Implications of the weaning pattern on macronutrient intake, food volume and energy density in non-breastfed infants during the first year of life

Association of Nutrition in Early Childhood with Body Composition and Leptin in Later Childhood and Early Adulthood

OBJECTIVES

Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), this study aimed to replicate the finding of the Etude Longitudinale Alimentation Nutrition Croissance des Enfants (ELANCE) that low fat intake in early childhood was associated with increased adiposity in adulthood.

METHODS

Diet was assessed at 8 and 18 months using 3-day food records. Body composition variables were measured at 9 and 17 years, and serum leptin at 9 years. Associations were modelled using adjusted linear regression.

RESULTS

In replication analyses, in contrast to ELANCE, there was a positive association between fat intake (% energy) at 18 months and fat mass (FM) at 9 years (B coefficient 0.10 (95% CI 0.03, 0.20) kg, p = 0.005). There was no association with serum leptin. In extended analyses fat intake at 18 months was positively associated with FM in boys (0.2 (0.00, 0.30), p = 0.008) at 9 years but not in girls. Fat intake was positively associated with serum leptin concentration in boys (0.2 (0.1, 0.4) ng/mL, p = 0.011) but not in girls.

CONCLUSIONS

Our results did not corroborate the findings from the ELANCE study. A high fat diet in early life may have implications for later childhood and adolescent obesity.

Metabolic adaptation in the human gut microbiota during pregnancy and the first year of life

Background

The relationship between the gut microbiome and the human host is dynamic and we may expect adjustments in microbiome function if host physiology changes. Metatranscriptomic approaches should be key in unraveling how such adjustments occur.

Methods

We employ metatranscriptomic sequencing analyses to study gene expression in the gut microbiota of infants through their first year of life, and of their mothers days before delivery and one year afterwards.

Findings

In infants, hallmarks of aerobic metabolism disappear from the microbial metatranscriptome as development proceeds, while the expression of functions related to carbohydrate transport and metabolism increases and diversifies, approaching that observed in non-pregnant women. Butyrate synthesis enzymes are overexpressed at three months of age, even though most butyrate-producing organisms are still rare. In late pregnancy, the microbiota readjusts the expression of carbohydrate-related functions in a manner consistent with a high availability of glucose.

Interpretation

Our findings suggest that butyrate production may be ensured in the gut of young infants before the typical butyrate synthesizers of the adult gut become abundant. The late pregnancy gut microbiota may be able to access the high levels of blood glucose characteristic of this period. Moreover, late pregnancy gut bacteria may reach stationary phase, which may affect their likelihood of translocating across the intestinal epithelium.

Funds

This work was supported by grants CSD2009-00006 (CONSOLIDER Program) and SAF2009-13032-C02-02 from MICINN (Ministry of Science and Innovation, Spain), and by grant SAF2012-31187 from MINECO (Ministry of Economics and Competitiveness, Spain).

Microbial succession in the gut: directional trends of taxonomic and functional change in a birth cohort of Spanish infants

In spite of its major impact on life-long health, the process of microbial succession in the gut of infants remains poorly understood. Here, we analyze the patterns of taxonomic and functional change in the gut microbiota during the first year of life for a birth cohort of 13 infants. We detect that individual instances of gut colonization vary in the temporal dynamics of microbiota richness, diversity, and composition at both functional and taxonomic levels. Nevertheless, trends discernible in a majority of infants indicate that gut colonization occurs in two distinct phases of succession, separated by the introduction of solid foods to the diet. This change in resource availability causes a sharp decrease in the taxonomic richness of the microbiota due to the loss of rare taxa (p = 2.06e-9), although the number of core genera shared by all infants increases substantially. Moreover, although the gut microbial succession is not strictly deterministic, we detect an overarching directionality of change through time towards the taxonomic and functional composition of the maternal microbiota. Succession is however not complete by the one year mark, as significant differences remain between one-year-olds and their mothers in terms of taxonomic (p = 0.009) and functional (p = 0.004) microbiota composition, and in taxonomic richness (p = 2.76e-37) and diversity (p = 0.016). Our results also indicate that the taxonomic composition of the microbiota shapes its functional capacities. Therefore, the observed inter-individual variability in taxonomic composition during succession is not fully compensated by functional equivalence among bacterial genera and may have important physiological consequences. Finally, network analyses suggest that positive interactions among core genera during community assembly contribute to ensure their permanence within the gut, and highlight an expansion of complexity in the interactions network as the core of taxa shared by all infants grows following the introduction of solid foods.

Although knowledge of the complex community of microbes that inhabits the human gut is constantly increasing, the successional process through which it develops during infancy remains poorly understood. Particularly, although gut microbiota composition is known to vary through time among infants, the effect of this variability on the functional capacities of the community has not been previously explored. We simultaneously analyze the taxonomic and functional development of the gut microbiota in a birth cohort of healthy infants during the first year of life, showing that individual instances of gut colonization vary in their temporal dynamics and that clear parallelisms exist between functional and taxonomic change. Therefore, taxonomic composition shapes the functional capacities of the microbiota, and, consequently, successional variability may affect host physiology, metabolism and immunity. Nevertheless, we detect some overarching trends in microbiota development, such as the existence of two distinct phases of succession, separated by the introduction of solid foods, and a strong directionality of change towards the taxonomic and functional composition of the maternal microbiota. Understanding the commonalities and differences among individual patterns of gut colonization in healthy infants will enable a better definition of the deviations in this process that result in microbiota imbalances and disease.

