Probiotic Bifidobacterium breve MCC1274 Mitigates Alzheimer's Disease-Related Pathologies in Wild-Type Mice

Probiotics improve brain function, including memory and cognition, via the microbiome-gut-brain axis. Oral administration of Bifidobacterium breve MCC1274 (B. breve MCC1274) improves cognitive function in App(NL-G-F) mice and mild cognitive impairment (MCI) subjects, and mitigates Alzheimer's disease (AD)-like pathologies. However, its effects on wild-type (WT) mice have not yet been explored. Thus, the effects of B. breve MCC1274 on AD-like pathologies in two-month-old WT mice were investigated, which were orally administered B. breve MCC1274 for four months. A beta levels, amyloid precursor protein (APP), APP processing enzymes, phosphorylated tau, synaptic protein levels, glial activity, and cell proliferation in the subgranular zone of the dentate gyrus were evaluated. Data analysis was performed using Student's t-test, and normality was tested using the Shapiro-Wilk test. Oral administration of B. breve MCC1274 in WT mice decreased soluble hippocampal A beta 42 levels by reducing presenilin1 protein levels, and reduced phosphorylated tau levels. It also activated the protein kinase B (Akt)/glycogen synthase kinase-3 beta (GSK-3 beta) pathway, which may be responsible for the reduction in presenilin1 levels and inhibition of tau phosphorylation. B. breve MCC1274 supplementation attenuated microglial activation and elevated synaptic protein levels in the hippocampus. These findings suggest that B. breve MCC1274 may mitigate AD-like pathologies in WT mice by decreasing A beta 42 levels, inhibiting tau phosphorylation, attenuating neuroinflammation, and improving synaptic protein levels.

Automated summary

Probiotics, specifically Bifidobacterium breve MCC1274, have beneficial effects on brain function by improving memory and cognition through the microbiome-gut-brain axis. This study investigates the potential of B. breve MCC1274 to mitigate Alzheimer's disease-like pathologies in wild-type mice. The results show that oral administration of B. breve MCC1274 reduces A beta 42 levels, inhibits tau phosphorylation, decreases neuroinflammation, and improves synaptic protein levels in the hippocampus. These findings suggest that B. breve MCC1274 may have potential therapeutic effects for Alzheimer's disease.