A Eucharistic miracle is any miracle involving the Eucharist, regarding which the most prominent Christian denominations, especially the Roman Catholic Church, teach that Christ is truly present in the Eucharist, which is by itself a Eucharistic miracle; however, this is to be distinguished from other manifestations of God. Eucharistic miracles are most known and emphasized within the context of the Catholic Church, which distinguishes between divine revelation, such as the Eucharist, and private revelation, such as Eucharistic miracles.
In general, reported Eucharistic miracles usually consist of unexplainable phenomena such as consecrated Hosts visibly transforming into myocardium tissue, being preserved for extremely long stretches of time, surviving being thrown into fire, bleeding, or even sustaining people for decades.
In the modern Catholic Church, commissions are appointed by local bishops to scientifically and theologically investigate supposed miracles before deciding whether they are worthy of belief. This has sometimes resulted in discoveries where Eucharistic miracles were caused by contamination of red colored microorganisms, such as Neurospora crassa or Serratia marcescens. A 2025 forensic study by Polish scientists of 25 reported Eucharistic miracle cases found no evidence of human blood or human tissue other than isolated epidermal cells and single erythrocytes, and no human DNA except once from trace contact with the genetic marker being I1. The authors identified microbial and fungal contamination in several cases, including pigment-producing species that could explain blood-like discoloration. Serratia marcescens was found only twice, thus casting doubt on its significance in such occurrences, while other fungal and microbial species producing reddish-pink or orange-reddish pigments were discovered.
As with other private revelations, such as Marian apparitions, belief in approved miracles is not mandated by the Catholic Church, but often serves to reassure believers of God's presence or as the means to "send a message" to the population at large.
Background
Theology of the Real Presence
Roman Catholic Eucharistic doctrine draws upon a quasi-Aristotelian understanding of reality,See Edward J. Kilmartin, The Eucharist in the West: History and Theology, ed. Robert J. Daly (Collegeville: Liturgical Press/Pueblo, 1998), 147-153. in which the core substance or essential reality of a given thing is bound to, but not equivalent with, its sensible realities or accidents. In the celebration of the Eucharist, by means of the consecratory Eucharistic Prayer, the actual substance of the bread and wine are changed into the body and blood of Christ. This change in substance is not, however, the outward appearances of the bread and wine—their accidents—which remain as before. This substantial change is called transubstantiation, a term reserved to describe the change itself. Scholastic philosophical terminology was used but is not a part of the dogma that defined Christ's presence for the Roman Catholic Church at the Council of Trent. In the 13th session of 11 October 1551, it promulgated the following conciliar decree:
Protestant views on the concept of Christ's presence in the Eucharist vary significantly from one denomination to another: while many, such as Lutherans, Anglicans, Methodists and the Reformed agree with Roman Catholics that Christ is really present in the Eucharist, they do not accept the definition of transubstantiation to describe it.See, e.g., Thomas J. Davis, This is My Body: The Presence of Christ in Reformation Thought (Grand Rapids: Baker Academic, 2008).
According to Thomas Aquinas, in the case of extraordinary Eucharistic miracles in which the appearance of the accidents are altered, this further alteration is not considered to be transubstantiation, but is a subsequent miracle that takes place for the building up of faith. Nor does the extraordinary manifestation alter or heighten the presence of Christ in the Eucharist, as the miracle does not manifest the physical presence of Christ:
Some denominations, especially Lutherans, have similar beliefs regarding the Eucharist and the Real Presence, though they reject the Roman Catholic concept of transubstantiation, preferring instead, the doctrine of the sacramental union, in which:
Lutherans hold that the miracle of the Eucharist is effected during the Words of Institution. Both the Eastern Orthodox Churches and the Oriental Orthodox Churches, such as the Coptic Church, insist "on the of the change from bread and wine into the body and the blood of Christ at the consecration of the elements," although they have "never attempted to explain the of the change," thus rejecting philosophical terms to describe it. The Methodist Church similarly holds that Christ is truly present in the Eucharist "through the elements of bread and wine," but maintains that how he is present is a Holy Mystery. All Anglicans affirm the real presence of Christ in the Eucharist, though Evangelical Anglicans (as with other Reformed Christians) believe that this is a pneumatic presence, while those of an Anglo-Catholic churchmanship believe this is a corporeal presence, but at the same time questioning the philosophical explanation of transubstantiation.
History
Jesuit scholar Francis Clark traces miracles involving the Eucharist back to the 3rd century, and states that the first miracle to involve a bleeding host was reported in the 5th century.
In 1264, Pope Urban IV instituted the Feast of Corpus Christi. This feast was, according to legend, prompted by the miracle at Bolsena.
