Reverting to a healthy diet during lactation normalizes maternal milk lipid content of diet-induced obese rats and prevents early alterations in the plasma lipidome of the offspring

Impact of Western diet on milk miRNAs and target genes in offspring adipose tissue: modulation by betaine during suckling

OBJECTIVE

We investigated how a maternal Western diet (WD) affects milk microRNA (miRNA) profile and associates with metabolic programming in adipose tissues in pups. We also explored the impact of betaine supplementation during suckling, as betaine levels are reported to be reduced in WD-fed dams' milk.

METHODS

A microarray analysis was performed to profile miRNA expression in dams' milk. Betaine levels were measured in the milk of dams and the plasma of their offspring. We also analyzed the expression of miRNA target genes in white and brown adipose tissues through gene expression analysis.

RESULTS

Our findings confirm decreased betaine levels in the milk of WD-fed dams and the plasma of their offspring. The miRNA screening identified 37 deregulated miRNAs (36 downregulated), with the following 6 as the most relevant: miR-223-3p; miR-32-5p; let-7i-5p; miR-140-5p; miR-29a-3p; and miR-29c-3p (downregulated). Some of their target genes were upregulated in brown and white adipose tissues, particularly those related to thermogenesis and browning. Betaine supplementation in pups demonstrated a slight protective effect in females by enhancing thermogenic capacity.

CONCLUSIONS

Our results underscore the profound impact of a maternal WD on milk miRNA composition, potentially influencing gene expression, thermogenesis, and adiposity in the offspring, with sex-related differences.

Composition of Breast Milk in Women with Obesity

Background/Objectives: Among US breastfeeding women, those with obesity have significantly increased breast milk fat and caloric content from foremilk to hindmilk, with a 4-fold increase in fat content from the first to last milk sample. In view of different dietary norms and nutritional standards, we sought to evaluate the relationship between maternal BMI with breast milk fat and calorie content in women from Brazil, a low-middle-income country. Methods: Women who delivered singleton-term neonates were recruited from the Ana Abrao Breastfeeding Center (AABC) and Human Milk Bank at the Federal University of Sao Paulo, Brazil. These women were then studied at 7-8 weeks postpartum. Women were grouped by BMI categories of nonobese (NonOB; BMI 18.5-29.9) and obese (OB; BMI ≥ 30). A breast pump was applied, and milk samples were obtained continuously in 10 mL aliquots from foremilk to hindmilk; samples were analyzed for macronutrients and lipids, and maternal blood was analyzed for serum lipids and glucose. Results: As compared to NonOB women, those with OB had significantly higher milk fat in the mid (4.9 ± 0.3 vs. 3.9 ± 0.2) and last hindmilk (6.6 ± 0.4 vs. 5.5 ± 0.3) samples, though not in the first foremilk sample, as compared to NonOB women. In both NonOB and OB subjects, milk caloric and fat content increased 1.5 to 2-fold from foremilk to hindmilk, with the average milk caloric value being 11% greater in OB women. Protein content was significantly increased in all three milk samples (first, middle, and last) in women with OB. Conclusions: Although the value of breastfeeding remains clear, these findings may have significant implications for infant nutrition and excessive infant weight gain in women with OB.

Maternal Dietary Improvement or Leptin Supplementation During Suckling Mitigates the Long-Term Impact of Maternal Obesogenic Conditions on Inflammatory and Oxidative Stress Biomarkers in the Offspring of Diet-Induced Obese Rats

This study investigates the impact of maternal nutrition during lactation on inflammation and oxidative stress in the offspring of diet-induced obese rats, along with the potential benefits of leptin supplementation during suckling. Dams were fed either a standard diet (SD), a western diet (WD) before and during gestation and lactation (WD-dams), or a WD switched to an SD during lactation (Rev-dams). Offspring were supplemented with leptin or vehicle during suckling and then fed an SD or WD until four months. Offspring of the Rev-dams exhibited improved metabolic indicators, including lower body weight, reduced plasma levels of TNF-alpha, a higher adiponectin/leptin (A/L) ratio, enhanced liver antioxidant defenses, and decreased inflammation markers in white adipose tissue (WAT) compared to WD-dams, with sex differences. Leptin supplementation further modulated these markers, reducing oxidative stress in liver and inflammation in WAT and liver (e.g., hepatic Tnfa expression decreased by 45% (males) and 41% (females) in the WD group on an SD), and improving the A/L ratio, with effects varying by maternal conditions and sex. In conclusion, this study underscores the importance of maternal nutrition and leptin intake during suckling in shaping long-term metabolic and inflammatory health in offspring, offering strategies to mitigate the adverse effects of maternal obesity on future generations.

