Impact of infant protein supply and other early life factors on plasma metabolome at 5.5 and 8 years of age: a randomized trial.

OBJECTIVES: A high dairy protein intake in infancy, maternal pre-pregnancy BMI, and delivery mode are documented early programming factors that modulate the later risk of obesity and other health outcomes, but the mechanisms of action are not understood. METHODS: The Childhood Obesity Project is a European multicenter, double-blind, randomized clinical trial that enrolled healthy infants. Participating infants were either breastfed (BF) or randomized to receive higher (HP) or lower protein (LP) content formula in the first year of life. At the ages 5.5 years (n = 276) and 8 years (n = 232), we determined plasma metabolites by liquid chromatography tandem-mass-spectrometry of which 226 and 185 passed quality control at 5.5 years and 8 years, respectively. We assessed the effects of infant feeding, maternal pre-pregnancy BMI, smoking in pregnancy, delivery mode, parity, birth weight and length, and weight gain (0-24 months) on the metabolome at 5.5 and 8 years. RESULTS: At 5.5 years, plasma alpha-ketoglutarate and the acylcarnitine/BCAA ratios tended to be higher in the HP than in the LP group, but no metabolite reached statistical significance (Pbonferroni>0.09). There were no group differences at 8 years. Quantification of the impact of early programming factors revealed that the intervention group explained 0.6% of metabolome variance at both time points. Except for country of residence that explained 16% and 12% at 5.5 years and 8 years, respectively, none of the other factors explained considerably more variance than expected by chance. CONCLUSIONS: Plasma metabolome was largely unaffected by feeding choice and other early programming factors and we could not prove the existence of a long term programming effect of the plasma metabolome.

Are All Breast-fed Infants Equal? Clustering Metabolomics Data to Identify Predictive Risk Clusters for Childhood Obesity.

OBJECTIVES: Fetal and early life represent a period of developmental plasticity during which metabolic pathways are modified by environmental and nutritional cues. Little is known on the pathways underlying this multifactorial complex. We explored whether 6 months old breast-fed infants could be clustered into metabolically similar groups and that those metabotypes could be used to predict later obesity risk. METHODS: Plasma samples were obtained from 183 breast-fed infants aged 6 months participating in the European multicenter Childhood Obesity Project study. We measured amino acids along with polar lipid concentrations (acylcarnitines, lysophosphatidylcholines, phosphatidylcholines, sphingomyelins). We determined the metabotypes using a Bayesian agglomerative clustering method and investigated the properties of these clusters with respect to clinical, programming, and metabolic factors up to 6 years of age. RESULTS: We identified 20 metabolite clusters comprising 1 to 39 children. Phosphatidylcholines predominantly influenced the clustering process. In the largest clusters (n ≥ 14), large differences existed for birth length (unadjusted P < 0.0001) and length and weight at 6 months (unadjusted P < 0.0001 and P = 0.012, respectively). Infants tended to cluster together by country (unadjusted P < 0.001). The body mass index (BMI) z score at 6 years of age tended to differ (unadjusted P = 0.07). CONCLUSIONS: Our exploratory study provided evidence that breast-fed infants are not metabolically homogeneous and that variation in metabolic profiles among infants may provide insight into later development and health. This work highlights the potential of metabotypes for identifying inter-individual differences that may form the basis for developing personalized early preventive strategies.

Hydrolyzed Formula With Reduced Protein Content Supports Adequate Growth: A Randomized Controlled Noninferiority Trial.

