51 I am the living bread which came down from heaven; if any one eats of this bread, he will live forever; and the bread which I shall give for the life of the world is my flesh (sarks)."
52 ¶ The Jews then disputed among themselves, saying, "How can this man give us his flesh (sarks) to eat (phagein)?"
53 So Jesus said to them, "Truly, truly, I say to you, unless you eat (phagein) the flesh (sarks) of the Son of man and drink his blood, you have no life in you;
54 he who eats (trogein) my flesh and drinks my blood has eternal life, and I will raise him up at the last day.
55 For my flesh (sarks) is food indeed, and my blood is drink indeed.
56 He who eats (trogein) my flesh (sarks) and drinks my blood abides in me, and I in him.
57 As the living Father sent me, and I live because of the Father, so he who eats (trogein) me will live because of me.
58 This is the bread which came down from heaven, not such as the fathers ate (phagein) and died; he who eats (trogein) this bread will live forever."
Sarks = Flesh
Phagein = Eat
Trogo = Gnaws or Chews
As you can tell, the difference between Phagein and Trogein is huge. We are truly called to gnaw/chew on the body of Christ. If you want to learn more about this, please listen to my homily, I think it offers a fairly good explanation. However, in the homily I did not use the word "gnaws" because I did not want to freak out any children, however "gnaws" would be a better translation.