Fig. 8

Worsened outcome in young mice transplanted with old mouse feces and improved outcome in old mice transplanted with young mouse feces. Young mice (8 weeks old) received saline, cefazolin, cefazolin, and then transplantation of old mouse feces or cefazolin and then transplantation of young mouse feces. They were subjected to 120-min MCAO 2 weeks after the fecal transplantation and named Young-saline, Young-antibiotic, Young-oFMT, and Young-yFMT, respectively. In another experiment, old mice (18 months old) received saline, cefazolin, cefazolin, and then transplantation of old mouse feces or cefazolin and then transplantation of young mouse feces. They were subjected to 60-min MCAO 2 weeks after the fecal transplantation and named Old-saline, Old-antibiotic, Old-oFMT, and Old-yFMT, respectively. Their body weights and survival curves were evaluated after MCAO. A Body weight changes of young mice. B Survival curve of young mice. C Body weight changes of old mice. D Survival curve of old mice. E Summary diagram for the mechanism of aging-dependent microbiota changes-induced increase of ischemic brain injury and inflammatory responses. Results in panels A and C are in mean ± S.E.M. (n = 4 to 9 for panel A and = 6–7 for panel C). *F(1, 11) = 8.635, P = 0.013 compared with old-saline mice. ^F(1,12) = 5.383, P = 0.034 compared with Old-oFMT mice. The survival curves of the four groups in panels B and D were different when analyzed by the Mantel-Cox test (P = 0.0014 for panel B and = 0.0035 for panel D). ^&P < 0.05, ^&&P < 0.01, ^&&&P < 0.001 compared with Young-oFMT mice by the Gehan-Breslow-Wilcoxon test; ^#P < 0.05 compared with Old-oFMT or Old-saline by the Gehan-Breslow-Wilcoxon test