Oral Presentation Australasian Diabetes in Pregnancy Society Annual Scientific Meeting 2016

Antibiotic exposure during pregnancy affects the oral microbiota in newborn infants (#15)

Luisa F Gomez Arango 1 2 , Helen L Barrett 1 2 , David McIntyre 2 , Leonie K Callaway 1 2 , Mark Morrison 3 , Marloes Dekker Nitert 1 4
  1. UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
  2. School of Medicine, The University of Queensland, Herston, QLD, Australia
  3. Diamantina Institute, The University of Queensland, Woolongabba, QLD, Australia
  4. University of Queensland, Herston, QLD, Australia

Background: Microorganisms residing in the oral cavity are important determinants of health and disease. The first microbial colonizers alter the environment and can shape the mature oral microbiota. It is not clear which factors dictate which bacteria are the first to colonize the infant's oral cavity. The aim of this study was to characterise the newborn’s oral microbiota and to elucidate plausible factors affecting early oral microbial colonization.

 

Methods: Oral microbiome profiles from mother-baby dyads participating in the SPRING trial (n=78) were determined by 16S rRNA sequencing. Data files were processed using QIIME software. To investigate the contribution of maternal oral microbiota, a Bayesian approach for bacterial source tracking (SourceTracker v 1.0) was used. The diversity of the infant’s oral microbiota was evaluated according to: mode of delivery, BMI, infant body composition, infant gender, gestational age and antibiotic intake throughout pregnancy. FDR-corrected P values are presented.

 

Results: Bacterial source-tracking analysis revealed in half of the newborns, the oral microbiota resembled that of their mothers (mean similarity 92.9% ± 23.2%). The oral microbiota of the other half of newborns showed little similarity to that of their mothers (mean similarity 22.0 ± 27.7%). Bacterial community composition was significantly different between the two groups (p=0.001). In infants with high similarity, the families Streptococcaceae (p= 0.002) and Gemellaceae (p= 0.03) were significantly enriched while bacteria belonging to phylum Proteobacteria, which is often associated with an inflammatory environment, dominated the oral microbiota of those with low similarity. Antibiotic treatment in pregnancy was associated with an oral microbiota of low similarity to the maternal oral microbiota (p= 0. 029).

 

Conclusions: These results suggest that the bacteria colonizing the infant’s oral microbiome may be of maternal origin. Maternal antibiotic intake in pregnancy may alter which bacteria colonize the oral cavity of their infants.