In a recent study, it shows that using larger doses of antibiotics in an effort to address the growing problem of drug resistance may lead to the strengthening of some bacteria.

In a United Nations description, it addresses antimicrobial resistance as "one of the greatest threats we face as a global society," and is expected to cause 10 million deaths per year by 2050.

Earlier research has shown that taking larger doses of antibiotics may slow down the ability of bacteria to develop resistance, yet no attention has been paid to how large doses affect the overall composition of microbes.

A team of researchers in Britain and Europe studied the way acritic colorectal groups interact with different concentrations of three commonly used antibiotics.

They found that while large doses of antibiotics slowed the rate of development of resistant bacteria, they also led to the emergence of "more potent" bacteria, meaning that they had a higher rate of reproduction.

"We consider the growth rate to be an indicator of strength, assuming that the breed growing faster is likely to dominate other types of bacteria and become dominant," said lead author Mato Lagatore of the School of Biological Sciences at the University of Manchester.

The team, published in Royal Susaite Biologic Leiters, wrote that their research showed how high doses of antibiotics were a "dilemma" and could eventually lead to more resistant bacteria.

Several studies in recent years have warned against over-labelling of antibiotics and overuse in livestock, with the American Centers for Disease Control and Prevention estimating that one in three antibiotic prescriptions is unnecessary.

With antibiotic-resistant bacteria expected to kill more people globally than cancer by the middle of the century, Lagator said more research is needed on how large doses affect long-term bacteria development.