January 20, 2026 | Source: Scientific American | by Vaughn S. Cooper

Let’s say it’s 2036, and scientists are working on a new class of drugs. These medications are mirror-image versions of the molecules your body uses to fight disease. Their big advantage is that reverse compounds last longer in the body because destructive enzymes don’t recognize them and rip them apart. Yet the compounds are still effective against invading microbes. Clinical trials have been promising, and the team is eager to scale up production.

The researchers turn to engineered mirror bacteria—single cells made of reversed molecules—for the job. Bacterial factories aren’t a far-fetched idea. Today, for instance, pharmaceutical companies use bacteria to manufacture synthetic insulin for diabetics. Curious about whether mirror cells could be used in a similar way, the scientists experiment on a mirrored version of the common bacterium Escherichia coli.

Unfortunately, a researcher with a small cut on her thumb from dry skin forgets to put on her gloves and touches a surface contaminated with just a few of these cells. The bacteria get into her blood.