Science has taught us that the good bacteria living inside our tummies help us stay healthy. But what can we do to return the favor? We know that antibiotics can be a problem; while they're effective at getting rid of harmful bugs, they don’t discriminate, killing friendly bacteria as well. What can we do to support the good guys?

Probiotics are popular option, and they have many benefits, but there is something you can do to fortify your tiny allies.

A new paper published in Nature Chemical Biology highlights the important role of some unusual sugars found in leafy greens. The researchers found a new enzyme produced by bacteria, fungi and other organisms, which allows them to feed on this unusual sugar named sulfoquinovose (SQ), the only sugar molecule known to contain sulfur.

But SQ is not rare. It's estimated that each year, leafy greens like spinach and kale produce as much of this sugar in their leaves as the world’s total iron ore production, which is 3.2 billion metric tons in 2014, according to U.S. Geological Survey data. So the question is how to harness that power.

Listen to your grandma and eat your leafy greens, they're even better for you than previously believed.Listen to your grandma and eat your leafy greens. They're even better for you than previously believed. (Photo: woodleywonderworks/flickr)

This discovery could help us understand how to encourage the growth of protective gut bacteria and help them better colonize our digestive system, protecting us against harmful invaders.

“Bacteria in the gut, such as crucial protective strains of E. coli, use SQ as a source of energy. E. coli provides a protective barrier that prevents growth and colonisation by bad bacteria, because the good bugs are taking up all the habitable real estate,” explains Dr. Goddard-Borger of the Walter and Eliza Hall Institute and the lead author of the study. “E. coli is a key bacterial coloniser needed by our gut. We speculate that consumption of this specific molecule within leafy greens will prove to be an important factor in improving and maintaining healthy gut bacteria and good digestive health.”

Professor Spencer Williams from the Bio21 Institute and The University of Melbourne and professor Gideon Davies from the University of York in the U.K. were the other key players behind this research.

The scientists also solved a 50-mystery: an enzyme called YihQ is used by gut bacteria to break down the sulfur-bearing SQ sugars. By better understanding these processes, the researchers may be able to use this knowledge to develop a new class of antibiotics to fight microbes that have evolved a resistance to common antibiotics.

“We think it will be possible to use these widespread enzymes to enable highly specific delivery of antibiotics to harmful forms of E. coli and other pathogens, such as Salmonella, responsible for food poisoning, while leaving the good gut bacteria untouched,” says Borger.

Michael Graham Richard ( @Michael_GR ) Michael writes for MNN and TreeHugger about science, space and technology and more.

Friendly gut bacteria love leafy greens
A special sugar in these greens keeps good bacteria happy.