Placental inflammation, oxidative stress, and fetal outcomes in maternal obesity

The obesity epidemic has led to a growing body of research investigating the consequences of maternal obesity on pregnancy and offspring health. The placenta, traditionally viewed as a passive intermediary between mother and fetus, is known to play a critical role in modulating the intrauterine environment and fetal development, and we now know that maternal obesity leads to increased inflammation, oxidative stress, and altered placental function. Here, we review recent research exploring the involvement of inflammation and oxidative stress as mechanisms impacting the placenta and fetus during obese pregnancy. Understanding them is crucial for informing strategies that can mitigate the adverse health effects of maternal obesity on offspring development and disease risk.

Hydrophilic Interaction Liquid Chromatography-Hydrogen/Deuterium Exchange-Mass Spectrometry (HILIC-HDX-MS) for Untargeted Metabolomics

Liquid chromatography with mass spectrometry (LC-MS)-based metabolomics detects thousands of molecular features (retention time-m/z pairs) in biological samples per analysis, yet the metabolite annotation rate remains low, with 90% of signals classified as unknowns. To enhance the metabolite annotation rates, researchers employ tandem mass spectral libraries and challenging in silico fragmentation software. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) may offer an additional layer of structural information in untargeted metabolomics, especially for identifying specific unidentified metabolites that are revealed to be statistically significant. Here, we investigate the potential of hydrophilic interaction liquid chromatography (HILIC)-HDX-MS in untargeted metabolomics. Specifically, we evaluate the effectiveness of two approaches using hypothetical targets: the post-column addition of deuterium oxide (D2O) and the on-column HILIC-HDX-MS method. To illustrate the practical application of HILIC-HDX-MS, we apply this methodology using the in silico fragmentation software MS-FINDER to an unknown compound detected in various biological samples, including plasma, serum, tissues, and feces during HILIC-MS profiling, subsequently identified as N1-acetylspermidine.

The Impact of Maternal Obesity on Adipose Progenitor Cells

The concept of Developmental Origin of Health and Disease (DOHaD) postulates that adult-onset metabolic disorders may originate from suboptimal conditions during critical embryonic and fetal programming windows. In particular, nutritional disturbance during key developmental stages may program the set point of adiposity and its associated metabolic diseases later in life. Numerous studies in mammals have reported that maternal obesity and the resulting accelerated growth in neonates may affect adipocyte development, resulting in persistent alterations in adipose tissue plasticity (i.e., adipocyte proliferation and storage) and adipocyte function (i.e., insulin resistance, impaired adipokine secretion, reduced thermogenesis, and higher inflammation) in a sex- and depot-specific manner. Over recent years, adipose progenitor cells (APCs) have been shown to play a crucial role in adipose tissue plasticity, essential for its development, maintenance, and expansion. In this review, we aim to provide insights into the developmental timeline of lineage commitment and differentiation of APCs and their role in predisposing individuals to obesity and metabolic diseases. We present data supporting the possible implication of dysregulated APCs and aberrant perinatal adipogenesis through epigenetic mechanisms as a primary mechanism responsible for long-lasting adipose tissue dysfunction in offspring born to obese mothers.

Stachydrine, N-acetylornithine and trimethylamine N-oxide levels as candidate milk biomarkers of maternal consumption of an obesogenic diet during lactation

We aimed to evaluate whether improving maternal diet during lactation in diet-induced obese rats reverts the impact of western diet (WD) consumption on the metabolome of milk and offspring plasma, as well as to identify potential biomarkers of these conditions. Three groups of dams were followed: control-dams (CON-dams), fed with standard diet (SD); WD-dams, fed with WD prior and during gestation and lactation; and reversion-dams (REV-dams), fed as WD-dams but moved to SD during lactation. Metabolomic analysis was performed in milk at lactation days 5, 10, and 15, and in plasma from their male and female offspring at postnatal day 15. Milk of WD-dams presented, throughout lactation and compared to CON-dams, altered profiles of amino acids and of the carnitine pool, accompanied by changes in other polar metabolites, being stachydrine, N-acetylornithine, and trimethylamine N-oxide the most relevant and discriminatory metabolites between groups. The plasma metabolome profile was also altered in the offspring of WD-dams in a sex-dependent manner, and stachydrine, ergothioneine and the acylcarnitine C12:1 appeared as the top three most discriminating metabolites in both sexes. Metabolomic changes were largely normalized to control levels both in the milk of REV-dams and in the plasma of their offspring. We have identified a set of polar metabolites in maternal milk and in the plasma of the offspring whose alterations may indicate maternal intake of an unbalanced diet during gestation and lactation. Levels of these metabolites may also reflect the beneficial effects of implementing a healthier diet during lactation.

