<span class="word">Synergistic <span class="word"><span class="changedDisabled">Effect <span class="word">of <em><span class="word italic">Bifidobacterium <span class="word italic">longum</em> <span class="word"><span class="changedDisabled">Postbiotics <span class="word">and <span class="word"><span class="changedDisabled">Dietary <span class="word"><span class="changedDisabled">Herbs <span class="word">on <span class="word"><span class="changedDisabled">Improving <span class="word"><span class="changedDisabled">Obesity <span class="word">and <span class="word"><span class="changedDisabled">Cognitive <span class="word"><span class="changedDisabled">Impairment <span class="word">in <span class="word"><span class="changedDisabled">Hyperlipidemic <span class="word"><span class="changedDisabled">Mice

Hyperlipidemia-associated obesity is frequently accompanied by hepatic injury, bile acid dysregulation, gut microbial remodeling, and cognitive impairment. Although postbi-otics have shown considerable cholesterol-lowering potential, the most effective postbiotic form and its compatibility with dietary herbs remain unclear. In this study, FB3-14-derived postbiotics were first screened in vitro for cholesterol micellar binding. Inactivated bacterial cells (Postcell) exhibited the strongest cholesterol-binding capacity and were therefore selected for in vivo validation, alone or in combination with dietary herbs (DH), in a high-fat, high-cholesterol (HFHC) mouse model. Consistently, Postcell showed superior efficacy in attenuating body weight gain, jejunal triglyceride accumu-lation, and hepatic dysfunction compared with other postbiotic forms. Importantly, Postcell_DH exerted broader metabolic benefits, including reductions in weight gain, food efficiency, bile acid dysregulation, and neuroinflammation. Multi-omics analysis further indicated that these effects may be mediated through remodeling of the gut microbiota and metabolome, particularly pathways involved in bile acid and tryptophan metabolism. Notably, Clostridioides and taurochenodeoxycholate-7-sulfate were nega-tively associated with total cholesterol (TC) and leptin, whereas Clostridium_sensu_stricto_1 and 3-Hydroxyindolin-2-1-sulfate were negatively correlated with brain inflammatory level, lipid, and bile acid-related index. This study provides a practical strategy for developing postbiotic–herbal combination interventions against hyperlipidemia and related cognitive disorders.