Aging often comes with muscle loss, weaker bones, and memory issues, but scientists may be closer to slowing that down. Researchers in Spain have found that a naturally occurring protein called Klotho—specifically its secreted form, s-KL—could help the body and brain stay healthier for longer. In a new study from Universitat Autònoma de Barcelona, researchers used gene therapy to increase s-KL levels in mice, helping them live longer and age better.

Mice treated with this therapy lived 15–20% longer on average. They stayed stronger, kept more muscle mass, and even showed better memory and brain activity compared to untreated mice. The research team delivered s-KL into the body using harmless viruses, sending the protein through the bloodstream and directly into the brain. The protein helped reduce muscle damage and increased the ability of muscle cells to repair themselves. Female mice also showed stronger bones—an important step toward fighting bone loss and fractures that come with aging.

Brain health improved too. Treated mice had more new brain cells in the memory center and better immune activity inside the brain. These changes suggest s-KL may help clean out toxic waste that builds up with age, possibly lowering the risk of diseases like Alzheimer’s. Unlike other versions of Klotho, the s-KL version seems safer and doesn’t mess with calcium levels in the body.

PMID: 39988871
PMCID: PMC11997498