Nestle Nutrition Institute workshop series最新文献

Establishing dietary recommendations for micronutrients in young children is difficult. Techniques used to evaluate nutrient intake and bioavailability are hard to apply in this age group. Additionally, large variations in growth rates, dietary patterns, and nutrient losses in early childhood make determinations of dietary requirements difficult. Most recent studies have utilized stable isotopes to determine mineral absorption for iron, zinc, calcium, and magnesium. Vitamin D requirements have been established based on the dietary intake required to maintain a presumed adequate serum 25-hydroxyvitamin D concentration. Comparisons of nutrient requirements established using factorial methods involving absorption determinations and usual population intake are important to identify nutrients of concern related to deficient or excess intakes. Generally, in the USA, the intakes of calcium and magnesium are adequate to meet requirements in most toddler diets which include a milk source or a mineral-fortified milk alternative. Zinc and iron intakes can be below requirements in a substantial proportion of toddlers throughout the world, especially those with minimal meat consumption. Dietary vitamin D is generally below dietary recommendations, but clearly deficient serum 25-hydroxyvitamin D concentrations are less common, and the global role for routine vitamin D supplementation or fortification of the diet remains uncertain.

The link between poor maternal nutrition and suboptimal outcomes in offspring is well established, but underlying mechanisms are not well understood. Modifications to the offspring epigenome are a plausible mechanism for the transmission of intergenerational signals that could extend to effects of paternal nutrition mediated by epigenetic modifications in sperm. The epigenome is extensively remodeled in the early embryo. Attention has therefore focused on the periconceptional period as a time when differences in parental nutrition might influence the establishment of epigenetic marks in offspring. So-called "natural experiments" in The Gambia and elsewhere have highlighted loci that may be especially sensitive to periconceptional nutrition, and some are associated with health-related outcomes in later life. There is speculation that some epigenetic signals could be transmitted across multiple generations, although this would require epigenetic marks to evade epigenetic reprogramming events at conception and in primordial germ cells, and evidence for this is lacking in humans. Effects on child development spanning one or more generations could impose an intergenerational "brake" on a child's growth potential, limiting, for example, the rate at which populations can escape from stunting.

Contrary to common belief, the human neonate is often born with a nonsterile gastrointestinal tract, suggesting fetal colonization. This has been substantiated by numerous studies showing microbes in meconium. Shortly after birth, the infant is further colonized by microbes that reflect the diet, which in the newborn consists of milk. When fed milk from the mother's breast, the infant derives a set of live microbes that have the capability of colonizing the gastrointestinal tract. This milk also provides a source of enzymes, such as lipase and alkaline phosphatase. Milk also provides a multitude of proteins, microRNAs, and other components that putatively interact with the host intestinal innate mucosal immune system to control infection, modulate intestinal inflammation, and provide signaling to distal sites for the development of adaptive immunity as well as growth and communication with the central nervous system. Colostrum differs from transitional and mature milk by being particularly rich in immunoglobulins as well as leukocytes. Live microbes found in fresh mother's milk may be personalized for her infant and thus provide an impetus for either ensuring delivery of this personalized milk to the infant or, if that is not possible, to develop the means to personalize donor milk or formula.