Comprehensive Analysis of Lipid Composition in Human Foremilk and Hindmilk

Exploring the association between human breast milk lipids and early adiposity rebound in children: A case-control study

OBJECTIVES

Adiposity rebound (AR) corresponds to the start of the second rise in the body mass index curve during infant growth. Early AR (before age 5) confers increased risk of adiposity and metabolic disorders but is less likely to occur in breastfed infants. Although lipids in breast milk are important in child growth, information is limited regarding which lipids are involved in AR. The object of this study was to explore the association between breast milk lipids and AR status in children.

METHODS

We designed a case-control study of 184 mother-child pairs (AR cases: n = 93; controls: n = 91) included from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Breast milk was collected 1 month postpartum and comprehensive lipid analysis was performed. Partial least square-discriminant analysis was used to explore candidate lipids, and multivariable logistic regression analysis was used to evaluate associations with the AR status of children.

RESULTS

We detected 667 lipid molecules in 12 lipid classes in breast milk. Partial least square-discriminant analysis revealed the association of fatty acid-hydroxy fatty acid (FAHFA) and cholesterol ester (ChE) with AR status. Multivariable logistic regression analysis showed that in pairs with exclusive breastfeeding at 1 month postpartum, FAHFA (odds ratio 1.57 [95% confidence interval, 1.06-2.32]) was positively associated with early AR, and ChE (odds ratio 0.55 [95% confidence interval, 0.36-0.86]) was negatively associated.

CONCLUSIONS

Breast milk lipids (FAHFA, ChE) associated with the AR status of children, indicating the potential to regulate a child's adiposity and possible metabolic disorders in adulthood.

Industrial Scale Production and Characterization of a Whey Fraction Enriched in Extracellular Vesicle Material

Human milk serves the sole nutritional role for the developing infant. During lactation, nano-sized extracellular vesicles (EVs) in milk containing a multitude of biologically active components are transferred from mother to offspring. Infant formula (IF) based on cow milk-derived ingredients has been reported to contain reduced levels of EVs as compared to human milk. There is therefore an unmet need to produce large-scale volumes of milk EVs to improve IF composition. Here, we report a scalable industrial production protocol for a bovine whey-derived ingredient that is highly enriched in EV material using a large-scale sequential ceramic membrane filtration setup. Furthermore, we demonstrate a robust and generally applicable analytical approach to determine the relative contributions of EVs and milk fat globule membrane (MFGM) using molar ratios of the membrane-bound proteins butyrophilin (BTN) and CD9 as surrogate markers for MFGM and EVs, respectively. Taken together, our findings provide a basis for comparing bovine milk-containing foods and aid in developing specialized ingredients that can minimize the compositional difference between infant formula and human milk.

Postpartum changes in maternal physiology and milk composition: a comprehensive database for developing lactation physiologically-based pharmacokinetic models

Introduction

Pharmacotherapy during lactation often lacks reliable drug safety data, resulting in delayed treatment or early cessation of breastfeeding. In silico tools, such as physiologically-based pharmacokinetic (PBPK) models, can help to bridge this knowledge gap. To increase the accuracy of these models, it is essential to account for the physiological changes that occur throughout the postpartum period.

Methods

This study aimed to collect and analyze data on the longitudinal changes in various physiological parameters that can affect drug distribution into breast milk during lactation. Following meta-analysis of the collated data, mathematical functions were fitted to the available data for each parameter. The best-performing functions were selected through numerical and visual diagnostics.

Results and Discussion

The literature search identified 230 studies, yielding a dataset of 36,689 data points from 20,801 postpartum women, covering data from immediately after childbirth to 12 months postpartum. Sufficient data were obtained to describe postpartum changes in maternal plasma volume, breast volume, cardiac output, glomerular filtration rate, haematocrit, human serum albumin, alpha-1-acid glycoprotein, milk pH, milk volume, milk fat, milk protein, milk water content, and daily infant milk intake. Although data beyond 7 months postpartum were limited for some parameters, mathematical functions were generated for all parameters. These functions can be integrated into lactation PBPK models to increase their predictive power and better inform medication efficacy and safety for breastfeeding women.

Donor Milk Expression Habits: Can we Favor Hindmilk Banking for Extremely Preterm Infants?

