Milk Polar Lipids Research Articles

Combination of Milk Polar Lipids and Casein Hydrolysate as a Healthy Emulsifier for Ice Cream

Combination of Milk Polar Lipids and Casein Hydrolysate as a Healthy Emulsifier for Ice Cream

Dietary Milk Phospholipids Increase Body Fat and Modulate Gut Permeability, Systemic Inflammation, and Lipid Metabolism in Mice

The study aimed at how dietary milk polar lipids affect gut permeability, systemic inflammation, and lipid metabolism during diet-induced obesity (DIO). C57BL/6J mice (n = 6x3) were fed diets with 34% fat as energy for 15 weeks: (1) modified AIN-93G diet (CO); (2) CO with milk gangliosides (GG); (3) CO with milk phospholipids (MPL). Gut permeability was assessed by FITC-dextran and sugar absorption tests. Intestinal tight junction proteins were evaluated by Western blot. Plasma cytokines were measured by immunoassay. Body composition was assessed by magnetic resonance imaging. Tissue lipid profiles were obtained by thin layer chromatography. Hepatic expression of genes associated with lipid metabolism was assessed by RT-qPCR. MPL increased the efficiency of converting food into body fat and facilitated body fat accumulation compared with CO. MPL and GG did not affect fasting glucose or HOMA-IR during DIO. MPL increased while GG decreased plasma TG compared with CO. MPL decreased phospholipids subclasses in the muscle while increased those in the liver compared with CO. GG and MPL had little effect on hepatic expression of genes associated with lipid metabolism. Compared with CO, MPL decreased polar lipids content in colon mucosa. Small intestinal permeability decreased while colon permeability increased and then recovered during the feeding period. High-fat feeding increased plasma endotoxin after DIO but did not affect plasma cytokines. MPL and GG did not affect plasma endotoxin, adipokines and inflammatory cytokines. After the establishment of obesity, MPL increased gut permeability to large molecules but decreased intestinal absorption of small molecules while GG tended to have the opposite effects. MPL and GG decreased mannitol and sucralose excretions, which peaked at d 45 in the CO group. MPL decreased occludin in jejunum mucosa compared with CO. GG and MPL did not affect zonula occludens-1 in gut mucosa. In conclusion, during DIO, milk GG decreased gut permeability, and had little effect on systemic inflammation and lipid metabolism; MPL facilitated body fat accumulation, decreased gut permeability, did not affect systemic inflammation.

Milk fat globule membrane proteins are crucial in regulating lipid digestion during simulated in vitro infant gastrointestinal digestion

Products of lipolysis released during digestion positively affect the metabolism of newborns. In contrast to the 3-layer biological membranes covering human milk (HM) fat, the lipid droplets in infant milk formula (IMF) are covered by a single membrane composed of casein and whey proteins. To reduce the differences in lipid structure between IMF and HM, studies have used milk fat globule membrane (MFGM) components such as milk polar lipids (MPL) to prepare emulsions mimicking HM fat globules However, few studies have elucidated the effect of membrane proteins (MP) on lipid digestion in infants. In this study, 3 kinds of emulsions were prepared: One with MPL as the interfaced of lipid droplets (RE-1), one with membrane protein concentrate (MPC) (RE-2) as the interface of lipid droplets, and one with both MPL and MPC (1:2) as the co-interface of lipid droplets (RE-3). The interfacial coverage of the emulsions was confirmed by measuring the contents of MPL and MPC at the lipid droplet interface, and by confocal laser scanning microscopy analyzed. By controlling the homogenization intensity, the specific surface area of lipid droplets was controlled at the same level among the 3 emulsions. The stability constants of the emulsions varied, and RE-1 was the most stable. During simulated in vitro infant gastrointestinal digestion, the amount of free fatty acids (FFA) released from the lipid droplets was significantly higher from those with MPC at the interface (RE-2, RE-3) than from that with MPL at the interface (RE-1). The amount of FFA released at the end of intestinal digestion of RE-1, RE-2, and RE-3 was 255.00 ± 3.54 µmol,328.75 ± 5.30 µmol, 298.50 ± 9.19 µmol, respectively. Compared with the lipid droplets in RE-2, those with MPL at the interface (RE-1, RE-3) released more unsaturated fatty acids (USFAs) during digestion. The emulsifying activity index was highest in RE-3 (MPL and MPC co-interface). The presence of MPL at the emulsion interface increased the release of USFAs, while the presence of MPC increased the release of FFA. These results show that both MPL and MP are indispensable in the construction of MFGM. Understanding their effects on digestion can provide new strategies for the development of infant foods.

