Human Milk Oligosaccharides, Growth, and Body Composition in Very Preterm Infants.

Human milk oligosaccharides (HMOs) are bioactive factors that benefit neonatal health, but little is known about effects on growth in very preterm infants (<32 weeks' gestation). We aimed to quantify HMO concentrations in human milk fed to very preterm infants during the neonatal hospitalization and investigate associations of HMOs with infant size and body composition at term-equivalent age. In 82 human-milk-fed very preterm infants, we measured HMO concentrations at two time points. We measured anthropometrics and body composition with air displacement plethysmography at term-equivalent age. We calculated means of individual and total HMOs, constructed tertiles of mean HMO concentrations, and assessed differences in outcomes comparing infants in the highest and intermediate tertiles with the lowest tertile using linear mixed effects models, adjusted for potential confounders. The mean (SD) infant gestational age was 28.2 (2.2) weeks, and birthweight was 1063 (386) grams. Exposure to the highest (vs. lowest) tertile of HMO concentrations was not associated with anthropometric or body composition z-scores at term-corrected age. Exposure to the intermediate (vs. lowest) tertile of 3FL was associated with a greater head circumference z-score (0.61, 95% CI 0.15, 1.07). Overall, the results do not support that higher HMO intakes influence growth outcomes in this very preterm cohort.

Human Milk Nutrient Composition Data is Critically Lacking in the United States and Canada: Results from a Systematic Scoping Review of 2017-2022.

Characterization of the nutrients in human milk is important to understand the dietary and developmental requirements of infants. The objective of this review was to summarize the state-of-the-science on the nutrient composition of human milk in the United States and Canada published from 2017 to 2022. Four databases were searched for randomized controlled studies and others given the scoping nature of this review. We limited type to mature milk collected 21 d postpartum and beyond from lactating individuals in the United States and Canada who gave birth at 37-wk gestation or later (full-term). Outcomes of interest included traditional macro- and micronutrients, including human milk oligosaccharides (HMOs), and milk volume. The publication date range was selected as January 1, 2017, to the day the literature search was performed. A total of 32 articles were included in the scoping review from primarily longitudinal cohort or cross-sectional designs. The most prevalent sample collection method was full-breast expression (n = 20) with most studies (n = 26) collecting samples from a single timepoint. Carbohydrates (HMOs [n = 12], glucose [n = 8], and lactose [n = 6]) and protein (n = 5) were the most frequently assessed nutrients in this body of work, with consensus among studies that glucose is present in limited concentrations compared to lactose (24-64 mg/dL compared with 6-7 g/dL) and that HMOs are influenced by temporality and secretor status. Included studies displayed an overall level of heterogeneity and sparsity paralleling previous reports and nutrient data in the USDA FoodData Central system. Much of the data extracted from retained articles generally provided analysis of a specific nutrient or group of nutrients. Moreover, many studies did not use the preferred analytical methods as outlined by the Human Milk Composition Initiative to increase measurement confidence. Up-to-date nutrient composition data of human milk is still greatly needed as it is paramount for the management of infant feeding, assessment of infant and maternal nutritional and health needs, and as a reference for infant formula development.

Human Milk Oligosaccharides and Infant Neurodevelopment: A Narrative Review.

The objective of this narrative review was to synthesize the literature on human milk oligosaccharides (HMOs) and neurodevelopmental outcomes in human milk-fed infants. We conducted a scoping review of the literature indexed in PubMed reporting observational or interventional studies on HMO exposure in relation to psychometric measures in infants. Studies were characterized based on study design and definitions of HMO exposure and neurodevelopmental outcomes. Six studies were identified; all were observational in design, and five were conducted in full-term infants. Sample sizes ranged from 35-659 infants. HMOs were defined as individual concentrations or relative abundances assessed at 1 and/or 6 months of age. Studies accounted for differences in HMO exposure based on maternal secretor status. Neurodevelopmental outcomes were assessed between 6 and 24 months of age and included four domains. Studies in full-term infants reported that total and individual fucosylated and sialylated HMOs were positively associated with cognitive, language, and motor skill domains between 18 and 24 months of age, while the single study in preterm infants reported no statistically significant findings in the full cohort. The presence of a maternal secretor did not consistently alter the associations between HMO exposure and neurodevelopmental outcomes. Emerging evidence from observational studies suggests that HMO exposure may be beneficial for neurodevelopment in infants.

