Compared to rats in the STD group, rats in the HF group had higher ileum injury scores (6 ± 0.707 vs. 3.3 ± 0.447, p < 0.001) (Supplementary  and ), increased DAO activity (1332.2102 ± 136.659 vs. 906.8835 ± 66.453, p < 0.001) and serum D-lactate (6625.0142 ± 501.387 vs. 5903.5772 ± 276.515, p = 0.022) (Supplementary ), and decreased expression of lysozyme (Supplementary  and ) and TJPs in the distal ileum (Figures 2(a) and 2(b) and Supplementary ) at 24 h. Here, DAO is linked to hydrops fetalis.