CLDN1 and polycystic ovary syndrome: Naringenin, a citrus flavonoid, was recently found to have beneficial effects in the treatment of PCOS by upregulating the expression of PGC-1α, SIRT1, occludin and claudin-1 in the colon and downregulating the abundance of Prevotella and Gemera to improve the intestinal mucosal barrier and glucose metabolic pathways in PCOS rats (Wu Y. X. et al., 2022).