Nestle Nutrition Institute workshop series最新文献

Secretory immunoglobulin A (SIgA) is intimately involved in the transfer of maternal immunity to the newborn breastfed infant. Recent research demonstrates the significance of SIgA in the initial development of the newborn's microbiota and in the establishment of a tolerogenic immunologic disposition towards nonpathogenic organisms and environmental antigens. SIgA has long been known to prevent pathogen binding to the host epithelium through immune exclusion involving numerous mechanisms. This process primarily involves T-cell-dependent, somatically hypermutated monoclonal antibodies with high specificity towards pathogen surface antigens, and the success of the immune response is dependent upon the specific antigen recognition. Whereas this role is important, there is an alternate, dual role for SIgA in the health of the host - protection and promotion of commensal colonization and maintenance of homeostatic immunity. This latter role is primarily dependent upon N- and O-glycan moieties lining the secretory component and heavy chain of the SIgA dimer, with interactions independent of immunoglobulin specificity. These SIgA molecules are nonspecific polyclonal antibodies generated from plasma cells activated by dendritic cell sampling of luminal contents in the absence of inflammation. Breast milk is the primary supply of such polyclonal polyreactive SIgA in the initial stages of neonatal colonization, and it provides vital pathogen resistance while promoting colonization of commensal microbiota.

Breastfeeding confers the infant short- and long-term health benefits and significantly modulates the developing infant gut microbiome. A specific human milk microbiome has relatively recently been discovered, but its origin remains poorly understood. Data from experimental and clinical studies suggest that the bacteria in milk may originate in the maternal gut and be transported via a specific enteromammary pathway, the details of which have not been elucidated yet. The milk microbiome is affected by the maternal metabolic state, antibiotic use, as well as the mode of delivery. We are only in the initial stages of understanding the biological function of the milk microbiome and its potential contribution to infant gut colonization. Several clinical studies indicate, however, that despite considerable differences in the overall composition of the milk and infant gut microbiomes, specific bacteria are detectable both in human milk and infant feces, and that the bacteria in milk are a source of microbes colonizing the neonatal gut. If the microbes in human milk are discovered to contribute to the beneficial effects of breastfeeding, modulating or mimicking the milk microbiome may provide a novel means of improving child health.

Cow's milk and dairy products intake increase linear growth in children and result in increased adult stature. This is supported by observational and intervention studies mainly from low- and middle-income countries. However, recent reviews primarily based on studies from well-nourished populations question the relation. The probable effects seem to be mediated by insulin-like growth factor-1 and insulin and to be more pronounced during periods of high growth velocity. Several components of cow's milk are suggested to stimulate growth: a high protein quality, bioavailable minerals that are important for growth, and perhaps lactose. Higher adult stature is associated with both positive and negative health effects. Growth stimulation is important in populations with undernutrition, but in well-nourished populations, it might not be important. A high intake of cow's milk and thereby a high protein intake early in life can increase the risk of later overweight and obesity, while a high protein intake later in childhood seems to be associated with a lower BMI later in childhood. A high dairy intake can limit the diversity of the diet and result in iron deficiency. Therefore, milk intake should not exceed 500 mL/day in young children. Most products for the treatment of undernutrition include dairy protein because of the well-documented effects on growth and recovery. However, as dairy is an expensive ingredient, the amount needed and the effects of alternative plant-based protein sources are considered.

Malnutrition during the first years of life has immediate adverse health consequences, including increased mortality risk, and impaired long-term health and capacities. Undernutrition is an important contributor to poor linear growth, stunting, which affects over 149 million children <5 years of age worldwide, one-third of whom live in India. Over 49 million children are wasted; yet globally, there are also 40 million overweight children. Up-to-date data on the magnitude and distribution of micronutrient malnutrition globally and in many countries are lacking. Anemia has been used as a proxy for micronutrient malnutrition; yet anemia, like stunting, has a complex etiology and numerous nonnutritional as well as nutritional causes. Undernutrition, specifically stunting, wasting, and micronutrient deficiency increasingly coexist with overweight, but accurate data to assess the extent to which these co-exist in countries, households, and individuals and the factors that predict it are scarce. Recent analyses in several countries suggest that there is substantial variability within and among regions in the prevalence and determinants of malnutrition. More and better data that can be used to tailor policies and programs to local contexts are urgently needed if we are to accelerate progress toward addressing malnutrition in all its forms.

