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Updated: Sep 4, 2025
Oral Biofilm Sampling for Microbiome Analysis in Healthy Children
Published on: December 31, 2017
Breastmilk influences development and composition of the oral microbiome
Catherine A Butler1, Geoffrey G Adams1, Jordan Blum1
1Centre for Oral Health Research, Melbourne Dental School, University of Melbourne, Carlton, Vic, Australia.
Insights
Breast milk influences infant oral microbiome development, promoting beneficial bacteria like Streptococcus mitis. Never breastfed infants show higher early bacterial diversity, with differences diminishing after solid food introduction.
Area of Science:
- Microbiology
- Human Microbiome Research
- Infant Health
Background:
- Human microbiomes develop predictably, but early oral microbiome assembly remains understudied.
- Understanding infant oral microbiome development is crucial for long-term health.
- Breast milk's role in shaping the infant oral microbiome is not fully understood.
Purpose of the Study:
- To investigate the impact of breast milk exposure on the infant oral microbiome.
- To analyze oral microbiome composition in breastfed versus never-breastfed infants over 20 months.
- To identify specific bacterial taxa affected by breast milk in early life.
Main Methods:
- Longitudinal study of 39 infants (13 never breastfed, 26 breastfed >10 months).
- Oral microbiomes analyzed at four time points up to 20 months of age.
- Bacterial 16S rRNA gene sequencing (V4 region) to identify and quantify 519 taxa in saliva.
Main Results:
- Significant differences observed in oral microbiome development between breastfed and never-breastfed infants.
- Higher bacterial diversity in never-breastfed infants at 2 months, notably increased Veillonella and Bacteroidetes.
- Breast milk likely promotes the growth of health-associated bacteria, such as the Streptococcus mitis group.
Conclusions:
- Breast milk may act as a prebiotic, selectively promoting beneficial early-colonizing oral bacteria.
- Introduction of solid foods led to increased microbiome heterogeneity in both infant groups.
- Breast milk plays a significant role in shaping the early-life oral microbiome composition and diversity.
Background:
Human microbiomes assemble in an ordered, reproducible manner yet there is limited information about early colonisation and development of bacterial communities that constitute the oral microbiome.
Aim:
The aim of this study was to determine the effect of exposure to breastmilk on assembly of the infant oral microbiome during the first 20 months of life.
Methods:
The oral microbiomes of 39 infants, 13 who were never breastfed and 26 who were breastfed for more than 10 months, from the longitudinal VicGeneration birth cohort study, were determined at four ages. In total, 519 bacterial taxa were identified and quantified in saliva by sequencing the V4 region of the bacterial 16S rRNA genes.
Results:
There were significant differences in the development of the oral microbiomes of never breastfed and breastfed infants. Bacterial diversity was significantly higher in never breastfed infants at 2 months, due largely to an increased abundance of Veillonella and species from the Bacteroidetes phylum compared with breastfed infants.
Conclusion:
These differences likely reflect breastmilk playing a prebiotic role in selection of early-colonising, health-associated oral bacteria, such as the Streptococcus mitis group. The microbiomes of both groups became more heterogenous following the introduction of solid foods.
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