The Gut-Longevity Connection: Nourishing Your Microbiome for a Longer Life

Coined as the microbiome in 2001, the collection of 100 trillion-plus bacteria that reside in our gastrointestinal tracts is now known to influence much more than just our digestion. From cognition to cardiovascular health, the makeup of bacteria in our guts has been linked to dozens of health outcomes—including longevity and aging. 

Although every person’s microbial makeup is unique—like a fingerprint—each individual microbiome tends to stay relatively stable in terms of the species it houses for most of its life. However, upon reaching mid-to-late adulthood, the bacteria in our guts start to shift—and these microbial changes can alter not only health outcomes but also how long we live. In this article, we’ll take a look at the recent research on gut microbes and lifespan, as well as the best ways to nourish your microbiome to support healthy aging and longevity. 

How Does the Gut Microbiome Impact Longevity?

One of the key differentiators of the gut microbiomes of healthy agers is not how many bacteria they have, but how unique and diverse those bacteria are. The gut microbiomes of younger adults lean heavily towards Bacteroides—one of the “core bacteria” humans have in common.

But as we inch closer to our fifth or sixth decade and beyond, healthy older adults will begin to have bacterial signatures that include more unique species, including those linked to better metabolic health and muscle function. Although Bacteroides are healthy bacterial species—and older adults still want to have them—retaining a higher gut dominance of this bacteria into older age predicted decreased survival in research with older adults. Plus, studies show that low microbial uniqueness with age is linked to increased frailty and physiological decline in older adults.

Conversely, semi-supercentenarians (people who live to be 105 years or older) show much higher levels of bacterial diversity. Other research has found that the healthiest “oldest-old” adults (those aged 90-plus) have increased levels of Akkermansia, which is associated with better metabolic function—an important marker of healthy aging.

A healthy gut is not only about what bacteria you do have, but also which types you don’t. In a study published in Nature Communications, researchers looked at the gut microbiomes of over 7,000 adults over a 15-year period. One of their findings was that people with the highest rates of mortality had an overabundance of bacteria in the Enterobacteriaceae family—a large group that comprises over 30 genera and 100 species, including the well-known E.coli and Salmonella.

Although this bacterial family is found in a normal microbiome, they typically represent only 1% of a healthy gut. Therefore, an overabundance of Enterobacteriaceae is a hallmark of microbial imbalance known as dysbiosis that can drive disease and infection. In this study, people with microbiomes with the highest abundance of Enterobacteriaceae had a 34% increased risk of death compared to people with the lowest abundance of this bacterial family. 

Top Tips for Nourishing Your Microbiome

As the studies mentioned here find that a higher abundance of unhealthy bacterial families (like Enterobacteriaceae) and a low abundance of healthy bacteria increase the risk of mortality, you may be wondering how to manage your gut microbiome to reduce this risk and extend your lifespan.

One of the quickest ways to alter your gut microbiome—for better or for worse—is through diet. While high amounts of sugar, alcohol, and inflammatory processed foods are known to be detrimental to our gut bugs, daily intake of fiber-rich, fermented, plant-based, and antioxidant-rich foods have been found to be beneficial to our bacteria.

Some of the best ways that you can maximize your microbiome health at any age include: 

• Eat foods that naturally contain probiotics, like fermented vegetables, sauerkraut, kimchi, yogurt, tempeh, miso, and kefir. 
• Consume foods high in prebiotics, which are fibrous compounds that the probiotics can feed on to stay alive in the gut. Prebiotic-rich foods include onions, garlic, apples, leeks, and greenish (less-ripe) bananas. 
• Vary your veggies. Just as different fruits and vegetables carry different colors, they also impact the gut in various ways. Consuming a diet with dozens of plant foods—rather than just sticking to your few favorites every day—can lead to a more diverse microbiome. 
• Up your antioxidants. Most plant foods are rich in polyphenolic antioxidants. Some antioxidants and the foods they’re found in include resveratrol (red grapes), curcumin (turmeric), quercetin (apples and onions), anthocyanins (berries), sulforaphane (broccoli), ellagic acid (berries and pomegranate) and catechins (green tea and cocoa). Antioxidant supplements like trans-resveratrol, spermidine, pterostilbene, fisetin, green tea extract (EGCG), and hydroxytyrosol can also help to support your antioxidant intake.
• Take a high-quality probiotic supplement that contains at least 1 billion CFU (colony-forming units) of healthy bacteria per capsule. Multi-strain probiotics are typically recommended for general gut health, while higher amounts of single-strain bacteria can target specific health concerns. 
• Supplement with gut-supporting compounds, like EGCG (green tea extract), digestive enzymes, bitter herbs, curcumin, L-glutamine, and collagen. 
• Limit added sugar and refined carbohydrates, which do not contain the fiber your gut microbes need to survive. In addition, excess sugar intake negatively impacts your gut microbial ecosystem by decreasing bacterial diversity. 
• Ditch or minimize alcohol. Drinking alcohol—especially chronically and in excess—can drastically alter your gut health, including increasing gut inflammation and intestinal permeability and causing dysbiosis.
• Get enough sleep. Many people don’t realize that how you sleep can also impact your gut microbiome. Most adults need 7-9 hours of high-quality sleep per night. 
• Exercising. Regular physical activity has been shown to enhance the number of beneficial microbial species and enrich bacterial diversity. 

Key Takeaways

Our gut microbiomes are complex and ever-changing, with alterations based on our age, diet, lifestyle, medications, environment, and more. Recent studies have shown that certain types of gut bacteria are linked to longer lives—while other harmful bacteria may increase mortality. However, the research in this area is still relatively new, and more studies are always needed to determine if supplementing with probiotics containing these healthy bacteria would produce any longevity-boosting effects.

In the meantime, there are many ways to improve overall microbiome health, which could naturally shift your microbes to more diverse and beneficial ones—including consuming plenty of fermented foods, prebiotics, and antioxidants, while reducing your intake of sugar, alcohol, and processed foods. 

Reviewed by: Heather L. Makar

References: 

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Monda V, Villano I, Messina A, et al. Exercise Modifies the Gut Microbiota with Positive Health Effects. Oxid Med Cell Longev. 2017;2017:3831972. doi:10.1155/2017/3831972

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