“Mirror bacteria” could pose serious risks to global health

A group of researchers published new findings in Science Policy forum on the potential risks associated with the development of mirror bacteria, i.e. synthetic organisms in which all molecules have inverted chirality (i.e. are “mirrored”).

Scientists had started working on creating mirrors bacteriaand although this capacity is at least a decade away, significant progress has been made in recent years. The new paper reveals that, if created, these organisms could pose significant dangers to human, animal, plant and environmental health.

The authors call for a broad conversation among scientists, policymakers, and a wide range of other stakeholders to chart a path toward better understanding and mitigating the potential risks of mirror bacteria.

The 38 authors working in nine countries include leading experts in immunology, plant pathologyecology, evolutionary biology, biosecurity and planetary sciences. Publication in Science is accompanied by a detailed technical report of 300 pages.

Even if no threat is imminent, the Science An article reveals that mirror bacteria can pose serious risks. Immune defenses in humans, animals and plants rely on the recognition of specific molecular shapes found in invading bacteria. If these shapes were mirrored – as they would be in mirror bacteria – recognition would be impaired and many basic immune defenses could fail, potentially leaving organisms vulnerable to infection.

The analysis also suggests that mirror bacteria in the environment may be able to escape natural predators such as phages and protists, which rely heavily on chirally mediated interactions to kill bacteria and limit their populations. Transport via animals and humans could enable spread between diverse ecosystems. Persistent and widespread environmental populations of mirror bacteria would put humans, animals and plants at ongoing risk of infection – a serious threat to humans and global ecosystems.

The authors call for further examination of their results and conclude that unless compelling evidence emerges that these organisms would not pose extraordinary dangers, mirror bacteria should not be created. The group notably includes several authors who previously considered the creation of mirror bacteria as an ambitious long-term goal.

This article marks the starting point for a broader discussion on the risks of mirror bacteria, with the participation of the global scientific community, policy makers, research funders and other stakeholders. Several of the paper’s authors are involved in planning a series of events throughout 2025, including a planned event at the Pasteur Institute in Paris, to review the paper’s findings and discuss measures which can be taken to prevent the risks associated with mirror bacteria.