Microbiome Insights from Centenarians: What Longevity Teaches Us.

Kristina Mitts in longevity 10 Mar 2026 • 3 min read

Author Bio

Kristina Mitts | Registered Nutritionist

Kristina is a Registered Nutritionist with experience working in the fields of Functional/Integrative Medicine and Microbiome Restoration. She began her career working in microbiome-focused clinics and realized that the clinics were missing an opportunity to improve outcomes for patients by not assessing the microbiome through the lens of 16s rRNA testing like Biomesight. In the last few years she branched more into functional medicine. Kristina loves to teach clients how to harness their microbiota to reduce bloating, brain fog, histamine and food/chemical intolerance, and other chronic or autoimmune health issues.

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When it comes to understanding healthy aging and lifespan, the people who live to 100 and beyond have always fascinated scientists (and lay people). In recent years, researchers have turned their attention to one of the body’s most dynamic systems — the gut microbiome — to ask: what is different about the gut microbiomes of centenarians? And what might their microbial ecosystems teach the rest of us about aging well?

What the research shows

Several recent studies highlight that the gut microbiomes of centenarians (people aged 100+ years) are distinct in ways that might support healthy aging. A few highlights:

A large study of 1,575 individuals (aged 20–117 years) in Guangxi, China (including 297 centenarians) found that older adults in the 100+ range exhibited “youth‑associated gut microbial signatures”: a Bacteroides‑dominated enterotype, increased species evenness, an enrichment of beneficial Bacteroidetes, and a depletion of potential harmful bacteria. 

Research in Hainan centenarians found sex‑specific microbiome patterns: male centenarians had higher microbiome diversity compared to females, and different species enriched by sex.

Another study found that centenarians show higher microbial diversity, greater capability of xenobiotic (foreign chemical) metabolism, more oxidative stress reducing activity, and enrichment of microbes such as Akkermansia, Lactobacillus, and butyrate‐producing members of Clostridiales/Ruminococcaceae. 

A cross‑sectional study in Sardinian centenarians (Italy) found enrichment of Bifidobacterium adolescentis in centenarians compared to younger/elderly adults. 

A narrative review (2025) summarising multiple studies notes that among long‐lived individuals (including semi‑supercentenarians aged 105+), health‑associated taxa such as Bifidobacterium appeared to increase gradually in some populations. However, a metagenomic cohort study of 75 healthy centenarians in Hainan, China found that two bacterial species increased before death: Bifidobacterium longum and Ruminococcus bromii.

Microbiome virome work (i.e., gut viruses) shows that centenarians have more diverse gut viral communities with enriched viral genes supporting sulfate/methionine/taurine metabolic pathways. 

Common Microbiome “Signatures” of Longevity

From the research, several recurring microbial themes emerge among centenarians:

High species evenness (rather than just high diversity). In other words, not just more species, but a more balanced distribution of species. 

Bacteroides‑dominant enterotype in many centenarians, which tends to mirror features seen in younger adults. 

Enrichment of microbes that support gut barrier integrity, anti‑inflammatory effects, and beneficial metabolite production (e.g., Akkermansia, Christensenellaceae, SCFA producers).

Enhanced microbial functional capacity: for xenobiotic metabolism, oxidoreductase activity, resilience to oxidative stress. 

Lower representation of potential pathobionts (i.e., bacteria that can cause disease when conditions tip) in many healthy centenarians. 

What This Might Mean for Gut Health & Aging

What do these findings tell us — beyond the fact that “yes, centenarians have different gut microbes”? A few implications:

The presence of youth‑like microbiome features in centenarians suggests that the gut ecosystem may play a role in resilience — the ability to sustain health, repair tissue, resist inflammation and maintain homeostasis.

A balanced microbiome (evenness, diversity) appears to correlate with stability — centenarians with low microbial evenness showed more instability over time. 

Microbes that support gut barrier integrity, metabolite production (like short‑chain fatty acids), xenobiotic detoxification, and anti‑inflammatory signalling may help modulate age‑related risks (inflammation, metabolic decline, gut permeability).

The microbiome may act as a “middle-man” between lifestyle/environment/genetics and physiological aging: how well you eat, move, sleep and live shows up in your gut, and then your gut shows up in how you age.

Caveats & What We Don’t Know Yet

Most studies are cross‑sectional (snapshot in time) — causal relationships aren’t clearly established. We don’t yet know for sure whether the microbiome is driving longevity or is simply a marker of those who age well.

Many centenarian studies are region‑specific (China, Italy, Japan) so findings may not generalize fully to all populations or lifestyles.

The interplay between genetics, lifestyle, diet, environment, and gut microbiome is complex — the gut is only one piece of the puzzle.

Microbiome research in centenarians often focuses on bacteria; other components like fungi (mycobiome), viruses (virome) and metabolites are less well explored — though emerging.

Interventions to “convert” your microbiome to a centenarian‑like state are not yet validated in large trials; what matters is building a resilient gut ecosystem over time.

Practical Takeaways

Even though we’re not prescribing “centenarian microbes in a pill” (yet!), there are take‑homes you can apply now:

Focus on diversity and evenness: Eat a wide variety of plant‑based fibres, vegetables, legumes and nuts — the more different substrates you feed your microbes, the better the ecosystem.

Support gut barrier health: Ensure good sleep, stress management, movement, minimal toxin load (alcohol, heavy metals, processed foods), healthy weight — as these influence how your gut microbes behave.

Include foods and patterns known to support beneficial microbes: For example, moderate fermented foods (if tolerated), foods that support SCFA production (resistant starches, whole grains), polyphenol‑rich plant foods, moderate protein and healthy fats.

Skip the obsession with a “perfect microbiome” and instead aim for stability: microbial shifts that persist rather than dramatic fluctuations.

Consider long‑term mindset: The gut ecosystem builds over years. Like the centenarians show, it’s more about resilience over decades than quick fixes.

Conclusion

The study of centenarians’ microbiomes offers a fascinating window into how our gut ecosystems may contribute to aging well. While we still have much to unravel, the consistent themes of diversity, balance, beneficial metabolite production and gut integrity give us actionable clues. Building a gut ecosystem that supports resilience — and thus possibly supports healthspan and lifespan — is less about chasing a single “miracle microbe” and more about nurturing a thriving community inside.

By taking steps now to feed and maintain your gut microbiome, you’re investing not just in gut health — but in your long‑term vitality.

1. Li, X., Yu, Q., Wong, S., et al. “Longevity of centenarians is reflected by the gut microbiome with youth‑associated features.” Nature Aging. 2023;3:341–353. 

2. Li, X., Yu, Q., Wong, S., et al. “Youth‑associated signatures in the gut microbiome of centenarians.” Nature Aging.2023;3:355‑368. 

3. Pivotal Review: “Gut microbiota in centenarians: A potential metabolic and aging link.” AGM2 – Ageing & Disease.2023; Volume etc. 

4. Smirnova, A., et al. “Comparative Analysis of Gut Microbiota in Centenarians and Young Adults.” Frontiers in Cellular and Infection Microbiology. 2022;12:851404.

5. Johansen, J., et al. “Gut Microbiomes of Japanese Centenarians Offer New Insights into Healthy Aging.” Technology Networks. 2023.

6. Honda, K., et al. “The distinct microbiome of centenarians may partially account for their longevity via microbial‑derived bile acids.” Research news, RIKEN Centre. 2021. 

7. Broad Institute News: “Centenarians have a distinct microbiome that may help support longevity.” July 2021.

8. “Healthy longevity: The role of the gut microbiome.” Medical News Today. 2023.