University of Hawaii researchers report in Scientific Reports that gut microbiome differences were associated with about 15% of the variation in a biological-aging measure among 123 adults, though the study cannot show cause and effect.
Researchers at the University of Hawaiʻi at Mānoa report in the journal Scientific Reports that the makeup of the gut microbiome is associated with how fast the body is biologically aging. The team compared stool and blood samples from 123 adults aged 17 to 82, about 63% of whom identified as Native Hawaiian or Pacific Islander, using a blood-based measure of the pace of aging called DunedinPACE. Their best species-level model explained about 15% of the variation in that measure (R² of 0.152), and adding chronological age did not improve it, which the authors read as evidence that the link is independent of age.
Two species stood out. Bifidobacterium adolescentis was among the microbes most strongly associated with slower biological aging, while Succinivibrio dextrinosolvens showed one of the strongest associations with faster aging. The authors describe these species as hypothesis-generating candidates for follow-up work rather than diagnostic markers, and the study found no predictive signal for several older epigenetic clocks, so the result applies specifically to the DunedinPACE measure.
The researchers stress that the study does not establish cause and effect: finding certain bacteria in people who age more slowly does not show those bacteria slow aging, and whether deliberately changing the microbiome would alter aging remains untested. The authors also list important limits, including a small sample for machine learning with a 37-person test set, no external validation, limited species-level resolution from 16S sequencing, a cross-sectional design and a cohort that may not generalise. The paper says the results are not intended for clinical or individual diagnostic use.
