I study the evolution of senescence.
Scientific Director at the Leibniz Institute on Aging.
Killifish, evolution, microbiome, and causal inference.
Bringing molecular genetics into field work.🇪🇺🐟🦠🧬
Dario Riccardo Valenzano
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If the model is right, age-associated dysbiosis is not the microbes turning on the host. It is the host losing its grip on them. The more persistent competitors expand into the space surveillance had been holding open. Often these are taxa with pathobiont potential.
Now the aging hypothesis. Immunosenescence is not uniform decline. The crude load-sensing arm stays on, even hyperactive: this is "inflammaging." The discriminating, dominance-braking arm erodes. Inflammation without precise control. The brake comes off.
To show the logic is sufficient, we built a simple model. Four microbes compete on a hexagonal lattice. Apply one rule: suppress whichever taxon dominates. The community stays diverse and stable. Remove the rule, a single winner takes over and diversity collapses.
We are grateful to Ines Alvarez-Garcia at PLOS Biology for inviting this piece and shepherding it through review, and to the two reviewers, whose pushback genuinely sharpened the argument.
This inverts the logic of most microbiome-targeted interventions in older adults. Restoring a diverse microbiome to a host that has lost the capacity to manage it provides the ecological complexity without the controls. Immune restoration may need to come first, or in parallel.
Copenhagen colleagues. Mid-June we may need to process fresh Greenland shark gut samples for an exciting microbiome project. Would you, or someone you know, have bench space for my postdoc for a day? Longest-lived vertebrate, exciting microbiome data. Boosts welcome 🦈 #aging #copenhagen #microbiome
Thrilled to see this out today in PLOS Biology. With postdocs Siqi Liu and Flávio Costa, we ask why the gut microbiome loses its balance with age. It's an Unsolved Mystery piece: a framework, not a finalized account, with predictions we lay out for the field to test. 🧵
