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Published on: March 23, 2018
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Relationship between Milk Microbiota, Bacterial Load, Macronutrients, and Human Cells during Lactation
Alba Boix-Amorós1, Maria C Collado2, Alex Mira3
1Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO FoundationValencia, Spain; Department of Biotechnology, Institute of Agrochemistry and Food Technology, Spanish National Research CouncilValencia, Spain.
Frontiers in Microbiology
|May 6, 2016
Summary
Human breast milk contains complex bacterial communities with individual-specific profiles. These milk microbes exist freely and with immune cells, and are not perceived as infection by the infant
Area of Science:
- Microbiology
- Human Lactation
- Infant Nutrition
Background:
- Human breast milk is optimal infant nutrition, containing nutrients, bioactive compounds, and its own microbiota.
- The interplay between milk components and the role of milk microorganisms remain largely unknown.
Purpose of the Study:
- To investigate the relationships between milk microbiota composition, bacterial load, macronutrients, and human cells during lactation.
- To characterize the bacterial load and microbiome structure in human milk.
Main Methods:
- Quantified bacterial load using bacteria-specific qPCR targeting the fusA gene in milk samples from 21 mothers.
- Assessed milk microbiome composition and diversity via 16S-pyrosequencing.
- Studied bacterial structure using flow cytometry, qPCR, and microscopy; analyzed milk macronutrients and somatic cells.
Main Results:
- Milk bacterial communities exhibited complex, individual-specific profiles, dominated by Staphylococcus, Pseudomonas, Streptococcus, and Acinetobacter.
- Median bacterial load was 10^6 cells/ml, higher than previously reported methods. Staphylococcus aureus was absent in healthy mothers.
- Bacteria were found both free-living and associated with human immune cells, with no correlation between bacterial load and immune cell count.
Conclusions:
- Human milk harbors a unique and variable microbiota, with bacteria existing in both planktonic and cell-associated states.
- The presence of milk bacteria does not appear to trigger an infection response from the infant's immune system.
- Further research is needed to elucidate the biological roles of milk microorganisms and their interactions within the milk environment.
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