OBJECTIVE: A high protein content of nonhydrolyzed infant formula exceeding metabolic requirements can induce rapid weight gain and obesity. Hydrolyzed formula with too low protein (LP) content may result in inadequate growth. The aim of this study was to investigate noninferiority of partial and extensively hydrolyzed formulas (pHF, eHF) with lower hydrolyzed protein content than conventionally, regularly used formulas, with or without synbiotics for normal growth of healthy term infants. METHODS: In an European multi-center, parallel, prospective, controlled, double-blind trial, 402 formula-fed infants were randomly assigned to four groups: LP-formulas (1.9 g protein/100 kcal) as pHF with or without synbiotics, LP-eHF formula with synbiotics, or regular protein eHF (2.3 g protein/100 kcal). One hundred and one breast-fed infants served as observational reference group. As primary endpoint, noninferiority of daily weight gain during the first 4 months of life was investigated comparing the LP-group to a regular protein eHF group. RESULTS: A comparison of daily weight gain in infants receiving LPpHF (2.15 g/day CI -0.18 to inf.) with infants receiving regular protein eHF showed noninferior weight gain (-3.5 g/day margin; per protocol [PP] population). Noninferiority was also confirmed for the other tested LP formulas. Likewise, analysis of metabolic parameters and plasma amino acid concentrations demonstrated a safe and balanced nutritional composition. Energetic efficiency for growth (weight) was slightly higher in LPeHF and synbiotics compared with LPpHF and synbiotics. CONCLUSIONS: All tested hydrolyzed LP formulas allowed normal weight gain without being inferior to regular protein eHF in the first 4 months of life. This trial was registered at clinicaltrials.gov, NCT01143233.

Early Programming of Obesity Throughout the Life Course: A Metabolomics Perspective.

BACKGROUND: Over the last decades, research on early life risk factors for obesity and its comorbidities in early life has gained attention within the field of developmental origins of health and diseases. Metabolomics studies that are trying to find early life biomarker and intervention targets for the early development of obesity and associated cardiovascular diseases could help break the inter-generational cycle of obesity. SUMMARY: Metabolomics studies in the field of early programming are scarce and causality is lacking at this stage, as most of the studies are cross-sectional. The main metabolites in the focus of obesity are branched-chain and aromatic amino acids, long-chain polyunsaturated fatty acids, lysophosphatidylcholines, and sphingomyelins. Sex and puberty have not been considered in most of the biomarker studies, but show differences in the metabolite associations to obesity. Key Messages: There is still a lot unknown about the associations between early programming exposures, metabolite concentrations, and the development of obesity. The few studies focusing on this topic find similar metabolite classes in the same age groups being associated with rapid early growth or obesity; but due to differences in the methodological and statistical approaches, the single species often differ. Therefore, more research, preferably with standardized approaches, is needed.

Investigating the early metabolic fingerprint of celiac disease - a prospective approach.

OBJECTIVES AND STUDY: In the development of Celiac Disease (CD) both genetic and environmental factors play a crucial role. The Human Leukocyte Antigen (HLA)-DQ2 and HLA-DQ8 loci are strongly related to the disease and are necessary but not sufficient for the development of CD. Therefore, increasing interest lies in examining the mechanisms of CD onset from the early beginning. Differences in serum and urine metabolic profiles between healthy individuals and CD patients have been reported previously. We aimed to investigate if the metabolic pathways were already altered in young, 4 month old infants, preceding the CD diagnosis. METHODS: Serum samples were available for 230 four month old infants of the PreventCD project, a multicenter, randomized, double-blind, dietary intervention study. All children were positive for HLA-DQ2 and/or HLA-DQ8 and had at least one first-degree relative diagnosed with CD. Amino acids were quantified after derivatization with liquid chromatography - tandem mass spectrometry (MS/MS) and polar lipid concentrations (acylcarnitines, lysophosphatidylcholines, phosphatidylcholines, and sphingomyelins) were determined with direct infusion MS/MS. We investigated the association of the metabolic profile with (1) the development of CD up to the age of 8 years (yes/no), (2) with HLA-risk groups, (3) with the age at CD diagnosis, using linear mixed models and cox proportional hazards models. Gender, intervention group, and age at blood withdrawal were included as potential confounder. RESULTS: By the end of 2014, thirty-three out of the 230 children (14%) were diagnosed with CD according to the ESPGHAN criteria. Median age at diagnosis was 3.4 years (IQR, 2.4-5.2). Testing each metabolite for a difference in the mean between healthy and CD children, we (1) could not identify a discriminant analyte or a pattern pointing towards an altered metabolism (Bonferroni corrected P > 0.05 for all). Metabolite concentrations (2) did not differ across the HLA-risk groups. When investigating the age at diagnosis using (3) survival models, we found no evidence for an association between the metabolic profile and the risk of a later CD diagnosis. CONCLUSION: The metabolic profile at 4 months of age was not predictive for the development of CD up to the age of 8 years. Our results suggest that metabolic pathways reflected in serum are affected only later in life and that the HLA-genotype does not influence the serum metabolic profile in young infants before introduction of solid food.

