Fig. 3

Correlation between tissue groups of microbial metabolites, xenobiotics, and fetal metabolites. A Schematic of how the correlation between tissue would identify the source of bacterial metabolites. \({\rho }_{Dec\_GI}\) denotes the correlation of metabolite abundance in between decidua and GI tissues, and \({\rho }_{Mec\_GI}\) denotes the correlation of metabolite abundance between meconium and GI tissues. Maternal microbiota-derived metabolites that cross as metabolites are expected to have \({\rho }_{Dec\_GI}\) \(\gg {\rho }_{Mec\_GI}\), while metabolites that are potentially locally produced by fetal microbiota within the GI track are expected to have \({\rho }_{Dec\_GI}\) \(\ll\) \({\rho }_{Mec\_GI}\). B Heatmap showing normalized abundance of the 41 microbial-associated metabolites across sample types. C Pairwise correlation matrix of the 41 microbial metabolites between paired tissue samples from subject no. 16. D Boxplots visualizing the correlations between GI and decidua groups and between GI and meconium groups based on 41 microbial metabolites, 47 xenobiotics, and 8 fetal-derived metabolites respectively from Supplementary Table S4. Red asterisk points represent the pairwise correlations between tissue samples from subject no. 16. *P < 0.05, ***P < 0.001