Höfundar:
Agnes Þóra Árnadóttir, Ingibjörg Gunnarsdóttir, Sigurlaug Skírnisdóttir, Stephen Knobloch, Alexandra M Klonowski, Viggó Marteinsson
Introduction: The first two years of life are critical for the development of the human gut microbiota, yet the influence of maternal vitamin D status on the infant microbiome development is not well understood.
Methods: Faecal samples were collected from 328 Icelandic mothers and their infants, before and after introduction of solid foods, as well as at one and two years of age. Dietary questionnaires were collected, and mother’s serum 25(OH)D was measured at week 11-14 of pregnancy. High serum 25(OH)D was defined as ≥75 nmol/L and low as <50 nmol/L.
Results: Lower alpha diversity was observed in infant gut microbiota around four months of age in infants born to mothers having high 25(OH)D in the first trimester of pregnancy. Gut microbial community composition based on beta diversity around six months of age was higher among infants with mothers with low 25(OH)D. Beneficial microbial taxa were more abundant in infants born from mothers with high 25(OH)D, whereas low 25(OH)D during pregnancy was associated with a higher abundancy of non-beneficial or potentially harmful microbial taxa in the infant gut microbiota.
Conclusion: Our results suggest an association between maternal serum 25(OH)D status during early pregnancy and the infant gut microbiota development during the first months of life. As differences were also detected in the postpartum maternal gut microbiota between high and low groups, it is still unclear if maternal vitamin D status has a direct influence on the infant gut microbiota or an indirect impact through maternal microbiota modulation and vertical transmission.