Strategies for the Preservation, Restoration and Modulation of the Human Milk Microbiota. Implications for Human Milk Banks and Neonatal Intensive Care Units.

Leónides Fernández,Belén Orgaz,Lorena Ruiz,Juan M Rodríguez,Josué Jara

doi:10.3389/fmicb.2018.02676

Abstract

Studies carried in the last years have revealed that human milk contains a site-specific microbiota and constitutes a source of potentially beneficial bacteria to the infant gut. Once in the infant gut, these bacteria contribute to the assembly of a physiological gut microbiota and may play several functions, contributing to infant metabolism, protection against infections, immunomodulation or neuromodulation. Many preterm neonates are fed with pasteurized donor’s human milk (DHM) or formula and, therefore, are devoid of contact with human milk microbes. As a consequence, new strategies are required to allow the exposition of a higher number of preterm infants to the human milk microbiota early in life. The first strategy would be to promote and to increase the use of own mother’s milk (OMM) in Neonatal Intensive Care Units (NICUs). Even small quantities of OMM can be very valuable since they would be added to DHM in order to microbiologically “customize” it. When OMM is not available, a better screening of donor women, including routine cytomegalovirus (CMV) screening of milk, may help to avoid the pasteurization of the milk provided by, at least, a relevant proportion of donors. Finally, when pasteurized DHM or formula are the only feeding option, their supplementation with probiotic bacteria isolated from human milk, such as lactic acid bacteria or bifidobacteria, may be an alternative to try to restore a human milk-like microbiota before feeding the babies. In the future, the design of human milk bacterial consortia (minimal human milk microbiotas), including well characterized strains representative of a healthy human milk microbiota, may be an attractive strategy to provide a complex mix of strains specifically tailored to this target population.

Highlights

Studies carried in the last years have revealed that human milk contains a site-specific microbiota and constitutes a source of potentially beneficial bacteria to the infant gut
When pasteurized donor’s human milk (DHM) or formula are the only feeding option, their supplementation with probiotic bacteria isolated from human milk, such as lactic acid bacteria or bifidobacteria, may be an alternative to try to restore a human milklike microbiota before feeding the babies
Fresh human milk is considered as the gold standard of infant nutrition because it provides all the nutrients and vitamins required for the optimal development of the infant (American Academy of Pediatrics [AAP], 2012)

Summary

Preterm Infants and Human Milk Microbiota

FROM OWN MOTHER’S MILK TO DONOR HUMAN MILK: THE “FALL” OF THE HUMAN MILK MICROBIOTA. Fresh human milk is considered as the gold standard of infant nutrition because it provides all the nutrients and vitamins required for the optimal development of the infant (American Academy of Pediatrics [AAP], 2012). Problems that mothers of preterm neonates have to face in order to provide OMM at the early post-birth period and to keep breastfeeding their infants after NICU discharge have been reviewed recently (Meier et al, 2017a,b) These facts should be a matter of reflection by HMBs and NICU’s managers. Fear to transmission of pathogenic microorganisms [ cytomegalovirus (CMV) in Western countries] is the basis of human milk pasteurization; it is true that use of OMM has an extraordinary history of safety despite women that provide OMM to their preterm infants are not screened for CMV and no differences in the level of hygiene formation have been reported between OMM and DHM providers so far. Studies including large cohorts and a careful safety and efficacy assessment will be required

PERSONALIZATION OF PASTEURIZED DONOR MILK WITH OMM

Findings

MODULATION OF THE MILK MICROBIOTA IN MOTHERS OF PRETERM INFANTS?