There are one or two differences between transubstantiation and being “born again.”
When one is born again, one is still oneself, and retains one’s identity. One becomes a “new creation,” but Legatus is still Legatus and sitetest is still sitetest.
When the sacrament is confected, the elements of bread and wine cease to exist. What is on the altar is now the Body, Blood, Soul and Divinity of Jesus Christ. Only the accidents (the appearances, not the reality of the thing) remain bread and wine. Thus, bread is no longer bread and wine is no longer wine.
There is certainly an analogy here, but it's not quite the same.
sitetest
Please notice I wrote “I repeat, in a VERY loose sense.” I don’t want anyone getting the idea my Eucharistic theology is unsound.