Researchers from the University of California San Diego have found a link between how much social support, compassion, and wisdom someone has and the microbial diversity of their gut.
The human gut microbiome contains trillions of microbes that both influence and are influenced by emotional and cognitive areas of the brain. Alterations in this two-way system can lead to changes in behavioral aspects from emotional arousal to higher-order cognitive abilities like decision-making.
For the new study, the researchers recruited 187 participants aged between 28 and 97. Each completed self-reported surveys to assess their levels of loneliness, wisdom, compassion, social support, and social engagement. The researchers then analyzed their fecal samples in two ways. They looked at their alpha-diversity, which is the ecological richness of microbial species in their gut, as well as their beta-diversity, or the differences in microbial species between individuals.
All in all, the researchers found that lower levels of loneliness and higher levels of wisdom, compassion, social support, and engagement were linked to more diverse gut bacteria. While the cause behind this is unknown, the researchers noted that reduced microbial diversity is commonly linked to worse physical and mental health, as well as a host of diseases, including inflammatory bowel disease and major depressive disorder.
While reduced microbial diversity does not necessarily cause disease per se, the researchers noted that it might lead one to be more susceptible to various illnesses. Loneliness, for example, may result in less stability in the gut microbiome and thus reduced resistance and resilience to stress-related disruptions. These disruptions may then have physiological effects such as systemic inflammation, which may reduce the gut microbiome's diversity and then increase one's chances of developing various diseases.
While interesting findings, the researchers note some limitations in their study. Importantly, their study lacked data on individuals' social networks as well as information on their diet and degree of objective social isolation as opposed to subjective social isolation. As such, larger, longer studies may be necessary to confirm their results.