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How Wisdom and Loneliness May Be Connected to Gut Health

Better intestinal health may mean more wisdom and less loneliness, study finds.

Key points

  • The diversity of a person's gut microbiome—the bacterial population in the intestinal tract—is linked to physical and mental well-being.
  • People with a richer and more diverse gut microbiome have higher levels of wisdom and lower levels of loneliness, according to research.
  • People can improve the health of their gut microbiome by eating a diet high in green, leafy vegetables, fiber-rich foods and probiotics.
pasja1000/Pixabay, used with permission
Loneliness is debilitating.
Source: pasja1000/Pixabay, used with permission

Scientists at the University of California, San Diego, in collaboration with the Veterans Affairs San Diego Healthcare System, looked at the association between loneliness, wisdom, and the health of the gut microbiome of 184 community-dwelling (non-institutionalized) men and women, ages 28 to 97. They found significant associations between microbiome diversity and loneliness, wisdom, social support, and participation in social activities. The richer and more diverse the gut microbiome, as measured by fecal analysis, the less the participants reported feelings of loneliness and the higher they scored on wisdom, social support and social engagement. With respect to loneliness, this association was especially strong for older adults.

A diverse microbiome is rich in healthful microbes, or bacteria living in your gastrointestinal tract. These healthful bacteria maintain intestinal balance by preventing an overgrowth of harmful microbes in your gut. A rich and diverse gut microbiome not only helps maintain the health of your digestive tract but also your heart and immune system. In addition, a healthy microbiome helps with weight control. A less diverse microbiome is associated with neurological and psychiatric disorders, including major depressive disorder.

Getting a Healthy Gut Microbiome

Just as a healthy gut microbiome is the result of a healthy and diverse diet rich in plant foods and fiber, an unhealthy microbiome is generally the result of a poor diet that’s high in processed foods and low in fiber. You can improve the health of your microbiome and increase the diversity of microbes residing in your gastrointestinal tract by consuming a diet that emphasizes eating lots of green, leafy vegetables (spinach, kale, broccoli, etc.) and other fiber-rich vegetables, fruits, legumes, and whole grains that encourage the growth of healthy microbes in your body. Probiotics, or foods such as yogurt, kefir and other fermented milk products, kombucha, kimchi and fresh sauerkraut, actually contain live, beneficial bacteria that contribute to the diversity and health of your gut.

Conventional wisdom holds that a less diverse community of microbes in the gastrointestinal tract results in poorer physical and mental health, and the San Diego study was not the first to link the composition and diversity of the gut microbiome with personality traits and psychosocial well-being. Other studies have found that gut bacteria are involved in social communications, behavior and interactions. While a less diverse microbiome may not directly cause feelings of loneliness and social isolation, these studies show that it could make you more susceptible to inflammation and related conditions, and less able to resist the effects of loneliness on your health.


Nguyen TT, Zhang X, Wu T-C, Liu J, Le C. Tu XM, Knight, R, Jeste DV. Association of Loneliness and Wisdom with Gut Microbial Diversity and Composition: An Exploratory Study. Frontiers in Psychiatry. March 25 2021.