Influence of the Microbiota-Gut-Brain Axis on Cognition in Alzheimer’s Disease

Abstract

The gut microbiota is made up of trillions of microbial cells including bacteria, viruses, fungi, and other microbial bodies and is greatly involved in the maintenance of proper health of the host body. In particular, the gut microbiota has been shown to not only be involved in brain development but also in the modulation of behavior, neuropsychiatric disorders, and neurodegenerative diseases including Alzheimer’s disease. The precise mechanism by which the gut microbiota can affect the development of Alzheimer’s disease is unknown, but the gut microbiota is thought to communicate with the brain directly via the vagus nerve or indirectly through signaling molecules such as cytokines, neuroendocrine hormones, bacterial components, neuroactive molecules, or microbial metabolites such as short-chain fatty acids. In particular, interventions such as probiotic supplementation, fecal microbiota transfer, and supplementation with microbial metabolites have been used not only to study the effects that the gut microbiota has on behavior and cognitive function, but also as potential therapeutics for Alzheimer’s disease. A few of these interventions, such as probiotics, are promising candidates for the improvement of cognition in Alzheimer ’s disease and are the focus of this review.

Interaction of Heavy Metal Lead with Gut Microbiota: Implications for Autism Spectrum Disorder

“…Moreover, germ-free mice have an abnormal response to stress, which can be normalized by recolonizing them with a complete microbiota (via stool transplant) or by monocolonization with Bifidobacterium Infantis [59]. It is now well recognized that GM can affect the integrity and the diverse functions of CNS including regulation of the mood and cognition [60][61][62][63].…”

The Effect of a Diet Enriched with Jerusalem artichoke, Inulin, and Fluoxetine on Cognitive Functions, Neurogenesis, and the Composition of the Intestinal Microbiota in Mice

“…This allows the identification of pathways that regulate BGM signaling between the digestive tract and the brain, including neural, endocrine, and immune pathways. It has been shown that the BGM axis plays an important role in the formation and maintenance of cognitive functions [ 16 , 17 , 18 , 19 ]. Moreover, the BGM axis was proved to be significant in the regulation of neurogenesis, one of the most essential processes of proliferation, migration, and differentiation of new neural cells [ 20 , 21 , 22 , 23 ].…”

Exercise combined with postbiotics treatment results in synergistic improvement of mitochondrial function in the brain of male transgenic mice for Alzheimer’s disease

“…One of the intriguing adaptive response to exercise training involves gut microbiome. The gut-brain axis has been proposed signi cantly interferes with the function of both organs and more and more data suggest that the microbiome of gut has a powerful effect in gut-brain axis (7,8). Clinical trial showed that Bi dobacterium bi dum and Bi dobacterium longum containing postbiotics caused changes in gut microbiota and promoted mental exibility, alleviated stress in healthy older adults, along with causing changes in gut microbiota (9).…”