Does your gut microbiome affect how healthfully you age? It appears so

By

Special to The Seattle Times

On Nutrition

The gut microbiome — the complex community of bacteria and other microorganisms that live in the large intestine — has been a hot topic for a few decades (the National Institutes of Health launched the Human Microbiome Project in 2007). As scientists learn more about the connections between the gut microbiome and overall health, the topic has grown even hotter. The health of the gut microbiome has been linked to everything from digestive health to bone health to brain health. Does it play a role in how well we age, too? Perhaps.

Scientists have found that our population of gut microorganisms does change with age, but it’s unclear if these changes contribute to the aging process, or if aging contributes to the changes in the gut. It’s likely that it’s a two-way street: the microbiome changes with age and in response to age-related diseases such as cardiovascular disease and type 2 diabetes, but the microbiome also influences how healthfully we age physically and cognitively.

Age-related changes in the gut microbiome vary from person to person based on personal, lifestyle, medical and environmental factors, and different patterns of change may be associated with different health outcomes later in life. Some research suggests that the diversity and uniqueness of your microbiome may be a key factor.

For example, a 2021 study that analyzed the gut microbiomes of 9,000 people ages 18 to 101 found that as people get older, the gut microbiome does tend to change — and the more change the better. Specifically, in healthy people, the types of microorganisms that play a major role in the gut during early adulthood gradually decrease in number with age, while the percentage of less common types of microorganisms starts to rise. Ultimately, this leads to an increasingly unique gut microbiome, which the study’s authors said appears to not just reflect healthy aging, but may also predict greater longevity. In less healthy people, gut microbiome composition changes very little with age and is less unique.

Researchers have reported similar findings from studies of centenarian populations from around the world. Some of these studies have even found that the gut microbiome continues to develop in the last decades of life. It may not be that your gut microbiome is supposed to stay forever young, but that it’s supposed to change appropriately. Again, it’s a chicken-or-the-egg scenario: it’s not clear whether appropriate age-related changes to the gut microbiome drive healthy aging, or if healthy aging drives age-appropriate changes.

So what can you do to support a healthy gut and healthy aging? Many of the same lifestyle and environmental factors that affect our overall health and well-being can also affect the gut microbiota. Because of the likely two-way relationship between a healthy gut microbiome and a healthy you, caring for the health of your gut may reap continued rewards as you age. Here are three factors to consider:

• Physical activity. Studies have found gut microbiome pattern differences in older adults who are physically active compared to their less-fit peers. Other research connected early frailty to reduced gut microbial diversity. 
• Healthy diet. A quality diet rich in plant foods — vegetables, fruits, whole grains, beans, nuts and seeds — supports your gut (and the rest of you) with an array of nutrients and, critically, fiber, including the prebiotic fiber that feeds beneficial gut microorganisms.
• Social connection and environment. Spending time with friends and family, volunteering, having pets, gardening and spending time outdoors can all benefit gut health.