Fig. 5

Inherited Card9^−/− microbiota controls Trp metabolism independently of the host genotype. A Schematic representation of the cross-fostering experiment with conventional WT and Card9^−/− mice showing the adoption of half of the offspring by a nursing mother of different phenotypes, leaving half of each original litter with their birth mother (WT mothers with half WT and half Card9^−/− pups; Card9^−/− mothers with half WT and half Card9^−/− pups). Pups were weaned at week 4 and kept in separate cages according to their genotype and nursing mother until week 9, when targeted metabolomics focused on Trp metabolism on feces and serum of the pups was performed, i.e., 5 weeks after weaning. B Beta-diversity analysis (PCoA) of the fecal microbiota of mothers and pups, separated according to the nursing mothers genotype (left) or the pups genotype (right), at week 9 of age, i.e., 5 weeks after weaning, using Jaccard index (binary) and PERMANOVA (based on 16 s sequencing). C Principal coordinates analysis showing metabolites composition of the feces (upper panel) and serum (lower panel) of the pups, separated according to the nursing mothers genotype (left) or the pups genotype (right), at week 9 of age. D Trp or E indoles concentration measured in feces (top) or serum (bottom) of the pups separated according to either the microbiota inherited from the nursing mother genotype (left) or the pups genotype (right) at week 9 of age. F Correlation between AhR activity induction (shown as fold change) and functionality of Card9 gene (in the nursing mother genotype and/or the pups genotype) at week 9 of age. Significance was determined by using Spearman linear. Data points represent individual mice. *P < 0.05, **P < 0.01, as determined by Mann–Whitney test. Trp, tryptophan