Fig. 5.

Dietary nitrate regulates the composition of the intestinal microbiota and promotes SCFAs production in aging mice. a–c Intestinal microbiota analysis of young (n = 4), aged (n = 5) and nitrate (n = 4). a Comparison of alpha diversity of the colonic microbiota using Shannon and Simpson index. b Average relative abundance of colonic microbiota at genus level in different groups. c The different microbiota in the colonic at genus level. d The difference of intestinal metabolites in three groups was analyzed by partial least squares discriminant analysis (PLA-DS). e Concentrations of butyric acid in aged and nitrate group. **Indicates significance at P < 0.01, *P < 0.05, ns no significant. Data were shown as mean ± SD