Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 13 2 2025 05 10 108 117 Mahdi Bozorgi Kashan University of Medical Sciences. Mohana Heydari Microbiology Department, Faculty of cellular and Molecular Biology, Islamic Azad University of Hamedan, Hamedan, Iran. Mobina Niknian Student Research Committee, Kurdistan University of Medical Science, Sanandaj, Iran. Atefeh Khodayar Department of Microbiology Tehran Medical Sciences Islamic Azad University, Tehran, Iran. Yeganeh Ghafarli Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran. Forozan Chamani Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur university of Medical Science, Ahvaz, Iran. Fatemeh Mahdavinasab Department of Medicine, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Najmeh Yazdekhasti Department of Physical education, Esfahan branch, Islamic azad University, Esfahan, Iran. Roya Haghighatjo Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran. Yalda Malekzadegan Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran Reza Yekani Department of Biochemistry and Biophysics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Mohammad Ebrahim Karimbakhsh Department of Medical Microbiology and Virology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Saina Najafi Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur university of Medical Science, Ahvaz, Iran. Delaram Jafari Department of Cell and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.. 2024 12 15 2024 12 25 Background:   The Alzheimer's association restated the necessity of the brain gut axis within the context of studying the disease. With its broad-spectrum impact cutting across mnemonics, degeneration of cortex, and neurology, Alzheimer's disease is known as a neurodegenerative disease. Rising gudiance implicate AD as a progressive disease of the Gut microbe dysbiosis with the gut ecosystem destruction resulting in the cascade of neuroinconsistency, accumulation of amyloid-β, compromise of blood brain barrier, and the impairment. Metabolic aberration along with the inflammation caused by microbes such as Chlamydia pneumoniae, Helicobacter pylori and Porphyromonas gingivalis have advanced the degeneration of the Alzhemers patient.  The cyclic attack set forth by the bacterials in the brain together with the systemic cytokine secretion creates an inflammation and neurodegeneration enhancing loop which cannot be broken. Such potential microb target therapies which aim not on the total elimination of the disease but on its on-going replacement are being later on presented within this review alongside with detailed explanation of the above mechanism.  Conclusion:   Alzheimer’s disease relates to gut-brain axis; gut issues can cause inflammation and cognitive problems. Certain bacteria may worsen AD. Microbiome therapies could help; future research should target key microbial strains and conduct clinical trials for treatments https://jmb.tums.ac.ir/index.php/jmb/article/view/552