Ants Select Better Microbes

Researchers identified the 3-step process leaf-cutter ants use to grow helpful bacteria on their bodies.

Beth Marie Mole
Sep 14, 2012

Researchers at the University of East Anglia in the United Kingdom have found that leaf-cutter ants have a simple system to build up healthful microbes on their exoskeletons—a system the researchers hope will have implications for human health.

Leaf-cutter ants—which get their name from cutting and collecting leaves on which they grow their fungus diet—rely on microbes to produce the antibiotics that protect the farmed fungus from harmful pathogens. "We argue that the ant host has evolved living conditions under which antibiotic-producing bacteria have a competitive advantage for the ant niche,” biologist at East Anglia and senior author of the study Douglas Yu told Phys.Org.

In the study, published online last month (August 22) in Ecology Letters, Yu and his colleagues generated a model in which leaf-cutter ants select for helpful microbes by passing on the beneficial bugs to the next generation, (1) and providing a lot of...

“Our model shows that if the host produces a lot of food for bacteria, it fuels fighting via antibiotics,” Yu told Phys.Org. “It's the reason bacteria produce antibiotics in the first place—to kill competitors.” The resulting antibiotic-producing bacteria, he adds, “kill pathogenic molds on the fungus that [the ants] farm for food.”

Yu hopes that the new information will help scientists understand the microbes in our own bodies, and how to shift their communities in our favor. “The good bacteria in our bodies help digest our food, protect us from infections, and perhaps even prevent some cancers,” Yu said.

The model, which Yu said may already apply to complex vaginal microbial communities, may help us understand how to select for helpful microbes for our bodies in the future. “But until now,” he added, “it hasn't been known how successful [microbial] partner choice evolves.”