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

A Nye, Gareth; J Rzepecka, Magdalena; E Jones, Christopher; Harrison, Kate

Abstract

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.

Methods: Donor 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 manufacturer’s instructions and analysed via statistical software packages based on the anonymised maternal characteristics.

Results: sIgA 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.

Conclusion: The 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.

• Working Paper Type: Preprint
• Publication Date: Feb 21, 2025
• Deposit Date: Feb 28, 2025
• DOI: https://doi.org/10.1101/2025.02.19.25322535