School of Human Nutrition, McGill University, 21111 Lakeshore Road, Ste-Anne de Bellevue QC, H9X 3V9, Canada.
Center for Studies of Sensory Impairment, Aging and Metabolism (CeSSIAM), Avenida 17, 16-89, Zona 11 (Anillo Periférico), Guatemala City, 01011, C.A. Guatemala.
J Trace Elem Med Biol. 2018 Mar;46:55-61. doi: 10.1016/j.jtemb.2017.11.010. Epub 2017 Nov 16.
The possibility that either subclinical mastitis (SCM), an inflammatory condition of the breast, or elevations in breast milk proinflammatory cytokines alter breast milk mineral and trace element composition in humans has not been investigated. In this cross-sectional study, breast milk samples (n=108) were collected from Guatemalan Mam-Mayan mothers at one of three stages of lactation (transitional, early and established), and categorized as SCM (Na:K >0.6) or non-SCM (Na:K ≤0.6). Milk concentrations of 12 minerals (calcium, copper, iron, magnesium, manganese, phosphorus, potassium, rubidium, selenium, sodium, strontium, and zinc) and 4 proinflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α) were measured by inductively coupled plasma mass spectrometry (ICP-MS), Lachat analyzer or Luminex multiplex bead cytokine assay. SCM was more prevalent during transitional (30%) than early (15.6%) and established (8.9%) lactation. Analysis of variance revealed that breast milk minerals differed by stage of lactation and SCM status. Breast milk minerals with the exception of magnesium were lower in established lactation, whereas SCM was associated with higher selenium and lower phosphorus. Regression models that controlled for lactation stage also confirmed that SCM was associated with lower milk phosphorus and higher milk selenium concentrations. Furthermore, cytokine concentrations were independently associated with several mineral concentrations: IL-1β with higher phosphorus and iron, IL-6 with higher calcium, magnesium, copper and manganese, IL-8 with higher calcium and zinc, and TNF-α with lower iron and manganese. We conclude that milk mineral and trace element concentrations are affected not only by the presence of SCM but also by proinflammatory cytokines in breast milk.
尚未研究人类亚临床乳腺炎（SCM）或母乳促炎细胞因子水平升高是否会改变母乳矿物质和微量元素组成。在这项横断面研究中，从危地马拉 Mam-Mayan 母亲的哺乳期三个阶段（过渡、早期和稳定）采集了 108 份母乳样本，并将其分为 SCM（Na:K >0.6）或非 SCM（Na:K ≤0.6）。通过电感耦合等离子体质谱（ICP-MS）、Lachat 分析仪或 Luminex 多指标 bead 细胞因子分析测定了 12 种矿物质（钙、铜、铁、镁、锰、磷、钾、铷、硒、钠、锶和锌）和 4 种促炎细胞因子（IL-1β、IL-6、IL-8、TNF-α）的浓度。SCM 在过渡（30%）期比早期（15.6%）和稳定（8.9%）期更常见。方差分析显示，母乳矿物质因泌乳阶段和 SCM 状态而异。除镁外，所有泌乳阶段的母乳矿物质均较低，而 SCM 与较高的硒和较低的磷有关。控制泌乳阶段的回归模型也证实 SCM 与较低的牛奶磷和较高的牛奶硒浓度有关。此外，细胞因子浓度与几种矿物质浓度独立相关：IL-1β与较高的磷和铁，IL-6 与较高的钙、镁、铜和锰，IL-8 与较高的钙和锌，以及 TNF-α与较低的铁和锰。我们的结论是，母乳矿物质和微量元素的浓度不仅受 SCM 的影响，还受母乳中促炎细胞因子的影响。
