NNIW97 - Intersections of Nutrition: Retracing Yesterday, Redefining Tomorrow

Studies have shown a dramatic increase in the incidence and the prevalence of chronic diseases such as type 2 diabetes mellitus and cardiovascular disorders over the last several decades. Environmental triggers and nutrition are considered major contributors to this increase. The first 1,000 days of life, which is the period between conception and the first 2 years of age, is considered the time for environmental factors, such as nutrition, to exert their positive and most crucial effects on a child’s health. Nutrigenomics, the study of how genes and food components interact, looks into diet-altering disease development by modulating processes involved with the onset, progression, and severity of disease. These factors affecting the development of these chronic diseases are thought to be mediated by epigenetic mechanisms, which are heritable and reversible, and carry genetic information without changing the nucleotide sequence of the genome and are also mediated by maternal and postnatal nutrition.

The development of the microbiome within the human digestive tract starts at birth and continues up to approximately 3 years of age when the microbial ecosystem resembles a more adulthood-like state. The pace of colonization and diversification of the gut microbiota in the early stages of life has been linked to short- and long-term health outcomes. Characterizing optimal maturation of the ecosystem may help identifying adverse events that impair the process and also factors that support and guide it, such as diet. To date, researchers have looked at the evolution over time of gut microbiota parameters such as diversity, taxa abundance, or specific functions. A more global approach has used “microbiota age” to capture maturation trajectory through machine learning models. In this review, the use and limitations of the latest methods to capture and understand microbiota maturation will be discussed. Then the role of nutrition in directing gut microbiota maturation in early life will be described together with the challenges that limit our comprehension of the effects of diet on the gut microbiota.

Human milk is the best source of infant nutrition and is recognized as a biological fluid vital for optimal growth and development. It has established short- and long-term benefits to infants and mothers. Sapiens’ milk has coevolved with mammalian species for millennia which has resulted in this remarkable secretory product of nutrient-rich milk. The nutritional composition and non nutritive bioactive factors in human milk are uniquely appropriate for the infant, which provides survival and healthy development. Research over the past 2–3 decades focused on increasing the understanding about the composition of human milk and different factors that influence the composition such as stage of lactation, impact of maternal diet, geographical location, gestational age at infant birth, and circadian rhythm. Presently, collaborative efforts are ongoing in communicating the clinical advantages of human milk composition in relation to public health. Different groups are also working on the establishment of reference in the form of databases using reference and growth standard methodology. Toward the future, with computational and modeling methods, the next stage is to understand human milk as a biological system. Cellular agriculture is also the next exciting field of human milk research.

Human milk contains all nutritive and bioactive compounds to give infants the best possible start in life. Human milk bioactives cover a broad range of components, including immune cells, antimicrobial proteins, microbes, and human milk oligosaccharides (HMOs). Over the last decade, HMOs have gained special attention as their industrial production has allowed the study of their structure-function relation in reductionist experimental setups. This has shed light on how HMOs steer microbiome and immune system development in early life but also how HMOs affect infant health (e.g., antibiotic use, respiratory tract infections). We are on the verge of a new era where we can examine human milk as a complex biological system. This allows not only study of the mode of action and causality of individual human milk components but also investigation of synergistic effects that might exist between different bioactives. This new wave in human milk research is largely fueled by significant advances in analytical tools in the field of systems biology and network analysis. It will be exciting to explore how human milk composition is affected by different factors, how different human milk compounds work together, and how this influences healthy infant development.

Overnutrition, expressed as overweight and obesity, sometimes combined with inadequate micronutrient intake, coexists together with undernutrition as the major threats of malnutrition in children. Appropriate growth and metabolism of children have been extensively studied as to their association with future metabolic diseases. It is appreciated that early growth is controlled via the biochemical pathways that support organ and tissue growth and development, energy release from dietary intake, and production and release of hormones and growth factors regulating the biochemical processes. Anthropometric measurements, body composition, and their trajectories have been the metrics to evaluate both age-appropriate growth and link to future metabolic disease risk. As factors associated with risk of metabolic disease like childhood obesity are fairly well known, a strategic framework that includes appropriate nutrition and healthy dietary habits, adoption of the right behavior, and healthy food choices from early infancy to childhood is necessary to decrease this risk. The role of industry in this is to provide foods rich in nutrients developmentally appropriate and to promote responsible consumption and age-adapted portion sizes.

The term “triple burden of malnutrition” refers to the coexistence of undernutrition (stunting and wasting), micronutrient deficiencies (often termed hidden hunger), and overnutrition (overweight and obesity). The three elements of the triple burden of malnutrition can be found simultaneously within many low-income populations and even within single families. There are common underlying causes to each element of the triple burden of malnutrition. In broad terms, these are as follows: poverty – a lack of access to the most nourishing foods; poor dietary choices – a lack of knowledge about what constitutes the most nourishing foods and a healthy diet; and food supply chain – production and marketing of cheap, low quality foods. It can be argued that the underlying influence of these distal factors is channeled through a single proximal cause – namely a low nutrient density of foods.

The early development of taste and food pleasure plays an important role in children and has long-lasting influences on subsequent food preferences and choices. Infants are born with a surprisingly sensitive sense of taste – they have more widely distributed taste buds (about 10,000) than adults. Thus, preferences for a variety of food flavors and textures develop early, through milk-related flavor exposure, or even during pregnancy, allowing for an easier acceptance to healthy foods. Breastfeeding favors the acquisition of a taste for a variety of foods. This process can continue throughout weaning and into childhood if infants are repeatedly exposed to a variety of healthful foods, even if they initially dislike them. Factors favoring the development of food acceptance at the beginning of complementary feeding include, in particular, the role of early variety, repeated exposure, timing of introducing the foods, and the sensory properties (texture, taste, and flavors). These early-life sensory experiences establish food preferences and dietary patterns that set the stage for lifelong dietary habits. This review provides the foundation for evidence-based recommendations to help parents promote healthy eating habits to their children.

Dietary patterns (DPs) have shifted the focus in nutrition epidemiology away from being nutrient centered. Foods are consumed not as single nutrients but as a combination of dietary components interacting with each other. DPs are indicators of diet quality. Two approaches are used to derive them: the index-based and data-driven approaches, each with its own advantages and disadvantages. Studies on diet–disease relationships are now concentrated on DPs. Most available studies are in adults, which emphasize the role of DPs as contributors to certain chronic diseases like cardiovascular diseases, diabetes, and certain cancers. Only few studies were conducted among children, mostly using a data-driven approach and population specific. The available studies identify associations with some diseases like obesity, neurobehavioral disorders, asthma, and cardiometabolic markers. Tracking of DP consumption from early childhood to later life stages including adulthood has been shown from longitudinal studies to predict certain cardiometabolic risk factors and adiposity that may predispose to certain diseases later in life. The influences of sociodemographic factors, most especially maternal education, have predictive effects on adherence to certain DPs, whether the “healthy” or “unhealthy” type. More studies are needed to strongly elucidate this DP–disease outcome relationship in children.