High-salt diet worsens cognitive dysfunction and hippocampal neuronal damage in APP/PS1 mice via gut dysbiosis
Six months of 8% NaCl diet intensified cognitive and emotional deficits, reduced hippocampal neuronal density, and altered gut microbiota composition in APP/PS1 transgenic mice.
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Context
High dietary salt is an established cardiovascular risk factor and is increasingly linked to cognitive function. Its chronic impact on the gut-brain axis in Alzheimer's disease models had not been well characterized.
What the study showed
High-salt diet exacerbated behavioral deficits across multiple tests and reduced neuronal density in hippocampal CA1 and CA2 regions. Gut microbiota dysbiosis, elevated inflammatory cytokines (TNF-α, IL-6, IL-1β) in brain and liver, and hippocampal metabolic perturbations were identified. The authors propose a mechanistic pathway from dysbiosis through peripheral and central inflammation to neuronal damage.
How it was done
Experimental study in 6-month-old male APP/PS1 mice randomized to normal diet (0.4% NaCl, n=43) or high-salt diet (8% NaCl, n=41) for 6 months; variable subgroup sizes per outcome (behavior n=10, histology n=4, microbiota n=12–13, metabolomics n=7–8).
Risk of bias
The transgenic mouse model does not fully replicate human Alzheimer's pathophysiology; the 8% NaCl concentration far exceeds typical human intake, limiting direct extrapolation. Analysis is based solely on the abstract; causality between dysbiosis and neuronal damage is inferred by correlation, not by direct microbiota manipulation.
What this study does NOT prove
The study does not prove that salt reduction in humans prevents or delays Alzheimer's disease, nor that dysbiosis causes rather than results from neuronal damage.
In clinical practice
These data do not support new clinical recommendations; they reinforce, in an animal model, the biological plausibility that chronic high-salt diet may aggravate Alzheimer-like pathology via the gut-brain axis. Dietary sodium reduction already has established cardiovascular indications.
Limitations
The transgenic mouse model does not fully replicate human Alzheimer's pathophysiology; the 8% NaCl concentration far exceeds typical human intake, limiting direct extrapolation. Analysis is based solely on the abstract; causality between dysbiosis and neuronal damage is inferred by correlation, not by direct microbiota manipulation.
Technical appendix
Version history
- 1.0 · 2026-11-04 — Auto-generated under Evidence Standard v1.0