Changes in the serum metabolite profile in obese children with weight loss.

PURPOSE: Childhood obesity is an increasing problem and is accompanied by metabolic disturbances. Recently, we have identified 14 serum metabolites by a metabolomics approach (FIA-MS/MS), which showed altered concentrations in obese children as compared to normal-weight children. Obese children demonstrated higher concentrations of two acylcarnitines and lower levels of three amino acids, six acyl-alkyl phosphatidylcholines, and three lysophosphatidylcholines. The aim of this study was to analyze whether these alterations normalize in weight loss. METHODS: We analyzed the changes of these 14 metabolites by the same metabolic kit as in our previous study in serum samples of 80 obese children with substantial weight loss (BMI-SDS reduction >0.5) and in 80 obese children with stable weight status all participating in a 1-year lifestyle intervention. RESULTS: In the children without weight change, no significant changes of metabolite concentrations could be observed. In children with substantial weight loss, glutamine, methionine, the lysophosphatidylcholines LPCaC18:1, LPCaC18:2, and LPCa20:4, as well as the acyl-alkyl phosphatidylcholine PCaeC36:2 increased significantly, while the acylcarnitines C12:1 and C16:1, proline, PCaeC34:1, PCaeC34:2, PCaeC34:3, PCaeC36:3, and PCaeC38:2 did not change significantly. CONCLUSIONS: The changes of glutamine, methionine, LPCaC18:1, LPCaC18:2, LPCa20:4, and PCaeC36:2 seem to be related to the changes of dieting or exercise habits in lifestyle intervention or to be a consequence of overweight since they normalized in weight loss. Further studies should substantiate our findings.

Dietary Effects on Plasma Glycerophospholipids.

OBJECTIVE: Human milk provides a complex mixture of animal lipids, whereas the fat supply of most modern infant formula is based on vegetable oils. We studied the effects of breast-feeding and of feeding infant formula either without or with dairy goat lipids on the composition of infant plasma glycerophospholipids. METHODS: Healthy-term infants were randomized double blind to feeding with infant formula based on whole goats' milk (GIF, approximately 60% milk fat and 40% vegetable oils) or a control cows' milk infant formula based on vegetable oils (VIF) from 2 weeks after birth. A reference group of fully breast-fed infants was also followed. At the age 4 months, blood samples were collected and plasma glycerophospholipids were analyzed with liquid chromatography coupled to triple quadrupole mass spectrometry. RESULTS: The group of breast-fed infants showed significantly higher contents of glycerophospholipid species containing sn-2 palmitic acid [PC(16:0/16:0) and PC(18:0/16:0)] and significantly higher contents of glycerophospholipid species containing long-chain polyunsaturated fatty acids than infants in both formula groups. The GIF group demonstrated significantly higher glycerophospholipid species containing myristic acid [LPC(14:0), PC(14:0/18:1), PC(16:0/14:0)] and palmitoleic acid [LPC(16:1), PC(16:0/16:1), and PC(16:1/18:1)] than the VIF group. CONCLUSIONS: We conclude that breast-feeding induces marked differences in infant plasma glycerophospholipid profiles compared with formula feeding, whereas the studied different sources of formula fat resulted in limited effects on plasma glycerophospholipids.

Excessive weight gain during full breast-feeding.

BACKGROUND: Breast-feeding is considered to offer optimal nutrition for healthy infant growth and development. Observational studies have linked breast-feeding to reduced obesity. CASE OBSERVATION: We observed an infant who was born macrosomic (4.56 kg) and showed excessive weight gain markedly exceeding the 97th percentile of weight during full breast-feeding. At the age of 4 months, the weight was greater than 11 kg. Clinical evaluation did not reveal any underlying pathology. After the introduction of complementary feeding and hence reduction of the breast milk intake, the excessive weight gain was attenuated and the slope of the percentile curve paralleled upper percentiles. Since this pattern suggested full breast-feeding as the driver of excessive weight gain, we analyzed the human milk composition at the infant age of 1 year and compared the results with published data on composition at this stage of lactation. RESULTS: The milk contents of lactose, fat, fatty acids, polar lipids, carnitine species, and insulin were similar to the reference data. The adiponectin content was increased. The most remarkable alteration was a high milk protein content (mean 1.25 g/dl, reference 0.8 g/dl). CONCLUSIONS: A very high protein supply in infancy has been previously shown to increase plasma concentrations of the growth factors insulin and IGF-1, weight gain, and later obesity. We speculate that interindividual variations in human milk adiponectin and protein contents may contribute to modulation of the growth of fully breast-fed infants and in this case may have contributed to excessive weight gain during full breast-feeding. This hypothesis merits being tested in future cohort studies.

