In a new letter to bishops, the Congregation for Divine Worship and the Discipline of the Sacraments denounced abuses against the Eucharist and "lack of respect in the sacred sphere," and reiterated existing norms regarding the Eucharist at Mass.
The letter, issued at the request of Pope Francis, reminds bishops of the norms concerning the Eucharist matter indicated in the Code of Canon Law and the Roman Missal, and explained in the Instruction Redemptionis Sacramentum of this Congregation of March 25, 2004.
According to those norms, "the bread used in the Holy Sacrifice of the Eucharist must be unleavened, of only wheat and made recently, so that there is no danger of it being corrupted." Therefore, "bread made with other substances" can not constitute the valid matter for the realization of the Sacrifice and the Eucharistic Sacrament.
In addition, they emphasized that "it is a serious abuse to introduce other substances such as fruit, sugar or honey in the manufacture of bread for the Eucharist."
As for wine, it states that it "must be natural, from the fruit of the vine, pure and without corrupting, without mixing of foreign substances," and insists that no other drinks “of any kind to be admitted for any reason, as they do not constitute valid matter.”
The letter also addressed norms regarding gluten-free hosts.
“Hosts that are completely gluten-free are invalid matter for the celebration of the Eucharist. Low-gluten hosts (partially gluten-free) are valid matter, provided they contain a sufficient amount of gluten to obtain the confection of bread without the addition of foreign materials and without the use of procedures that would alter the nature of bread,” the letter states.
The Congregation also issued a norm regarding GMOs, saying that “Eucharistic matter made with genetically modified organisms can be considered valid matter.”
In the letter, the Congregation emphasized that it is primarily the responsibility of diocesan bishops to ensure that these norms are being followed and that abuse is not occurring in their parishes.
Finally, it suggests that bishops work together to carry out out “the necessary checks on production, conservation and sale of the Eucharistic bread and wine in a given country and for other countries to which they are exported. It is recommended that the bread and wine to be used in the Eucharist be treated accordingly in the places where they are sold.”