FNDC5 and polycystic ovary syndrome: Using the Wilcoxon analysis, the heat maps of differential abundance between the vehicle versus PCOS and PCOS versus PCOS + irisin group were constructed, respectively, and further showed that DHEA and HFD exposure significantly changed the abundance of bacteria at the different species classification levels, while r-irisin treatment also changed the abundance of multiple strains in the gut flora of PCOS mice at the multispecies level (Figures 5A,B).