LAY SUMMARY Adaptive immune proteins in mothers' milk are more variable than innate immune proteins across populations and subsistence strategies. These results suggest that the immune defenses in milk are shaped by a mother's environment throughout her life. BACKGROUND AND OBJECTIVES Mother's milk contains immune proteins that play critical roles in protecting the infant from infection and priming the infant's developing immune system during early life. The composition of these molecules in milk, particularly the acquired immune proteins, is thought to reflect a mother's immunological exposures throughout her life. In this study, we examine the composition of innate and acquired immune proteins in milk across seven populations with diverse disease and cultural ecologies. METHODOLOGY Milk samples (n = 164) were collected in Argentina, Bolivia, Nepal, Namibia, Philippines, Poland and the USA. Populations were classified as having one of four subsistence patterns: urban-industrialism, rural-shop, horticulturalist-forager or agro-pastoralism. Milk innate (lactalbumin, lactoferrin and lysozyme) and acquired (Secretory IgA, IgG and IgM) protein concentrations were determined using triple-quadrupole mass spectrometry. RESULTS Both innate and acquired immune protein composition in milk varied among populations, though the acquired immune protein composition of milk differed more among populations. Populations living in closer geographic proximity or having similar subsistence strategies (e.g. agro-pastoralists from Nepal and Namibia) had more similar milk immune protein compositions. Agro-pastoralists had different milk innate immune protein composition from horticulturalist-foragers and urban-industrialists. Acquired immune protein composition differed among all subsistence strategies except horticulturist-foragers and rural-shop. CONCLUSIONS AND IMPLICATIONS Our results reveal fundamental variation in milk composition that has not been previously explored in human milk research. Further study is needed to understand what specific aspects of the local environment influence milk composition and the effects this variation may have on infant health outcomes.

中文翻译：

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不同人群母乳中免疫蛋白组成的差异反映了生存模式。


总结 母乳中的适应性免疫蛋白在不同人群和生存策略中比先天免疫蛋白变化更大。这些结果表明，牛奶中的免疫防御是由母亲一生的环境决定的。背景和目标 母乳中含有免疫蛋白，在保护婴儿免受感染和促进婴儿生命早期免疫系统的发育方面发挥着关键作用。牛奶中这些分子的组成，特别是获得性免疫蛋白，被认为反映了母亲一生中的免疫暴露。在这项研究中，我们研究了七个患有不同疾病和文化生态的人群的牛奶中先天性和后天性免疫蛋白的组成。方法学 牛奶样品 (n = 164) 采集于阿根廷、玻利维亚、尼泊尔、纳米比亚、菲律宾、波兰和美国。人口被分为四种生存模式之一：城市工业主义、农村商店、园艺采集者或农牧业。使用三重四极杆质谱法测定牛奶固有（乳清蛋白、乳铁蛋白和溶菌酶）和获得性（分泌性 IgA、IgG 和 IgM）蛋白质浓度。结果 牛奶中的先天性和获得性免疫蛋白组成在人群中存在差异，但牛奶中的获得性免疫蛋白组成在人群中差异较大。居住在地理位置较近或具有相似生存策略的人群（例如来自尼泊尔和纳米比亚的农牧民）具有更相似的乳汁免疫蛋白成分。农牧民的乳汁先天免疫蛋白组成与园艺采集者和城市工业家不同。 除园艺采集者和农村商店外，所有生存策略的获得性免疫蛋白组成均不同。结论和意义 我们的结果揭示了母乳研究中尚未探索过的乳成分的根本变化。需要进一步研究以了解当地环境的哪些具体方面会影响牛奶成分以及这种变化可能对婴儿健康结果产生的影响。