Could gut microbes hold the secret to aging well? A researcher unpacks the emerging science
People have long since abandoned the search for Fountain of Youtha mythical source that could reverse aging. But for some scientists, the hunt is not over: it has simply moved to another location. These modern-day Ponce de Leóns are studying whether intestinal microbes hold the secret to aging well.
THE intestinal microbiota refers to the vast collection of microscopic organisms – bacteria, fungi and viruses – that largely inhabit the colon. These microbes aid digestion and produce molecules that affect your physiology and psychology. The composition of the microbiome is influenced by a combination of factorsincluding genetics, diet, environment, medications and age.
You are as old as your gut microbes
People are more familiar with the outward signs of aging, such as wrinkles And graying hairbut microscopic changes also occur deep within us. The gut microbes of older adults tend to be less diverse, with more bacteria that promote inflammation and other characteristics of aging. Changes in the microbiome by age are so consistent that algorithms can reliably predict a person’s health status. age based on the composition of their microbiome.
There are exceptions to this rule. Older adults and supercentenarians who age well have a gut microbiome that looks more like those of the youngest. These results support the idea that maintaining a a youthful microbiome promotes healthy aging and longevity.
Look on it
To confirm that youthful microbes influence aging, scientists use a technique called fecal microbiota transplantation. This procedure involves erasing a person’s current gut microbiome and replacing it with microbes harvested from a donor’s stool. Transplantation of the microbiota from a young mouse to an aged mouse reverses age-associated inflammation in the gut, brain and eyes. Conversely, transplanting the microbiota from an old mouse to a young one accelerates these aging parameters. Other studies suggest that the microbiota of young mice change metabolism so as to reduce inflammation that accelerates aging.
The evidence that aging is linked to the microbiome is compelling. However, fecal transplantation is not without risk and is only approved as a last resort treat harshly C. difficile infections. These gaps have prompted researchers to look for safer and more refined ways to cultivate a microbiome suitable for older adults.
Diet and exercise can slow aging
Good nutrition and exercise have long been linked to better aging and longevity. These lifestyle habits can be beneficial in particular thanks to their influence on intestinal microbes.
What people eat – or don’t eat – has a demonstrable effect on their gut microbiome. THE standard american dietenriched with ultra-processed foods high in sugar, fat and salt and low in nutrients and fiber, depletes the microbiome diversity in a few days. Moving from a non-Western country to the United States is also associated with loss of gut microbiome diversitypartly due to dietary changes.
Lack of fiber is a major reason the microbiome adopts a configuration associated with poor aging. Studies in roundworms, mouse And rats found that fiber supplements improved overall health and extended lifespan by 20 to 35 percent. A 2025 study showed that increasing the amount of fiber in your diet is linked to a 37% more likely to age healthily among women.
Fiber functions as a prebiotica non-digestible food component that nourishes the microbiome. Gut bacteria convert fiber into compounds such as short chain fatty acids which promote better aging by improving metabolic, brain and immune functions while reducing chronic inflammation. Good sources of prebiotics include most fruits and vegetables, whole grains, legumes, nuts and seeds.
Certain foods, such as yogurt and kefir, or food supplements contain probiotics — live microbes that can benefit the gut microbiome. Research on probiotic foods and supplements is mixed, complicated by variation in bacterial species and dosage of these products. The health benefits that different types of probiotics can confer are still under study.
Physical activity is also linked to a young microbiome. Regular exercise can reshape the microbiome older adults to resemble those observed in younger adults. One study showed that when people aged 50 to 75 completed 24 weeks of cardiovascular and resistance exercise, their the microbiota became populated with healthier bacteria and their blood had high levels of aging-promoting short-chain fatty acids.
Treatments to manipulate the microbiome
Making healthy lifestyle changes is a non-invasive way to cultivate a youthful microbiome that can slow aging. Scientists are also exploring treatments to adapt the intestinal microbiome for better health outcomes.
An option can be postbiotics, non-living but active compounds that probiotic microbes produce. For example, studies in mice have shown that short-chain fatty acid supplements can improve age-related heart And lung problems. Likewise, aged mice having received heat-killed bacteria from a human infant found a reduction in metabolic dysfunction and inflammation, as well as an improvement in cognitive function.
The microbiome can also be altered by medications, including antibiotics. A low-dose oral antibiotic can trigger gut bacteria to release factors that may promote good health and aging, for example by strengthening the intestinal barrier or reducing inflammation. One of these antibiotics, cephaloridine, extends the lifespan of roundworms and mice by triggering the production of intestinal bacteria colanic acid, an anti-aging compound.
Bacteriophages, or phagesoffer yet another potential means of manipulating the microbiome for health. The phages are highly selective viruses that infect and kill specific species of bacteria. Phages have been used to treat serious infections from bacteria resistant to antibiotics. Since phages can modify the gut microbiome of miceresearchers are studying whether they could be used to eliminate gut bacteria associated with unhealthy aging.
Aging is a natural process that can bring many rewards. Cultivating a healthy microbiome could help people make the most of their golden years.
This edited article is republished from The conversation under Creative Commons license. Read the original article.
