Lactobacillaceae improve cognitive dysfunction via regulating gut microbiota and suppressing Aβ deposits and neuroinflammation in APP/PS1 mice.

Alzheimer's disease (AD), the most prevalent neurodegenerative disease, has a significant relationship with alteration of the gut microbiota (GM), and the GM-gut-brain axis has been explored to find novel therapeutic approaches for AD. The present study aimed to evaluate the effect of human Lactobacillaceae (HLL) on cognitive function in APP/PS1 mice. The results showed that HLL treatment significantly improved the cognitive function of mice via MWM and NOR tests. Furthermore, the expression of Aβ plaques, tau phosphorylation and neuroinflammation were markedly reduced in the hippocampus. Meanwhile, HLL treatment significantly increased the activity of GSH-PX and decreased the expression levels of IL-6 and MDA in the brain, and simultaneously increased the abundance of beneficial bacteria and restrained pathogenic bacteria in the intestine. Interestingly, significant correlations were observed between significant changes in abundance of GMs and AD-related markers. Collectively, these findings reveal that HLL is a promising therapeutic agent and potential probiotics, which might improve the cognitive function and AD pathologies.