Lactobacillus plantarum C29‐Fermented Soybean (DW2009) Alleviates Memory Impairment in 5XFAD Transgenic Mice by Regulating Microglia Activation and Gut Microbiota Composition

Scope The study aims to determine whether Lactobacillus plantarum C29‐fermented defatted soybean (FDS, DW2009) can attenuate memory impairment in 5XFAD transgenic (Tg) mice. Methods and results Oral administration of FDS or C29 increases cognitive function in Tg mice in passive avoidance, Y‐maze, novel object recognition, and Morris water maze tasks. FDS or C29 treatment significantly suppresses amyloid‐β, β/γ‐secretases, caspase‐3 expression, and NF‐κB activation, and activates microglia and apoptotic neuron cell populations, and increases BDNF expression in the brain. FDS or C29 treatment suppresses blood and fecal lipopolysaccharide levels and Enterobacteriaceae population and increases lactobacilli/bifidobacteria populations. Conclusion FDS and C29 alleviates the decrease in cognitive function and inhibited amyloid‐β expression in Tg mice by regulating microglia activation and gut microbiota composition.