A pool of investors who manage a collective $1 trillion want major restaurant chains to lay out their plans for pulling antibiotics out of their meat supply.

The Farm Animal Investment Risk & Return (FAIRR), an initiative of Coller Capital that combines 53 other investment groups, announced this week they’ve sent letters to some of the biggest restaurant chains in the U.S. and the U.K.

The chains include McDonald’s, Wendy’s, Domino’s, Chili’s, Olive Garden, Burger King, Tim Hortons, KFC, Pizza Hut, and Taco Bell, among others.

Several of the companies, including McDonald’s and Domino’s Pizza, told The Guardian they have already begun to develop policies for tackling antibiotic use on farms.

Jeremy Coller, founder of the FAIRR Initiative and chief investment officer of Coller Capital, said these large food companies are “key ingredients” in the portfolios of most of their pensions and savings. He said asking how these companies plan to meet the challenge of reducing antibiotic use is a matter of proper risk management.

“The world is changing, regulation on antibiotic use is set to tighten, and consumer preferences are shifting away from factory farmed food,” Coller said in a press release. “As stewards of these food companies and responsible investors, we want to protect both human health and shareholder value.”

Read More: Use of Antibiotics in Agriculture Expected to Skyrocket Worldwide »

Failing Grades on Antibiotic Policy

According to a FAIRR report released this week, only half of the top 10 restaurant chains have a publicly available policy to manage potential antibiotic overuse in their food supply.

None of those companies, the report states, have a comprehensive policy to deal with the issue.

Seeing the continuing threat of antibiotic resistance, these investors are urging major food brands to set a timeline for curbing the use of antibiotics in animals meant for the dinner table.

In the U.K., about 45 percent of all antibiotics go to livestock. In the U.S., it’s about 80 percent, according to the U.S. Food and Drug Administration (FDA).

According to the latest report from the FDA, antibiotics vital to human health used for livestock increased 23 percent from 2009 to 2014. Ninety-six percent of the antibiotics used for livestock were sold for use in feed and water.

Lena Brook, food policy advocate for the Natural Resources Defense Council (NRDC), said she hopes letters like these send a strong message at a scale not seen before.

“It’s terrific to see the investment community step up and put some weight behind it,” Brook told Healthline.

The NRDC and dozens of other food and health groups sent Yum! — the parent company of KFC, Taco Bell, and Pizza Hut — a letter in January regarding its pledge to eliminate the use of “critically important” antibiotics in its poultry supply by the end of 2016.

The letter states that focusing on “this very limited set of drugs may create the false impression that Yum! is taking substantial action, even though the vast majority of medically important antibiotic use would likely not be affected.”

Read More: Weakening Antibiotics Could Result in 6,300 More Infection-Related Deaths Every Year »

Antibiotics’ Impact on Human Health

One report by the U.K. government estimated that drug-resistant infections could cost the world up to $100 trillion in lost output by 2050.

Currently in the U.S., drug-resistant bacteria cause an estimated 2 million infections a year, 23,000 of which are fatal.

The routine administration of antibiotics, in low doses in feed and water, helps protect animals in cramped, dirty conditions from getting sick and helps them gain weight more quickly. It does, however, give bacteria the opportunity to develop defenses around these drugs.

While policy makers and regulators have been slow to curb the routine use of antibiotics in livestock in the U.S., the scientific jury has reached its verdict: using antibiotics necessary for human health in animals directly impacts people’s well-being.

Between unnecessary prescriptions for humans and a lag in discovering new antibiotics, experts at the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) warn that humanity may find itself in a “pre-antibiotic era” where even routine medical procedures and dental work could cause fatal infections.

The investor groups urge these major brands to get ahead of the curve.

They cite the costs associated with restructuring facilities if regulators ban the routine use of antibiotics as well as the reputational damage as consumer attitudes shift away from giving antibiotics to livestock.

Consumers have been increasingly vocal about their preferences for beef, poultry, pork, and fish raised without antibiotics.

Other major brands, such as Chik-Fil-A, Panera Bread, Chipotle, and Subway, have already pledged to restructure their food supply to eliminate livestock raised on a steady diet of antibiotics.

“There is a tremendous momentum that’s building,” Brook said.