Oat phenolic compounds regulate metabolic syndrome in high fat diet-fed mice via gut microbiota

This study aimed to better understand the beneficial effect of oat phenolic compounds (OPC) in improving metabolic syndrome via regulating metabolites and gut microbiota composition. The oral administration of OPC can alleviate a range of metabolic syndromes in mice caused by high-fat dietary feeding, such as weight gain, glucose intolerance, elevated serum lipid levels (TC, TG, HDL-C, and LDL-C) and oxidative stress (GSH-Px, T-AOC, SOD and MDA) as well as adipocyte hypertrophy. Besides, OPC-treated mice also have reduced chronic inflammation, which indicates that OPC can interfere with the expression of genes related to glycolipid metabolism. Furthermore, HFD-fed mice can cause an imbalance in gut microbiota, while the addition of OPC can improve this negative effect, which also further demonstrated the importance of gut microbiota in the regulation of metabolic disorders. The OPC significantly increased the abundance of Bacteroidetes and reduced the diversity of Firmicutes (p < 0.05) compared with the HFD-fed mice. OPC treatment rebuilt gut microbiota composition via increasing Eubacterium levels and reducing numbers of Alistipes and Lachnospiraceae NK4A136 groups in HFD-fed mice. This result also provided a potential explanation for polyphenols benefit from whole grains in glycolipid metabolism disorders.