Department of Anthropology, University of South Florida, Tampa, Florida.
Am J Phys Anthropol. 2018 Oct;167(2):389-399. doi: 10.1002/ajpa.23639. Epub 2018 Aug 20.
Previous research has established population variation in anti-inflammatory immunological biomarkers in human milk. This immunity is potentially ecology-dependent and may alter the life history trade-off between growth and maintenance in infants. The current study has two aims: (1) to assess the ecological differences in milk immunity in two populations, one from the urban U.S. and one from rural Kenya; and (2) to test the hypothesis that milk immunity can affect infant growth indicators.
Kenyan Ariaal (n = 233) and U.S. (n = 75) breastfeeding mother-infant pairs participated in a cross-sectional study at two separate field sites. Laboratory analysis was performed on milk for the anti-inflammatory biomarkers TGF-β2, sTNF-αRI, sTNF-αRII, and IL-1ra using ELISA. Multiple imputation was used to extrapolate data below the limit of detection before multivariate analysis.
There were significant differences between U.S. and Kenyan mothers on all four milk biomarkers, with Kenyan mothers having significantly higher sTNF-αRI and sTNF-αRII and lower TGF-β2 and IL-1ra than U.S. mothers. U.S. mothers with higher milk TGF-β2 and IL-1ra have infants that are significantly longer and heavier for their age, while Kenyan mothers with higher sTNF-αRI have significantly longer and heavier infants for their age, and those with higher TGF-β2 have marginally significantly longer infants.
There were significant differences in ecological milk immunity between U.S. and Kenyan mothers. These differences potentially play a role in the growth of their infants. Further research in milk immunity should consider the possibility of shared maternal-infant life histories.
先前的研究已经确定了人乳中抗炎免疫生物标志物的群体变异。这种免疫能力可能依赖于生态环境，并可能改变婴儿在生长和维持之间的生活史权衡。本研究有两个目的：（1）评估来自美国城市和肯尼亚农村的两个人群的乳汁免疫的生态差异；（2）检验乳汁免疫可以影响婴儿生长指标的假设。
肯尼亚 Ariaal（n=233）和美国（n=75）哺乳期母婴对参加了两项独立的横断面研究。使用 ELISA 法对乳汁中的抗炎生物标志物 TGF-β2、sTNF-αRI、sTNF-αRII 和 IL-1ra 进行实验室分析。在进行多变量分析之前，使用多重插补法推断低于检测限的数据。
美国和肯尼亚母亲在所有四个乳汁生物标志物上均存在显著差异，肯尼亚母亲的 sTNF-αRI 和 sTNF-αRII 显著高于美国母亲，而 TGF-β2 和 IL-1ra 显著低于美国母亲。乳汁 TGF-β2 和 IL-1ra 较高的美国母亲的婴儿在其年龄时显著更长和更重，而 sTNF-αRI 较高的肯尼亚母亲的婴儿在其年龄时显著更长和更重，而 TGF-β2 较高的婴儿则略有更长。
美国和肯尼亚母亲的乳汁免疫存在显著差异。这些差异可能在其婴儿的生长中起作用。乳汁免疫的进一步研究应考虑到母婴共享生活史的可能性。
