Ergosterol originated from <i>Auricularia auricula</i> attenuates high fat diet-induced obesity and cognitive impairment in mice

Excessive intake of a high fat diet (HFD) leads to accumulation of fat and obesity. Ergosterol (ERG) is a characteristic sterol of fungi with various bioactive functions; however, there are few studies on the ERG function of ameliorating obesity and following cognitive impairment. It was previously found that Zhashui <i>Auricularia auricula</i> (AA) is rich in ERG; therefore it was selected to enrich ERG through the intervention of exogenous inducers of rice bran oil (RBO), methyl jasmonate (Me JA) and salicylic acid (SA). The accumulated ERG was used to investigate alleviative effects on mouse obesity and cognitive impairment. According to LEfSe analysis of intestinal flora species, ERG reduced the abundance of obesity or inflammation-related intestinal microbial genera, while increasing the relative abundance of beneficial bacteria. The ERG sourced from AA significantly ameliorated HFD-induced mouse obesity by reducing lipid levels and liver oxidative stress, recovering memory and learning abilities of the mice by restoring the hippocampus function and downregulating inflammatory factors.