Stability of Human-Milk Oligosaccharide Concentrations Over 1 Week of Lactation and Over 6 Hours Following a Standard Meal

Background Our previous studies revealed that human-milk oligosaccharides (HMOs) have health benefits for nursing infants and their concentrations change dynamically over 24 mo of lactation. Yet, the extent to which HMOs vary over the short term (days) and in response to acute factors such as maternal diet is unclear. Objective The purpose of this study was to determine the stability of HMO concentrations over 7 d and in response to a standard meal and sugar-sweetened beverage (SSB) over 6 h. Methods In this ancillary study, lactating mothers were enrolled at 6 wk postpartum. Participants received in-person instructions and materials to complete procedures at home. In the 1-wk experiment (n = 11), mothers pumped a milk sample at 07:00 h for 7 consecutive days. In the 6-h experiment (n = 35), mothers pumped a milk sample after an overnight fast at 06:00 h and then consumed a standard meal plus SSB provided by the study team. Mothers pumped a milk sample every hour for 6 consecutive hours. Samples were analyzed for the 19 most abundant HMOs. Repeated-measures ANOVA was used to test changes in HMO concentrations over time, reported as F(df(time), df(error)) = F value, P value. Results Concentrations of all assayed HMOs were stable over 7 consecutive days, including, for example, the most widely studied HMOs in relation to infant health: 2 '-fucosyllactose (2 ' FL) [F(2,17) = 0.39, P = 0.65], disialyl-lacto-N-tetraose (DSLNT) [F(4, 37) = 0.60, P = 0.66], and lacto-N-neotetraose (LNnT) [F(3, 32) = 1.5, P = 0.23]. Concentrations of all assayed HMOs were stable in response to a standard meal plus SSB. For example, fasted baseline concentrations of 2 ' FL, DSLNT, and LNnT were 2310 +/- 1620 mu g/mL, 560 +/- 290 mu g/mL, and 630 +/- 290 mu g/mL, respectively, and there were no changes in 2 ' FL [F(4, 119) = 1.9, P = 0.13], DSLNT [F(4, 136) = 0.39, P = 0.83], and LNnT [F(4, 120) = 0.64, P = 0.63] over 6 consecutive hours. Conclusions HMO concentrations are stable over 1 wk of lactation and are not acutely affected by a standard meal plus SSB in mothers.