Extraordinary Eucharistic miracles in the Catholic Church
The Catholic Church regards every administration of the Eucharist to be a miracle, as in their conception the Eucharist becomes the true body of Christ. The title 'extraordinary Eucharistic miracle' is used to distinguish numerous reported miracles regarding the Eucharist from the miracle of standard transubstantiation. This section describes a variety of events and phenomena that fall under the category of Extraordinary Eucharistic miracles in the Catholic Church.
Host becoming flesh and blood
One type of Eucharistic miracle is where the Eucharist becomes human flesh as in the miracle of Lanciano which some believe occurred at Lanciano, Italy, in the 8th century,Linoli O. "Histological, immunological and biochemical studies on the flesh and blood of the eucharistic miracle of Lanciano (8th century)." Quad Sclavo Diagn. 1971 Sep; 7(3):661-74The Eucharistic miracle of Lanciano, Italy in The Eucharistic Miracles of the World (Catalogue of the Vatican International Exhibition). Eternal Life; 1st edition (January 1, 2009), 330 pages. ISBN 9781931101028 or the Eucharist becomes human blood as in the miracle of Santarém which some believe occurred at Santarém, Portugal, in the 13th century.The Eucharistic miracle of Santarém, Portugal in The Eucharistic Miracles of the World (Catalogue of the Vatican International Exhibition). Eternal Life; 1st edition (January 1, 2009), 330 pages. ISBN 9781931101028 The Catholic Church officially recognized both miracles as authentic. However, a Eucharistic miracle more commonly reported is that of the bleeding Host, where blood starts to trickle from a consecrated host, the bread consecrated during Mass. Other types of purported miracles include consecrated hosts being preserved for hundreds of years, such as the event of the Miraculous Hosts of Siena.
The Mass at Bolsena, depicted in a famous fresco by Raphael at the Vatican in Rome, was an incident said to have taken place in 1263. A Bohemian priest who doubted the doctrine of transubstantiation celebrated Mass at Bolsena, a town north of Rome. During the Mass the bread of the eucharist began to bleed. The blood from the host fell onto the altar linen in the shape of the face of Jesus as traditionally represented, and the priest came to believe.
An alleged 1370 Brussels miracle involves an allegation of host desecration; Jews were accused of desecrating several Hosts, but they miraculously bled and were otherwise unharmed. The Hosts were venerated in later centuries.
Caesarius of Heisterbach recounts various tales of Eucharistic miracles in his book Dialogue on Miracles; most of the stories he tells are from word of mouth. They include Gotteschalk of Volmarstein who saw an infant in the Eucharist, a priest from Wickindisburg who saw the Host turn into raw flesh, and a man from Hemmenrode who saw an image of a crucified Jesus and blood dripping from the Host. All of these images, however, eventually reverted into the Host. Caesarius also recounts more extraordinary tales, such as bees creating a shrine to Jesus after a piece of the Eucharist was placed in a beehive, a church that was burnt to ashes while the pyx containing the Eucharist was still intact, and a woman who found the Host transformed into congealed blood after she stored it in a box.
In 1998, in Venezuela at a convent in Los Teques, a video of the Eucharistic host supposedly bleeding and pulsating like a heart on fire inside its shrine was recorded by pilgrim Daniel Sanford, although skeptics assert that his footage only shows the reflection in the dented metal tray of nearby lamps or votive candles.
In 2016, in Aalst, a small town in Flanders (Belgium), a 200-year-old Eucharistic host in a monstrance suddenly showed blood red color. On 7 July at 17:45 this Eucharistic host spontaneously started coloring, in the presence of several witnesses. The phenomenon occurred in the home of Father Eric Jacqmin, a sedevacantist, who was formerly a member of SSPX. Professor Liesbeth Jacxsens has offered to scientifically investigate the host and thinks the color could be caused by Serratia marcescens, Monilia sitophila or Oidium.
In March 2024, in Chümoukedima, Nagaland, a consecrated host that was not consumed and had been kept for dissolving in water developed a layer from which blood oozed out.
Scientific analysis of flesh and blood miracles
The Catholic Church differentiates between true miracles and occurrences that are explainable by natural causes. For example, in 2006, the Roman Catholic Diocese of Dallas gave over a Eucharist host that turned red while in a glass for the analysis by two University of Dallas biology professors who concluded it was naturally explicable, as Bishop Charles Victor Grahmann wrote that "the object is a combination of fungal mycelia and bacterial colonies that have been incubated within the aquatic environment of the glass during the four-week period in which it was stored in the open air."