en Gastroentrology Gastroentrology Review Article Review Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background:</span></i></b> The interaction between commensal bacteria and the host is essential for health and the gut microbiota-brain axis plays a vital role in this regard. Obesity as a medical problem not only affect the health of the individuals, but also the economic and social aspects of communities. The presence of any dysbiosis in the composition of the&nbsp;gut microbiota disrupts in the gut microbiota-brain axis, which in turn leads to an increase in appetite and then obesity. Because common treatments for obesity have several drawbacks, the use of microbiota-based therapy in addition to treatment and prevention of obesity can have other numerous benefits for the individual. In this review, we intend to investigate the relationship between obesity and the gut microbiota-brain axis as well as novel treatment strategies based on this axis with an emphasis on gut microbiota.</span></span></span><span style="font-size:12pt"><span style="line-height:14pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:10.0pt"><span style="color:#0033cc"></span></span></i></b></span></span></span><br> &nbsp; Gut–brain axis, Obesity, Gut microbiota, Probiotic, Prebiotic, Fecal Microbiota transplantation. 215 227 http://caspjim.com/browse.php?a_code=A-10-3031-1&slc_lang=en&sid=1 Romina Kardan rominakardan@gmail.com 100319475328460047665 100319475328460047665 No Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran Jaber Hemmati jaberhemmati@gmail.com 100319475328460047666 100319475328460047666 No Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran Mohsen Nazari mohsennazari911@gmail.com 100319475328460047667 100319475328460047667 No Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran Amjad Ahmadi microbiology90@gmail.com 100319475328460047668 100319475328460047668 No Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran Babak Asghari bab.asghari@gmail.com 100319475328460047669 100319475328460047669 No Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran Mehdi Azizi amjadahmadi1364@gmail.com 100319475328460047670 100319475328460047670 No Department of Tissue Engineering and Biomaterials, School of Advanced Medical Sciences and Technologies, Hamadan University of Medical Sciences, Hamadan, Iran Mansoor Khaledi ahmadi.nader1368@gmail.com 100319475328460047671 100319475328460047671 No Department of Microbiology and Immunology, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran Mohammad Reza Arabestani rezaeeit93@gmail.com 100319475328460047672 100319475328460047672 Yes Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran