An antibiotic commonly used in veterinary medicine has been identified as a compound capable of turning the gut into a “factory” for producing life-extending substances. This discovery could transform the approach to developing drugs aimed at increasing lifespan.

Cefaloridine: History and Properties

The antibiotic in question is cefaloridine, a beta-lactam antibiotic similar to penicillin. In the 1960s and 1970s, it was used to treat people, especially for respiratory and urinary tract infections. However, the drug is poorly absorbed in the digestive tract and is only effective when administered by injection. Additionally, cefaloridine can cause kidney toxicity, which led to its discontinuation in human medicine. Today, it is mainly used to treat dogs with staphylococcal infections and skin diseases.

Unexpected Effects of the Antibiotic

Although cefaloridine is no longer considered suitable for humans, researchers at the Howard Hughes Medical Institute in Maryland have discovered a new property. In animal experiments, administering low doses of cefaloridine prompted gut bacteria E. coli to produce colonic acid. This acid acts as a protective mechanism for bacteria, and previous studies have shown it can extend the lifespan of nematodes and fruit flies.

Experiments and Results

In a new study, scientists investigated whether drugs could directly stimulate the production of colonic acid. They found that when the antibiotic was added, nematodes lived up to 30% longer due to increased production of colonic acid by E. coli in their intestines.

Researchers then gave mice colonic acid produced by E. coli treated with cefaloridine. As a result, the mice showed reduced aging markers: intestinal permeability decreased, systemic inflammation was reduced, mitochondrial function improved, and overall levels of biological aging markers dropped. In male mice, “good” cholesterol (HDL) increased and “bad” cholesterol (LDL) decreased, while in females, insulin levels were reduced.

Advantages and Prospects

One advantage of using cefaloridine to reprogram the gut microbiome is that the drug is poorly absorbed when administered this way and is almost entirely eliminated from the body without entering the bloodstream.

Nevertheless, researchers do not recommend using cefaloridine in humans as a life-extending agent due to its potential toxicity. However, they note that their discovery could change the approach to drug development, including those aimed at prolonging life. Instead of creating drugs that act directly on the body, it may be possible to focus on medications that influence the gut microbiome, turning it into a source of essential compounds.

Connection with Other Studies

This work complements other research showing that altering the gut microbiome can, among other things, help combat multiple sclerosis, increase the effectiveness of cancer immunotherapy, and potentially ease insomnia.

The results of the study have been published in the journal PLOS Biology.