Complementary Feeding and Child Appetitive Traits in a Sample of Hispanic Mother-Child Dyads.

BACKGROUND: Complementary feeding practices may contribute to toddler eating practices that affect weight outcomes. Studies are needed to understand the relationship between complementary feeding practices and toddler dietary self-regulation. OBJECTIVE: This study tests the hypothesis that earlier complementary food introduction predicts toddler food responsiveness and emotional overeating (ie, tendency to overeat in response to food cues and emotions, respectively), and considers whether introduction of certain foods better predict toddler dietary self-regulation. DESIGN: This study is a secondary analysis of data from a parent longitudinal birth cohort study on early growth/development among Hispanic mother-infant dyads. PARTICIPANTS/SETTING: The analytic sample included 174 mother-child dyads recruited from maternity clinics affiliated with the University of Southern California in Los Angeles County. Recruitment and data collection were ongoing from July 2016 to April 2020. At 1-, 6-, 12-, and 24-months postpartum, mothers reported exclusive breastfeeding duration and age of complementary food introduction via questionnaire. MAIN OUTCOME MEASURES: Child food responsiveness and emotional overeating scores calculated from the Child Eating Behavior Questionnaire at 12 and 24 months of age. STATISTICAL ANALYSES PERFORMED: Separate linear mixed models with repeated measures were used to examine associations between age of complementary food introduction as a predictor of child food responsiveness or emotional overeating, controlling for infant sex, birth body mass index z score, duration of exclusive breastfeeding, and mother's body mass index. RESULTS: In separate models, delaying complementary food introduction by 1 month was associated with a 6% reduction in food responsiveness (P = 0.007) and a 5% reduction in emotional overeating scores (P = 0.013). Fifty-eight unique combinations of complementary foods introduced first were found, precluding analyses to examine whether specific combinations were related to eating behavior outcomes due to sample size limitations. CONCLUSIONS: Earlier complementary feeding was associated with higher food responsiveness and emotional overeating scores among Hispanic children. Future studies in larger samples are needed to characterize patterns of complementary food introduction and their influence on child self-regulation.

Stability of Human-Milk Oligosaccharide Concentrations Over 1 Week of Lactation and Over 6 Hours Following a Standard Meal.

BACKGROUND: Our previous studies revealed that human-milk oligosaccharides (HMOs) have health benefits for nursing infants and their concentrations change dynamically over 24 mo of lactation. Yet, the extent to which HMOs vary over the short term (days) and in response to acute factors such as maternal diet is unclear. OBJECTIVE: The purpose of this study was to determine the stability of HMO concentrations over 7 d and in response to a standard meal and sugar-sweetened beverage (SSB) over 6 h. METHODS: In this ancillary study, lactating mothers were enrolled at 6 wk postpartum. Participants received in-person instructions and materials to complete procedures at home. In the 1-wk experiment (n = 11), mothers pumped a milk sample at 07:00 h for 7 consecutive days. In the 6-h experiment (n = 35), mothers pumped a milk sample after an overnight fast at 06:00 h and then consumed a standard meal plus SSB provided by the study team. Mothers pumped a milk sample every hour for 6 consecutive hours. Samples were analyzed for the 19 most abundant HMOs. Repeated-measures ANOVA was used to test changes in HMO concentrations over time, reported as F(dftime, dferror) = F value, P value. RESULTS: Concentrations of all assayed HMOs were stable over 7 consecutive days, including, for example, the most widely studied HMOs in relation to infant health: 2'-fucosyllactose (2'FL) [F(2,17) = 0.39, P = 0.65], disialyl-lacto-N-tetraose (DSLNT) [F(4, 37) = 0.60, P = 0.66], and lacto-N-neotetraose (LNnT) [F(3, 32) = 1.5, P = 0.23]. Concentrations of all assayed HMOs were stable in response to a standard meal plus SSB. For example, fasted baseline concentrations of 2'FL, DSLNT, and LNnT were 2310 ± 1620 µg/mL, 560 ± 290 µg/mL, and 630 ± 290 µg/mL, respectively, and there were no changes in 2'FL [F(4, 119) = 1.9, P = 0.13], DSLNT [F(4, 136) = 0.39, P = 0.83], and LNnT [F(4, 120) = 0.64, P = 0.63] over 6 consecutive hours. CONCLUSIONS: HMO concentrations are stable over 1 wk of lactation and are not acutely affected by a standard meal plus SSB in mothers.