Background: Extremely preterm infants often receive donor milk. Hindmilk, which is released more than 3 minutes after letdown, could be advantageous due to its elevated levels of fat and calorie density. Donor milk expression habits may influence milk composition but have not yet been investigated. This study aims to assess the practices of milk donors and the feasibility of hindmilk expression. Methods: Active milk donors in Québec were questioned using an online survey about their milk expression habits and whether hindmilk donation would be acceptable to them. Answers were analyzed using mixed methods. Results: Of 181 donors, 126 fully completed the questionnaire (70%); 57% reported expressing donated milk between breastfeeds; 15% reported simultaneously breastfeeding while expressing donated milk from the other breast; 12% reported breastfeeding their baby on each breast, then expressing donated milk (hindmilk). The majority (66%) would be willing to change their habits most or all the time to provide hindmilk for preterm infants. The main themes invoked by respondents in open-ended answers were altruism and gratitude for being able to help others. However, 15% commented on the complexity of milk expression or that adding further complexity might discourage them from donating. Conclusions: Expression practices are variable, which may lead to variability in donor milk composition. Most donors would agree to change their expression habits in favor of giving hindmilk to help the most fragile infants. More information is needed on how changing recommendations for milk expression might impact the supply and composition of donor milk.

Human milk and breastfeeding during ketogenic diet therapy in infants with epilepsy: Clinical practice guideline

Ketogenic diet therapy (KDT) is a safe and effective treatment for epilepsy and glucose transporter type 1 (GLUT1) deficiency syndrome in infancy. Complete weaning from breastfeeding is not required to implement KDT; however, breastfeeding remains uncommon. Barriers include feasibility concerns and lack of referrals to expert centres. Therefore, practical strategies are needed to help mothers and professionals overcome these barriers and facilitate the inclusion of breastfeeding and human milk during KDT. A multidisciplinary expert panel met online to address clinical concerns, systematically reviewed the literature, and conducted two international surveys to develop an expert consensus of practical recommendations for including human milk and breastfeeding in KDT. The need to educate about the nutritional benefits of human milk and to increase breastfeeding rates is emphasized. Prospective real-world registries could help to collect data on the implementation of breastfeeding and the use of human milk in KDT, while systematically including non-seizure-related outcomes, such as quality of life, and social and emotional well-being, which could improve outcomes for infants and mothers. WHAT THIS PAPER ADDS: Human milk and breastfeeding can be incorporated safely into ketogenic diet therapy. With expert guidance, human milk and breastfeeding do not reduce diet effectiveness. We show two strategies for clinical practice to include human milk. Mothers can be encouraged to continue breastfeeding.

Organelle communication maintains mitochondrial and endosomal homeostasis during podocyte lipotoxicity

Organelle stress exacerbates podocyte injury, contributing to perturbed lipid metabolism. Simultaneous organelle stresses can occur in the kidney in the diseased state; therefore, a thorough analysis of organelle communication is crucial for understanding the progression of kidney diseases. Although organelles closely interact with one another at membrane contact sites, limited studies have explored their involvement in kidney homeostasis. The endoplasmic reticulum (ER) protein, PDZ domain-containing 8 (PDZD8), is implicated in multiple-organelle-tethering processes and cellular lipid homeostasis. In this study, we aimed to elucidate the role of organelle communication in podocyte injury using podocyte-specific Pdzd8-knockout mice. Our findings demonstrated that Pdzd8 deletion exacerbated podocyte injury in an accelerated obesity-related kidney disease model. Proteomic analysis of isolated glomeruli revealed that Pdzd8 deletion exacerbated mitochondrial and endosomal dysfunction during podocyte lipotoxicity. Additionally, electron microscopy revealed the accumulation of abnormal, fatty endosomes in Pdzd8-deficient podocytes during obesity-related kidney diseases. Lipidomic analysis indicated that glucosylceramide accumulated in Pdzd8-deficient podocytes, owing to accelerated production and decelerated degradation. Thus, the organelle-tethering factor, PDZD8, plays a crucial role in maintaining mitochondrial and endosomal homeostasis during podocyte lipotoxicity. Collectively, our findings highlight the importance of organelle communication at the 3-way junction among the ER, mitochondria, and endosomes in preserving podocyte homeostasis.

