Furthermore, immunofluorescence detection, immunohistochemical analysis, and RT-qPCR results indicate that FCD maintains the integrity of the intestinal mucosal barrier by enhancing the expression of Zonula occludens-1 (ZO-1), occludin, and claudin-1 proteins and their corresponding mRNAs, in addition, FCD can regulate the gut microbiota and promote its diversity. Here, CLDN1 is linked to fleck corneal dystrophy.