Subclinical Vascular Dysfunction in Mothers of Children with Anorectal Malformations: A Multiomics Study

Background

Anorectal malformations (ARMs) are rare birth defects with established maternal risk factors. However, the molecular mechanisms linking these risk factors to ARM development remain unclear. Maternal vascular dysfunction may serve as a unifying mechanistic pathway.

Objective

To investigate whether mothers of ARM-affected children exhibit molecular signatures of vascular dysfunction using integrated microbiome and metabolomic profiling.

Methods

Mothers of ARM children (cases; n = 10) and matched healthy controls (n = 10), recruited more than one year postpartum, were analyzed using 16S rRNA sequencing and untargeted LC-MS-based serum metabolomics. Microbial diversity was assessed using Shannon and Chao1 indices; compositional differences were evaluated by PERMANOVA across multiple distance metrics. Metabolites were analyzed using univariate and multivariate methods with FDR correction (q < 0.05).

Results

Cases exhibited elevated Firmicutes:Bacteroidetes ratios (70.1% vs 51.6%) and significant depletion of Olsenella (6.2% vs 16.4%, p < 0.05), a genus associated with cortisol metabolism. Metabolomic profiling revealed 174 significantly altered serum metabolites (p < 0.05, fold change >1.5). Among these, reduced D-glutamic acid, elevated thromboxane A , and decreased hexacosanoic acid emerged as key discriminants, mapping to pathways involved in oxidative stress, vasoconstriction, and peroxisomal dysfunction.

Conclusions

This pilot study reveals maternal microbiome-metabolome signatures suggestive of subclinical vascular dysfunction, resembling aspects of pre-eclampsia, in mothers of children with ARMs. These findings support the hypothesis that maternal vascular health influences ARM risk and warrant validation in larger, prospective cohorts.

Graphical Abstract