Smelly microbes help hyenas to communicate

Bacteria in scent glands give information about hosts’ species, sex and reproductive state.

The hordes of microbes that inhabit every nook and cranny of every animal are not just passive hitchhikers: they actively shape their hosts’ well-being and even behaviour. Now, researchers have found evidence that bacteria living in the scent glands of hyenas help to produce the smells that the animals use to identify group members and tell when females are ready to mate.

Kevin Theis, a microbial ecologist at Michigan State University in East Lansing, had been studying hyena scent communication for several years when, after he gave a talk on the subject, someone asked him what part the bacteria might play. “I just said, ‘I don’t know’,” he says. He started investigating. Read more in Nature.

Silver makes antibiotics thousands of times more effective

Ancient antimicrobial treatment could help to solve modern bacterial resistance.

Like werewolves and vampires, bacteria have a weakness: silver. The precious metal has been used to fight infection for thousands of years — Hippocrates first described its antimicrobial properties in 400 bc — but how it works has been a mystery. Now, a team led by James Collins, a biomedical engineer at Boston University in Massachusetts, has described how silver can disrupt bacteria, and shown that the ancient treatment could help to deal with the thoroughly modern scourge of antibiotic resistance. The work is published today in Science Translational MedicineRead more in Nature.

Gut microbe may fight obesity and diabetes

Bacterium helps to regulate metabolism in mice.

The gut is home to innumerable different bacteria — a complex ecosystem that has an active role in a variety of bodily functions. In a study published this week in Proceedings of the National Academy of Sciences, a team of researchers finds that in mice, just one of those bacterial species plays a major part in controlling obesity and metabolic disorders such as type 2 diabetes.

The bacterium, Akkermansia muciniphila, digests mucus and makes up 3–5% of the microbes in a healthy mammalian gut. But the intestines of obese humans and mice, and those with type 2 diabetes, have much lower levels. A team led by Patrice Cani, who studies the interaction between gut bacteria and metabolism at the Catholic University of Louvain in Belgium, decided to investigate the link. Read more in Nature.