Probiotic Bifidobacterium breve decreases Aβ production via the upregulation of ADAM10 level and attenuates microglia activation in an APP knock‐in mouse model of Alzheimer’s disease

Abstract

Background: Probiotics supplementation reinstates microbiome diversity and improves brain function, including memory and learning abilities, although the molecular mechanisms have not been fully elucidated. In the current study, we investigated the effects of orally supplemented Bifidobacterium breve MCC1274 (B. breve MCC1274, synonym B. breve A1) on memory impairment and Alzheimer's disease (AD) pathogenesis in amyloid precursor protein knock-in (APP-KI) mice, (App NL-G-F ).Method: Three-month-old App NL-G-F mice were orally supplemented with B. breve MCC1274 for four months. Novel object recognition test was used to evaluate memory-ameliorating effect of B. breve MCC1274. Amyloid plaques, Aβ levels, amyloid precursor protein (APP) and its processing enzymes, its metabolic products, and glial activity were assessed by immunohistochemistry, Aβ ELISA, Western blotting, and immunofluorescence staining. The mRNA expression levels of neuroinflammatory cytokines determined by quantitative RT-PCR analysis.

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