Associations of Human Milk Oligosaccharides with Infant Brain Tissue Organization and Regional Blood Flow at 1 Month of Age.

Animal studies have shown that human milk oligosaccharides (HMOs) are important in early brain development, yet their roles have not been assessed in humans. The purpose of this study was to determine the associations of HMOs with MRI indices of tissue microstructure and regional cerebral blood flow (rCBF) in infants. Mother-infant pairs (N = 20) were recruited at 1 month postpartum. Milk was assayed for the concentrations of the HMOs 2'-fucosyllactose (2'FL), 3-fucosyllactose (3FL), 3'-sialyllactose (3'SL), and 6'-sialyllactose (6'SL). Diffusion and arterial spin labeling measures were acquired using a 3.0-Tesla MRI scanner. Multiple linear regression was used to assess the voxel-wise associations of HMOs with fractional anisotropy (FA), mean diffusivity (MD), and rCBF values across the brain. After adjusting for pre-pregnancy BMI, sex, birthweight, and postmenstrual age at time of scan, a higher 2'FL concentration was associated with reduced FA, increased MD, and reduced rCBF in similar locations within the cortical mantle. Higher 3FL and 3'SL concentrations were associated with increased FA, reduced MD, and increased rCBF in similar regions within the developing white matter. The concentration of 6'SL was not associated with MRI indices. Our data reveal that fucosylated and sialylated HMOs differentially associate with indices of tissue microstructure and rCBF, suggesting specific roles for 2'FL, 3FL, and 3'SL in early brain maturation.

Postnatal exposure to ambient air pollutants is associated with the composition of the infant gut microbiota at 6-months of age.

Epidemiological studies in adults have shown that exposure to ambient air pollution (AAP) is associated with the composition of the adult gut microbiome, but these relationships have not been examined in infancy. We aimed to determine if 6-month postnatal AAP exposure was associated with the infant gut microbiota at 6 months of age in a cohort of Latino mother-infant dyads from the Southern California Mother's Milk Study (n = 103). We estimated particulate matter (PM2.5 and PM10) and nitrogen dioxide (NO2) exposure from birth to 6-months based on residential address histories. We characterized the infant gut microbiota using 16S rRNA amplicon sequencing at 6-months of age. At 6-months, the gut microbiota was dominated by the phyla Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. Our results show that, after adjusting for important confounders, postnatal AAP exposure was associated with the composition of the gut microbiota. As an example, PM10 exposure was positively associated with Dialister, Dorea, Acinetobacter, and Campylobacter while PM2.5 was positively associated with Actinomyces. Further, exposure to PM10 and PM2.5 was inversely associated with Alistipes and NO2 exposure was positively associated with Actinomyces, Enterococcus, Clostridium, and Eubacterium. Several of these taxa have previously been linked with systemic inflammation, including the genera Dialister and Dorea. This study provides the first evidence of significant associations between exposure to AAP and the composition of the infant gut microbiota, which may have important implications for future infant health and development.

Adverse Effects of Infant Formula Made with Corn-Syrup Solids on the Development of Eating Behaviors in Hispanic Children.

Few studies have investigated the influence of infant formulas made with added corn-syrup solids on the development of child eating behaviors. We examined associations of breastmilk (BM), traditional formula (TF), and formula containing corn-syrup solids (CSSF) with changes in eating behaviors over a period of 2 years. Feeding type was assessed at 6 months in 115 mother−infant pairs. Eating behaviors were assessed at 12, 18 and 24 months. Repeated Measures ANCOVA was used to determine changes in eating behaviors over time as a function of feeding type. Food fussiness and enjoyment of food differed between the feeding groups (p < 0.05) and changed over time for CSSF and TF (p < 0.01). Food fussiness increased from 12 to 18 and 12 to 24 months for CSSF and from 12 to 24 months for TF (p < 0.01), while it remained stable for BM. Enjoyment of food decreased from 12 to 24 months for CSSF (p < 0.01), while it remained stable for TF and BM. There was an interaction between feeding type and time for food fussiness and enjoyment of food (p < 0.01). Our findings suggest that Hispanic infants consuming CSSF may develop greater food fussiness and reduced enjoyment of food in the first 2 years of life compared to BM-fed infants.

