I am certainly not disrespecting Catholic beliefs about the Eucharist. But when a scientific claim is made I feel able to question it. In this case it was claimed that the ‘accidents’ of the Eucharist, the bread and wine, could not be corrupted. I know of no evidence tht this is so, and it seems most unlikely. Bacteria and other substances in human bodies act on the Eucharist after it is consumed, and as I dimly recall from my time as an altar boy there are protocols to follow to dispose of any ‘spoiled’ consecrated hosts. I would not myself raise disease as an issue in conjunction with the Eucharist, as I can see the potential for offence. But I am happy to discuss it once it is raised. The question I asked was about catholic teaching, and I think RobG has given a good reply above. As to the idea of Christ the healer being unable to transmit disease - do you believe this was true during his earthly life? Did he never pass on a cold? Did bacteria an parasites live in his body just as they do with all humans? Until now I would have thought this was a part of being fully human, and I would be interested to know if there is a belief or tradition which says this is not so. And yes, I admit to being most grievously off-topic,

and apologise to the OP, but the thread appeared to have cooled down.
. . . I didn’t mean to imply you were
intentionally disrespecting Catholic beliefs Hokomai . Yet, however inadvertent it may be, anything which weakens (or attacks or diverts) a Catholic’s faith in the True personal Presence of our Blessed Lord in the Eucharist, is not a good thing ; so one really should anticipate a firm response on that account – at least, at CAF. In the previous post , a link was provided to an article, whose title comes from Lumen Gentium :
The Holy Eucharist is the Source and Summit of the Christian Life. In other words , it is the Heart of our faith ; as the Catechism of the Catholic Church says (highlights mine) . . .
**VI. THE PASCHAL BANQUET
1382 **The Mass is at the same time, and inseparably, the sacrificial memorial in which the sacrifice of the cross is perpetuated and the sacred banquet of communion with the Lord’s body and blood. But the celebration of the Eucharistic sacrifice is wholly directed toward the intimate union of the faithful with Christ through communion. To receive communion is to receive Christ himself who has offered himself for us.
Anyone who interferes with that “intimate union”, should understand that they are not only getting in the faithful’s way, they are also obstructing Christ - from intimately uniting himself with them. If we present people with thoughts, sugggestions which are going to distract them at that particular moment, or make them apprehensive of receiving Holy Communion, that also is interfering.
. . . And yes, I admit to being most grievously off-topic,

and apologise to the OP, but the thread appeared to have cooled down.
I’m just as guilty in that respect too. But if the OP didn’t object , I wouldn’t be against discussing it with you further. Still, I continue to think you may not be interpreting IanGE’s post correctly (perhaps even his user name too ? I don’t seem to be able to find any posts by “RobG” -

)
Maybe we should begin there.
I believe you’re referring to this part
. . . it is not wine but the blood of Jesus and the host is His body. Incorruptible! . . .
It is quite common to refer to God as “incorruptible”. It is the very essence of God to exist (I AM)
Exodus 3:14
God replied, “I am who am.” Then he added, “This is what you shall tell the Israelites: I AM sent me to you.”
God is from everlasting to everlasting and He does not change – He doesn’t need to. So it is also correct to say that God is
absolute incorruptibility.
All following definitions quoted from
MODERN CATHOLIC DICTIONARY; Fr. John Hardon, S.J.
** INCORRUPTIBILITY**.
Incapacity of decay or destruction. This may be absolute, as God, who is wholly unchangeable by nature; or natural, as the angels and souls, which, being spirits, cannot disintegrate by decomposition; or substantial, as in physical nature, whose elements can be variously recombined but in their ultimate constituents are not destroyed.
IanGE is also correct when he says, *“it is not wine, but the Blood of Jesus.” *The substance is the Blood of Christ , only the accidents of wine (and bread) remain. Now one funny thing about accidents is that they cannot exist in and of themselves ; they must inhere in a substance or subject , yet transubstantiation says that the substance ( the essence – how it is defined) is the “Body and Blood of Christ.” The only reason the accidents ( appearances) of the bread and wine remain, is because they are “sustained in existence by divine power.”
TRANSUBSTANTIATION.
The complete change of the substance of bread and wine into the substance of Christ’s body and blood by a validly ordained priest during the consecration at Mass, so that only the accidents of bread and wine remain. While the faith behind the term was already believed in apostolic times, the term itself was a later development. With the Eastern Fathers before the sixth century, the favored expression was meta-ousiosis “change of being”; the Latin tradition coined the word transubstantiatio, “change of substance,” which was incorporated into the creed of the Fourth Lateran Council in 1215. The Council of Trent, in defining the “wonderful and singular conversion of the whole substance of the bread into the body, and the whole substance of the wine into the blood” of Christ, added “which conversion the Catholic Church calls transubstantiation” (Denzinger 1652). After transubstantiation, the accidents of bread and wine do not inhere in any subject or substance whatever. Yet they are not make-believe; they are sustained in existence by divine power. (Etym. Latin trans-, so as to change + substantia, substance: transubstantiatio, change of substance.)
ACCIDENTS
Things whose essence naturally requires that they exist in another being. Accidents are also called the appearances, species, or properties of a thing. These may be either physical, such as quantity, or modal, such as size or shape. Supernaturally, accidents can exist, in the absence of their natural substance, as happens with the physical properties of bread and wine after Eucharistic consecration.
SUBSTANCE.
A being whose essence requires that it exist in itself. It is an ens per se (a being by itself) or ens in se (a being in itself). It is commonly distinguished from an accident, whose essence is to exist in another, that is, in a substance. (Etym. Latin substantia, that which stands under, principle, foundation.)