Transubstantiation represents the literal conversion of the bread and wine into the body and blood of Christ during the communion ritual. It is one of the fundamental differences between the Protestant churches (mostly) and the Catholic Church as Protestant theology is less dogmatic on the ‘literal’ interpretation. For many Protestant churches, the bread and wine merely represent the body and blood of Christ.
Of course as Brewers, we are fully behind the literal conversion of sugars to alcohol and carbon dioxide. Fermentation definitely gets a resounding yes!