Q - If the Church believes in transubstantiation, that the bread and wine become "entirely" Jesus, and that the "appearance" of the bread and wine only remains, why then do some people need gluten free host? If there is no more wheat present, then people should not become ill whether they truly believe or not....right? Does that mean some one could get drunk off of drinking too much of the Precious Blood? Gluten free host to me sends a conflicting message about the true Presence of Jesus in the Holy Eucharist.
A - Thanks for the question. There are some misconceptions about what the Church teaches in your question. So, let me clear them up for you.
First of all, Christ is present in the Eucharist "body, blood, soul, and divinity". This means that all of Christ is present, as you have said.
But, the Eucharist still has all the properties of bread and wine. These are called the "accidents" of the Eucharist. While the Eucharist has changed completely - in its essence - it still has all the properties of bread and wine.
Thus, the effects of drinking the Blood of Christ or eating the Body of Christ will mean that that our bodies will experience it as if it were still bread and wine. If we drink two chalices of the Sacred Blood - we will feel the alcohol. If a person with celiac disease eats the Body of Christ - they will have an allergic reaction.
To be accurate with language, to say that the Eucharist has the "appearance" of bread and wine does not just mean they look like they are bread and wine, but retain the properties of bread and wine - though it is no longer bread and wine after the consecration. Thus, every time consecration of bread and wine happens in Mass, we have a true miracle - the properties of the natural world are no longer in control as the essence of what is on the altar changes, all while the physical properties appear the same.
I hope this helps.