Fig. 1

L. reuteri alters the intestinal microbiota composition and microbial tryptophan metabolite. A Differential enrichment of the mouse colonic microbiota in response to L. reuteri supplementation on day 28 (see the Figure S1A legend for the experimental scheme). The taxonomic classifications of the bacteria are shown in the left panel. Blanks are unassigned taxa. The 36 differentially enriched bacterial taxa are ranked by estimating the mean decrease in accuracy based on random forest analysis. The right panel shows the LEfSe analysis of the 36 bacterial taxa. B Serum concentrations of metabolites in tryptophan metabolism among three groups of mice (n = 10). C Volcano plot showing differential gene expression in the colon of DSS-treated mice with or without L. reuteri supplementation. Each red dot indicates a significantly upregulated gene, while a blue dot represents a significantly downregulated gene, with each gray dot showing a gene with no significant difference. D Pairwise comparisons of tryptophan metabolites, with a color gradient denoting Spearman’s correlation coefficient. The correlation between the bacterial/gene expression profiles and each metabolite using partial Mantel tests. The edge width corresponds to Mantel’s R statistic for the corresponding distance correlations, and the edge color denotes statistical significance. E Real-time PCR assay showing the expression of Pxr and its target genes (n = 5). *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001