The prevalence of restrictive diets, mainly vegetarian and vegan, is markedly on the increase in Europe and other Western countries. In young children and adolescents, not only weight and height but also neurocognitive and psychomotor development are all strongly influenced by the source, quantity, and quality of their nutrition. In studies done mainly in adult populations, a plant-based diet showed benefits in the reduced risk of chronic diseases such as obesity, type 2 diabetes, cardiovascular diseases, and some types of cancer. However, there is no clear evidence that a vegan diet started in early childhood confers a lasting health benefit. On the other hand, a vegan diet can be potentially critical for young children with risks of inadequate supply in terms of protein quality and energy as well as long-chain fatty acids, iron, zinc, vitamin D, iodine, calcium, and particularly vitamin B12. Deficiencies in these nutrients can lead to severe and sometimes irreversible developmental disorders. If such a diet is chosen for ethical, ecological, or health reasons, a well-planned, diversified diet with additional supplementation of vitamin B12, vitamin D, iodine, and potentially other micronutrients is crucial to ensure a healthy and nutritious intake during childhood.

Aggregated analyses of child growth in low- and middle-income countries (LMICs) reveal a remarkably consistent picture of serious growth failure compared to the WHO reference growth curves. Impoverished diets with low dietary diversity are a key driver of poor growth, but there are important additional environmental factors that limit the uptake and utilization of nutrients. This paper considers such factors. A large proportion of the rapid growth deterioration in later infancy can be ascribed to infections and to wider nonspecific effects of living in an unhygienic environment, including the ingestion of toxins such as aflatoxin. Despite never revealing themselves as clinical syndromes, the great majority of children in rural low-income settings of Africa and Asia are antibody positive to numerous pathogens (CMV, EB, HepB, Helicobacter pylori, and many more) by 24 m; these infections must take their toll. Additionally, there is a syndrome widely termed environmental enteric disease that combines gut leakage with a chronic inflammation leading to nutrient losses and cytokine-mediated growth retardation. Systemic inflammation also inhibits nutrient uptake and utilization. Elimination of these environmental barriers will be key to achieving optimal child growth and development in LMICs.

Osteopontin (OPN) is an acidic phosphorylated glycoprotein involved in a wide range of biological activities, such as cell proliferation and differentiation, as well as immunomodulatory functions. OPN contains integrin and CD44 binding sites, and it exerts its multiple functions by binding to its receptors on the cell membrane to trigger various cellular signaling pathways. It is generated by a variety of cell types, including epithelial cells and immune cells. OPN appears in most body fluids, such as milk and blood, and is present at a high concentration in human milk but not in bovine milk. Milk OPN is relatively resistant to digestion, and orally ingested OPN can enter the circulatory system. Milk OPN may, therefore, play essential roles in the development in early life. The impact of milk OPN on development has been investigated using cell models, animal models, and randomized clinical trials. Recent OPN studies strongly suggest that milk OPN plays important roles in intestinal proliferation and maturation, brain myelination, and neurodevelopment, as well as immune development.

Children reportedly consume a variety of adequate vegetables during the introduction of complementary foods, and breastfeeding helps to facilitate child food acceptance. However, dietary intake of vegetables is reported to fall when children begin to eat foods of the family table. In laboratory settings, repeated exposure is effective in promoting children's acceptance and consumption of novel foods. We have recently explored mother and child early experiences (from infancy to toddlerhood) with offering hard-to-like foods. Our findings suggest a "sweet spot" for food introduction and acceptance during the early complementary feeding period (6-12 months) with increasing variability in acceptance and negative child behaviors occurring during toddlerhood. When queried, most mothers are familiar with repeated exposure concepts, but their persistence in continuing to offer disliked foods differs. Some report they will "never give up" - a stance linked to health beliefs and that children should "eat what we eat." Others seem more influenced by children's resistance and food dislikes, and the amounts their child eat. The majority believe that children's tastes change and that their child will accept rejected foods later. These mothers may reoffer a rejected food after "a break." Opportunities exist to translate repeated exposure paradigms to practical methods mothers can successfully adopt in the home.

Motor skills are important for development. Everything infants do involves motor skills - postural, locomotor, and manual actions; exploratory actions; social interactions; and actions with artifacts. Put another way, all behavior is motor behavior, and thus motor skill acquisition is synonymous with behavioral development. Age norms for basic motor skills provide useful diagnostics for "typical" development, but cultural differences in child-rearing practices influence skill onset ages. Whenever they emerge, motor skills lay the foundation for development by opening up new opportunities for learning. Postural control brings new parts of the environment into view and into reach; locomotion makes the larger world accessible; manual skills promote new forms of interactions with objects; and motor skills involving every part of the body enhance opportunities for social interaction. Thus, motor skills can instigate a cascade of developments in domains far afield from motor behavior - perception and cognition, language and communication, emotional expression and regulation, physical growth and health, and so on. Finally, motor skill acquisition makes behavior increasingly functional and flexible. Infants learn to tailor behavior to variations in their body and environment and to discover or construct new means to achieve their goals.