Dietary milk polar lipids modulate gut barrier integrity and lipid metabolism in C57BL/6J mice during systemic inflammation induced by Escherichia coli lipopolysaccharide

The focus of this work is the role milk polar lipids play in affecting gut permeability, systemic inflammation, and lipid metabolism during acute and chronic inflammation induced by a single subcutaneous injection of lipopolysaccharide. Three groups of C57BL/6J mice were fed: modified AIN-93G diet with moderate level of fat (CO); CO with milk gangliosides (GG); CO with milk phospholipids (MPL). The MPL did not prevent a gut permeability increase upon LPS stress but increased the expression of tight junction proteins zonula occludens-1 and occludin in colon mucosa. The GG prevented the gut permeability increase upon LPS stress. The MPL decreased absolute and relative liver mass and decreased hepatic gene expression of acetyl-CoA carboxylase 2 and 3-hydroxy-3-methylglutaryl-CoA reductase. The GG increased hepatic gene expression of acetyl-CoA acyltransferase 2. In conclusion, milk GG protected the intestinal barrier integrity but had little effect on systemic inflammation and lipid metabolism; milk MPL, conversely, had complex effects on gut permeability, did not affect systemic inflammation, and had beneficial effect on hepatic lipid metabolism.

Camel milk polar lipids ameliorate dextran sulfate sodium-induced colitis in mice by modulating the gut microbiota

Milk contains abundant polar lipids, which are vital constituents of biological membranes. These polar lipids are present in the human diet as phospholipids and sphingolipids. Nevertheless, the limited focus has been on the attributes and role of camel milk polar lipids (MPL). In this study, camel MPL were isolated, and the composition of their lipidome was determined using ultra-high-performance liquid chromatography-tandem MS. This study characterized a total of 333 polar lipids, which encompassed glycerophospholipids and sphingolipids. Camel milk is rich in polar lipids, mainly phosphatidylethanolamine, sphingomyelin, and phosphatidylcholine. The results indicated that MPL intervention relieved the clinical symptoms and colon tissue damage in mice with dextran sulfate sodium-induced colitis, along with suppressing the expression of proinflammatory cytokines. Moreover, the administration of MPL partially alleviated mouse gut microbiota dysbiosis by increasing the abundance of probiotics (such as Lachnospiraceae_NK4A136_group and Muribaculaceae) and decreasing the number of harmful bacteria (such as Bacteroides and Parabacteroides). This study was conducted to investigate the potent protective effects of MPL in camel milk treatments on a mouse model of colitis and provided new ideas for the application of camel milk.

Solubilization of free β-sitosterol in milk sphingomyelin and polar lipid vesicles as carriers: Structural characterization of the membranes and sphingosome morphology

High consumption of plant sterols reduces the risk of cardiovascular diseases in humans and provides health benefits. Increasing the amount of plant sterols in the diet is therefore necessary to reach the recommended daily dietary intake. However, food supplementation with free plant sterols is challenging because of their low solubility in fats and water. The objectives of this study were to investigate the capacity of milk-sphingomyelin (milk-SM) and milk polar lipids to solubilise β-sitosterol molecules in bilayer membranes organised as vesicles called sphingosomes. The thermal and structural properties of milk-SM containing bilayers composed of various amounts of β-sitosterol were examined by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the molecular interactions were studied using the Langmuir film technique, the morphologies of sphingosomes and β-sitosterol crystals were observed by microscopy. We showed that the milk-SM bilayers devoid of β-sitosterol exhibited a gel to fluid Lα phase transition for Tm = 34.5 °C and formed facetted spherical sphingosomes below Tm. The solubilisation of β-sitosterol within milk-SM bilayers induced a liquid-ordered Lo phaseabove 25 %mol (1.7 %wt) β-sitosterol and a softening of the membranes leading to the formation of elongated sphingosomes. Attractive molecular interactions revealed a condensing effect of β-sitosterol on milk-SM Langmuir monolayers. Above 40 %mol (25.7 %wt) β-sitosterol, partitioning occured with the formation of β-sitosterol microcrystals in the aqueous phase. Similar results were obtained with the solubilization of β-sitosterol within milk polar lipid vesicles. For the first time, this study highlighted the efficient solubilization of free β-sitosterol within milk-SM based vesicles, which opens new market opportunities for the formulation of functional foods enriched in non-crystalline free plant sterols.

