Flavonoids are phytochemicals that widely exist in plants, fruits, and vegetables and have a variety of activities. However, due to their complex structure, it is often rarely absorbed into the blood. Intestinal bacteria regarded as the third kind of human organ have attracted extensive attention in recent years. Complex structural flavonoids can be catabolized into low molecular weight phenolic acids under the action of intestinal bacteria and then absorbed into the blood, showing several protective effects on the body. In addition, the intake of flavonoids can also regulate the composition and function of intestinal flora. This paper comprehensively summarizes the interaction between flavonoids and intestinal flora, as well as the impact on human health, in order to provide some insights on how to combine intestinal microorganisms to select and ingest dietary polyphenols for future applications in medicine.

Myricetin shows great anti‐inflammatory effect on colitis and supplementation with myricetin could improve gut microbiota dysbiosis. It is reported that the abnormal blood glucose condition of prediabetes could aggravate the progression of inflammation. However, there is no report on whether myricetin has the protective effect on inflammation comorbid prediabetes. This study aimed to explore the effect and potential mechanism of myricetin on dextran sulfate sodium (DSS)‐induced colitis in prediabetic mice. Several indexes related to colitis were evaluated on DSS‐induced prediabetic mice. Myricetin intervention improved body weight loss, disease activity index score in DSS‐induced colitis in prediabetic mice. Myricetin alleviated inflammation by inhibiting proinflammatory cytokines and myeloperoxidase production in DSS‐induced colitis in prediabetic mice. Furthermore, myricetin showed recovery of intestinal barrier integrity by increasing the expression of tight junction proteins (ZO‐1, Occludin and Claudin‐1). At the gut microbiota level, myricetin showed protective effects via modulating gut dysbiosis associated with DSS‐induced colitis in prediabetic mice. In addition, myricetin could significantly increase the short chain fatty acids produced by gut microbiota. Myricetin may be serving as a novel therapeutic agent which could be used in the treatment of DSS‐induced colitis in prediabetic patients in the future with its added value as well reported antidiabetic agent.