Bioactive Food Abates Metabolic and Synaptic Alterations by Modulation of Gut Microbiota in a Mouse Model of Alzheimer’s Disease

Effect of Clostridium butyricum against Microglia‐Mediated Neuroinflammation in Alzheimer's Disease via Regulating Gut Microbiota and Metabolites Butyrate

“…Recent evidence demonstrated an altered GM in AD . The change of α diversity of AD is controversial, some studies have demonstrated a significant decrease in fecal microbiota samples from patients or animal with AD, while other studies demonstrated there was no significant difference . Our results showed that there was no significant difference between APP7PS1 mice and CB‐treated mice, suggesting that the greater microbe richness might not be a definitive sign of a healthy GM, but might be attributed to the overgrowth of a variety of harmful bacteria or archaea.…”

Cognitive-Behavioural Correlates of Dysbiosis: A Review

“…An increase in Enterobacteriaceae, belonging to Proteobacteria phylum, was shown to be correlated with cognitive impairment in several studies [ 13 , 15 , 17 ]. Several animal models, including diet-induced obesity (DIO) and transgenic AD model, demonstrated a link between gut dysbiosis and cognitive impairment [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Most of the studies reported that a high-fat diet (HFD) consumption could alter the composition of gut microbiota and lead to further pathophysiological processes in cognitive impairment in HFD-fed animals [ 18 , 19 , 20 , 21 ].…”

“…The strain of animal, duration and composition of the diet may account for the discrepancy in the results. The studies using the transgenic mouse models for AD also revealed a relationship between gut dysbiosis and cognitive impairment [ 22 , 23 , 24 , 25 , 26 ]. Proteobacteria and Verrucomicrobia at the phylum level, Helicobacteraceae and Desulfovibrionaceae at the family level, and Akkermansia sp.…”

“…In the 3xTg-AD mouse model, the F/B ratio was found to be elevated when compared to the control group [ 24 ]. Another study found that the abundance of both Firmicutes and Bacteroidetes was increased in 3xTg-AD mice [ 25 ]. However, some genus in the phylum of Firmicutes was reported to be lower in 3xTg-AD mice [ 26 ].…”

“…The systemic alterations affect the brain, thus favouring the neurodegenerative pathway via the following events: increased neuronal cell apoptosis and brain mitochondrial dysfunction, elevated hippocampal oxidative stress, decreased hippocampal synaptic plasticity, decreased number of dendritic spine density at CA1 area of the hippocampus, microglial over-activation in the hippocampus, increased amyloid-beta deposition [ 19 , 20 ]. The treatments restoring gut microbiota composition are able to attenuate the inflammatory status providing a beneficial effect on cognitive function [ 19 , 22 , 23 , 25 , 26 , 30 ]. Indeed, several studies demonstrated that the administration of some types of probiotics not only improved the integrity of the intestinal epithelium, but also attenuated the inflammatory status in the GIT [ 31 , 32 , 33 ].…”