Fig. 4

Correlation between the PC1 score of the metabolome and that of the microbiome. Scores for each principal component 1 (PC1) of the metabolome and microbiome were plotted in the X-Y axis, followed by calculation of Pearson’s product-moment correlation coefficient. a PC1 of classification data by RDP classifier. At the genus and family levels, a stronger correlation (r > 0.7) between the PC1 of the metabolome and microbiome was observed compared to the case of phylum, order, or class. b PC1 of family-, genus-, and species-level classification data after OTU-based analysis