Abstracto

The role of the microbiota-gut-brain axis on Alzheimer's disease pathology and progression.

Sree Giridharan

Alzheimer's disease and related dementias are still a serious global public health concern more than a century after the German neuropathologist and psychiatrist described the first case. The World Health Organization (WHO) estimates that over 50 million people worldwide suffer from dementia, with AD accounting for 60–70% of all cases. In addition, the global dementia epidemic is estimated to affect 82 million individuals by 2030 and 152 million by 2050. Along with genetic factors, environmental factors, and aging also increase the risks of developing neurodegenerative disorders. For example, gut microbiota can serve as non-genetic factors that define a threshold for maintaining a homeostatic balance or developing illnesses. The scientific community has explored and identified that patients with AD often present with dysbiosis of the bowel and dysregulated gastrointestinal tract. Research describes it as a bidirectional relationship by which the brain communicates with the gut's microbiome through the vagus nerve, immune and neuroimmune systems, enteroendocrine system, neurotransmitters, branched-chain amino acids, short-chain fatty acids, agonists of aryl hydrocarbon receptors (AHRs), bile acids, and the hypothalamic-pituitary-adrenal axis. In this narrative review, we explore and clarify the involvement of the microbiota-gut-brain axis in AD pathology.