Gut signals revive aging memory by reactivating the vagus nerve

A Stanford study in mice links age-related memory loss to gut microbiome changes, specifically an rise in Parabacteroides goldsteinii that triggers gut inflammation and muffles the vagus nerve, dulling hippocampal memory encoding. Remarkably, boosting vagal activity or reshaping the gut microbiome reversed the deficits, suggesting peripheral gut–brain interventions could counteract cognitive aging in humans.