Role of circulating sphingolipids in lipid metabolism: Why dietary lipids matter.

Sphingolipids are structural components of cell membranes and lipoproteins but also act as signaling molecules in many pathophysiological processes. Although sphingolipids comprise a small part of the plasma lipidome, some plasma sphingolipids are recognized as implicated in the development of metabolic diseases and cardiovascular diseases. Plasma sphingolipids are mostly carried out into lipoproteins and may modulate their functional properties. Lipids ingested from the diet contribute to the plasma lipid pool besides lipids produced by the liver and released from the adipose tissue. Depending on their source, quality and quantity, dietary lipids may modulate sphingolipids both in plasma and lipoproteins. A few human dietary intervention studies investigated the impact of dietary lipids on circulating sphingolipids and lipid-related cardiovascular risk markers. On the one hand, dietary saturated fatty acids, mainly palmitic acid, may increase ceramide concentrations in plasma, triglyceride-rich lipoproteins and HDL. On the other hand, milk polar lipids may decrease some molecular species of sphingomyelins and ceramides in plasma and intestine-derived chylomicrons. Altogether, different dietary fatty acids and lipid species can modulate circulating sphingolipids vehicled by postprandial lipoproteins, which should be part of future nutritional strategies for prevention of cardiovascular diseases.

Effects of Milk Polar Lipids on DSS-Induced Colitis Severity Are Dependent on Dietary Fat Content

In the United States, over three million adults suffer from inflammatory bowel disease (IBD). The gut microbiome, host immune response, and nutrient-microbial interactions are known to play a role in IBD. The relationship between dairy and IBD is controversial; thus, the objectives of this study were to identify how milk polar lipids (MPLs) and anhydrous milk fat affect colitis disease activity, the colonic transcriptome, and the gut microbiome in a mouse model of chemical-induced colitis. Male and female C57BL/6J mice (n = 120) were randomized into either a low (5% w/w) milk fat or a high (21% w/w) milk fat diet supplemented with either 0%, 1%, or 2% w/w of MPLs for three weeks (n = 10/group/sex). Afterwards, colitis was induced using 1% dextran sodium sulfate in drinking water for five days (colitis induction) and then switched to regular water for five days (colitis recovery). Mice fed added MPLs were protected against colitis when fed a high-fat diet, while added MPLs during low-fat diet attenuated disease activity during the colitis induction period yet promoted colitis and inflammation in male mice during the recovery period. Dietary fat content can alter colitis and influence the anti-inflammatory effect of milk polar lipids.

Effects of Milk Polar Lipids on Cardiometabolic Disease Risk Factors, Gut Microbiome, and Lipid Metabolites in Healthy Adults

ObjectivesDietary modification to manage blood lipids is recommended as the primary preventive strategy for atherosclerosis. Polar lipids from milk (phospholipids and sphingolipids) have hypolipidemic effects and dose-dependently reduce intestinal cholesterol absorption in rodent models. The objective of the current study was to evaluate the effect of supplementation of milk polar lipids (MPL) added to milk fat on serum lipids, gut microbiome, and lipid metabolites in healthy adults. MethodsNineteen healthy adults (age: 28.7 ± 5.8, BMI: 22.1 ± 5.6) consumed either 5.3 g/day of MPL-rich powder containing 20 g/day milk fat or a nutritionally matched milk fat-containing control powder (0.3 g MPL/day) for 4 weeks, separated by a 3-week washout period in a randomized, single-blinded crossover study. The primary outcome of the study was serum total cholesterol. Secondary outcomes were other serum lipids, anthropometric measurements, gut microbiome, and fecal and plasma metabolites. ResultsConsumption of additional 5 g/day of MPL did not alter serum lipid concentrations when compared to the control. However, the additional MPL attenuated the increase in waist circumference participants experienced when consuming control powder. MPL consumption increased the levels of total ceramides and very-long-chain fatty acids (VLCFAs) in stool compared to control, while an increase in plasma d39:1 ceramide was observed after supplementing with MPL when compared to the baseline. There was also an increase in fecal acyl alpha-hydroxyl fatty acid (AAHFA) 2:0/24:0, which was found to be positively correlated with the VLCFAs, after consuming the MPL powder. The MPL and control powder significantly reduced the relative abundance of gut bacteria belonging to the order Clostridiales when compared to baseline. However, no other changes in gut microbiota composition were observed with MPL or control supplementation compared to baseline. ConclusionsMPL consumption did not influence serum lipids or gut microbiome composition in this cohort of healthy adults. However, it was shown to increase sphingolipid metabolites in the plasma and feces. Funding SourcesThis research was supported by USDA Hatch/Multi-State Grant to C. Blesso.