Metabolomic biomarkers for obesity in humans: a short review.

BACKGROUND: The prevalence and incidence of obesity have become a major public health problem during the last decades, but the underlying biochemical and metabolic processes are not fully understood. Metabolomics, the science of small molecules of the metabolism, is helping to unravel these mechanisms via the identification of markers related to obesity. These biomarkers are used to prevent diseases in later life or for the early diagnosis of diseases. This review focuses on articles dealing with biomarkers for obesity. KEY MESSAGES: Branched-chain amino acids (BCAA), nonesterified fatty acids, organic acids, acylcarnitines, and phospholipids were identified as potential biomarkers for obesity. This indicates a relation between elevated BCAA, and other amino acids, and the obese state. Furthermore, deregulation of ß-oxidation is associated with the development of obesity. The results have several limitations, including the differing ages of the subjects in the studies, the fact that all of the studies had a case-control design and therefore no causal explanatory power, and that most looked for similar metabolites and reported almost equal results. CONCLUSION: The strength of this review is that it gives a comprehensive overview of the current status of the knowledge on metabolomics biomarkers for obesity, but further research is needed because the methods used in the studies to date are very homogenous, e.g. most used a targeted approach and therefore analyzed almost the same group of metabolites. Moreover, prospective studies are lacking since all of the studies are either case-control or cross-sectional studies.

Regulation of early human growth: impact on long-term health.

Growth and development are central characteristics of childhood. Deviations from normal growth can indicate serious health challenges. The adverse impact of early growth faltering and malnutrition on later health has long been known. In contrast, the impact of rapid early weight and body fat gain on programming of later disease risk have only recently received increased attention. Numerous observational studies related diet in early childhood and rapid early growth to the risk of later obesity and associated disorders. Causality was confirmed in a large, double-blind randomised trial testing the 'Early Protein Hypothesis'. In this trial we found that attenuation of protein supply in infancy normalized early growth and markedly reduced obesity prevalence in early school age. These results indicate the need to describe and analyse growth patterns and their regulation through diet in more detail and to characterize the underlying metabolic and epigenetic mechanisms, given the potential major relevance for public health and policy. Better understanding of growth patterns and their regulation could have major benefits for the promotion of public health, consumer-orientated nutrition recommendations, and the development of improved food products for specific target populations.

The Power of Programming and the EarlyNutrition project: opportunities for health promotion by nutrition during the first thousand days of life and beyond.

At The Power of Programming 2014 Conference, researchers from multiple disciplines presented and discussed the effects of early nutrition and other environmental cues during the first thousand days of life and beyond on the lifelong risk of noncommunicable diseases. This paper aims to summarize the concepts and some of the first achievements of the EarlyNutrition research project that initiated the conference. The EarlyNutrition consortium is a multinational, multidisciplinary research collaboration of researchers from Europe, the USA, and Australia. A focus is placed on exploration of the developmental origins of obesity, adiposity, and related health outcomes. Here we report on the first findings of experimental approaches, cohort studies, randomized clinical trials, and systematic reviews of current information, as well as position papers, which have all been developed with the involvement of project partners. We conclude that the EarlyNutrition project has successfully established itself during the first 2 project years as a very strong platform for collaborative research on early programming effects. The first results, available already at this early stage of the project, point to great opportunities for health prevention strategies via the implementation of dietary and lifestyle modifications, with large effect sizes. Further results are expected which should support improved recommendations and related policies for optimized nutrition and lifestyle choices before and during pregnancy, in infancy, and in early childhood.

Rapid growth and childhood obesity are strongly associated with lysoPC(14:0).