Human milk sphingomyelin: Function, metabolism, composition and mimicking

Human milk, which contains various nutrients, is the "gold standard" for infant nutrition. Healthy human milk meets all the nutritional needs of early infant development. Polar lipids mainly exist in the milk fat globule membrane, accounting for approximately 1-2% of human milk lipids; sphingomyelin (SM) accounts for approximately 21-24% of polar lipids. SM plays an important role in promoting the development of the brain and nervous system, regulating intestinal flora, and improving skin barriers. Though SM could be synthesized de novo, SM nutrition from dietary is also important for infants. The content and composition of SM in human milk has been reported, however, the molecular mechanisms of nutritional functions of SM for infants required further research. This review summarizes the functional mechanisms, metabolic pathways, and compositional, influencing factors, and mimicking of SM in human milk, and highlights the challenges of improving maternal and infant early/long-term nutrition.

Comprehensive analysis of phospholipid in milk and their biological roles as nutrients and biomarkers

Phospholipids (PL) have garnered significant attention due to their physiological activities. Milk and other dairy products are important dietary sources for humans and have been extensively used to analyze the presence of PL by various analytical techniques. In this paper, the analysis techniques of PL were reviewed with the eight trigrams of phospholipidomics and a comprehensive fingerprint of 1295 PLs covering 8 subclasses in milk and other dairy products, especially. Technology is the primary productive force. Based on phospholipidomics technology, we further review the relationship between the composition of PL and factors that may be involved in processing and experimental operation, and emphasized the significance of the biological role played by PL in dietary supplements and biomarkers (production, processing and clinical research), and providing the future research directions.

High-Fat, High-Calorie Breast Milk in Women with Overweight or Obesity and Its Association with Maternal Serum Insulin Concentration and Triglycerides Levels

The childhood obesity epidemic continues to be a challenge. Maternal obesity and excessive infant weight gain are strong predictors of childhood obesity, which itself is a major risk factor for adult obesity. The primary source of nutrition during early life is breast milk, and its composition is impacted by maternal habitus and diet. We thus studied the relationship between maternal BMI, serum lipids and insulin, and breast milk fat and calorie content from foremilk to hindmilk. Women who were exclusively breastfeeding at 7-8 weeks postpartum were BMI classified as Normal (18.5-24.9, n = 9) and women with Overweight/Obese (OW/OB ≥ 25, n = 13). Maternal blood and continuous breast milk samples obtained from foremilk to hindmilk were analyzed, and infant milk intake was assessed. Women with OW/OB had significantly higher milk fat and calorie content in the first foremilk and last hindmilk sample as compared to Normal BMI women. Amongst all women, maternal serum triglycerides, insulin, and HOMA were significantly correlated with foremilk triglyceride concentration, suggesting that maternal serum triglyceride and insulin action contribute to human milk fat content. As the milk fat content of OW/OB women has caloric implications for infant growth and childhood obesity, these results suggest the potential for modulating milk fat content by a reduction in maternal serum lipids or insulin.

The relationship between creamatocrit and cumulative percentage of total milk volume: a cross-sectional study in mothers of very preterm infants in Bangkok, Thailand

BACKGROUND

Human hindmilk contains higher concentrations of fat than foremilk and is more desirable for growth in preterm infants who can tolerate limited volumes of breastmilk. There is currently no clear demarcation between foremilk and hindmilk. This study characterized the change in breastmilk's fat content from the start to end of milk flow and defined this demarcation.

METHODS

Mothers of infants born at ≤ 32 weeks gestational age and ≥ 14 days after childbirth in a University hospital in Bangkok, Thailand between July, 2011, and April, 2012 were included in this cross-sectional study. Breastmilk samples were sequentially collected from the start to end of milk flow in 5-mL aliquots using breast pumps. The fat content of each aliquot from each breast was determined through creamatocrit. The average creamatocrit of foremilk and hindmilk were compared in predefined foremilk to hindmilk ratios of 20:80, 25:75, 33:67, and 50:50. Creamatocrit of the first and last aliquots were compared for mothers who expressed low- (≤ 25-mL per breast) and high-volumes (> 25-mL per breast) of breastmilk.