Effects of Milk Polar Lipids on Colitis Are Dependent on Dietary Fat Content

ObjectivesIn North America, over 1.5 million people suffer from inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn’s disease. Changes in environmental and lifestyle factors coinciding with westernization has driven a rapid acceleration in IBD prevalence worldwide. The objectives of this study were to identify how different milk lipids affect colitis disease activity, the colonic transcriptome, and the microbiome in a mouse model of chemical-induced colitis. MethodsMale and female C57BL6/J mice (n = 120) were randomized into either a low (5% w/w) milk fat (LFD) or high (21% w/w) milk fat diet (HFD) supplemented with either 0%, 1%, or 2% w/w of milk polar lipids (MPLs) for 3 weeks (n = 10/group/sex). Afterwards, colitis was induced using 1% dextran sodium sulfate (DSS) in drinking water for 5 days and regular drinking water was given for the final 5 days. Colons were used for histology, transcriptomics by RNA-sequencing, and real-time qRT-PCR, and cecal feces were collected for 16S rRNA sequencing for microbiome analysis. Disease Activity Index (DAI) was recorded daily consisting of a weight loss, bleeding, and stool consistency score. ResultsMPLs attenuated DAI score in HFD compared to control during the colitis induction and recovery phase, while MPLs in LFD exacerbated DAI during the recovery period. Colon transcriptomics showed that males fed HFD with MPLs had lower expression of genes associated with inflammatory signaling compared to the HFD without MPLs. Colons of the males fed LFD with MPLs had upregulated pathways involved in inflammatory cytokines and antimicrobial activity and downregulated pathways involved in cAMP signaling and extracellular matrix constituents. Fecal Verrucomicrobia was the most abundant bacterial phyla, while MPLs increased Proteobacteria and Bacteroidetes in LFD compared to HFD in males. Male mice had higher microbial diversity and MPLs increased alpha diversity measures. ConclusionsMPLs protected against colitis in mice fed HFD but promoted the disease under LFD conditions. These results suggest the influence of MPLs on colitis is dependent on dietary fat content. Funding SourcesThis research was supported by a USDA NIFA AFRI grant to C. Blesso.

Comprehensive lipidomic analysis of milk polar lipids using ultraperformance supercritical fluid chromatography-mass spectrometry

Polar lipids in milk are receiving increasing interest due to their bioactivities. However, milk polar lipids present a wide range of physical–chemical properties at different concentrations, making their analysis challenging. In this study, we presented a comprehensive lipidomic method using ultraperformance supercritical fluid chromatography (UPSFC)-quadrupole-time of flight-mass spectrometry (Q-TOF-MS), which enabled the separation of 18 lipid classes (including nonpolar lipids, cholesterol, ceramide, glycerophospholipids, sphingomyelin, and gangliosides) within 10 min. The method was used to analyze the polar lipids in seven samples, including human milk, other mammalian milk and milk fat globule membrane ingredients, identifying 14 lipid classes containing 219 lipid molecular species. A mass spectrometry data processing strategy applicable for high-throughput studies was also developed and validated.

Gut microbiota mediates the alleviative effect of polar lipids-enriched milk fat globule membrane on obesity-induced glucose metabolism disorders in peripheral tissues in rat dams.

Obesity during pregnancy and lactation not only increases the incidence of metabolic disorders and gestational diabetes in mothers, but also programs adiposity and related metabolic diseases in offspring. The aim of this study was to investigate the effects of milk polar lipids on gut microbiota and glucose metabolism in high-fat diet (HFD)-fed rat dams. Sprague Dawley (SD) female rats were fed a HFD for 8 weeks to induce obesity, followed by HFD with or without oral administration of polar lipids-enriched milk fat globule membrane (MFGM-PL) at 400 mg/kg BW during pregnancy and lactation. At the end of lactation, fresh fecal samples of dams were collected, the gut microbiota was assessed, and the insulin-signaling protein expression in peripheral tissues (adipose tissue, liver and skeletal muscle) were measured. MFGM-PL supplementation attenuated body weight gain, ameliorated serum lipid profiles and improved insulin sensitivity in obese dams at the end of lactation. 16 S rDNA sequencing revealed that MFGM-PL increased the community richness and diversity of gut microbiota. The composition of gut microbiota was also changed after MFGM-PL supplementation as shown by an increase in the ratio of Bacteroidetes/Firmicutes and the relative abundance of Akkermansia, as well as a decrease in the relative abundance of Ruminococcaceae. The functional prediction of microbial communities by PICRUSt analysis showed that there were 7 KEGG pathways related to carbohydrate metabolism changed after MFGM-PL supplementation to HFD dams, including glycolysis/gluconeogenesis and insulin signaling pathway. Furthermore, MFGM-PL improved insulin signaling in the peripheral tissues including liver, adipose tissue and skeletal muscle. MFGM-PL supplementation during pregnancy and lactation improves the glucose metabolism disorders in HFD-induced obese dams, which may be linked to the regulation of gut microbiota induced by MFGM-PL.

