Fecal tryptophan catabolite profiling in newborns in relation to microbiota and antibiotic treatment

In the first days of life the newborns intestinal microbiota develops simultaneously with the intestinal gut barrier and following intestinal immunity. The mode of delivery shows significant impact on microbial development and thus the initiation of tryptophan catabolism pathway. Further ATB treatment of mothers before or during delivery affects the microbial and tryptophan metabolites composition of stool of the caesarian and vaginal delivered newborn. The determination of microbiome and levels of tryptophane microbial metabolites in meconium and stool can characterize intestinal colonization of a newborn. From 134 samples from the CELSPAC: TNG cohort study, 16S rRNA gene sequencing was performed, microbial tryptophan metabolites were quantified using ultra-high-performance liquid chromatography with triple-quadrupole mass spectrometry. Microbial diversity and concentrations of tryptophan metabolites were significantly higher in stool compared to meconium. Treatment of mothers with ATB before or during delivery affects metabolite composition and microbial diversity in stool of vaginal and Caesarian delivered newborns. Correlation of microbial and metabolite composition shows significant positive correlations of indol-3-lactic acid, N-acetyl-tryptophan and indol-3-acetic acid with Bifidobacterium, Bacteriodes and Peptoclostridium. The positive affect of vaginal delivery on newborns microbiome development is degraded when mother is treated with ATB before or during delivery. Specific bacterial genera is associated with tryptophan metabolites indol-3-lactic acid, N-acetyl-tryptophan and indol-3-acetic acid.