Consumption of oleogel alleviates lipid metabolism disorders in high-fat diet-fed rats by inhibiting LPS-induced gut microbiota-mediated inflammation

This study investigated the effect of oleogel consumption on lipid metabolism, gut microbiota and low-grade inflammation in rats fed with a high-fat diet. Male SD rats received either a control diet or high-fat diets for six weeks. The high-fat diets included a regular high-fat diet and high-fat diets in which lard was replaced with pure sunflower oil, un-gelled sunflower oil containing a dispersed gelator, or gelled sunflower oil with the gelator (oleogel). Results showed that compared to regular fat, pure sunflower oil and un-gelled sunflower oil consumption, oleogel consumption significantly suppressed weight gain and adipose tissue accumulation as well as serum and liver lipid accumulation. Microscopic observations further confirmed that oleogel intake alleviated white adipose tissue and liver steatosis caused by high-fat diet. <i>Ex vivo</i> biodistribution studies indicated an increased movement of TAGs toward the large intestine in the oleogel group. In the meantime, the dysregulation of gut microbiota was restored by reducing the <i>Firmicutes</i>/<i>Bacteroidetes</i> ratio and the relative abundance of <i>Desulfobacterota</i> and <i>Proteobacteria</i>. The oleogel group also exhibited reduced LPS levels in faeces, serum and liver. Furthermore, oleogel consumption alleviated inflammation, including decreased gene expression of pro-inflammatory cytokines, such as IL-6 and TNF-α, as well as suppressed protein expression of TLR4 and NF-κB in the liver. These results provide theoretical guidance for the regulation of oleogel properties and the potential application of oleogels as healthy fat replacers in high-fat diets.