The validation of biomarkers of metabolic efficacy in infant nutrition

母乳喂养是婴儿生命最好的开端。世界卫生组织（WHO）建议，所有女性都应该纯母乳喂养婴儿直到6个月大。然而，并非所有妇女都有机会纯母乳喂养婴儿。据报道，在英国，81%的母亲从母乳喂养开始，只有17%的婴儿在3个月前完全母乳喂养，1%的婴儿在6个月前完全母乳喂养。这并不一定是母亲的选择，已经有13%的母乳喂养的母亲在第一个星期得到建议，为婴儿提供额外的喂养。因此，有必要设计出尽可能接近母乳营养质量的母乳替代品。最近的证据表明，非母乳喂养的婴儿在以后的生活中肥胖和患高血压的风险增加。目前尚不清楚为什么婴儿喂养方式对以后生活的健康结果有如此大的影响。然而，婴儿对母乳喂养的代谢方式似乎与配方奶不同；我们的研究表明，与奶瓶喂养的婴儿相比，母乳喂养的婴儿的血脂（脂肪）特征明显不同。该项目的目的是开发新的方法来帮助我们了解奶瓶喂养的婴儿和母乳喂养的婴儿代谢差异的机制。我们想要确定特定的脂质，可以作为反映母乳喂养益处的标记物。我们将通过探索英国婴儿在他们生命的第一年的脂质谱变化来做到这一点。通过将血液标记物与婴儿生长模式进行比较，我们将能够确定可用于评估母乳替代品代谢反应的标记物。我们还将包括来自撒哈拉以南非洲农村和城市的母亲和婴儿，以探索喂养方式、血脂水平和婴儿健康结果之间的人口差异。喂养方式影响婴儿新陈代谢的一种可能方式是通过肠道中的细菌（肠道微生物群）。据信，食物中的化合物会影响肠道中的细菌，肠道中细菌的不同组合会产生不同的代谢产物，这些代谢产物将被吸收到血液中。我们不知道肠道微生物组的这些差异是否也会影响血液中的脂质。为了探索这种潜在的联系，我们还将研究婴儿肠道微生物组对他们新陈代谢的影响。最近，我们开发了一种方法，使用高分辨率质谱法来确定详细的脂质谱，覆盖100多个脂质，来自一个干燥的血点。这是一份从脚后跟刺破处采集的血液样本只需要在纸上滴上一滴血。这是研究婴儿新陈代谢最合适的方法。我们将采用这种基于干血点的方法来捕获依赖于肠道微生物组的脂质和代谢物。确定的标记物以及测量这些标记物的方法将供科学家和产业界使用，以研究新的配方奶粉或新的喂养方法对没有机会接受纯母乳喂养的婴儿的影响，并为这些婴儿提供最好的生命开端。

Breastfeeding is the best start for a baby's life. The World Health Organisation (WHO) recommends that all women should exclusively breastfeed their babies until six months of age. However not all women have the opportunity to exclusively breastfeed their babies. In the UK it is reported that whilst 81% of mothers start with breast feeding only 17% of infants are exclusively breast-fed until 3 months, and 1% until 6 months of age. This does not have to be the mother's choice, already in the first weeks 13% of the breast feeding mothers get advice to provide the baby with extra feeding. Thus there is a need to design breast-milk alternatives that mimic the nutritional quality of breast milk as closely as possible.Recent evidence suggests that non breast-fed infants have an increased risk of becoming obese and an increased risk of high blood pressure in later life. It is currently unclear why infant feeding practices have such a big impact on health outcomes later in life. However, breastfeeding seems to be metabolised differently by infants than formula milk; our research showed that babies that are breast fed have a significantly different blood lipid (fat) profile compared to bottle fed babies.The aim of this project is to develop novel methods to help us understand the mechanism(s) of the differences in the metabolism of bottle fed babies and breast fed babies. We want to identify specific lipids that can be used as markers that reflect the benefits of breastfeeding. We will do this by exploring changes in the lipid profiles of babies in the UK during their first year of life. By comparing blood markers with patterns of infant growth we will be able to identify markers that can be used to assess the metabolic response to breast-milk alternatives. We will also include mothers and infants from rural and urban sub-Saharan Africa to explore between population differences in the association between mode of feeding, blood lipid levels, and infant health outcomes'. One possible way in which mode of feeding may impact on the baby's metabolism is via bacteria in the gut (the gut microbiome). It is believed that, compounds in food, affect which bacteria live in the gut and that the different combinations of bacteria in the gut leads to different metabolic products that will be taken up into the blood stream. We do not know if these differences in the gut microbiome also affect the lipids in the blood. To explore this potential link, we will also study what the effect is of the gut microbiome of the babies on their metabolism. Recently we developed a method using high resolution mass spectrometry to determine a detailed lipid profile covering over a 100 lipids from one dried blood spot. This is a blood sample obtained from a heel prick and only requires a drop of blood spotted on paper. This is the most suitable method to study the metabolism of babies. We will adapt this dried blood spot based method to captures both lipids and metabolites dependent on gut microbiome. The identified markers, and the methods to measure these, will then be available for use by scientist and industry to study the effect of new formula or new feeding methods for infants who do not have the chance to be exclusively breast fed and give these babies the best possible start in life.