Goehring Karen C, Kennedy Adam D, Prieto Pedro A, Buck Rachael H
Department of Global Discovery Research, Abbott Nutrition, Columbus, Ohio, United States of America.
Metabolon, Inc., Durham, North Carolina, United States of America.
PLoS One. 2014 Jul 7;9(7):e101692. doi: 10.1371/journal.pone.0101692. eCollection 2014.
It has been hypothesized that human milk oligosaccharides (HMOs) confer systemic health benefits to breastfed infants; however, plausible mechanisms for some effects, such as systemic immunomodulation, require HMOs to access the bloodstream of the developing infant. While small concentrations of HMOs have been detected in the urine of breastfed infants there are no published studies of these oligosaccharides accessing the plasma compartment of breastfed infants. Here we determined the relative fractions of several ingested HMOs in infant urine and plasma. Plasma from formula-fed infants was used as a control.
Using gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry/tandem mass spectrometry (LC/MS/MS), and high performance liquid chromatography (HPLC), we analyzed the urine and plasma from 17 healthy formula-fed infants and 16 healthy breast-fed infants (and the milk from their mothers).
Multiple HMOs were detected in the urine and plasma of breastfed infants, but not in formula-fed infants. Levels of 2'-fucosyllactose (2'FL), 3FL and lacto-N-neotetraose (LNnT) in both plasma (r = 0.98, p<0.001; r = 0.75, p = 0.002; r = 0.71, p = 0.004) and urine (r = 0.81, p<0.001; r = 0.56, p = 0.026; NS) correlated significantly with concentrations in the corresponding breast milk. The relative fractions of HMOs were low, 0.1% of milk levels for plasma and 4% of milk levels for urine. Within the breastfed cohort, there were significant differences between secretor and nonsecretor groups in levels of several fucosylated HMOs.
At least some ingested HMOs are absorbed intact into the circulation and excreted in the urine and their concentrations in these fluids correlate with levels of the corresponding mother's milk. While relative fractions of absorbed HMOs were low, these levels have been shown to have biological effects in vitro, and could explain some of the postulated benefits of human milk.
据推测，人乳寡糖（HMOs）能为母乳喂养的婴儿带来全身性健康益处；然而，某些效应（如全身免疫调节）的合理机制需要HMOs进入发育中婴儿的血液循环。虽然在母乳喂养婴儿的尿液中检测到了少量HMOs，但尚未有关于这些寡糖进入母乳喂养婴儿血浆成分的公开研究。在此，我们测定了几种摄入的HMOs在婴儿尿液和血浆中的相对比例。以配方奶喂养婴儿的血浆作为对照。
我们使用气相色谱/质谱联用仪（GC/MS）、液相色谱/质谱联用仪/串联质谱仪（LC/MS/MS）和高效液相色谱仪（HPLC），分析了17名健康配方奶喂养婴儿和16名健康母乳喂养婴儿（以及他们母亲的乳汁）的尿液和血浆。
在母乳喂养婴儿的尿液和血浆中检测到多种HMOs，但在配方奶喂养婴儿中未检测到。血浆中2'-岩藻糖基乳糖（2'FL）、3FL和乳糖-N-新四糖（LNnT）的水平（r = 0.98，p<0.001；r = 0.75，p = 0.002；r = 0.71，p = 0.004）以及尿液中这些物质的水平（r = 0.81，p<0.001；r = 0.56，p = 0.026；无显著性差异）与相应母乳中的浓度显著相关。HMOs的相对比例较低，血浆中为母乳水平的0.1%，尿液中为母乳水平的4%。在母乳喂养队列中，分泌型和非分泌型组之间几种岩藻糖基化HMOs的水平存在显著差异。
至少一些摄入的HMOs能完整地被吸收进入循环系统并通过尿液排出，且它们在这些体液中的浓度与相应母乳中的水平相关。虽然吸收的HMOs相对比例较低，但这些水平已被证明在体外具有生物学效应，并且可以解释人乳的一些假定益处。