BACKGROUND: Despite the growing interest in the early-origins-of-later-disease hypothesis, little is known about the metabolic underpinnings linking infant weight gain and childhood obesity. OBJECTIVE: To discover biomarkers reflective of weight change in the first 6 months and overweight/obesity at age 6 years via a targeted metabolomics approach. DESIGN: This analysis comprised 726 infants from a European multicenter randomized trial (Childhood Obesity Programme, CHOP) for whom plasma blood samples at age 6 months and anthropometric data up to the age of 6 years were available. 'Rapid growth' was defined as a positive difference in weight within the first 6 months of life standardized to WHO growth standards. Weight change was regressed on each of 168 metabolites (acylcarnitines, lysophosphatidylcholines, sphingomyelins, and amino acids). Metabolites significant after Bonferroni's correction were tested as predictors of later overweight/obesity. RESULTS: Among the overall 19 significant metabolites, 4 were associated with rapid growth and 15 were associated with a less-than-ideal weight change. After adjusting for feeding group, only the lysophosphatidylcholine LPCaC14:0 remained significantly associated with rapid weight gain (ß = 0.18). Only LPCaC14:0 at age 6 months was predictive of overweight/obesity at age 6 years (OR 1.33; 95% CI 1.04-1.69). CONCLUSION: LPCa14:0 is strongly related to rapid growth in infancy and childhood overweight/obesity. This suggests that LPCaC14:0 levels may represent a metabolically programmed effect of infant weight gain on the later obesity risk. However, these results require confirmation by independent cohorts.

Nonesterified fatty acid determination for functional lipidomics: comprehensive ultrahigh performance liquid chromatography-tandem mass spectrometry quantitation, qualification, and parameter prediction.

Despite their central importance for lipid metabolism, straightforward quantitative methods for determination of nonesterified fatty acid (NEFA) species are still missing. The protocol presented here provides unbiased quantitation of plasma NEFA species by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Simple deproteination of plasma in organic solvent solution yields high accuracy, including both the unbound and initially protein-bound fractions, while avoiding interferences from hydrolysis of esterified fatty acids from other lipid classes. Sample preparation is fast and nonexpensive, hence well suited for automation and high-throughput applications. Separation of isotopologic NEFA is achieved using ultrahigh-performance liquid chromatography (UPLC) coupled to triple quadrupole LC-MS/MS detection. In combination with automated liquid handling, total assay time per sample is less than 15 min. The analytical spectrum extends beyond readily available NEFA standard compounds by a regression model predicting all the relevant analytical parameters (retention time, ion path settings, and response factor) of NEFA species based on chain length and number of double bonds. Detection of 50 NEFA species and accurate quantification of 36 NEFA species in human plasma is described, the highest numbers ever reported for a LC-MS application. Accuracy and precision are within widely accepted limits. The use of qualifier ions supports unequivocal analyte verification.

Determination of acylglycerols from biological samples with chromatography-based methods.

Lipids are the most diverse class of metabolites in mammalian physiology and dysregulation of lipid metabolism is linked to various diseases. Alterations in acylglycerols, a major class of lipids in plasma and adipose tissue, are involved in the pathogenesis of obesity and type 2 diabetes. Therefore, determination of acylglycerols is important to depict and unravel cellular mechanisms related to pathological outcomes, and specific molecular species of acylglycerols might be promising biomarker candidates. The variety of acylglycerols can be characterized in different ways. Enzymatic assays enable the determination of total tri- or diacylglycerols showing a possible relation to diseases, but they do not allow clarification of molecular mechanism. While gas chromatography can provide an overview of the fatty acid composition of total or separated lipids, a very detailed description of the individual molecular acylglycerol species is possible via liquid chromatography, particularly when combined with mass spectrometry. This review describes the determination of acylglycerols considering recent developments, with a focus on mammalian serum/plasma and tissue.

Associations of maternal and fetal SCD-1 markers with infant anthropometry and maternal diet: Findings from the ROLO study.

