“If you want to live longer, don’t be alone, surround yourself with people you love and with whom you can share life’s moments.” More and more doctors are giving this kind of advice to their patients, as socialising is believed to help us live longer and healthier. It could also act as a protective shield against much-feared neurodegenerative diseases like Alzheimer’s and other dementia. But the benefits of a good social life do not end there.
According to a new study published in Science Advances, being in contact with others may be linked to a healthy, rich and diverse microbiota, at least in chimpanzees, thus providing a healthier and longer existence.
In an eight-year research project conducted at Gombe National Park in Tanzania, scientists observed that the more sociable the primates, the greater their microbial diversity, which may, in turn, protect the animals from diseases.
In this study, they followed a community of 40 wild chimps ranging from infants to seniors between 2000 and 2008. The social calendar of these primates depends on the season: during the dry period, they tend to spend most of their time alone; but, when the rainy season comes, they prefer to stay together foraging for food.
Researchers observed their behaviour during each season and took faecal samples to sequence the genes of the bacteria and thus determine the composition of the microorganisms they hosted. They found that when the animals spent more time together grooming, they carried roughly 20 to 25 per cent more bacterial species than during the dry season. What’s more, the microbial composition was similar among the group’s individuals. The researchers believe this diversity may be linked to protection against pathogens that individuals with low species richness are missing.
The researchers also wanted to know whether these seasonal changes in microbiota were also inherited by subsequent generations and their findings confirmed that this was the case. More interestingly, they also compared microbial inheritance from parents to offspring with transfer through social interaction with unrelated primates and discovered that the transmission of the bacterial colonies occurred, overall, through socialisation.
Gut bacteria probably pass from chimp to chimp during grooming, mating or other forms of physical contact, or when they inadvertently step on other chimps’ stools. Researchers speculate that from an evolutionary point of view, this could be beneficial in order to maintain microbial health over time.
What about humans? Does the same thing happen? That will be the next step in the research – to find out whether having a good social life also fosters diversity in our microbial community. And this might help scientists understand more about some gut-related conditions while also figuring out a medical mystery: the exact mechanism behind why social people tend to live longer.
Moeller AH, Foerster S, Wilson ML, Pusey AE, Hahn BH, Ochman H. Social behavior shapes the chimpanzee pan-microbiome. Sci Adv. 2016;2(1):e1500997.