Tracking between cardiovascular-related measures at 4 and 8 years of age in the INMA-Asturias cohort

Identifying cardiovascular-related measures that track from early childhood into later ages may help inform early prevention targets for cardiovascular disease. In this study, the tracking of triglycerides (TG), high-density cholesterol (HDL-c), atherogenic coefficient (AC), waist circumference to height ratio (WC/Height), mean arterial pressure (MAP), and homeostatic model assessment of insulin resistance (HOMA-IR) was examined in the INMA-Asturias cohort between 4 and 8 years of age. The analysis was conducted in 307 children who participated in the INMA-Asturias cohort (Spain) at 4 and at 8 years of age. Quantile regression models were used to evaluate tracking between measures at both ages, with each measure at 8 years as the dependent variable and the rank transformation of the same measure at 4 years as the independent variable. We found a positive association between HDL-c rank at 4 years and higher quantiles of the HDL-c distribution at 8 years, with an increase of 2.93 mg/dL (95% CI: 1.98, 3.87) per decile in the 0.9 quantile. A positive association was also found for WC/Height, with an increase of 0.008 (95% CI: 0.004, 0.012) per decile in the 0.9 quantile. We observed that tracking for AC increased in the higher quantiles of the distribution at 8 years, with an increase of 0.11 (95% CI: 0.09, 0.14) in the 0.6 quantile compared to an effect of 0.15 (95% CI: 0.09, 0.21) in the 0.9 quantile.  Conclusions: Adult markers of dyslipidemia and central obesity tracked between ages 4 and 8 years. For AC, tracking increased in the higher quantiles of the distribution. What is Known: • Atherosclerosis begins in early life, so preventive efforts that start in childhood may delay progression to clinical disease. Determine what cardiovascular risk factors track into time since childhood bring the opportunity to identified those subjects at risk for later cardiovascular disease. • The study of risk factors in health populations and, particularly in children, copes with not clear and/or controversial thresholds definition. This makes it challenging to study tracking in pediatric ages. What is New: • Quantile regression is a useful tool for assessing the tracking of risk factors for which there are no clinically meaningful thresholds. The increasing trend observed in the tracking of dyslipidemia suggests the possible difficulty that children with abnormal values at 4 years of age might have in normalizing them in future years. • The findings of this article may help to determine which cardiovascular-related measures could be screened and followed-up in children.

Influence of Maternal Metabolic Status and Diet during the Perinatal Period on the Metabolic Programming by Leptin Ingested during the Suckling Period in Rats

We aimed to analyze the long-term metabolic effects of leptin supplementation at physiological doses during suckling in the offspring of diet-induced obese rats, together with the potential benefits of improving maternal diet during lactation. Thus, the offspring of: dams fed standard-diet (SD) (CON-dams), dams fed western-diet (WD) before and during gestation and lactation (WD-dams), and dams fed as WD-dams but moved to SD during lactation (REV-dams) were supplemented throughout suckling with leptin or vehicle, and fed SD or WD from weaning to four months. Under SD, leptin treatment significantly improved metabolic profile and body fat accumulation, with stronger effects in the male offspring of CON-dams and REV-dams. Under WD, the offspring of WD-dams presented metabolic alterations that were not evident in the offspring of REV-dams. Moreover, leptin supplementation improved glucose homeostasis in the male offspring of REV-dams. Conversely, leptin supplementation in females born to WD-dams and fed WD from weaning resulted in impaired insulin sensitivity and increased hepatic lipid content. These results highlight the importance of a balanced maternal diet during the perinatal period, especially lactation, for the subsequent metabolic health of the offspring and for the beneficial effects of leptin supplementation during suckling, more evident in the male offspring.

Maternal high-fat diet decreases milk endocannabinoids with sex-specific changes in the cannabinoid and dopamine signaling and food preference in rat offspring

INTRODUCTION

Maternal high-fat (HF) diet during gestation and lactation programs obesity in rat offspring associated with sex-dependent and tissue-specific changes of the endocannabinoid system (ECS). The ECS activation induces food intake and preference for fat as well as lipogenesis. We hypothesized that maternal HF diet would increase the lipid endocannabinoid levels in breast milk programming cannabinoid and dopamine signaling and food preference in rat offspring.

METHODS

Female Wistar rats were assigned into two experimental groups: control group (C), which received a standard diet (10% fat), or HF group, which received a high-fat diet (29% fat) for 8 weeks before mating and during gestation and lactation. Milk samples were collected to measure endocannabinoids and fatty acids by mass spectrometry. Cannabinoid and dopamine signaling were evaluated in the nucleus accumbens (NAc) of male and female weanling offspring. C and HF offspring received C diet after weaning and food preference was assessed in adolescence.

RESULTS

Maternal HF diet reduced the milk content of anandamide (AEA) (p<0.05) and 2-arachidonoylglycerol (2-AG) (p<0.05). In parallel, maternal HF diet increased adiposity in male (p<0.05) and female offspring (p<0.05) at weaning. Maternal HF diet increased cannabinoid and dopamine signaling in the NAc only in male offspring (p<0.05), which was associated with higher preference for fat in adolescence (p<0.05).

CONCLUSION

Contrary to our hypothesis, maternal HF diet reduced AEA and 2-AG in breast milk. We speculate that decreased endocannabinoid exposure during lactation may induce sex-dependent adaptive changes of the cannabinoid-dopamine crosstalk signaling in the developing NAc, contributing to alterations in neurodevelopment and programming of preference for fat in adolescent male offspring.