title: Maturation of the infant microbiome community structure and function across multiple body sites and in relation to mode of delivery.
abstract: Human microbial communities are characterized by their taxonomic, metagenomic and metabolic diversity, which varies by distinct body sites and influences human physiology. However, when and how microbial communities within each body niche acquire unique taxonomical and functional signatures in early life remains underexplored. We thus sought to determine the taxonomic composition and potential metabolic function of the neonatal and early infant microbiota across multiple body sites and assess the effect of the mode of delivery and its potential confounders or modifiers. A cohort of pregnant women in their early third trimester (n = 81) were prospectively enrolled for longitudinal sampling through 6 weeks after delivery, and a second matched cross-sectional cohort (n = 81) was additionally recruited for sampling once at the time of delivery. Samples across multiple body sites, including stool, oral gingiva, nares, skin and vagina were collected for each maternal-infant dyad. Whole-genome shotgun sequencing and sequencing analysis of the gene encoding the 16S rRNA were performed to interrogate the composition and function of the neonatal and maternal microbiota. We found that the neonatal microbiota and its associated functional pathways were relatively homogeneous across all body sites at delivery, with the notable exception of the neonatal meconium. However, by 6 weeks after delivery, the infant microbiota structure and function had substantially expanded and diversified, with the body site serving as the primary determinant of the composition of the bacterial community and its functional capacity. Although minor variations in the neonatal (immediately at birth) microbiota community structure were associated with the cesarean mode of delivery in some body sites (oral gingiva, nares and skin; R2= 0.038), this was not true for neonatal stool (meconium; Mann-Whitney P > 0.05), and there was no observable difference in community function regardless of delivery mode. For infants at 6 weeks of age, the microbiota structure and function had expanded and diversified with demonstrable body site specificity (P < 0.001, R2= 0.189) but without discernable differences in community structure or function between infants delivered vaginally or by cesarean surgery (P = 0.057, R2= 0.007). We conclude that within the first 6 weeks of life, the infant microbiota undergoes substantial reorganization, which is primarily driven by body site and not by mode of delivery.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, Texas, USA.|Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, Texas, USA.|Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Derrick M
authors.initials: DM
authors.lastname: Chu
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Prince
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Antony
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Maxim D
authors.initials: MD
authors.lastname: Seferovic
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine, Houston, Texas, USA.|Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, Texas, USA.|Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA.|Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.|Department of Molecular and Cell Biology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Kjersti M
authors.initials: KM
authors.lastname: Aagaard
mesh_terms: D000328:Adult; D002585:Cesarean Section; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000235:genetics*; D005881:Gingiva / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008470:Meconium / Q000382:microbiology; D056186:Metagenomics; D009297:Nasal Mucosa / Q000382:microbiology; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012867:Skin / Q000382:microbiology; D055815:Young Adult
chemical_list: D012336:RNA, Ribosomal, 16S