Alzheimer’s disease (AD) is the most common neurodegenerative disease, with symptoms appearing in the cerebral cortex and hippocampus. amyloid β peptide (Aβ) has been shown to deposit in the brain, causing oxidative stress and inflammation, leading to impaired memory and learning. Lactocaseibacillus fermentation can produce deglycosylated isoflavones with high physiological activity, which can scavenge free radicals, enhance total antioxidant capacity and inhibit oxidative inflammatory responses. Therefore, in this study, Lactocaseibacillus paracasei subsp. paracasei NTU101 (NTU101) fermented soybean milk and its extracts were used as test substances, and AD model rats were established by infusion of Aβ40 in the brain for 28 days, and the preventive and ameliorating effects of NTU 101 fermented soymilk were discussed. Effects of soymilk and unfermented soymilk on AD, and explore its effects on AD. Main functional ingredients. The results showed that deglycosylated isoflavones in NTU101 fermented soybean milk improved AD symptoms. Mechanisms of actions include the inhibition of oxidative inflammation; reduction in the expression of risk factors for tau protein and apo E protein production, the deposition of Aβ40 around the hippocampus, and the expression of TLR-2 and RAGE proteins in astrocytes and microglia; and improvement in the memory and learning ability.