RESULTS

Of the 25 mothers enrolled, one was excluded due to unsuccessful creamatocrit measurement. The last aliquot of breastmilk had a significantly higher creamatocrit than the first from the same breast (median [interquartile range] of 12.7% [8.9%, 15.3%] vs. 5.6% [4.3%, 7.7%]; test statistic 1128, p < 0.001). Mean creamatocrit in hindmilk portions (9.23%, 9.35%, 9.81%, and 10.62%, respectively) was significantly higher than foremilk portions (6.28%, 6.33%, 6.72%, and 7.17%, respectively) at all predefined ratios. Creamatocrit increased by 1% for every 10% incremental increase in expressed breastmilk volume until the breast was emptied. Low-volume mothers had a significantly higher creamatocrit in the first aliquot compared with high-volume mothers (U = 437, p = 0.002). No significant difference in breastmilk volume was observed between mothers with and without breastfeeding experience.

CONCLUSIONS

Fat content in breastmilk increased on an incremental basis. More fluid definitions of foremilk and hindmilk should be adopted. Mothers should prepare their breastmilk into aliquots based on the required feeding volume of their infant. Hindmilk aliquots can be prioritized over foremilk aliquots to ensure infants obtain optimal caloric intake.

Recent Approaches for Analytical Characterization of Phospholipids in Food Matrices. Is the Phospholipid Fraction Exploited in the Authentication of Food Lipids?

Phospholipids (PhLs) are essential components of cell membranes, characterized by a hydrophobic tail and a hydrophilic headgroup. They play several roles in biological systems, including energy storage, protection, and antioxidant properties. PhLs are found naturally in foods such as egg yolks, milk, or vegetable oils. The composition and concentration of PhLs observed in these foods vary according to the analytical methodology applied, mainly in the extraction and sample treatment process. Analytical targeted approaches for characterized PhLs involve liquid chromatography and mass spectrometry techniques. These methods provide insights into the composition and content of PhLs in food matrices. However, there is limited research on using PhL profiles for food quality evaluation and authentication purposes. Untargeted approaches, such as fingerprinting, have the potential to assess the authenticity of food products by capturing analytical signals linked to the PhL fraction. This review focusses on recent analytical strategies used in characterizing PhLs in distinctive foodstuffs (eggs, milk, and vegetable oils). It discusses sample preparation, analytical separation, and detection techniques. The review also highlights the potential of multivariate approaches to incorporate information on PhL composition to assess the authenticity of food products, an area that has been largely overlooked in previous studies.

Association between Adherence to the Healthy Food Pyramid and Breast Milk Fatty Acids in the First Month of Lactation

In lactating women, breast milk (BM) fatty acids may come from the diet or stored adipose tissue. Our objective was to evaluate the influence of the adherence to the healthy food pyramid (HFP), the dietary pattern in the Mediterranean region, and the maternal body composition on the BM fatty acids pattern. Fifty breastfeeding women answered a socioeconomic survey and the adherence to the HFP questionnaire (AP-Q). In addition, they provided a BM sample at 7 ± 1, 14 ± 1, and 28 ± 1 days postpartum. The body's composition was analyzed at days 7 and 28 by bioimpedance. The BM fatty acids were analyzed by gas chromatography-mass spectroscopy. We found a negative association between the consumption of olive oil and the BM palmitic acid levels (β = -3.19 ± 1.40; p = 0.030), and the intake of cereals and legumes was positively associated with the BM saturated fatty acids (β = 11.48 ± 3.87; p = 0.005). The intake of proteins and vegetables was positively associated with the omega-3 fatty acids and negatively with the omega-6:omega-3 ratio in BM. A negative association between the maternal age (β = -0.43 ± 0.11; p = 0.001) and the α-linolenic acid (ALA) levels was observed, being overall AP-Q positively associated with the ALA levels (β = 0.39 ± 0.15; p = 0.016). Physical activity reduced both the omega-3 and omega-6 fatty acids in BM. Diet had a larger influence than the maternal body's composition on BM fatty acids during the first month of lactation, demonstrating a better adherence to the HFP and positively impacting on the omega-3 content in BM, a fact that is modulated by one's maternal age.