Fig. 6

Temporal alteration of the density and centralization of bacterial correlation network under the three regimens. a Network density, which describes the portion of potential connections among bacteria. Before day 28, the density increased with time for all three groups and the probiotic group exhibit the highest density overall. Network density of the probiotic group peaked first and then dropped to the same level as the antibiotic group on day 42, while that of the control group gradually increased during the whole 42 days. b Network centralization, which measures the degree of dispersion of all node centrality scores in a network from the maximum centrality score obtained in the network. The highest centralization was found in the probiotic group (followed by the control group and the antibiotic group), which might suggest strongest resistance to propagation of pathogens in this group. The distinct impacts of antibiotics and probiotics on these key features of bacterial correlation network appeared to take place at an early phase