Detection of the Presence of Fungi in Human Breastmilk Samples from Healthy Mothers

Researches from the “Instituto de Agroquímica y Tecnología de Alimentos (IATA)” that belongs to the Consejo Superior de Investigaciones Científicas (CSIC), from ”Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)” and from the “Hospital Clínico Universitario de Valencia”, have detected the presence of fungi in breastmilk samples obtained from healthy women. The results of this study, published in Scientific Reports, increases the knowledge on infant health.

Microbiome development in the newborn is a stepwise and crucial process, contributing at the physiological level and influencing the development and maturation of the immune system. During delivery, the neonate is exposed to maternal microbes, first from the mother’s reproductive system, rapidly after from the maternal skin and the environment, and later influenced by diet, including breastfeeding. Breastmilk plays an important role in the microbial supply as it contains a variety of potential beneficial bacteria, as well as a wide source of nutrients and essential protective substances that makes it the optimal nutrition for the infant.

María Carmen Collado, CSIC researcher at the IATA, explains “Bacteria residing in breastmilk are transmitted to the infant during breastfeeding, getting to the intestine and contributing to the settlement of the gut microbiota and acquired immunity. Although bacteria in human milk have been widely assessed, information about the natural presence of fungal species is generally lacking, and it is limited to a few studies. However, fungal presence in the milk of other mammals has been widely described in several studies, which supports the idea that human breastmilk could also contain fungi under normal, healthy conditions”.

In this work, researchers have analysed breastmilk samples from 41 healthy lactating mothers within 1 month after giving birth.

Fungal presence was assessed by different techniques, including microscopy, growth and identification of cultured isolates and genome sequencing. In addition, milk macronutrients and human somatic cells were quantified by spectrophotometry and cytometry. Data showed that 89% of samples had detectable levels of fungal DNA. Using different culture media, 33 strains were isolated and identified, confirming the presence of viable fungal species. Fluorescent microscopy confirmed that the most common genera were Malassezia (44%), followed by Candida (19%) and Saccharomyces (12%).

Amparo Querol, researcher at the IATA and expert in industrial fungi and food safety, highlights “the relevance of the origin of the S. cerevisiae strains isolated in this work since they are part of a population commonly used in industry, such as bread yeast. Probably, the origin of these fungi is similar to that of bacteria found in breastmilk, which could be transmitted to the baby during breastfeeding. Knowing the fungal origins and their role in baby immunity is quite relevant”. 

Alex Mira, researcher at Fundación FISABIO, stresses that “the detection of bacteria and fungi in human samples is usually associated to infectious organisms; however, when we talk about microorganisms found naturally in breast milk, we refer to harmless or beneficial microbes. The newborn needs to be exposed to microorganisms to develop their immune system and other vital functions that we are just beginning to understand” 

Future work should study the origin of these fungi and their potential contribution to infant health.

This article has been republished from materials provided by the Spanish National Research Council. Note: material may have been edited for length and content. For further information, please contact the cited source.

Reference
Alba Boix-Amorós, Cecilia Martínez-Costa, Amparo Querol, María Carmen Collado y Alex Mira. Multiple Approaches Detect the Presence of Fungi in Human Breastmilk Samples from Healthy Mothers. Sci Rep. 7(1):13016. doi: 10.1038/s41598-017-13270-x.