67 Infant Health Status Impacts the Neutrophil Phenotypes and Polyunsaturated Fatty Acids Composition in Human Milk

Abstract Background The abundance of human milk leukocytes, including neutrophils, changes in response to the health status mothers and their infants. Elevated leukocyte counts occur during infant infection return baseline levels upon recovery. However, it is unclear how can affect neutrophil phenotypes concentration fatty acids mothers’ milk. Objectives This study investigates association between activation state, acid levels, Design/Methods a prospective cohort 50 healthy breastfeeding recruited from St. Michael’s hospital, Toronto, Ontario, who were followed up 2-4 weeks until 4 months postpartum. Human samples collected participants data regarding self-reported questionnaires completed by at both timepoints, then imputed based on whether infants had taken antibiotics, been hospitalized, or diagnosed with medical condition, least 2 prior collection. Neutrophils quantified using flow cytometry labelled panel antibodies detect specific cluster differentiation (CD) biomarkers. Fatty identified gas chromatography-flame ionization detector (GC-FID). Linear mixed-effects models used evaluate correlation counts, along expressed CD markers, composition lactation. Results markers classified into categories function: degranulation/activation (CD63, CD64, CD66a), an immunoregulation marker (CD16), adhesion (CD11b, CD18), lipopolysaccharide receptor (CD14). whose condition neutrophils which significantly elevated CD64 biomarker (β: 85.65, p=0.009 adjusted models), compared there no significant associations status, absolute hmPMN andother biomarkers (p>0.05). There also arachidonic 0.12, p=0.013) C22:5n-6 0.06, p=0.015) infants, after adjusting for maternal age, post-pregnancy body mass index, sex, feeding pattern. Conclusion demonstrates that associated immunological components, suggesting inflammatory protective mechanism mammary glands triggered infection. How these alterations outcomes short longer terms need critical consideration.