Phys.org passes along research led by Dr. Katerina Johnson of Oxford and Dr. Karli Watson of UC Boulder, who found that the more social a monkey is, the healthier its gut biome is – which can affect everything from neurological well-being to the ability to resist infections:
The scientists focused on a single social group (with 22 males and 16 females between the ages of six and 20 years) of rhesus macaques on the island of Cayo Santiago, off the eastern coast of Puerto Rico.
…
Between 2012 and 2013, the authors collected a total of 50 uncontaminated stool samples from this social group. As a measure of social connectedness, they used the time each monkey spent grooming or being groomed in 2012 and 2013, and his or her number of grooming partners.
…
Johnson, Watson, and their team analyzed DNA sequence data from the stool samples to measure the composition and diversity of the gut microbial community, and looked at the relationship with social connectivity. They also took into account sex, age, season, and rank within the group’s hierarchy. They focused on microbes that have been repeatedly shown to be either more or less abundant in people or rodents with autism-like symptoms (commonly accompanied by social disconnection) or who are socially deprived.
…
For example, genera more abundant in the most sociable monkeys included Faecalibacterium and Prevotella. Conversely, the genus Streptococcus, which in humans can cause diseases such as strep throat and pneumonia, was most abundant in less sociable monkeys.
“It is particularly striking that we find a strong positive relationship between the abundance of the gut microbe Faecalibacterium and how sociable the animals are. Faecalibacterium is well known for its potent anti-inflammatory properties and is associated with good health,” said Johnson.
—
You can read more of their research here, in Frontiers in Microbiology.