Alteration in gut microbiota diversity and composition at different ages. Mice at 3-, 6-, 18- and 28 months of age (3M, 6M, 18M, 28M) were used (n=8, 9, 10 and 6, respectively). (A) Box-and-whisker plot showing the bacterial α-diversity measurements, including richness (observed species and chao1), and overall sample diversity measured according to Shannon metrics. One-way ANOVA with age as an independent factor. (B) PCoA analysis plot representing microbial β-diversity. (C) Microbiome composition at the level of major phyla. (D) Correlation analysis of the abundance of the major phyla with age. Heatmap shows the abundance-fold-change of bacteria with age. In red: bacteria which are more abundant, in blue: bacteria which are less abundant. Scale: Log2 (Fold change) = -1 (blue) < 0 (white) < 1 (red).