Beta diversity of the fecal bacterial community in pigs fed with low-protein diets supplemented with a corn-expressed phytase. (A) Principal Coordinates Analysis (PCoA) of unweighted UniFrac distances showing the diversity of fecal microbiota across individual animals assigned to 6 dietary groups. Each node represents an individual pig, (B) Unweighted UniFrac distances shown for each dietary group, (C) PCoA of weighted UniFrac distances showing the diversity of fecal microbiota across animals assigned to 6 dietary groups. Each node represents an individual pig, (D) Weighted UniFrac distances shown for each dietary group. Pigs are grouped based on their dietary treatments: PC (positive control): normal protein, adequate Ca and available phosphorous (aP), no corn-expressed phytase (CEP) added; NC (negative control): low protein, adequate Ca and aP, no CEP added; LD: NC + CEP added at low dose, i.e., 2000 FTU/kg of diet; HD: NC + CEP added at high dose, i.e., 4000 FTU/kg of diet; LDR: LD with reduced calcium (Ca) and phosphorus (P); HDR: HD with reduced Ca and P. The values are means ± standard errors. Different letters in the box plots indicate significant differences (p ≤ 0.05, Wilcoxon test). n = 6 for each dietary group.