Gut bugs team up to fight disease by eating invading bacteria’s lunch

Unlock the Editor’s Digest for free

Roula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter.

Teams of bacteria in the gut help fight disease by eating the food that invading pathogens need to thrive, according to research that underscores the health benefits of fostering humans’ rich digestive ecology.

Intestinal bugs’ wide-ranging appetites have the secondary impact of starving incoming microbes that cause infections such as salmonella and pneumonia, says the paper published in Science on Thursday.

The findings boost a growing research effort to improve human resistance to bacteria that are introduced via eating and drinking but can cause illness elsewhere in the body. They offer the prospect of making intestinal tracts more hostile to dangerous new entrants through dietary changes and bespoke supplements of beneficial bugs.

This field is becoming increasingly important as the rise in antibiotic resistance triggers a quest for alternative methods of treating and preventing bacterial diseases.

“The eureka moment was when we put groups of gut bacteria together and they acted against the pathogens,” said Kevin Foster, a professor at Oxford university and a co-author of a paper in the journal Science. “The human host, by allowing non-harmful bugs to grow, can prevent the growth of harmful ones.”

The research focused on two pathogens: Salmonella enterica Serovar Typhimurium and Klebsiella pneumoniae, which occurs in the gut naturally but can cause diseases ranging from meningitis to urinary tract infections.

The scientists then tested 100 gut microbes to gauge their effectiveness at stopping the two invading bacteria — a phenomenon known as “colonisation resistance”.

The defending microbes offered little or no obstacle to the pathogen pair when deployed alone but were much more effective when introduced in certain combinations, the research found.  

The resident gut bacteria compete with each other for food and in doing so achieve what Foster dubbed the “knock-on effect” of depriving the pathogens of nourishment.

The research adds to a growing interest in the gut microbiome as a tool to combat disease and promote good health throughout the body.

Companies such as Microbiotica, a Cambridge-based 2016 spinout from the Wellcome Sanger Institute, are working to develop therapeutics based on bugs in the digestive system.

Deeper understanding of gut microbe activity potentially opens the way to devising sophisticated “probiotic” mixes of beneficial bugs, according to a commentary published separately in Science on Thursday and written by authors unconnected to the latest research paper.

“[This] could allow clinicians to administer tailored probiotic communities that prevent difficult or impossible-to-treat infections from occurring in the first place,” write the commentary’s co-authors, Lauren Radlinski and Prof Andreas Bäumler of the University of California Davis.