faithful (sancta) are fed by Christ's holy body and blood (sancta) to grow in the communion of the Holy Spirit (koinonia) and to communicate it to the world.
Source: Catechism of the Catholic Church (Vatican.va)