Maternal anemia during pregnancy and its association with the gut microbiota profile in pregnant and postpartum women, and their infants: a cohort study

Abstract

Background: Anemia is highly prevalent in resource-limited settings, especially during pregnancy and postpartum, and is linked to adverse maternal-infant health outcomes. The role of gut microbiota in anemia during pregnancy remains poorly understood, despite the recognized links between microbiota and maternal-infant health.

Objectives: This study evaluated the association between maternal anemia during pregnancy and the gut microbiota profile in pregnant and postpartum women and their infants.

Methods: A longitudinal cohort study was conducted in Pune, India. A total of 218 pregnant women were enrolled at 13-34 weeks of gestation and followed through 1 year postpartum. We examined the cross-sectional association of maternal anemia (hemoglobin <110 g/L) with gut microbiota during the second and third trimesters and the prospective association of maternal anemia during pregnancy with gut microbiota at 6 months for postpartum mothers and infants. Multivariable models (linear, permutational multivariate analysis of variance, and Analysis of Compositions of Microbiomes with Bias Correction) were used to compare α-diversity, β-diversity (Bray-Curtis distance), and abundance of taxa by anemia status.

Results: Although gut microbial α-diversity and β-diversity did not differ significantly by maternal anemia status, significant differences in taxa abundance by maternal anemia status among mothers were observed, with log fold changes for Flavonifractor [0.523; 95% confidence interval (CI): 0.27, 0.77] and Enterococcus (0.821; 95% CI: 0.542, 1.1). In infants, significant differences in taxa abundance by maternal anemia status were also found, including Coproccocus_2 (-0.628; 95% CI: -0.91, -0.36) and Desulfovibrio (-2.05; 95% CI: -2.31, -1.78).

Conclusions: Our findings reveal a distinct gut microbiota profile in mothers and infants by maternal anemia status. We identified specific taxa that are linked to anemia-related conditions (e.g., iron deficiency) and maternal-infant health outcomes. Future longitudinal studies should explore potential transgenerational associations of maternal anemia with infant microbiota and evaluate whether microbiota-informed interventions, alongside anemia treatments, could improve maternal-infant health outcomes.

Keywords: bacterial abundance; dysbiosis; infant morbidity; microbiome; micronutrient deficiencies; nutritional status; perinatal and postnatal outcomes.