BACKGROUND: Elevated stearoyl-CoA desaturase 1 (SCD-1) activity showed associations with obesity in cross-sectional studies. In non-pregnant populations, nutrition regulates SCD-1 transcription and activity. OBJECTIVE: To investigate the longitudinal associations of maternal and fetal SCD-1 activity markers with infant anthropometry up to 2 years of age, and to explore how selected dietary intakes modulate SCD-1 activity in pregnancy. METHODS: As a secondary analysis from the ROLO intervention study, which was conducted in a population at risk for macrosomia, non-esterified fatty acids (NEFA) from maternal plasma at 13 and 28 weeks' gestation and in cord blood were measured via liquid-chromatography-mass-spectrometry. Fatty acid ratios 18:1/18:0 and 16:1/16:0 were used as markers for SCD-1 activity ('desaturation indices', DIs). Relationships of DIs with infant anthropometry up to 2 years of age and maternal dietary parameters during pregnancy were investigated using adjusted linear regression models and p-values correction for multiple testing. RESULTS: 18:1/18:0, but not 16:1/16:0, was associated with measures of infant anthropometry at birth (maternal and fetal markers) and up to 2 years of age (maternal markers only). Dietary intakes did not show strong associations with 18:1/18:0, but 16:1/16:0 was associated with absolute and relative dietary intakes. CONCLUSIONS: In a population at risk for macrosomia, maternal SCD-1 activity measured via 18:1/18:0 was involved in the fetal programming of infant obesity, but could not be substantially modulated by short-term diet in pregnancy. CLINICAL TRIAL REGISTRATION: ISRCTN Registration number: ISRCTN54392969 (http://www.isrctn.com/ISRCTN54392969).

Maternal Metabolomic Profile and Fetal Programming of Offspring Adiposity: Identification of Potentially Protective Lipid Metabolites.

SCOPE: The fetal programming paradigm posits that the origins of obesity can be traced, in part, to the intrauterine period of life. However, the mechanisms underlying fetal programming are not well understood, and few studies have measured offspring adiposity in the neonatal period. The aim of this study is to identify maternal metabolites, and their determinants, that are associated with neonatal adiposity. METHODS AND RESULTS: A targeted metabolomics approach is applied to analyze plasma samples collected across gestation from a well-characterized cohort of 253 pregnant women participating in a prospective study at the University of California, Irvine. Whole-body dual X-ray absorptiometry (DXA) imaging of body composition is obtained in N = 121 newborns. Statistical models are adjusted for potential confounders and multiple testing. The authors identify six alkyl-linked phosphatidylcholines (PCae), containing fatty acid 20:4, that are significantly and negatively associated with neonatal body fat percentage. Factors indicating higher socioeconomic status, non-Hispanic ethnicity, and higher nonesterified fatty acid percentages are positively associated with these PCae. CONCLUSIONS: The polyunsaturated fatty acid 20:4 contained in PCae may exert a beneficial effect with respect to future propensity for obesity development. Prepregnancy and early pregnancy factors are determinants of these PCae, highlighting the importance of addressing preconceptional conditions for fetal programming of newborn adiposity.

Prolonged monitoring of postprandial lipid metabolism after a western meal rich in linoleic acid and carbohydrates.

Today, awareness has been raised regarding high consumption of n-6 polyunsaturated fatty acids (PUFA) in western diets. A comprehensive analysis of total and individual postprandial fatty acids profiles would provide insights into metabolic turnover and related health effects. After an overnight fast, 9 healthy adults consumed a mixed meal comprising 97 g carbohydrate and 45 g fat, of which 26.4 g was linoleic acid (LA). Nonesterified fatty acids (NEFA), phospholipid fatty acids (PL-FA) and triacylglycerol fatty acids (TG-FA) were monitored in plasma samples, at baseline and hourly over a 7-h postprandial period. Total TG-FA concentration peaked at 2 h after the meal and steadily decreased thereafter. LA from TG18:2n-6 and behenic acid from TG22:0 showed the highest response among TG-FA, with a biphasic response detected for the former. PL-FA exhibited no change. Total NEFA initially decreased to nadir at 1 h, then increased to peak at 7 h. The individual NEFA showed the same response curve except LA and some very-long-chain saturated fatty acids (VLCSFA, ≥20 carbon chain length) that markedly increased shortly after the meal intake. The similarities and dissimilarities in lipid profiles between study subjects at different time points were visualized using nonmetric multi-dimensional scaling. Overall, the results indicate that postprandial levels of LA and VLCSFA, either as NEFA or TG, were most affected by the test meal, which might provide an explanation for the health effects of this dietary lifestyle characterized by high intake of mixed meals rich in n-6 PUFA.

Variation and Interdependencies of Human Milk Macronutrients, Fatty Acids, Adiponectin, Insulin, and IGF-II in the European PreventCD Cohort.

