Background: Prior to 2012, the mesentery was perceived as a fragmented structure, lacking distinct functional and anatomical characteristics, and was merely considered part of other digestive organs. Dr. J. Calvin Coffey's in 2012 in his study redefined the mesentery as a distinct organ with a clearly defined anatomical and histological structure, although its specific function remains under investigation. The continuous structure and unique tissue properties of the mesentery classify it as the 78th independent organ in the human body. Insights into mesenteric adipose tissue have enhanced our understanding of normal metabolic processes and disease etiology, impacting health significantly. Experimental and clinical research highlights the vital roles of visceral adipose tissue, influencing neighboring organ function. The interaction within the brain-gut-liver axis is illuminated by the newfound functions of mesenteric adipose tissue, emphasizing its independent organ status. Objective: This study aims to evaluate the latest findings on the structure and function of the mesentery, focusing on visceral-mesenteric adipose tissue, and assess its role as a new organ in the brain-gut-liver axis. Methods: A comprehensive analysis of clinical and experimental studies on the mesentery's structure and function was conducted, focusing on recent discoveries regarding mesenteric adipose tissue and its role in the brain-gut-liver axis. Results and Discussion: Recent research has revealed the mesentery's unique functions, particularly in mesenteric adipose tissue. Mesenteric adipose tissue plays a crucial role in metabolic functions and influences disease onset. It acts as a vital link in the brain-gut-liver axis, directly influencing hepatic metabolism and disorders such as metabolic syndrome. Conclusion: Scientific evidence confirms the mesentery's anatomical and functional specificities, solidifying its status as the 78th independent organ in the human body. It serves as a crucial link in the brain-mesentery-small intestine-liver axis, impacting health and disease. Ongoing research holds promise for advancing our understanding of pathophysiological mechanisms and treatment approaches for metabolic syndrome and other chronic diseases.