Chummy chimps harbour richer gut bacteria

New York: Monitoring social behaviour of wild chimpanzees, researchers have found that being gregarious may help transmit beneficial microbes and increase diversity of gut bacteria.

The research -- linked to a number of chimpanzees studied over eight years in the Gombe National Park, Tanzania, found that the number of bacteria species in each chimp's gastrointestinal tract (GI) increases when the chimps are more gregarious.

The results can help scientists better understand the factors that maintain a healthy gut microbiome.

The warm, soft folds of our intestines are home to hundreds of species of bacteria and other microbes that help break down food, synthesise vitamins, train the immune system and fight infections.

Reduced gut microbial diversity in humans has been linked to obesity, diabetes, Crohn's and other diseases.

"The more diverse people's microbiomes are, the more resistant they seem to be to opportunistic infections," said study co-author Andrew Moeller, research fellow at the University of California - Berkeley, US.

The researchers analysed the bacterial DNA in droppings collected from 40 chimpanzees between 2000 and 2008. The chimpanzees ranged in age from infants to seniors.

The researchers identified thousands of species of bacteria thriving in the animals' guts, many of which are also commonly found in humans, such as Olsenella and Prevotella.

The team then combined the microbial data with daily records of what the animals ate and how much time they spent with other chimps versus alone.

"Chimpanzees tend to spend more time together during the wet season when food is more abundant," study co-author Steffen Foerster from Duke University in North Carolina, US, said.

"During the dry season they spend more time alone," Foerster said.

The researchers found that each chimpanzee carried roughly 20 to 25 percent more bacterial species during the abundant and social wet season than during the dry season.

The study was published in the journal Science Advances.