After further analysis, we analyzed the correlations between 15 differential metabolites, five differentially abundant metabolites, and body weight of squabs through Spearman’s correlation analysis. The results are presented in
Figure 7, where the left columns show that primary bile acid biosynthesis (
r = 0.88, p<0.001), secondary bile acid biosynthesis (
r = 0.88, p<0.001), benzoate degradation (
r = 0.85, p<0.001), dioxin degradation (
r = 0.95, p<0.001), ascorbate and aldarate metabolism (
r = −0.95, p<0.001), bacterial chemotaxis (
r = −0.82, p<0.001), flagellar assembly (
r = −0.82, p<0.001) correlated strongly with
Lactobacillus. Biotin metabolism (
r = 0.90, p<0.001), bacterial chemotaxis (
r = 0.88, p<0.001), flagellar assembly (
r = 0.85, p<0.001) were strongly correlated with
Romboutsia.
Turicibacter was correlated with ascorbate and aldarate metabolism (
r = 0.47, p<0.01), primary bile acid biosynthesis (
r = −0.40, p<0.05), secondary bile acid biosynthesis (
r = −0.40, p<0.05), amino sugar and nucleotide sugar metabolism (
r = 0.45, p<0.05), toluene degradation (
r = −0.39, p<0.05), biotin metabolism (
r = 0.61, p<0.001), caprolactam degradation (
r = −0.49, p<0.01), tropane, piperidine and pyridine alkaloid biosynthesis (
r = 0.47, p<0.01), bacterial chemotaxis (
r = 0.59, p<0.001), and flagellar assembly (
r = 0.58, p<0.001). A statistically significant correlation was detected between
Muribaculaceae and sphingolipid metabolism (
r = 0.90, p<0.001). However, in all the comparisons, the differences were not statistically significant between
Megasphaera and any of the 15 differentially abundant metabolites (p>0.05). The results of Spearman’s correlational analysis between differentially abundant metabolites and body weight are presented in the last column in
Figure 7. Ascorbate and aldarate metabolism (
r = −0.56, p<0.001), primary bile acid biosynthesis (
r = 0.51, p<0.001), secondary bile acid biosynthesis (
r = 0.51, p<0.001), taurine and hypotaurine metabolism (
r = 0.42, p<0.001), glutathione metabolism (
r = 0.54, p<0.05), sphingolipid metabolism (
r = 0.36, p<0.001), biotin metabolism (
r = −0.50, p<0.001), caprolactam degradation (
r = 0.54, p<0.05), tropane, piperidine and pyridine alkaloid biosynthesis (
r = −0.46, p<0.05), bacterial chemotaxis (
r = −0.51, p<0.001), and flagellar assembly (
r = −0.47, p<0.001) correlated with body weight. Amino sugar and nucleotide sugar metabolism (
r = −0.05, p>0.05) and toluene degradation (
r = 0.27, p>0.05) were hardly correlated with body weight.