Clinical Intervention to Reduce Dietary Sugar Does Not Affect Liver Fat in Latino Youth, Regardless of PNPLA3 Genotype: A Randomized Controlled Trial.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) among Latinos is partially attributed to a prevalent C>G polymorphism in the patatin-like phospholipase 3 (PNPLA3) gene. Cross-sectional analyses in Latino children showed the association between dietary sugar and liver fat was exacerbated by GG genotype. Pediatric feeding studies show extreme sugar restriction improves liver fat, but no prior trial has examined the impact of a clinical intervention or whether effects differ by PNPLA3 genotype. OBJECTIVES: We aimed to test effects of a clinical intervention to reduce dietary sugar compared with standard dietary advice on change in liver fat, and secondary-endpoint changes in liver fibrosis, liver enzymes, and anthropometrics; and whether effects differ by PNPLA3 genotype (assessed retrospectively) in Latino youth with obesity (BMI ≥ 95th percentile). METHODS: This parallel-design trial randomly assigned participants (n = 105; mean baseline liver fat: 12.7%; mean age: 14.8 y) to control or sugar reduction (goal of ≤10% of calories from free sugar) for 12 wk. Intervention participants met with a dietitian monthly and received delivery of bottled water. Changes in liver fat, by MRI, were assessed by intervention group via general linear models. RESULTS: Mean free sugar intake decreased in intervention compared with control [11.5% to 7.3% compared with 13.9% to 10.7% (% energy), respectively; P = 0.02], but there were no significant effects on liver outcomes or anthropometrics (Pall > 0.10), and no PNPLA3 interactions (Pall > 0.10). In exploratory analyses, participants with whole-body fat mass (FM) reduction (mean ± SD: -1.9 ± 2.4 kg), irrespective of randomization, had significant reductions in liver fat compared with participants without FM reduction (median: -2.1%; IQR: -6.5% to -0.8% compared with 0.3%; IQR: -1.0% to 1.1%; P < 0.001). CONCLUSIONS: In Latino youth with obesity, a dietitian-led sugar reduction intervention did not improve liver outcomes compared with control, regardless of PNPLA3 genotype. Results suggest FM reduction is important for liver fat reduction, confirming clinical recommendations of weight loss and a healthy diet for pediatric NAFLD.This trial was registered at clinicaltrials.gov as NCT02948647.

Bioactive compounds in mothers milk affecting offspring outcomes: A narrative review.

BACKGROUND: Compared to the exhaustive study of transgenerational programming of obesity and diabetes through exposures in the prenatal period, postnatal programming mechanisms are understudied, including the potential role of breast milk composition linking maternal metabolic status (body mass index and diabetes) and offspring growth, metabolic health and future disease risk. METHODS: This narrative review will principally focus on four emergent bioactive compounds [microRNA's (miRNA), lipokines/signalling lipids, small molecules/metabolites and fructose] that, until recently were not known to exist in breast milk. The objective of this narrative review is to integrate evidence across multiple fields of study that demonstrate the importance of these compositional elements of breast milk during lactation and the subsequent effect of breast milk components on the health of the infant. RESULTS: Current knowledge on the presence of miRNA's, lipokines/signalling lipids, small molecules/metabolites and fructose in breast milk and their associations with infant outcomes is compelling, but far from resolved. Two themes emerge: (1) maternal metabolic phenotypes are associated with these bioactives and (2) though existing in milk at low concentrations, they are also associated with offspring growth and body composition. CONCLUSION: Breast milk research is gaining momentum though we must remain focused on understanding how non-nutritive bioactive components are affected by the maternal phenotype, how they subsequently impact infant outcomes. Though early, there is evidence to suggest fructose is associated with fat mass in the 1st months of life whereas 12,13 diHOME (brown fat activator) and betaine are negatively associated with early adiposity and growth.

Development and Validation of a Prediction Model for Infant Fat Mass.

