We know that the menu for the Last Supper included bread and wine.

Now the Vatican has released a list of approved ingredients for the bread and wine that the Roman Catholic Church serves at Eucharistic communion. For a valid sacrament, it says, the bread must come from wheat, may contain GMOs, and cannot be gluten-free.

Although Vatican has said these things before, the new announcement went viral earlier this month when it came in the form of a letterissued at the request of the Holy Father, Pope Francisfrom Cardinal Robert Sarah, who oversees the liturgical practices of the Roman Catholic Church.

The responses were rapid and wide-ranging, from first-rate explainer journalism to occasions for joking about gluten-free faddists.

“Last Supper” by Leonardo Da Vinci

For me, however, the takeaway point was simple: This is an excellent example of an ancient and important institution remaining true to its principles while also keeping up with the times.

Im a farmer in MexicoI am not a theologian. Im also more of a believing Catholic than a practicing one, though Catholicism is a central part of my family and countrys culture. I remember everything about my first communion, when I was nine, and I have a six-year-old goddaughter who will start her own preparations soon.

First communion is a rite of passage, but every communion is important. The Catholic catechism teaches that the Eucharist is an act of thanksgiving as well as a sacrificial memorial that celebrates the presence of Christ. What material food produces in our bodily life, it says, Holy Communion wonderfully achieves in our spiritual life.

There are about 1.2 billion Roman Catholics around the world. More than four in ten are Latin American, like Pope Francis and me; nearly one in four live in Europe; about 15 percent are African, like Cardinal Sarah; and lesser amounts are at home in Asia, the United States, and Canada.

So this is a global churchand one of its challenges is to maintain consistent practices across cultures and continents.

Thats why Cardinal Sarah released his letter, which calls on bishops to watch over the quality of the bread and wine to be used at the Eucharist. It also lays out a few rules because not just any bread or wine will do. Chad Pecknold, a theology professor at the Catholic University of America, put it this way: Christ did not institute the Eucharist as rice and sake, or sweet potatoes and stout.

The catechism specifically calls for wheat bread and grape wine.

But what exactly does this mean?

According to Cardinal Sarah, the bread must be unleavened, purely of wheat and the wine must come from the fruit of grapes. Yet the bread and wine may take advantage of biotechnology: Eucharistic matter made with genetically modified organisms can be considered valid.

For a church that is still challenged for the persecution of Galileo 400 years ago, this statement shows that todays Vatican is happy to cooperate with sound scienceand recognize that in the 21st century, GMO foods are an ordinary part of the food and agriculture.

Yet the church also drew a line with respect to bread: Hosts that are completely gluten-free are invalid matter for the celebration of the Eucharist. Low-gluten hosts, however, are acceptable 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 Benedictine Sisters of Perpetual Adoration, a monastic community that makes altar bread, already sells a low-gluten variety on its websitea valuable product for the tiny number of people who suffer from celiac disease.

Scientists who study GMOs are trying to produce gluten-free wheat that would be an important quality of life and health innovation for the victims of celiac disease. Whether the Vatican would approve this crop as an ingredient for communion remains to be seen, but Im hopeful that it would continue to find a way to accommodate both its long-held traditions and the benefits of biotechnology.

One of Catholicisms goals, after all, is to have as many people as possible partake in the sacrament of communion. As the priests say at every Mass: Take this, all of you, and eat of it.