Available evidence on human milk composition in relation to infant growth is sparse. This review summarizes recent publications investigating human milk composition; including micro- and macronutrients, human milk oligosaccharides, hormones and other bioactive components, and the association with infant weight, length, body mass index, and body composition.

BackgroundSepsis caused by Staphylococcus aureus constitutes an important cause of morbidity and mortality in humans, and the incidence of this disease-entity is increasing. In this paper we describe the initial microbial dynamics and lesions in pigs experimentally infected with S. aureus, with the aim of mimicking human sepsis and pyemia.MethodsThe study was conducted in anaesthetized and intravenously inoculated pigs, and was based on bacteriological examination of blood and testing of blood for IL-6 and C-reactive protein. Following killing of the animals and necropsy bacteriological and histological examinations of different organs were performed 4, 5 or 6 h after inoculation.ResultsClearance of bacteria from the blood was completed within the first 2 h in some of the pigs and the highest bacterial load was recorded in the lungs as compared to the spleen, liver and bones. This probably was a consequence of both the intravenous route of inoculation and the presence of pulmonary intravascular macrophages. Inoculation of bacteria induced formation of acute microabscesses in the lungs, spleen and liver, but not in the kidneys or bones. No generalized inflammatory response was recorded, i.e. IL-6 was not detected in the blood and C-reactive protein did not increase, probably because of the short time course of the study.ConclusionThis study demonstrates the successful induction of acute pyemia (microabscesses), and forms a basis for future experiments that should include inoculation with strains of S. aureus isolated from man and an extension of the timeframe aiming at inducing sepsis, severe sepsis and septic shock.

Little valid information is available on human milk nutrient concentrations, especially for micronutrients (MN), and there are no valid Reference Values (RVs) across lactation. In this multi-center collaborative study, RVs will be established for human milk nutrients across the first 8.5 months postpartum. Well-nourished, unsupplemented women in Bangladesh, Brazil, Denmark, and The Gambia (n = 250/site) were recruited during the third trimester of pregnancy. Milk, blood, saliva, urine, and stool samples from mothers and their infants are collected identically at three visits (1–3.49, 3.5–5.99, 6.0–8.49 months postpartum). Milk analyses include macronutrients, selected vitamins, trace- elements and minerals, iodine, metabolomics, amino acids, human milk oligosaccharides, and bioactive peptides. We measure milk volume; maternal and infant diets, anthropometry, and morbidity; infant development, maternal genome, and the infant and maternal microbiome. RVs will be constructed based on methods for the WHO Child Growth Standards and the Intergrowth-21st Project. Clinical trials.gov registration number: NCT03254329.

BackgroundAppetite-regulating hormones (ARH) in human milk (HM) are suggested to affect infants’ milk intake and possibly infant growth. Maternal adiposity might contribute to higher levels of ARH in HM, either from the mammary gland or from raised circulating levels due to higher adiposity. Counterfactual-based mediation analysis can define indirect and direct effects between HM ARH and maternal and infant factors, and might be an important tool when investigating the mother-milk-infant triad.ObjectiveWe aim to investigate whether potential associations between (1) maternal adiposity and HM ARH and (2) HM ARH and infant milk intake and growth are mediated through maternal and infant plasma ARH, respectively.Materials and methodsMaternal and infant anthropometry and body composition, HM and blood samples were collected from 223 mother-infant dyads participating in the Mother, Infant and Lactation Quality study at three postpartum visits from 1 to 8.49 months. Leptin, insulin and adiponectin were analyzed using immunoassays. Mediation analyses using linear mixed-effect models were applied to investigate the direct and indirect effects through maternal and infant plasma hormone concentrations.ResultsA positive association between maternal body-mass-index (BMI) and HM leptin was mediated by maternal plasma leptin by 29% when fixing BMI to < 25 kg/m2, and through 51% when fixing BMI to ≥ 25 kg/m2 (pinteraction < 0.01). There was no mediated effect through plasma insulin in the association between BMI and HM insulin (p = 0.068). We found negative and positive associations between HM insulin and total milk intake and infant weight, respectively, however, these diminished in mediation analyses with reduced sample sizes.ConclusionOur main results suggest that the association between maternal adiposity and HM leptin was mediated through circulating leptin to a stronger degree for mothers with overweight compared to mothers with normal-weight. This indicates that excess maternal adiposity, and the resulting rise of circulating leptin and possible concomitant low-grade inflammation, may be reflected in HM composition.Clinical trials registry numberNCT03254329.

Researchers conducting systematic reviews and meta-analyses have suggested that the odds of childhood overweight and obesity are lower in breastfed infants (

Adequate vitamin B12 and folate concentrations are essential for neural development in early childhood but studies in well-nourished children are lacking. We investigated the relation between plasma vitamin B12 and folate at 9 and 36 months and psychomotor development at 36 months in well-nourished Danish children. Subjects from the SKOT cohorts with vitamin B12 measurement and completed Ages and Stages Questionnaire (ASQ-3) at 36 months were included (n=280). Dietary intake, vitamin B12- and folate concentrations were collected at 9 and 36 months, and ASQ-3 was assessed at 36 months. Associations between vitamin B12 and folate at 9 and 36 months and ASQ-3 were analyzed using regression models. Associations between diet and vitamin B12 were also investigated. No children had insufficient vitamin B12(<148pmol/L) at 36 months. Vitamin B12 at 36 month was positively associated with total ASQ-3 corresponding to an increase of 100 pmol/L vitamin B12 per 1.5 increase in total ASQ-3 score; p=0.019) which remained significant after adjustment for potential confounders including 9 months values. Vitamin B12 at 9 months or folate at any time point was not associated with total ASQ-3. Intake of milk products was associated with vitamin B12 at 36 months (p=0.003) and showed a trend at 9 months (p=0.069). Intake of meat products was not associated with vitamin B12. In conclusion, vitamin B12 was positively related to psychomotor development at 3 years in well-nourished children, indicating that the impact of having marginally low vitamin B12 status on psychomotor development in well-nourished children should be examined further.

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