Food poisoning is far from a fun experience, and usually all you can do is just ride out the storm. But soon you might be able to chase a bad burger with a "virus cocktail" loaded with bacteria-hunting viruses (bacteriophages) that will kill off the invading E. coli without harming the helpful bugs that call your gut home.
Of course, not everybody wants to weather the violent evacuations, and in the event of downing some suspect sushi, doctors can prescribe antibiotics to clear out the bad bugs. Unfortunately, the drugs don't discriminate and will go off like a nuke in your gut, which results in a lot of innocent casualties in your gut microbiome – the complex ecosystem of bacteria that plays a surprisingly large role in your overall health. There's also the growing concern of antibiotic resistance to contend with.
So, researchers at the University of Copenhagen and the pharmaceutical company Intralytix set out to design a more targeted approach. The idea was to use bacteriophages that would hunt down and kill specific species of bacteria – in this case, E. coli – like a sniper shot, instead of a scattergun blast. The team settled on three species of lytic phages that, together, were able to wipe out hundreds of different E. coli species.
"The research shows that we have an opportunity to kill specific bacteria without collateral damage to the other, and otherwise healthy, intestinal flora," says Dennis Sandris Nielsen, an author of the study.
These phages were singled out through rigorous tests in a model of the small intestine, which the team calls the TSI. To make the model as realistic as possible, it contained all the fluids and enzymes that would normally be present in the human gut, as well as a batch of intestinal flora matching that of a healthy person. Then, the researchers added E. coli, before sending in their virus cocktail to clean up the mess.
"The novelty of the TSI model is that it simulates the presence of the small intestinal microbiota, which has largely been overlooked in other models of the small intestine," says Tomasz Cieplak, an author of the study. "Other models existing on the market simulate only the purely biophysical processes, such as bile salts and digestive enzymes or pH, but here we included this important aspect of human gut physiology to mimic the small intestine more closely."
The results showed that the three lytic phage species were the most effective at killing the bad bugs while leaving the good ones alone. To continue working on the promising treatment, the researchers plan to test the cocktail on mice and eventually humans.
The research was published in the journal Gut Microbes.
Source: University of Copenhagen