The fat:carbohydrate energy ratio of the weaning diet programs later susceptibility to obesity in male sprague dawley rats

Dietary fat intake, which is high during suckling, is markedly reduced when food and drinks are introduced into the diet. We investigated whether alterations in the fat:carbohydrate (CHO) content of the weaning diet influenced the later development of adiposity and insulin sensitivity. Three groups of male rats (24/group) were fed from age 16-37 d (phase I) with weaning diets varying in their fat:CHO energy (E) ratios, 10:70 low-fat, high-CHO (LFHC); 30:50 medium-fat, medium-CHO (MFMC), and 60:30 high-fat, high-CHO (HFLC), on an isocaloric basis. Then, all groups consumed ad libitum first a low-fat diet (13% fat E) for 30 wk (phase II) and subsequently a high-fat diet (45% fat E) for another 18 wk (phase III). At the end of phase I, the group fed the HFLC diet demonstrated higher plasma glucose and insulin responses to an oral glucose tolerance test (P < 0.05), but this effect was transient and did not persist into adulthood (phases II and III). By contrast, when challenged with a high-fat diet later in life (age 35.3-53.3 wk), the LFHC group had greater gains in weight (as percent initial weight) and body fat (as absolute and percent body weight) than the other 2 groups that had been weaned with diets higher in fat (P < 0.04 for all). These results provide evidence that metabolic programming by altering the dietary fat:CHO ratio can occur during the weaning period and emphasizes the importance of the fat:CHO ratio of the complementary diet and its relation to the susceptibility to develop adiposity later in life.

Little evidence for early programming of weight and insulin resistance for contemporary children: EarlyBird Diabetes Study report 19

OBJECTIVE

The aim of this study was to evaluate whether adaptive responses made to the uterine or very early infant environment are affecting the current metabolic health of young children in the United Kingdom.

METHODS

Participants were 300 healthy children and their parents from the EarlyBird Diabetes Study cohort. Children were recruited from randomly selected schools at 5 years of age. Retrospective measures were maternal prepregnancy weight (n = 230), maternal fasting glucose levels at 28 weeks of pregnancy (n = 27), birth weight, and infant weight at ages 3 and 6 weeks. Prospective measures were insulin resistance, height, weight, and percentage of body fat (sum of 5 skinfold measurements) at ages 5, 6, 7, and 8 years.

RESULTS

Maternal third-trimester fasting glucose levels were associated positively with birth weight but were not associated with either weight or insulin resistance for the same children at 8 years. Birth weight was unrelated to insulin resistance at 8 years. There were no relationships between weight change in the first weeks of life and weight, percentage of fat, or insulin resistance at 8 years. Longer breastfeeding correlated inversely, although weakly, with percentage of body fat for boys only. Current weight was correlated with insulin resistance at 8 years.

CONCLUSIONS

For these contemporary children, neither the gestational environment nor early postnatal growth predicted insulin resistance, which was best predicted by current weight. There was no evidence that predictive adaptive responses made by the fetus or infant affected the child's weight or insulin resistance later in childhood.

Determination of macronutrients, by chemical analysis, of home-prepared milk feeding bottles and their contribution to the energy and protein requirements of infants from high and low socioeconomic classes

OBJECTIVES

To determine the macronutrients composition of home-prepared milk feeding bottles, by chemical analysis, and assess their contribution to the energy and protein requirements of children under two years of age from high (HSE) and low (LSE) socioeconomic classes.

METHODS

72 samples were analyzed for energy density and protein, fat and carbohydrate content: 41 from the LSE group and 31 from the HSE group. The assessment of the percentages of the energy and protein requirements met by the consumption of the milk bottles was calculated as follows: the energy and protein per 100 mL obtained through chemical analysis were multiplied by the volume consumed at each feeding, then by the number of feedings per day, the results divided by the energy and protein requirements and multiplied by 100. Energy and protein requirements were those recommended by the FAO/WHO/UNU Committee and the Food and Nutrition Board. The children's weight-for-age index was assessed.

RESULTS

Unmodified cow's milk was largely consumed by both groups. The addition of sugar and other ingredients to the milk was significantly higher in the LSE group. Moisture, protein and fat content were lower in the LSE group, whereas carbohydrate and energy content were higher. The percentages of energy and protein requirements provided by feeding bottles were higher in the LSE group. Children in the LSE group had lower z-scores for weight-for-age.

CONCLUSIONS

Differences in the preparation practices led to differences in the chemical results. The feeding bottles in the LSE group were high in energy, due to the addition of sugar and cereals to the milk in the bottle. The milk feeding bottles were an important weaning food providing more than 50% and 100% of the children's energy and protein requirements, respectively. The children's weight-for-age index was within the normal limits.

Dietary energy density and weight regulation

Dietary energy density (ED) has been suggested as an important determinant of energy intake and, therefore, energy regulation. This review summarizes published studies on the effects of dietary ED on hunger, satiety, energy intake, and body weight in healthy individuals, and compares the relative effects of ED manipulated by dietary fat only, fat and fiber, water, and type of sweetener. In short-term studies, consumption of low-ED foods promotes satiety, reduces hunger, and decreases energy intake with no marked differences between different dietary manipulations used to change ED. In addition, low-ED diets promote moderate weight loss in long-term studies. In studies lasting longer than 6 months, weight loss was more than three times as great in individuals consuming diets both low in fat and high in fiber compared with diets only low in fat (-3.4 kg versus -1.0 kg). Combined, these studies suggest that diets low in fat and high in fiber may be the most effective low-ED diets for promoting weight loss. Further research is needed on the effects of dietary ED by changing water or sweetener content.