OCLN and type 2 diabetes mellitus: We think it is likely that this oxidative stress of the intestine disrupts the occludin-ZO-1 complex-associated intestinal barrier and thus increases systemic influx of LPS (Fig. 8), leading to chronic inflammation-associated IR (Fig. 9a), a typical feature of T2D, and subsequent hyperglycemia (Fig. 9b) and related indexes (Figs. 3, 4, Tables 2, and 3).