Prenatal and Peripartum Exposure to Antibiotics and Cesarean Section Delivery Are Associated with Differences in Diversity and Composition of the Infant Meconium MicrobiomeOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This birth-cohort study asked whether prenatal and peripartum antibiotic exposure and delivery mode are linked to the meconium microbiome, the earliest infant gut community. It also tested links to infant excess weight at 12 months. Meconium, the first stool passed, was collected within 48 hours of life and frozen. Bacterial DNA was profiled by 16S ribosomal RNA gene sequencing, then analyzed for diversity and taxon abundance.
Who was studied?
The cohort was 105 full-term infants recruited within a longitudinal birth cohort study in Virginia, USA. Meconium sequenced successfully from all 105. Forty-five infants (43 percent) were male; 62 (59 percent) were born vaginally and 43 (41 percent) by cesarean section. Among cesarean births, 27 were scheduled and 16 emergency. Seventeen mothers (16 percent) received prenatal antibiotics, and all cesarean mothers received peripartum antibiotics.
What were the most important findings?
After multivariable adjustment, beta-diversity was associated with delivery mode (p = 0.044), prenatal antibiotics (p = 0.005), and peripartum antibiotics (p < 0.001). Cesarean birth and peripartum antibiotics raised alpha diversity by Shannon and Simpson indices (p < 0.05). Proteobacteria dominated meconium at 65.2 percent mean abundance, followed by Firmicutes at 26.3 percent and Bacteroidetes at 4.2 percent. Cesarean meconium had lower relative abundance of a facultative anaerobic genus. A total of 214 taxa differed between infants of mothers with versus without peripartum antibiotics.
What are the greatest implications of this study?
The findings suggest maternal antibiotics and cesarean delivery may reach or shape the earliest infant gut microbes, altering the meconium community that reflects intrauterine and peripartum exposures. This adds human evidence to a largely murine hypothesis. No differences appeared with infant weight status at 12 months, so any obesity link may act through later microbiome development. The sample was modest and meconium had low bacterial abundance, so contamination risk and small subgroups temper conclusions.