The number of species of bacteria in the gastrointestinal tract of chimpanzees increases the more gregarious and sociable they are, in light of research from several US universities published in Science Advances . The study authors monitored changes in gut microbes and social behavior in these animals in the wild for more than 8 years in Gombe National Park, Tanzania. Among other things, they found that the folds of the intestines are home to hundreds of species of bacteria and other microbes that help break down food, synthesize vitamins, train the immune system and fight infection. In fact, the decline in gut microbial diversity in humans has been linked to obesity, diabetes, Crohn’s disease, and other disorders.
Andrew Moeller, a researcher at the University of California at Berkeley and a co-author of the study, believes that “the more diverse people’s microbiome, the more resistant they are to infection.” The same is true of chimpanzees, whose bacterial DNA in the droppings collected from 40 specimens between 2000 and 2008 of various ages – from young to adult – was thoroughly studied by researchers. Well, thousands of species of bacteria were identified that thrive in the guts of primates, many of which are also often found in humans, such as the Olsenella and Prevotella. They then collated the microbial data with daily records of what the animals ate and the time they spent with other chimpanzees and alone. The researchers found that these monkeys tend to spend more time together during the rainy season , when food is most abundant. In contrast, in the dry season they spend more time alone.
The researchers found that chimpanzees carried between 20 and 25% more species of bacteria during the social season of heavy rains than during the dry season, and found that the differences in the microbiome were not only due to seasonal changes in fruits. , leaves and insects that make up their diet, but lonely lifestyles or relationships also played a role. Gut bacteria probably pass from chimpanzee to chimpanzee during grooming , mating or other forms of physical contact or when they inadvertently step on where other chimpanzees have defecated, according to Anne Pusey, chair of the Department of Evolutionary Anthropology at Duke University.
The mix of bacteria in the animals’ intestines was as similar between unrelated individuals as it was between mothers and offspring , which is surprising because the young collect their first microbiomes from their mother when they pass through the birth canal, suggesting that Throughout life, social interactions with other chimpanzees play a role in both gut microbial diversity and initial transmission from the mother. Scientists don’t yet know if social contact helps maintain gut microbiome diversity in humans, but they are working on it. “One of the reasons we started studying the chimpanzee microbiome was that it allows us to do research that we can’t do with people yet,” says study co-author Howard Ochman of the University of Texas at Austin.
Image credit: DLILLC / Corbis
