Gut Bacteria Linked to Biological Aging Rates, Study Reveals

Scientists at the University of Hawaiʻi at Mānoa have uncovered a significant connection between the bacteria residing in the human gut and the speed at which the body biologically ages. Their study, published in Scientific Reports in 2026, found that differences in gut bacterial communities accounted for approximately 15% of the variation in participants' biological aging rates, suggesting the gut microbiome offers valuable insights into aging at a molecular level.

Senior author Alika K. Maunakea emphasized that microbial patterns in the gut were strongly associated with molecular measures of aging, independently of chronological age. The research identified specific bacterial species with strong relationships to aging; for instance, *Bifidobacterium adolescentis* was linked to slower biological aging, while *Succinivibrio dextrinosolvens* showed a strong association with accelerated aging. These findings open new avenues for understanding how modifiable biological systems influence long-term health and longevity.

To investigate this relationship, researchers analyzed stool and blood samples from 123 adults across a broad age range. They compared the identified gut bacteria with blood-based molecular markers, such as DunedinPACE, an advanced biomarker that measures the pace of biological aging. These biological measurements assess the rate of aging-related changes within the body, which differs from a person's chronological age.

Lead author Braden P. Kunihiro noted that this discovery contributes to growing evidence suggesting the gut microbiome's role in precision health research. Unlike chronological age, the gut microbiome's composition is responsive to daily influences like diet, lifestyle, and environmental conditions, making it an intriguing area for healthy aging studies. The research also included Native Hawaiian and Pacific Islander participants, addressing historical underrepresentation in aging and gut microbiome studies. Co-author Ruben Juarez explained that this inclusion helps investigate how social circumstances and environmental conditions leave lasting biological effects throughout a person's life.

While the findings reveal a meaningful association, researchers stress that the study does not establish a cause-and-effect relationship. It is not yet clear whether deliberately altering the gut microbiome can directly influence biological aging or improve long-term health. Future research is necessary to clarify the underlying mechanisms and to determine if these microbial signatures could eventually contribute to personalized approaches for promoting health and wellness.

What to watch: Future studies exploring direct interventions on the gut microbiome and their impact on aging.

Editor's note: The draft effectively synthesizes the research findings, methodology, and expert commentary from the provided full text.