Gut-Brain Signaling Reverses Age-Related Memory Decline in Mice

A Nature study shows aging gut microbiomes produce molecules that blunt gut-brain signaling via the vagus nerve, contributing to memory decline in mice. When older microbiomes were transferred to young mice, memory worsened, but antibiotics or a targeted phage against Parabacteroides_goldsteinii restored function. Direct vagus nerve stimulation through gut hormones also reversed memory deficits in old mice, suggesting that age-related memory loss may be driven by body-wide signals and could be reversible with existing or developing therapies, though human applicability remains to be determined.