Aging is universal, but the pace and quality of aging differ widely among people. Emerging evidence shows the gut microbiome—a complex ecosystem of bacteria, viruses, fungi and other microbes—plays a significant role in biological aging processes. Understanding this relationship offers practical avenues to support healthier aging trajectories and reduce risk factors associated with age-related conditions. The gut microbial community is dynamic and influenced by diet, medications, lifestyle and chronological age. As diversity and stability decline with aging, many older adults experience shifts in relative abundances of beneficial and potentially harmful taxa, which can increase systemic inflammation and susceptibility to infection. For a focused discussion on how the gut influences healthy aging, see [The Gut-Longevity Connection: How Your Microbiome Shapes the Way You Age](https://www.innerbuddies.com/blogs/longevity-healthy-aging/gut-microbiome-longevity-connection). Studies of exceptionally long-lived individuals provide important clues. Research on centenarians has repeatedly found microbiome profiles that resemble those of much younger adults, including higher representations of certain beneficial bacteria and an overall more balanced community structure. These observations support the idea that a resilient, diverse microbiome may contribute to preserved function and reduced frailty in late life. Several microbial groups repeatedly associate with healthy aging. Akkermansia muciniphila supports the gut barrier and modulates immune signaling, correlating with lower inflammation and improved metabolic health. Faecalibacterium prausnitzii produces butyrate, a short‑chain fatty acid (SCFA) that nourishes colonocytes and maintains mucosal integrity. Members of the Christensenellaceae family associate with healthier body composition and reduced frailty risk. Maintaining populations of these microbes tends to support physiological systems that decline with age. SCFAs such as butyrate, propionate and acetate are microbial metabolites produced from dietary fibers. They contribute to gut barrier function, help regulate immune responses and influence glucose and lipid metabolism—mechanisms directly relevant to age-related disease risk. Reduced SCFA production is a common feature of dysbiosis and may underlie increased gut permeability and chronic low-grade inflammation observed in many older adults. Dysbiosis—an imbalance in microbial composition—can therefore have broad implications, including heightened risk for metabolic disease, neurodegenerative conditions and impaired immune resilience. Addressing dysbiosis through targeted, evidence-based strategies is a practical component of promoting healthy aging. Modifiable lifestyle factors exert strong effects on the microbiome. A diverse, plant-rich diet high in varied fibers and fermented foods supports microbial diversity. Regular physical activity is associated with greater microbiome diversity and enrichment of beneficial taxa. Adequate sleep and stress management also contribute to microbial balance and systemic homeostasis. For foundational information on diet and the microbiome, see How diet can add years to your life and What is gut microbiota and why it matters. Advances in microbiome testing enable personalized assessment of community composition and function; these results can inform individualized dietary and lifestyle interventions. Some people also consider clinical or research tools such as a microbiome test (microbiome test) to guide tailored strategies. In summary, the gut microbiome is a modifiable factor that influences aging through multiple biological pathways. Supporting microbial diversity and function via diet, activity, sleep and other lifestyle measures can be an evidence-based part of an integrated approach to healthier aging.