Some people live past 100 with remarkable health, and researchers at Boston University may have identified part of the reason why in the chemistry of their blood.
A study published in GeroScience by researchers at Boston University's Chobanian & Avedisian School of Medicine found that centenarians carry a distinct metabolic profile that is not simply an older version of the typical aging pattern. Specifically, people who reached 100 years of age showed elevated levels of certain primary and secondary bile acids — including chenodeoxycholic acid (CDCA) and lithocholic acid (LCA) — and preserved levels of several steroids, compared to their non-centenarian counterparts.
Both of those patterns were independently associated with lower mortality risk. The researchers describe them as a kind of biological "fingerprint" of extreme longevity that may eventually serve as a tool for estimating biological age and identifying pathways worth targeting to extend healthspan.
Why This Matters
Why do some people reach 100 in good health while their peers do not? Genetics explains up to 50% of the variation, according to BU researchers. Healthy lifestyle factors — plant-rich diets, consistent physical activity, strong social connections — account for much of the rest. But the biological mechanisms through which those inputs produce extreme longevity remain largely unknown.
Identifying measurable blood chemical patterns that differ between centenarians and typical agers creates a foundation for understanding those mechanisms. Bile acids are not merely digestive molecules — they are signaling compounds that regulate gut microbiome composition, systemic inflammation, and metabolic function. Steroids regulate a wide range of hormonal and anti-inflammatory pathways. Both categories are increasingly recognized as important in the biology of aging.
What We Know So Far
From EurekAlert/BU School of Medicine, ScienceDaily's GeroScience coverage, and the published GeroScience study:
- Study population : 213 participants from the New England Centenarian Study (NECS) — 70 centenarians, their offspring (a genetic comparison group), and age-matched controls
- Method : Untargeted serum metabolomics assessing approximately 1,495 small molecules in the blood
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Key finding
: Compared to offspring and matched controls, centenarians showed:
- Higher levels of primary and secondary bile acids , including chenodeoxycholic acid (CDCA) and lithocholic acid (LCA)
- Preserved (stable) levels of several steroids — patterns that do not follow the typical age-related decline
- Lower levels of biliverdin and bilirubin (both markers of oxidative stress)
- Mortality association : Both elevated bile acids and preserved steroid levels were independently associated with lower mortality risk
- What the finding does not include : Any evidence that supplementing bile acids or steroids produces longevity benefits — the direction of causality is not established
"Our study points to measurable chemical fingerprints in the blood that are associated with living a very long and healthy life," said Stefano Monti, PhD, a computational biomedicine researcher at BU and lead author of the study.
Where the Research Fits in the Aging Science Landscape
This study adds to a growing field connecting the gut microbiome to aging trajectories. Bile acids are produced in the liver but chemically modified by gut bacteria into secondary forms — including the specific bile acids found elevated in centenarians. This means centenarians' unusually high secondary bile acid levels may reflect an unusually healthy and well-preserved gut microbiome that produces these beneficial metabolites throughout life.
That connection is consistent with other centenarian research showing distinct gut microbiome compositions in very long-lived individuals, including a higher abundance of bacteria from the family Odoribacteraceae, which produce bile acid metabolites associated with reduced infection risk and inflammation.
What Doctors and Experts Say
"Discovering a fingerprint of extreme longevity opens up new avenues for research and clinical applications aimed at extending the healthspan," researchers noted in the study's coverage.
Independent longevity researchers have noted that the finding is consistent with the growing evidence base linking bile acid metabolism, gut microbiome health, and inflammatory regulation to the pace of biological aging. The preserved steroid profile in centenarians is also consistent with the observation that centenarians often maintain hormonal balance better than average agers — potentially reflecting a slower rate of hormonal decline across the lifespan.
What the Evidence Shows — and What It Does Not
This is an observational, cross-sectional study. It identifies associations between blood metabolite patterns and extreme longevity — it does not establish that the bile acid and steroid patterns caused longevity, or that artificially increasing bile acids or steroids in other people would extend their lives.
MedicalDaily Evidence Check
- Study type : Observational, cross-sectional metabolomics study
- Published in : GeroScience (March 27, 2026)
- Participants : 213 (70 centenarians, their offspring, and matched controls)
- Institution : Boston University Chobanian & Avedisian School of Medicine; New England Centenarian Study
- What it found : Centenarians have elevated specific bile acids and preserved steroid levels compared to non-centenarians; both are associated with lower mortality
- What it did not prove : That these metabolite patterns cause longevity; that supplementing these compounds would extend life in other populations
- Key limitation : Cross-sectional design cannot separate cause and effect; the centenarian-level pattern may result from decades of healthy metabolic function rather than driving it
- What readers should know : These are candidate biomarkers for biological age and longevity research — not a protocol to follow
Who May Eventually Benefit From This Research?
If future studies identify interventions that can promote the centenarian metabolite pattern in other aging populations, potential beneficiaries include:
- Adults in midlife who are interested in biological aging markers beyond cholesterol and glucose
- People with metabolic syndrome, where bile acid metabolism is known to be disrupted
- Researchers developing biomarker panels for biological age assessment
- Drug development programs targeting the gut microbiome as a longevity intervention
Symptoms and Warning Signs to Watch For
This research is not oriented toward a clinical condition with acute symptoms. However, patterns associated with poor bile acid metabolism and accelerated aging include:
- Persistent digestive issues, including constipation, bloating, or fat malabsorption
- Elevated inflammatory markers on routine labs (CRP, ferritin)
- Gut microbiome dysbiosis, sometimes associated with frequent antibiotic use, highly processed food diets, or chronic illness
If any of these patterns concern you in the context of your overall metabolic health, discuss them with a primary care provider.
What You Can Do Now
- Support gut microbiome health. The bile acid patterns in centenarians are partly a product of a well-preserved, diverse gut microbiome. Dietary fiber, fermented foods, and limiting ultra-processed food intake all support microbiome diversity.
- Maintain physical activity throughout aging. Both exercise and physical activity are associated with preservation of bile acid metabolism and gut microbiome composition in older adults.
- Do not supplement bile acids or steroids based on this research. These are systemic signaling molecules with complex regulatory effects; supplementation is not indicated and could have adverse effects.
- Discuss biological age testing with your physician if you are interested in metabolomics-based health assessment. Clinical metabolomics panels are beginning to enter the consumer health space, though they are not yet standard of care.
Cost and Access: What Patients Should Know
The New England Centenarian Study continues to recruit participants and their families — people interested in contributing to longevity research can contact Boston University's program directly. Metabolomics testing is not currently a standard clinical service in most healthcare settings; research and commercial panels exist but should be interpreted cautiously without established clinical reference ranges.
What Happens Next
The BU research team plans to expand the study population and integrate the metabolomics findings with genomic and microbiome data from NECS participants. Future research will examine whether the metabolite patterns can predict survival or disease trajectory in younger populations — the necessary step for developing clinical biomarker tools.
The Bottom Line
People who live past 100 in good health have different blood chemistry than their peers — specifically, higher levels of certain bile acids and preserved levels of several steroids that are associated with lower mortality. This finding from Boston University's landmark centenarian study does not reveal a secret formula for reaching 100. But it identifies specific, measurable biological patterns that may eventually allow researchers and clinicians to assess biological aging more precisely, and intervene before the metabolic drift of typical aging becomes irreversible.