OBJECTIVES: To develop and validate a prediction model for fat mass in infants ≤12 kg using easily accessible measurements such as weight and length. STUDY DESIGN: We used data from a pooled cohort of 359 infants age 1-24 months and weighing 3-12 kg from 3 studies across Southern California and New York City. The training data set (75% of the cohort) included 269 infants and the testing data set (25% of the cohort) included 90 infants age 1-24 months. Quantitative magnetic resonance was used as the standard measure for fat mass. We used multivariable linear regression analysis, with backwards selection of predictor variables and fractional polynomials for nonlinear relationships to predict infant fat mass (from which lean mass can be estimated by subtracting resulting estimates from total mass) in the training data set. We used 5-fold cross-validation to examine overfitting and generalizability of the model's predictive performance. Finally, we tested the adjusted model on the testing data set. RESULTS: The final model included weight, length, sex, and age, and had high predictive ability for fat mass with good calibration of observed and predicted values in the training data set (optimism-adjusted R2: 92.1%). Performance on the test dataset showed promising generalizability (adjusted R2: 85.4%). The mean difference between observed and predicted values in the testing dataset was 0.015 kg (-0.043 to -0.072 kg; 0.7% of the mean). CONCLUSIONS: Our model accurately predicted infant fat mass and could be used to improve the accuracy of assessments of infant body composition for effective early identification, surveillance, prevention, and management of obesity and future chronic disease risk.

Risk of Micronutrient Inadequacy among Hispanic, Lactating Mothers: Preliminary Evidence from the Southern California Mother's Milk Study.

Micronutrients are dietary components important for health and physiological function, and inadequate intake of these nutrients can contribute to poor health outcomes. The risk of inadequate micronutrient intake has been shown to be greater among low-income Hispanics and postpartum and lactating women. Therefore, we aimed to determine the risk of nutrient inadequacies based on preliminary evidence among postpartum, Hispanic women. Risk of micronutrient inadequacy for Hispanic women (29-45 years of age) from the Southern California Mother's Milk Study (n = 188) was assessed using 24 h dietary recalls at 1 and 6 months postpartum and the estimated average requirement (EAR) fixed cut-point approach. Women were considered at risk of inadequate intake for a nutrient if more than 50% of women were consuming below the EAR. The Chronic Disease Risk Reduction (CDRR) value was also used to assess sodium intake. These women were at risk of inadequate intake for folate and vitamins A, D, and E, with 87.0%, 93.4%, 43.8%, and 95% of women consuming less than the EAR for these nutrients, respectively. Lastly, 71.7% of women consumed excess sodium. Results from this preliminary analysis indicate that Hispanic women are at risk of inadequate intake of important micronutrients for maternal and child health.

Early life gut microbiota is associated with rapid infant growth in Hispanics from Southern California.

We aimed to determine if the newborn gut microbiota is an underlying determinant of early life growth trajectories. 132 Hispanic infants were recruited at 1-month postpartum. The infant gut microbiome was characterized using 16S rRNA amplicon sequencing. Rapid infant growth was defined as a weight-for-age z-score (WAZ) change greater than 0.67 between birth and 12-months of age. Measures of infant growth included change in WAZ, weight-for-length z-score (WLZ), and body mass index (BMI) z-scores from birth to 12-months and infant anthropometrics at 12-months (weight, skinfold thickness). Of the 132 infants, 40% had rapid growth in the first year of life. Multiple metrics of alpha-diversity predicted rapid infant growth, including a higher Shannon diversity (OR = 1.83; 95% CI: 1.07-3.29; p = .03), Faith's phylogenic diversity (OR = 1.41, 95% CI: 1.05-1.94; p = .03), and richness (OR = 1.04, 95% CI: 1.01-1.08; p = .02). Many of these alpha-diversity metrics were also positively associated with increases in WAZ, WLZ, and BMI z-scores from birth to 12-months (pall<0.05). Importantly, we identified subsets of microbial consortia whose abundance were correlated with these same measures of infant growth. We also found that rapid growers were enriched in multiple taxa belonging to genera such as Acinetobacter, Collinsella, Enterococcus, Neisseria, and Parabacteroides. Moreover, measures of the newborn gut microbiota explained up to an additional 5% of the variance in rapid growth beyond known clinical predictors (R2 = 0.37 vs. 0.32, p < .01). These findings indicate that a more mature gut microbiota, characterized by increased alpha-diversity, at as early as 1-month of age, may influence infant growth trajectories in the first year of life.

