trained immunity is a functional defense amplifier, not a higher-priority longevity bottleneck than thymic source restoration

trained immunity is a functional defense amplifier, not a higher-priority longevity bottleneck than thymic source restoration

''结论'': β-glucan-induced trained immunity can enhance host resistance to infection in aged mice (18–20 mo old), but the public evidence currently remains at infection resistance / innate immune readout level; it does not yet establish lifespan or broad healthspan benefit.

''可复用判断'':
# If an immune candidate improves infection challenge, vaccination response, or short-term innate readouts only, treat it first as a functional defense amplifier.
# Do not upgrade trained immunity to a universal longevity bottleneck without lifespan or multi-organ healthspan evidence.
# In the immune bottleneck ranking, prioritize upstream reversible sources (e.g. thymic restoration) above immune-state tuning.

''证据锚点'': Trained immunity enhances host resistance to infection in aged mice（PMC12022634；PubMed 39722231）。