Dietary Oat β‐Glucan Alleviates High‐Fat Induced Insulin Resistance through Regulating Circadian Clock and Gut Microbiome

Scope High‐fat diet induced circadian rhythm disorders (CRD) are associated with metabolic diseases. As the main functional bioactive component in oat, β‐glucan (GLU) can improve metabolic disorders, however its regulatory effect on CRD remains unclear. In this research, the effects of GLU on high‐fat diet induced insulin resistance and its mechanisms are investigated, especially focusing on circadian rhythm‐related process. Methods and results Male C57BL/6 mice are fed a low fat diet, a high‐fat diet (HFD), and HFD supplemented 3% GLU for 13 weeks. The results show that GLU treatment alleviates HFD‐induced insulin resistance and intestinal barrier dysfunction in obese mice. The rhythmic expressions of circadian clock genes ( Bmal1 , Clock , and Cry1 ) in the colon impaired by HFD diet are also restored by GLU. Further analysis shows that GLU treatment restores the oscillatory nature of gut microbiome, which can enhance glucagon‐like peptide (GLP‐1) secretion via short‐chain fatty acids (SCFAs) mediated activation of G protein‐coupled receptors (GPCRs). Meanwhile, GLU consumption significantly relieves colonic inflammation and insulin resistance through modulating HDAC3/NF‐κB signaling pathway. Conclusion GLU can ameliorate insulin resistance due to its regulation of colonic circadian clock and gut microbiome.