Human milk composition is variable. The identification of influencing factors and interdependencies of components may help to understand the physiology of lactation. In this study, we analyzed linear trends in human milk composition over time, the variation across different European countries and the influence of maternal celiac disease. Within a multicenter European study exploring potential prevention of celiac disease in a high-risk population (PreventCD), 569 human milk samples were donated by women from five European countries between 16 and 163 days postpartum. Some 202 mothers provided two samples at different time points. Protein, carbohydrates, fat and fatty acids, insulin, adiponectin, and insulin-like growth factor II (IGF-II) were analyzed. Milk protein and n-6 long chain polyunsaturated fatty acids decreased during the first three months of lactation. Fatty acid composition was significantly influenced by the country of residence. IGF-II and adiponectin concentrations correlated with protein content (r = 0.24 and r = 0.35), and IGF-II also correlated with fat content (r = 0.36), suggesting a possible regulatory role of IGF in milk macronutrient synthesis. Regarding the impact of celiac disease, only the level in palmitic acid was influenced by this disease, suggesting that breastfeeding by celiac disease mothers should not be discouraged.

An individual participant data meta-analysis on metabolomics profiles for obesity and insulin resistance in European children.

Childhood obesity prevalence is rising in countries worldwide. A variety of etiologic factors contribute to childhood obesity but little is known about underlying biochemical mechanisms. We performed an individual participant meta-analysis including 1,020 pre-pubertal children from three European studies and investigated the associations of 285 metabolites measured by LC/MS-MS with BMI z-score, height, weight, HOMA, and lipoprotein concentrations. Seventeen metabolites were significantly associated with BMI z-score. Sphingomyelin (SM) 32:2 showed the strongest association with BMI z-score (P = 4.68 × 10-23) and was also closely related to weight, and less strongly to height and LDL, but not to HOMA. Mass spectrometric analyses identified SM 32:2 as myristic acid containing SM d18:2/14:0. Thirty-five metabolites were significantly associated to HOMA index. Alanine showed the strongest positive association with HOMA (P = 9.77 × 10-16), while acylcarnitines and non-esterified fatty acids were negatively associated with HOMA. SM d18:2/14:0 is a powerful marker for molecular changes in childhood obesity. Tracing back the origin of SM 32:2 to dietary source in combination with genetic predisposition will path the way for early intervention programs. Metabolic profiling might facilitate risk prediction and personalized interventions in overweight children.

Association of infant formula composition and anthropometry at 4 years: Follow-up of a randomized controlled trial (BeMIM study).

The relationships between nutrition, metabolic response, early growth and later body weight have been investigated in human studies. The aim of this follow-up study was to assess the long-term effect of infant feeding on growth and to study whether the infant metabolome at the age of 4 months might predict anthropometry at 4 years of age. The Belgrade-Munich infant milk trial (BeMIM) was a randomized controlled trial in which healthy term infants received either a protein-reduced infant formula (1.89 g protein/100 kcal) containing alpha-lactalbumin enriched whey and long-chain polyunsaturated fatty acids (LC-PUFA), or a standard formula (2.2 g protein/100 kcal) without LC-PUFA, focusing on safety and suitability. Non-randomized breastfed infants were used as a reference group. Of the 259 infants that completed the BeMIM study at the age of 4 months (anthropometry assessment and blood sampling), 187 children participated in a follow-up visit at 4 years of age. Anthropometry including weight, standing height, head circumference, and percent body fat was determined using skinfolds (triceps, subscapular) and bioelectrical impedance analysis. Plasma metabolite concentration, collected in samples at the age of 4 months, was measured using flow-injection tandem mass spectrometry. A linear regression model was applied to estimate the associations between each metabolite and growth with metabolites as an independent variable. At 4 years of age, there were no significant group differences in anthropometry and body composition between formula groups. Six metabolites (Asn, Lys, Met, Phe, Trp, Tyr) measured at 4 months of age were significantly associated with changes in weight-for-age z-score between 1 to 4 months of age and BMI-for-age z-score (Tyr only), after adjustment for feeding group. No correlation was found between measured metabolites and long-term growth (up to 4 years of age). No long-term effects of early growth patterns were shown on anthropometry at 4 years of age. The composition of infant formula influences the metabolic profile and early growth, while long-term programming effects were not observed in this study.