INTRODUCTION: Obesity, a growing public health issue, is closely associated with excessive energy intake and gut microbiota imbalances. Despite the increasing attention given to black jujube as a blackened fermented food in recent years, the role of its melanoidins (MLD) in obesity-related biological mechanisms has yet to be thoroughly investigated. METHODS: This study investigated the effects of black jujube MLD on obesity induced by a high-fat diet in C57BL/6J mice. We hypothesize that MLD exerts an anti-obesity effect, potentially mediated by alterations in gut microbiota composition and the modulation of metabolic responses. RESULTS: The results demonstrate that MLD administration mitigated HFD-induced weight gain, improved insulin resistance, and enhanced glucose metabolism by reducing blood glucose and insulin levels ( < 0.05). MLD also protected the liver, as evidenced by a 16.4% decrease in alanine aminotransferase (ALT) levels and a 29.6% decrease in aspartate aminotransferase (AST) levels ( < 0.05). Furthermore, MLD treatment restored the compromised intestinal microbiota to a healthier state at the genus level by lowering the / ratio (38.9%), suppressing the abundance of pathogenic bacteria, such as and descendants, and promoting the growth of beneficial bacteria, including . Metabolomic profiling revealed that MLD can alleviate metabolic disorders by downregulating arginine metabolism and sphingolipid metabolism. Its metabolites are significantly correlated with several bacterial genera, including , and . DISCUSSION: Based on these findings, MLD may mitigate obesity and other associated metabolic disorders by modulating the gut microbiome-metabolism axis.