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.

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.

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.

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. Key Messages Research has long shown that human breast milk is best for the development of newborn immune systems and gut microbiota In neonatal settings, donor breast milk is used to supplement in times of need This study shows for the first time that immunological factors can be altered based on fetal outcome measures This may inform the provision of donor breast milk in neonatal feeding to ensure maximum immune development in preterm babies. Competing Interest Statement The authors have declared no competing interest. Funding Statement This study did not receive any funding Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Faculty Ethics Research Committee of University of Chester gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability All data produced in the present work are contained in the manuscript