Association of Prenatal Sugar Consumption with Newborn Brain Tissue Organization.

Animal studies have shown that exposure to excess sugar during the prenatal and postnatal periods may alter early brain structure in rat pups. However, evidence in humans is lacking. The aim of this study was to determine associations of maternal total and added sugar intake in pregnancy with early brain tissue organization in infants. Adolescent mothers (n = 41) were recruited during pregnancy and completed 24 h dietary recalls during the second trimester. Diffusion tensor imaging was performed on infants using a 3.0 Tesla Magnetic Resonance Imaging Scanner at 3 weeks. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were constructed. A multiple linear regression was used to examine voxel-wise associations across the brain. Adjusting for postmenstrual age, sex, birth weight, and total energy intake revealed that maternal total and added sugar consumption were associated inversely and diffusely with infant MD values, not FA values. Inverse associations were distributed throughout all of the cortical mantle, including the posterior periphery (Bs = -6.78 to -0.57, Ps < 0.001) and frontal lobe (Bs = -4.72 to -0.77, Ps ≤ 0.002). Our findings suggest that maternal total and added sugar intake during the second trimester are significantly associated with features of brain tissue organization in infants, the foundation for future functional outcomes.

PNPLA3 Genotype, Arachidonic Acid Intake, and Unsaturated Fat Intake Influences Liver Fibrosis in Hispanic Youth with Obesity.

Non-alcoholic fatty liver disease impacts 15.2% of Hispanic adolescents and can progress to a build-up of scared tissue called liver fibrosis. If diagnosed early, liver fibrosis may be reversible, so it is necessary to understand risk factors. The aims of this study in 59 Hispanic adolescents with obesity were to: (1) identify potential biological predictors of liver fibrosis and dietary components that influence liver fibrosis, and (2) determine if the association between dietary components and liver fibrosis differs by PNPLA3 genotype, which is highly prevalent in Hispanic adolescents and associated with elevated liver fat. We examined liver fat and fibrosis, genotyped for PNPLA3 gene, and assessed diet via 24-h diet recalls. The prevalence of increased fibrosis was 20.9% greater in males, whereas participants with the GG genotype showed 23.7% greater prevalence. Arachidonic acid was associated with liver fibrosis after accounting for sex, genotype, and liver fat (ß = 0.072, p = 0.033). Intakes of several dietary types of unsaturated fat have different associations with liver fibrosis by PNPLA3 genotype after accounting for sex, caloric intake, and liver fat. These included monounsaturated fat (ßCC/CG = -0.0007, ßGG = 0.03, p-value = 0.004), polyunsaturated fat (ßCC/CG = -0.01, ßGG = 0.02, p-value = 0.01), and omega-6 (ßCC/CG = -0.0102, ßGG = 0.028, p-value = 0.01). Results from this study suggest that reduction of arachidonic acid and polyunsaturated fatty acid intake might be important for the prevention of non-alcoholic fatty liver disease progression, especially among those with PNPLA3 risk alleles.

Prenatal exposure to ambient air pollutants and early infant growth and adiposity in the Southern California Mother's Milk Study.

