Microbiota-gut-brain axis in the Alzheimer's disease pathology - an overview

Author: Vijayasree V Giridharan1, Carlos E Barichello de Quevedo2, Fabricia Petronilho3
Affiliation: <sup>1</sup> Translational Psychiatry Program, Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA. Electronic address: vijayasree.v.giridharan@uth.tmc.edu. <sup>2</sup> Translational Psychiatry Program, Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA; Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil. <sup>3</sup> Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil.
Conference/Journal: Neurosci Res
Date published: 2022 May 13
Other: Special Notes: doi: 10.1016/j.neures.2022.05.003. , Word Count: 205


Alzheimer's disease (AD) and related dementias are still a serious global public health concern more than a century after the German neuropathologist and psychiatrist Dr. Aloysius Alzheimer described the first case. The World Health Organization (WHO) estimates that over 50 million people worldwide suffer from dementia, with AD accounting for 60 to 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 (GI) 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 (SCFAs), agonists of aryl hydrocarbon receptors (AHRs), bile acids, and the hypothalamic-pituitary-adrenal (HPA) axis. In this narrative review, we explore and clarify the involvement of the microbiota-gut-brain axis in AD pathology.

Keywords: Alzheimer's disease; SCFAs; immune system; microbiota-gut-brain axis.

PMID: 35577241 DOI: 10.1016/j.neures.2022.05.003