Fig. 4

Patterns of organismal and functional-gene abundance for the broiler intestinal microbiota in the three regimens. a Patterns of organismal abundance. On day 7, day 28, and day 42, the relative abundance of each genus was respectively compared to day 1. Those genera that were significantly changed among the groups are highlighted via red font. b Principle component analysis (PCA) based on the profile of functional genes, which supported the discrimination between the antibiotic group and the probiotic group at the functional level (PC1, 70.4%, p = 0.009; PC2, 12%, p = 0.6). However, neither the antibiotic group (PC1, p = 0.161; PC2, p = 0.229) nor the probiotic group (PC1, p = 0.123; PC2, p = 1) was distinguishable from the control group