Scientists Revive 160-Million-Year-Old Proteins to Fight Drug-Resistant Bacteria

Scientists have reconstructed antimicrobial proteins from mammals that lived around 160 million years ago and discovered that some of the ancient molecules can attack drug-resistant bacteria.

The research, led by biologists at the University of Oregon, explores how the natural defenses of extinct animals could provide clues for developing new ways to combat bacterial infections.

Bringing an Ancient Defense Back to Life

The researchers focused on lactoferrin, an immune protein found in mammals. Lactoferrin is present in body fluids such as breast milk, tears and saliva and helps protect the body from harmful microbes.

Scientists used genetic information from living mammals to reconstruct versions of the protein that belonged to extinct ancestors. The oldest reconstructed versions date back roughly 160 million years, around the time the earliest placental mammals were emerging.

Testing Proteins From the Distant Past

After reconstructing the ancient genes, the team produced the proteins in laboratory cells and tested their antimicrobial activity.

The researchers exposed the reconstructed peptides to several disease-causing bacteria, including Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.

Some of the ancient peptides were able to damage bacterial membranes. More recent versions reconstructed from mammalian ancestors were even more effective and, in some tests, performed better than the corresponding human peptide.

A Tiny Genetic Change Made a Big Difference

The researchers found that a relatively small change in the amino-acid sequence could substantially alter the peptide’s antimicrobial power.

This finding provides an example of how evolutionary changes can gradually improve the ability of natural molecules to fight microbes.

Why Ancient Proteins Could Help Modern Medicine

Antibiotic resistance has made some bacterial infections increasingly difficult to treat. Scientists are therefore investigating alternatives and additional tools that could attack bacteria in different ways.

The researchers believe ancient proteins can act as a kind of biological archive, showing scientists which molecular strategies worked during millions of years of evolution.

Not Yet a New Medicine

The discovery does not mean that the ancient peptides are ready to be used as medicines. The molecules can be unstable and may be broken down quickly inside the human body.

Further research would be needed to improve their stability, test their safety and determine whether they could eventually be developed into practical treatments.

Evolution as a Source of New Ideas

The study demonstrates how scientists can look into the distant evolutionary past for potential solutions to modern biological problems.

By reconstructing molecules that disappeared millions of years ago, researchers can examine natural experiments that occurred during evolution and use those insights to guide the search for new antimicrobial technologies.

Sources

• University of Oregon — Research on the evolution of antimicrobial peptides within mammalian lactoferrin — September 2026.
• ScienceDaily — “160-million-year-old proteins show surprising power against superbugs” — September 28, 2026.
• PLOS Biology — “Retracing the origin and evolution of a cryptic antimicrobial peptide within mammalian lactoferrin” — 2026.