Specific class of intrapartum antibiotics relates to maturation of the infant gut microbiota: a prospective cohort studyOriginal 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 prospective cohort study evaluated whether intrapartum antibiotics, and specific classes of those antibiotics given during labor and delivery, affect the maturation of the infant gut microbiota over the first year of life. Intrapartum antibiotic exposure was abstracted from maternal medical records. Infant fecal samples were collected at six weeks and one year of age and characterized using 16S rRNA sequencing, with metagenomic analysis performed on a subset of samples to capture taxonomic and functional profiles.
Who was studied?
The study population consisted of 266 full-term infants enrolled in the New Hampshire Birth Cohort Study (NHBCS), a prospective cohort based in rural New Hampshire, USA. Infants were classified according to their mothers' exposure to antibiotics, including specific antibiotic classes, during labor and delivery. Fecal samples from these infants were analyzed at two time points, six weeks and one year, to track microbiota development.
What were the most important findings?
Exposure to intrapartum antibiotics, particularly to two or more antibiotic classes, was independently associated with lower microbial diversity and a distinct bacterial community composition at six weeks of age. At one year, infants exposed only to penicillins during labor and delivery had significantly lower alpha diversity scores compared with infants not exposed to any intrapartum antibiotics. Penicillin exposure specifically was also related to a significantly smaller increase over the first year in several bacterial taxa, including Bacteroides.
What are the greatest implications of this study?
The findings suggest that not all intrapartum antibiotics affect infant gut microbiota development equally, with penicillin-class exposure and multi-class exposure showing the clearest associations with reduced diversity and altered taxa such as Bacteroides. This class-specific effect implies that clinical decisions about which antibiotic to use during labor and delivery could have lasting consequences for infant microbiome maturation. These results support more granular research into antibiotic stewardship during childbirth, distinguishing between antibiotic classes rather than treating intrapartum antibiotic exposure as a single uniform category.