BACKGROUND: Prior epidemiological and animal work has linked in utero exposure to ambient air pollutants (AAP) with accelerated postnatal weight gain, which is predictive of increased cardiometabolic risk factors in childhood and adolescence. However, few studies have assessed changes in infant body composition or multiple pollutant exposures. Therefore, the objective of this study was to examine relationships between prenatal residential AAP exposure with infant growth and adiposity. METHODS: Residential exposure to AAP (particulate matter < 2.5 and 10 microns in aerodynamic diameter [PM2.5, PM10]; nitrogen dioxide [NO2]; ozone [O3]; oxidative capacity [Oxwt: redox-weighted oxidative potential of O3 and NO2]) was modeled by spatial interpolation of monitoring stations via an inverse distance-squared weighting (IDW2) algorithm for 123 participants from the longitudinal Mother's Milk Study, an ongoing cohort of Hispanic mother-infant dyads from Southern California. Outcomes included changes in infant growth (weight, length), total subcutaneous fat (TSF; calculated via infant skinfold thickness measures) and fat distribution (umbilical circumference, central to total subcutaneous fat [CTSF]) and were calculated by subtracting 1-month measures from 6-month measures. Multivariable linear regression was performed to examine relationships between prenatal AAP exposure and infant outcomes. Models adjusted for maternal age, pre-pregnancy body mass index, socioeconomic status, infant age, sex, and breastfeeding frequency. Sex interactions were tested, and effects are reported for each standard deviation increase in exposure. RESULTS: NO2 was associated with greater infant weight gain (ß = 0.14, p = 0.02) and TSF (ß = 1.69, p = 0.02). PM10 and PM2.5 were associated with change in umbilical circumference (ß = 0.73, p = 0.003) and TSF (ß = 1.53, p = 0.04), respectively. Associations of Oxwt (pinteractions < 0.10) with infant length change, umbilical circumference, and CTSF were modified by infant sex. Oxwt was associated with attenuated infant length change among males (ß = -0.60, p = 0.01), but not females (ß = 0.16, p = 0.49); umbilical circumference among females (ß = 0.92, p = 0.009), but not males (ß = -0.00, p = 0.99); and CTSF among males (ß = 0.01, p = 0.03), but not females (ß = 0.00, p = 0.51). CONCLUSION: Prenatal AAP exposure was associated with increased weight gain and anthropometric measures from 1-to-6 months of life among Hispanic infants. Sex-specific associations suggest differential consequences of in utero oxidative stress. These results indicate that prenatal AAP exposure may alter infant growth, which has potential to increase childhood obesity risk.

Specific amino acids but not total protein attenuate postpartum weight gain among Hispanic women from Southern California.

There is a high prevalence of obesity and type 2 diabetes in the United States, particularly among Hispanic women, which may be partly explained by failure to lose gestational weight during the postpartum period. Previous work indicates that protein and amino acids may protect against weight gain; therefore, this study examined the impact of dietary protein and amino acid intake on changes in postpartum weight and the percent of women meeting the Estimated Average Requirement (EAR) for these dietary variables among Hispanic women from the Southern California Mother's Milk Study (n = 99). Multivariable linear regression analysis was used to examine the associations between protein and amino acid intake with change in weight after adjusting for maternal age, height, and energy intake. Women's weight increased from prepregnancy to 1-month and 6-months postpartum (71.1 ± 14.6 vs. 73.1 ± 13.1 vs. 74.5 ± 14.6 kg, p < .0001). Although dietary protein was not associated with weight change (ß = -1.09; p = .13), phenylalanine (ß = -1.46; p = .04), tryptophan (ß = -1.71; p = .009), valine (ß = -1.34; p = .04), isoleucine (ß = -1.26; p = .045), and cysteine (ß = -1.52; p = .02) intake were inversely associated with weight change. Additionally, fewer women met the EAR values for cysteine (11.1%), phenylalanine (60.6%), and methionine (69.7%), whereas most women met the EAR values for tryptophan (92.9%), valine (96.0%), and isoleucine (94.9%). Study results indicate that several essential and conditionally essential amino acids were associated with postpartum weight loss, with a significant portion of women not meeting recommended intake levels for some of these amino acids. These results highlight the importance of postpartum maternal diet as a potential modifiable risk factor.

Longitudinal Changes in Human Milk Oligosaccharides (HMOs) Over the Course of 24 Months of Lactation.

