Research on how gut bacteria breaks down dietary fiber could lead to helpful new probiotics

There are trillions of bacteria in the human gut microbiome. When we eat fruits and vegetables, some of these bacteria break down the dietary fiber and provide us with metabolites, small molecules our body can use for energy or cell repair.

Researchers from the University of British Columbia (UBC) have used the Canadian Light Source (CLS) at the University of Saskatchewan to study a particular bacterium commonly found in the gut of people who eat a plant-rich diet.

The specifics of how bacteria break down our food is still a “black box,” according to Dr. Harry Brumer, the UBC professor who led this research.

“Our team is trying to determine what molecular machinery the bacteria have that give them the unique ability to break down dietary fiber,” he said.

Using ultrabright synchrotron X-rays at the CLS and the Stanford Synchrotron Radiation Lightsource in California, Brumer and colleagues determined the three-dimensional structure and function of the proteins and enzymes this bacterium uses to break down food, and the details of that process.

“The CLS made it possible for us to study these mechanics on the atomic level,” said Brumer. “It’s really cool to understand how gut bacteria perform those complex processes and contribute to our health.” The team published their findings in the Journal of Biological Chemistry.

As scientists continue to learn more about how the microbiome works, says Brumer, they might uncover how to influence it to improve health.

“Ultimately, we’d like to know how to alter a diet to increase the population of good bacteria, perhaps to the detriment of harmful bacteria,” Brumer said. “There’s a huge population of bacteria like the one we researched that might eventually make good probiotics. And by changing their abundance in the gut, we might be able to make people healthier, reduce disease, and improve nutrition.”