Scientists have identified a significant link between the microorganisms living in the human digestive system and the speed at which the body ages. A study published in Scientific Reports by researchers at the University of Hawaii at Manoa reveals that the composition of gut bacteria can serve as a marker for biological aging rates.
The research indicates that differences in gut bacterial communities account for approximately 15% of the variation in participants’ biological aging speeds. This finding suggests that the gut microbiome, the vast ecosystem of microbes in the digestive tract, provides valuable insights into molecular aging processes.
Microbial Patterns and Aging Markers
To reach these conclusions, the research team analyzed stool and blood samples from 123 adults spanning a wide age range. They compared the bacterial species present in each participant’s gut against blood-based molecular markers designed to estimate the body’s rate of aging. These biological measurements differ from chronological age, which simply counts the number of years a person has lived.

The study focused on DunedinPACE, an advanced biomarker that measures the pace of biological aging. The analysis revealed a notable association between the gut microbiome composition and this specific aging metric. The results demonstrate that microbial patterns in the gut are significantly associated with molecular measures of aging, even when independent of chronological age.
Senior author Alika K. Maunakea of the UH Manoa John A. Burns School of Medicine stated that the study advances the understanding of the relationship between the gut microbiome and biological aging. He noted that these findings open new directions for understanding how modifiable biological systems influence long-term health trajectories and longevity.
Specific Bacteria Linked to Aging Speed
The investigation highlighted specific bacterial species with strong relationships to aging. Bifidobacterium adolescentis emerged as one of the microbes most strongly associated with slower biological aging. In contrast, Succinivibrio dextrinosolvens showed one of the strongest associations with faster aging.
Lead author Braden P. Kunihiro explained that the discovery adds to evidence that the gut microbiome could play a critical role in precision health research. This field aims to better understand individual differences in health and disease. Unlike chronological age, the composition of the gut microbiome can change in response to everyday influences, including diet, lifestyle, and environmental conditions.

Kunihiro emphasized that the gut microbiome is highly responsive to lifestyle, diet, environment, and other everyday exposures. He suggested that the microbiome may reflect important aspects of biological resilience and aging in ways that could eventually help inform future wellness and healthy aging strategies.
Diverse Participant Groups and Future Research
The research included Native Hawaiian and Pacific Islander participants, groups that have historically received limited representation in studies of aging and gut microorganisms. Co-author Ruben Juarez explained that including these populations helps scientists investigate how social circumstances and environmental conditions leave lasting biological effects over the course of a person’s life.
Juarez noted that the microbiome exists at the intersection of behavior, environment, and human biology. He stated that studies like this help illuminate potential pathways through which lived experiences and social factors influence long-term health outcomes.

Researchers stress that the study does not establish cause and effect. Finding certain microbes in people who age more slowly does not necessarily mean those bacteria are responsible for slowing the aging process. Further studies will be needed to determine whether deliberately changing the gut microbiome can influence biological aging or improve long-term health.
Maunakea described the work as an important early step toward understanding the gut microbiome’s relationship with healthy aging. He added that future research will help clarify the mechanisms involved and whether these microbial signatures may eventually contribute to precision approaches for promoting long-term health and wellness.
Source: ScienceDaily