BACKGROUND: Human milk oligosaccharides (HMOs) are complex glycans that are highly abundant in human milk. While over 150 HMOs have been identified, it is unknown how individual HMOs change in concentration over 24 months of lactation. OBJECTIVES: To understand how HMO concentrations change over 24 months of lactation. METHODS: Breast milk samples were collected from participants in a longitudinal cohort study of Hispanic mother-infant pairs at 1, 6, 12, 18, and 24 months postpartum. Concentrations of 19 of the most abundant HMOs were measured using HPLC. Because the parent study is ongoing and not all participants have finished all time points yet, the sample sizes ranged per time point (n = 207 at 1 month; n = 109 at 6 months; n = 83 at 12 months; n = 59 at 18 months; and n = 28 at 24 months). Approximately 88% of participants were classified as HMO secretors-a genetic factor that affects concentrations of HMOs such as 2'fucosyllactose (2'FL) and lacto-N-fucopentaose I-while the remaining 12% were classified as nonsecretors. Mixed models were used to examine changes in HMO concentrations and relative abundances over the course of lactation. RESULTS: The majority of HMOs significantly decreased in concentration over the course of lactation. The exceptions were 2'FL, sialyl-lacto-N-tetraose b, and disialyl-lacto-N-tetraose, which did not change with time, and 3-fucosyllactose (3FL) and 3'-sialyllactose (3'SL), which significantly increased. The concentration of 3FL increased 10-fold, from 195 (IQR 138-415) µg/mL at 1 month to 1930 (1100-2630) µg/mL at 24 months, while 3'SL increased 2-fold, from 277 (198-377) µg/mL to 568 (448-708) µg/mL over the same time period. CONCLUSIONS: These results indicate that HMOs do not decrease in concentration uniformly across lactation. In particular, 3FL and 3'SL increased over the course of lactation in this cohort. Future studies are required to fully understand the functions of these HMOs.

Timing of food consumption in Hispanic adolescents with obesity.

BACKGROUND: Little is known about the normal eating time periods in adolescents with obesity and how these patterns change throughout development. As the obesity epidemic continues to rise in adolescence, it becomes imperative to understand developmentally appropriate eating behaviours and to create weight management strategies that build on those innate patterns and preferences. The purpose of this study was to determine the most common habitual eating windows observed in adolescents with obesity. METHODS: Participants were 101 Hispanic adolescents (mean age 14.8 ± 2.1 years; 48 male/53 female) with obesity (BMI ≥95th percentile) who were recruited as part of a larger clinical trial. Dietary intake and meal timing was determined using multiple pass 24-hours recalls. Histograms were utilized to determine the natural distribution of percent consumption of total kilocalories, carbohydrates and added sugar per hour. RESULTS: The majority of total kilocalories (65.4%), carbohydrates (65.3%) and added sugar (59.1%) occurred between 11:00 and 19:00. Adolescents were 2.5 to 2.9 times more likely to consume kilocalories, carbohydrates, and added sugar during the 8-hour window between 11:00 am and 19:00 pm than other time windows examined (all P < .001). The consumption of these calories did not differ between weekdays and weekend (P > .05) or by sex. CONCLUSIONS: In this cohort, more than 60% of calories, carbohydrates and added sugar were consumed between 11:00 am and 19:00 pm, which is concordant with an afternoon/evening chronotype that is common in adolescents. Our findings support this 8-hour period as a practical window for weight loss interventions that target pre-specified eating periods in this population.

Learning to overeat in infancy: Concurrent and prospective relationships between maternal BMI, feeding practices and child eating response among Hispanic mothers and children.

BACKGROUND: Parents play a key role in shaping children's eating behaviours and self-regulation. There is limited data on how maternal weight influences feeding practices in the first year of life. OBJECTIVE: To examine the relationships between maternal BMI, feeding practices and infant eating behaviours related to self-regulation. METHODS: Participants were 160 mother-infant dyads. A longitudinal design was used to examine concurrent and prospective associations between maternal 6-month postpartum BMI, mothers' feeding practices at 6 months (Infant Feeding Practices Questionnaire) and children's eating behaviours at 6 months (Baby Eating Behaviour Questionnaire) and 12 months (Child Eating Behaviour Questionnaire). RESULTS: Higher maternal BMI was associated positively with mothers' use of restrictive feeding practices (ß = 0.036, p = 0.033), and inversely with responsivity to infant satiety cues (Spearman partial r = -0.249, p = 0.002) at 6 months. Mother's restrictive feeding practices were associated with infant food responsiveness (ß = 0.157, p = 0.009) and emotional overeating (ß = 0.118, p = 0.005) at 12 months. Maternal use of responsive feeding practices was associated with lower infant food responsiveness at 6 months (Spearman partial r = -0.173, p = 0.031) and lower emotional overeating at 12 months (Spearman partial r = -0.183, p = 0.022). CONCLUSIONS: Our findings add to studies suggesting that feeding practices can provide mechanistic pathways in the intergenerational transmission of obesity. Postpartum family-system approaches focusing on maternal health while integrating infant feeding guidance may confer benefits in improving maternal-child health.