Differential expression patterns of sIgA in Human Breast milk (HBM) is dependent on birth outcome

Breast milk is key for the development of newborns, particularly their immune systems and gut microbiota. In times of neonatal care, newborns are often supplemented with donor breast milk for a range of practical and medical reasons. However, we do not currently understand whether specific breast milk samples may be better suited at boosting the immune system. One of the most influential immune components is sIgA immunoglobulin. MethodsDonor human breast milk samples provided by the North West Human Milk Bank were analysed for levels of sIgA using Abnova sIgA (Human) ELISA Kit according to the manufacturers instructions and analysed via statistical software packages based on the anonymised maternal characteristics. ResultssIgA levels were significantly increased in breast milk samples following preterm and stillbirth outcomes compared with term and live deliveries. In preterm deliveries, sIgA levels remained significantly higher in breast milk for a longer postnatal period when compared with term deliveries. There was no significant changes in sIgA levels with antibiotic use. ConclusionThe results presented in this study suggest that human breast milk is tailored to the baby from an immunological perspective. Higher levels of sIgA in breast milk being seen in pregnancies which did not end in a healthy baby i.e. pregnancies ending in preterm delivery or stillbirth would suggest there is an internal mechanism within the mother to provide additional support to a baby which is failing to grow successfully. This may open up new avenues to select donor samples specifically to assist in babies which are born premature to improve their immune systems. Key MessagesO_LIResearch has long shown that human breast milk is best for the development of newborn immune systems and gut microbiota C_LIO_LIIn neonatal settings, donor breast milk is used to supplement in times of need C_LIO_LIThis study shows for the first time that immunological factors can be altered based on fetal outcome measures C_LIO_LIThis may inform the provision of donor breast milk in neonatal feeding to ensure maximum immune development in preterm babies. C_LI