p-Cresol impacts microbial composition and selective bacterial taxa predict social deficits and stereotypies. A–C α-diversity as measured by Observed number of ASV (A), Shannon’s (B), and Pielou evenness’ (C) indexes (n = 30 control, n = 29 p-Cresol); Kruskall-Wallis pairwise test: p > 0.05. D β-diversity as measured by Aitchison distances from control and p-Cresol groups based on 16S rRNA gene sequencing (n = 30 control, n = 29 p-Cresol). Group differences were tested by pairwise PERMANOVA, p = 0.001. E Synthetic cladogram presenting dysregulated ASV and bacterial taxa increased (green) or depleted (blue) upon p-Cresol exposure identified by ANCOM. Symbol size reflects the value of the corresponding CLR. F, G Pseudocounts plots from selected ASV increased (F) or depleted (G) upon p-Cresol exposure identified by ANCOM (n = 30 control, n = 29 p-Cresol); Mann-Whitney U-Test: *p < 0.05, **p < 0.01, ***p < 0.001. H, I Microbial composition prediction of behavioral scores. ASV best predicting social behavior (H) or stereotypies (I) as identified by random forest analysis. Only ASV contributing > 1% accuracy in behavioral scores prediction are presented. ASV identical to or ASV pointing towards the same species as ASV identified by ANCOM as increased or depleted upon p-Cresol exposure are labeled in green and blue respectively. A–D, F, G Data are presented as violin plots featuring frequency distribution of data, median (dashed line) and quartiles (dotted line).