World-renowned scientists have called for an immediate halt to research on creating "mirror life" microbes, citing concerns that these synthetic organisms could pose an "unprecedented risk" to life on Earth.

A group of Nobel laureates and other experts has warned that mirror bacteria, which are made from mirror images of naturally occurring molecules, could potentially establish themselves in the environment and evade the immune defenses of living organisms, putting humans, animals, and plants at risk of fatal infections.

While it might take at least a decade to develop a viable mirror microbe, a new risk assessment has raised serious alarms, prompting the 38-member group to urge researchers to cease their work on this project and to request that funding bodies make it clear they will no longer support such research.

“The threat we’re talking about is unprecedented,” said Prof Vaughn Cooper, an evolutionary biologist at the University of Pittsburgh.

“Mirror bacteria would likely evade many human, animal, and plant immune system responses and in each case would cause lethal infections that would spread without check,” Cooper added.

The expert group includes Dr. Craig Venter, the US scientist who led the private effort to sequence the human genome in the 1990s, along with Nobel laureates Prof Greg Winter of the University of Cambridge and Prof Jack Szostak of the University of Chicago.

Why it matters

Many life molecules exist in two forms, mirror images of each other. For example, the DNA in all living organisms is composed of “right-handed” nucleotides, while proteins are made of “left-handed” amino acids.

While scientists have already synthesized large, functional mirror molecules for study, creating a whole organism from mirror molecules is currently beyond our capabilities. The research is motivated by curiosity and potential benefits, such as using mirror molecules for therapies for chronic diseases or employing mirror microbes in bioproduction facilities to improve contamination resistance.

Despite the excitement around mirror molecules, the expert group’s report and a commentary in the journal Science express concerns about the risks associated with mirror microbes. The report calls for a global debate on the topic.

Researchers worry that mirror microbes could not be safely contained or regulated by natural predators and competitors, and existing antibiotics would likely be ineffective against them.

“Unless compelling evidence emerges that mirror life would not pose extraordinary dangers, we believe that mirror bacteria and other mirror organisms, even those with engineered biocontainment measures, should not be created,” the authors wrote in Science.

“We therefore recommend that research with the goal of creating mirror bacteria not be permitted, and that funders make clear that they will not support such work,” they added.

Dr. Kate Adamala, a synthetic biologist at the University of Minnesota and a co-author of the report, was initially working on creating mirror cells but changed her approach last year after considering the risks in detail.

“We should not be making mirror life,” she said. “We have time for the conversation. And that’s what we were trying to do with this paper, to start a global conversation.”

Prof. Paul Freemont at Imperial College London, who was not involved in the report, described it as an “excellent example of responsible research and innovation.”

He acknowledged the need for an open debate on the development of mirror organisms but also highlighted the promise of mirror chemistry in biological systems, which he suggested could be useful in a limited, regulated manner in the future.