(P10-078-24) Variability in Presence, Abundance, and Timing of Bovine Milk- and Soy-Derived Peptides in Human Milk After Maternal Bovine Milk and Soy Beverage Consumption

Objectives: Food-borne allergens can transfer to human milk (HM) leading to a potential allergic response in breastfed infants, but variability of allergen transfer complicates best-practice recommendations for women breastfeeding infants with signs/symptoms of allergy. Our objective was to identify bovine- and soy-derived peptides in HM after maternal consumption of bovine milk (BM) and soy beverage (SB). We hypothesized that BM- and SB-derived peptides would be present in HM collected 2 and 4 h after consumption.

Methods: Lactating women (n=38) participated in this prospective, randomized, cross-over dietary intervention trial consisting of 2 study phases, each consisting of a 5-d diet elimination, 3-d diet intervention, and 2-d washout period. Participants eliminated and then consumed BM-containing products during one phase and eliminated and then consumed soy-containing products during the other. Each 3-d diet intervention required daily consumption of increasing amounts of BM or SB (175, 295, and 415 mL). Participants collected HM samples at baseline and 3 times daily during the diet interventions (prior to BM or SB consumption and 2 and 4 h after). Peptidomics was performed on 75 of the HM samples collected from a subset of 25 women. Specifically, we analyzed HM samples collected after the 5-d diet elimination (before consuming BM or SB), and 2 and 4 h after consumption of 415 mL of SB or BM. Peptides were isolated from HM by ethanol precipitation, cleaned by C18 solid-phase extraction, analyzed by LC-MS/MS, and identified with Proteome Discoverer.

Results: We identified 121 peptides (associated with 6 proteins) of bovine origin in HM collected after BM consumption. From most to least abundant, these proteins were β-lactoglobulin, κ-casein, α-s1-casein, β-casein, α-lactalbumin protein variant D, and glycosylation-dependent cell adhesion molecule 1. Relative abundance and timing of the appearance of these peptides were variable. Results from analysis of HM samples do not support the appearance of soy-derived peptides after SB consumption.

Conclusions: There is interindividual variation in timing and abundance of BM peptides in HM following maternal ingestion of BM. More research is needed to evaluate transfer of other potential allergens, such as soy, and factors impacting peptide appearance.

Funding Sources: Idaho Global Entrepreneurial Mission Grant