Rapamycin may increase brain blood flow and change metabolism, inflammation, and gut bacteria in healthy middle-aged people with APOE4

Rapamycin significantly increased cerebral blood flow in APOE4 carriers by more than 15% across multiple brain regions.

• Cerebrovascular dysfunction and systemic alterations are observed in APOE4 carriers decades before Alzheimer's disease symptoms.
• A single arm trial of low dose rapamycin (1 mg/day for 4 weeks) was conducted in cognitively normal adults aged 45 to 65.
• Increases in cerebral blood flow were significant in APOE4 carriers, while non-carriers showed no significant change.
• Rapamycin also improved metabolic and inflammatory profiles with minimal adverse effects in participants.
• Distinct physiological responses were noted between APOE4 carriers and non-carriers, suggesting genotype-dependent effects.

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