Aging reduces vaccine efficacy through two interconnected mechanisms: disruption of gut microbial composition and dysregulated mTOR signaling. Restoring microbial diversity and moderating mTOR activity represent tractable targets for improving immune protection in older adults.
Key Points
- Gut dysbiosis reduces short-chain fatty acid production, amplifying inflammation
- mTOR hyperactivation suppresses autophagy and impairs antibody formation
- Microbiota-mTOR modulation may restore vaccine response in aging
Longevity Analysis
The integrity of immune surveillance declines predictably with age, but this research identifies specific microbial and metabolic drivers that are modifiable. The bidirectional relationship between intestinal bacterial composition and cellular signaling reveals how local dysbiosis propagates systemic inflammation, which in turn perpetuates further microbial dysfunction—a degenerative cycle. Interrupting this cascade through targeted dietary approaches, strategic microbial recolonization, or mTOR-modulating interventions addresses a fundamental vulnerability in aging: the loss of protective immunity. For practitioners, this shifts vaccine strategy from passive acceptance of age-related immune decline toward active restoration of the microbial and metabolic environments on which effective immune memory depends.
Original published by Wiley Aging Cell, by Jiaxuan Li, Yuhong Zhang, Daijun Yu, Jianhua Li, Keda Chen, Lisheng Chu .