Triacylglycerols (TG) in milk derive from different sources, and their composition may be influenced by both maternal diet and obesity. We used two rat models to ascertain potential changes in TG composition in milk associated to maternal intake of an obesogenic diet during lactation and to distinguish them from the effects attributable to maternal adiposity. Milk samples were obtained from dams fed a cafeteria diet during lactation (CAF) and from dams made obese by cafeteria diet feeding, with dietary normalization before gestation (PCaf). Levels of specific TG species in milk collected at different time points of lactation were determined by shotgun lipidomics. CAF and PCaf dams presented a greater adiposity than their respective controls. The principal component analysis of TG peaks showed a clear separation between milk from CAF dams and milk from control and Pcaf dams, already evident at 5 days of lactation. Milk from CAF dams was enriched with TG species with greater number of carbons and double bonds and reduced in TG with lower number of carbons. TG composition of milk from Pcaf dams was similar to controls, although specific differences were observed at day 5 of lactation. Thus, the intake of a cafeteria diet during lactation, rather than maternal adiposity, alters milk composition. This effect is avoided with dietary normalization before gestation, although the remaining fat reserves may also influence TG composition at initial stages of lactation. Therefore, normalization of maternal diet prior to pregnancy should be considered as a strategy for achieving optimal milk composition.

中文翻译：

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母体饮食而不是肥胖本身对饮食性肥胖大鼠的牛奶三酰甘油谱具有主要影响。

牛奶中的三酰甘油（TG）来自不同的来源，其成分可能会受到孕产妇饮食和肥胖的影响。我们使用了两种大鼠模型来确定与母乳喂养期间母体摄入致肥胖饮食相关的牛奶中TG含量的潜在变化，并将它们与母体肥胖引起的影响区分开来。牛奶样品是从哺乳期以食堂饮食喂养的大坝（CAF）和通过食堂饮食喂养而肥胖并经妊娠前饮食恢复正常的大坝（PCaf）获得的。通过散弹枪脂质组学确定在哺乳的不同时间点收集的牛奶中特定TG物质的水平。CAF和PCaf大坝的肥胖大于它们各自的对照。TG峰的主成分分析显示，在哺乳期5天时，来自CAF大坝的牛奶与来自对照和Pcaf大坝的牛奶之间存在明显的分离。来自CAF大坝的牛奶富含碳和双键数量较多的TG种类，碳含量较低的TG含量较低。尽管在哺乳第5天观察到了特异性差异，但来自Pcaf水坝的牛奶的TG组成与对照相似。因此，在哺乳期间摄入食堂饮食而不是母体肥胖会改变牛奶成分。妊娠前饮食正常化可以避免这种影响，尽管剩余的脂肪储备也可能在泌乳初期影响TG的组成。所以，