Philo of Alexandria was the most influential Jewish-Greek theologian in the first century AD; it was he that originally introduced the idea that Logos is the son of the One god. (That, ostensibly, is how Apollos of Alexandria was able to preach accurately about the logos without knowing about Jesus, Acts 18:24-25)
In the Platonizing esoteric context of Philo, it seems straightforward to view epi-ousia as a kind of "soul" bread. That is, we should pray for the nourishment of our soul.
Soul, in the Platonizing context of Philo, is the noetic realm of mathematics and ideas—and typically placed above the material realm. The question of materialism vs epi-materialism is still a vibrant debate; Max Tegmark, Karl Popper and Roger Penrose for instance, advocate for the meaningful existence of non-material being. For instance, that the concept of a sphere exists universally, not merely through human conception.
Puts another spin on "soul food", too.
Except that in the Old Testament there was manna:
> Manna (Hebrew: מָן mān, Greek: μάννα; Arabic: اَلْمَنُّ; sometimes or archaically spelled mana) is, according to the Bible, an edible substance which God provided for the Israelites during their travels in the desert during the 40-year period following the Exodus and prior to the conquest of Canaan. It is also mentioned in the Quran three times.[1]
* https://en.wikipedia.org/wiki/Manna
God (YHWH) feeding his people was a concept that the Jewish people of Jesus' time would be very familiar with. Bread was quite sacred even in the Old Testament, as the Ark of the Covenant contained, in addition to the Ten Commandment tablets (as we learned from Indiana Jones), there was manna as well:
> And Moses said to Aaron, “Take a jar, and put an omer of manna in it, and place it before the Lord to be kept throughout your generations.” As the Lord commanded Moses, so Aaron placed it before the testimony to be kept.
* Exodus 16:33–34
There was also to be cereal offerings/sacrifices made in the Temple:
* https://en.wikipedia.org/wiki/Wave_offering
* https://en.wikipedia.org/wiki/Dough_offering
See also unleavened bread during the Passover:
* https://en.wikipedia.org/wiki/Passover#Matzah
Dr. Brant Pitre has a book called Jesus and the Jewish Roots of the Eucharist; presentation:
Mana is a Melanesian word for some sort of spiritual life force!