New Discovery: Some breastmilk microbiome contains yeast and fungi: Do these harm the infant?
It is well established breastfeeding is the strongest modifiable factor shaping infant microbiome development. Decades of research have shown milk contains a diverse collection of bacteria, and while these were initially viewed as unwanted contaminants, it is now becoming clear microbes (both bacterium and fungi) are naturally present in milk from healthy mothers of all mammalian species.
“Our research demonstrates the presence of yeasts and other fungi in breast milk in healthy mothers, supporting the hypothesis that breast milk is an important source of microorganisms to the growing infant,” said principal investigator Maria Carmen Collado, PhD, Senior Researcher, the Institute of Agrochemistry and Food Technology, National Research Council, Valencia, Spain. “Currently, some yeast species are used as potential probiotics to promote infant health,” said Dr. Collado. “The most common one is Saccharomyces boulardii. Our study identifies more fungal species that could potentially confer benefits for human health, and the possibility of isolating appropriate strains from breast milk. Those potential benefits should now be studied in detail.”
“Our data confirm the presence of fungi in breast milk across continents and support the potential role of breast milk on the initial seeding of fungal species to the infant gut,” the investigators wrote. “This supports the existence of a ‘breast milk mycobiota’ under healthy conditions and their findings reinforce the potential influence of environmental factors, in particular geographic location, on the species of yeast and fungi that make up the breast milk mycobiome,” said Dr. Collado.
According to Dr. Collado, he found the following facts
- Despite the similarities of the mycrobiomes across multiple countries, the findings reinforce the potential influence of environmental factors.
- Some milk bacterial communities are more permissive to fungal presence and proliferation.
- Milk bacterial dynamics are influenced by fungi when they are present, and milk bacterial composition is influenced by the milk environment, which also independently facilitates fungal inoculation or colonisation.
Kathy Fray, managing director of MothersWise.com and founding director of the IIMHCO [Intl Integrative Maternity HealthCare Org] explains further “The vast majority of previous studies into breastmilk microbiology have focused exclusively on bacteria. However, motivated by the growing interest in Fungi as being an important part of human microbiome, new research is discovering fungi is also contained within breastmilk microbiome”.
Fray continues “We know breastfeeding modulates infant microbiota development, and even though investigators are yet to identify where the source of where the breastmilk fungi originates from, it is strongly hypothesised the fungal microbes also positively influence the development of infants’ mycobiotia. It becomes not just plausible, but actually completely logical, that both breastmilk fungi and bacteria influence the trajectory of infant gut health.”