Effect of diet and genotype on gut microbiota composition. Boxplots showing the most abundant microbial phyla. Features are ordered by decreasing median of the relative abundance among subjects. Boxplots are colored based on the relative phylum. Asterisks indicate statistical significance of phylum changes for each genotype when comparing the two diets (*p < 0.05; **p < 0.01; ***p < 0.001).