By Michael Irving

Your body is home to trillions of bacteria – but before you go reaching for the soap, it’s important to remember that many of them are good for you. Not only do they assist in vital bodily functions, but they can help keep bad bugs at bay. Now, researchers at Instituto Gulbenkian de Ciência (IGC) in Portugal and Stanford in the US have identified one particular bacterium, Klebsiella michiganensis, that could be administered to help prevent harmful infections.

Antibiotics are currently our best defense against pathogenic infections, but the problem is they aren’t very selective. Taking antibiotics is akin to carpet-bombing your insides, killing good and bad bacteria alike. So, while the drugs may kill off whatever infection was troubling you, they also take out good bugs and leave the door open for opportunistic pathogens, like E. coli and Salmonella, to recolonize in unhealthy amounts.

In the new study, researchers at IGC and Stanford isolated one particular bacteria species that seems to protect against these pests. K. michiganensis is often present in the gut in relatively low numbers, but it’s better at metabolizing certain nutrients than E. coli, Salmonella and other bad bugs, meaning they struggle to get a foothold.

The team says that this discovery could lead to new treatments for preventing infections. After a patient takes a course of antibiotics, doctors could then follow it up by administering good bacteria like K. michiganensis, to help prevent bad bacteria taking up residence in the gut microbiome.

“This study opens doors to the hope that for each human pathogen there is one or more bacteria of the microbiota that can be administered as a direct competitor of that pathogen,” says Rita Oliveira.

The researchers made their discovery in studies in mice while trying to determine why some animals developed infections post-antibiotics and some didn’t. It was eventually found that higher numbers of K. michiganensis were present in mice that resisted new infections, while those that acquired new infections had lower levels of the good bugs.

This isn’t the first time scientists have turned to microbes to fight other microbes. An emerging area of research involves harnessing tiny viruses called phages, which naturally kill bacteria. In other studies, researchers found some success by reducing nutrients in the gut, which caused the bacteria to fight each other for survival.

The team on the new study plans to continue researching other bacteria that might be able to outcompete pathogens for resources in the gut.

“In the future, what is desirable is that anytime we use antibiotics we also take complements that can restore the microbiota and potentiate the beneficial effects it entails,” says Karina Xavier, lead researcher on the study. “For that, the identification of super competitive bacteria like this one is essential.”

The research was published in the journal Nature Microbiology.

Source: IGC