(A) Experimental scheme of Ts-infected mice received antibiotics (ABX) treatment. (B) Whole heart images of the controls (Con) (n = 6), Ts-infected mice (Ts) (n = 6) and Ts-infected mice with antibiotics (Ts+ABX) (n = 6). Representative images are shown. (C) Heart mass-to-body weight ratio (HM/BW). (D and E) Ejection fraction (EF) and left ventricular weight (LVM) obtained by cardiac ultrasound. (F, G and H) qPCR analysis of Collagen-1 (Col1), α-SMA and TGF-β expression in the heart tissue of mice. (I and J) Masson staining and Col1 immunohistochemistry results of heart tissues. Magnification, 200×. Scale bars, 100 μm. Representative images are shown. Data are shown as individual data points and mean ± SD. Data were compared by one-way ANOVA followed by Tukey multiple comparison tests. ns, not significant; *, p < 0.05; **, p < 0.01, ***, p <0.001, ****, p <0.0001.