Scientists have uncovered a surprising connection between the bacteria living in the human gut and the speed at which the body ages. Researchers at the University of Hawaiʻi at Mānoa found that certain gut microbes are associated with slower biological aging, while others are linked to faster aging.
The study, published in Scientific Reports, found that differences in gut bacterial communities accounted for approximately 15% of the variation in participants’ biological aging rates. The results suggest that the gut microbiome, the vast community of microorganisms living in the digestive system, may provide valuable clues about aging at the molecular level.
“This study advances our understanding of the relationship between the gut microbiome and biological aging,” said senior author Alika K. Maunakea of the UH Mānoa John A. Burns School of Medicine. “We found that microbial patterns in the gut were significantly associated with molecular measures of aging, even independent of chronological age. These findings open important new directions for understanding how modifiable biological systems influence long-term health trajectories and longevity.”
Scientists Identify Gut Bacteria Linked to Faster and Slower Aging
To investigate the relationship between gut bacteria and aging, researchers examined stool and blood samples collected from 123 adults across a wide range of ages. They identified the bacteria present in each participant’s gut and compared those findings with blood-based molecular markers used to estimate the body’s rate of aging.
These biological measurements differ from chronological age, which simply reflects how many years someone has been alive. Instead, they are designed to assess how quickly aging-related changes are occurring within the body.
The researchers found a notable association between the composition of the gut microbiome and DunedinPACE, an advanced biomarker that measures the pace of biological aging.
Some bacterial species stood out for their particularly strong relationships with aging. Bifidobacterium adolescentis was among the microbes most strongly associated with slower biological aging. In contrast, Succinivibrio dextrinosolvens showed one of the strongest associations with faster aging.
These differences suggest that particular patterns of gut bacteria may offer important information about how rapidly the body is aging.
How Diet, Lifestyle, and Environment May Influence Gut Health
Lead author Braden P. Kunihiro said the discovery adds to growing evidence that the gut microbiome could play an important role in precision health research, which 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. This makes it a particularly interesting area of investigation for scientists studying healthy aging.
“The gut microbiome is highly responsive to lifestyle, diet, environment and other everyday exposures,” Kunihiro said. “Our findings suggest 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.”
The research also 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 could help scientists investigate how social circumstances and environmental conditions leave lasting biological effects over the course of a person’s life.
“The microbiome exists at the intersection of behavior, environment and human biology,” Juarez said. “Studies like this help illuminate potential pathways through which lived experiences and social factors influence long-term health outcomes.”
Could Changing Gut Bacteria Influence How We Age?
Although the findings reveal a meaningful relationship between gut bacteria and biological aging, researchers stress that the study does not establish cause and effect. In other words, 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.
Still, the findings offer a promising starting point for exploring how the microorganisms living inside us relate to the aging process and whether they could eventually help guide more personalized approaches to healthy aging.
“This is an important early step toward understanding the gut microbiome’s relationship with healthy aging,” Maunakea said. “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.”
