Synergistic amelioration of obesity in high‐fat diet–fed mice by Bifidobacterium longum and green banana powder through targeting multiple pathways

Abstract Long‐term consumption of high‐fat diet (HFD) is a major significant risk factor for various diseases, including hyperlipidemia, diabetes, cardiovascular disease, and certain cancers. Recently, there has been a focus on effective dietary methods to improve lipid absorption and accumulation in the body. Simultaneously, exploring non‐pharmacological interventions to counteract the adverse consequences of obesity is crucial. Probiotics and prebiotics emerge as promising alternatives in this context, with their combined utilization yielding substantial effects surpassing those achieved by individual application alone. The aim of this study was to investigate the combined effects of Bifidobacterium longum (BL) SYP‐B4138 and green banana powder (GBP) on HFD‐induced obesity while exploring their underlying mechanisms. The findings demonstrated that the combined intervention exhibited significantly greater efficacy than BL or GBP alone, including in mitigating weight gain and organ weight among obese mice, while also improving lipid profile, glucose tolerance, and inflammation levels. Furthermore, it effectively reduced liver fat accumulation. The mechanism study revealed that the combined intervention increased the expression of gene‐related lipid metabolism, such as Ppar α, Cpt1 a, Fxr , Cyp7a1 , and Bsep , while decreasing expression of the regulatory genes involved in fat synthesis, Acc1 , Srebpf1 , and Pparγ . The correlation analysis of gut microbes and metabolites suggests that the combined effect of BL and GBP can reverse the intestinal microecological imbalance, leading to changes in bile acids, glycerophospholipids, and other related metabolites. Overall, this study demonstrates that BL combined with GBP can effectively alleviate dietary obesity, highlighting its potential as a non‐pharmacological intervention for weight reduction.