Inoculation of mother\u2019s own milk could personalize pasteurized donor human milk used for feeding preterm infants

D Mallardi,P Roggero,O Amato,B Castiglioni,I De Noni,S Morandi,N Liotto,F Mosca,T Silvetti,M Stuknyte,P Piemontese,V Pica,F Biscarini,P Cremonesi,C Tabasso

doi:10.1186/s12967-021-03096-7

Abstract

BackgroundHuman milk is a vehicle for bioactive compounds and beneficial bacteria which promote the establishment of a healthy gut microbiome of newborns, especially of preterm infants. Pasteurized donor human milk (PDHM) is the second-best option when preterm mother’s own milk is unavailable. Since pasteurization affect the microbiological quality of donor milk, PDHM was inoculated with different preterm milk samples and then incubated, in order to evaluate the effect in terms of bacterial growth, human milk microbiome and proteolytic phenomena.MethodsIn an in-vitro study PDHM was inoculated at 10% v/v using ten preterm milk samples. Microbiological, metataxonomic and peptidomic analyses, on preterm milk samples at the baseline (T0), on PDHM and on inoculated milk (IM) samples at T0, after 2 h (T1) and 4 h (T2) of incubation at 37 °C, were conducted.ResultsIM samples at T2 showed a Total Bacterial Count not significantly different (p > 0.01) compared to preterm milk samples. At T2 lactic acid bacteria level was restored in all IM. After inoculation, metataxonomic analysis in IM samples showed that Proteobacteria remained the predominant phylum while Firmicutes moved from 3% at T1 to 9.4% at T2. Peptidomic profile of IM resembled that of PDHM, incubated for the same time, in terms of number and type of peptides.ConclusionThe study demonstrated that inoculation of PDHM with mother’s own milk could restore bacterial growth and personalize human milk microbiome in PDHM. This effect could be beneficial because of the presence of maternal probiotic bacteria which make PDHM more similar to mother’s own milk.

Highlights

Human milk is a vehicle for bioactive compounds and beneficial bacteria which promote the establishment of a healthy gut microbiome of newborns, especially of preterm infants
Microbiological features of Pasteurized donor human milk (PDHM), Preterm mother’s own milk (PM) and inoculated milk (IM) samples at different time points of incubation Total bacterial count (TBC) of PDHM did not change through the incubation with an average load of 2.56 log10 CFU/mL, which probably included heat-resistant spore-forming bacteria
Most of the reads for PDHM and IM samples belonged to the Proteobacteria and Firmicutes phyla (Fig. 3), which accounted for almost 100% of the entire microbiota at all time points (Table 3)

Summary

Introduction

Human milk is a vehicle for bioactive compounds and beneficial bacteria which promote the establishment of a healthy gut microbiome of newborns, especially of preterm infants. Different culture -dependent and -independent methods indicated the presence in HM of a complex community of bacteria which comprises many viable commensals, mutualistic or potentially probiotic bacteria such as Bifidobacteria, Lactic acid bacteria (LAB) and other genera as Staphylococcus, Enterococcus and Streptococcus. These indigenous bacteria, supported by the entero-mammary translocation, characterize the HM microbiome which can be affected by several maternal and environmental factors. The healthy gut microbiota could limit the growth of potential pathogens, by exerting a protective and nutritive role, especially for preterm infants [5, 6]

Methods

Results

Discussion

Conclusion