Optimization of Extraction Process and Composition Identification of Polar Lipids in Milk

In order to develop and utilize the milk polar lipids, the chloroform-methanol extraction method was used to extract the polar lipids from buttermilk. The phosphorus content as an index, the condition of chloroform-methanol volume ratio, liquid-to-methanol ratio, extraction temperature and time were optimized by single-factor experiment and the analysis of response surface methodology determined the optimum extraction conditions. The obtained samples were analyzed and identified by thin-layer chromatography(TLC). The results indicated that the optimal extraction conditions for polar lipids were: Chloroform-methanol volume ratio 2:1(v/v, %), 1:4(v/v, %) for the ratio of material to liquid, 20 ℃ for extraction temperature, and 10 min for extraction time. The phospholipid contents in the sample under this extracted condition was (1.647±0.010) mg/g, and there were polar lipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin. This process aims to provide a research basis for the extraction and development of milk polar lipids.

Cardiometabolic health benefits of dairy-milk polar lipids.

Low-quality dietary patterns impair cardiometabolic health by increasing the risk of obesity-related disorders. Cardiometabolic risk relative to dairy-food consumption continues to be a controversial topic, due to recommendations that endorse low-fat and nonfat dairy foods over full-fat varieties despite accumulated evidence that does not strongly support these recommendations. Controlled human studies and mechanistic preclinical investigations support that full-fat dairy foods decrease cardiometabolic risk by promoting gut health, reducing inflammation, and managing dyslipidemia. These gut- and systemic-level cardiometabolic benefits are attributed, at least in part, to milk polar lipids (MPLs) derived from the phospholipid- and sphingolipid-rich milk fat globule membrane that is of higher abundance in full-fat dairy milk. The controversy surrounding full-fat dairy food consumption is discussed in this review relative to cardiometabolic health and MPL bioactivities that alleviate dyslipidemia, shift gut microbiota composition, and reduce inflammation. This summary, therefore, is expected to advance the understanding of full-fat dairy foods through their MPLs and the need for translational research to establish evidence-based dietary recommendations.

Milk fat as a source of bioactive compounds

Milk fat as a source of bioactive compounds

Triacylglycerols and Polar Lipids in Cow and Goat Milk are Differentially Affected by Various Lipid Supplemented Diets

AbstractThis study characterizes milk triacylglycerol (TAG) and polar lipid (PL) fractions from cows and goats fed various lipid supplements modulating milk fat content. Twelve Holstein cows and 12 Alpine goats, at 86 ± 24.9 and 61 ± 1.8 days in milk, respectively, are allocated to one of 4 groups to receive diets supplemented with either corn oil [5% dry matter intake (DMI)] plus wheat starch (COS), marine algae powder (MAP; 1.5% DMI) or hydrogenated palm oil (HPO; 3% DMI), or a no‐added‐lipid control diet (CTL), according to a 4 × 4 Latin square design with 28 d experimental periods. Milk TAG and PL contents are determined by liquid chromatography‐mass spectrometry (LC‐MS). Multivariate analysis and ANOVA demonstrate major between‐species differences in diet effects. In cows, COS specifically increases TAG 54:3 and 54:4 associated with milk fat depression (MFD), and increases the sum of phosphatidylcholines (PC) and phosphatidylinositols (PI). In addition to causing a MFD, MAP diet increases long‐chain polyunsaturated TAG in both species, with higher magnitude in cows than in goats, and decreases the sum of PI in goats. HPO increases TAG 52:1 and the sum of PI in cows, but not in goats.Practical applications: Feed strategies can quickly and efficiently modulate the ruminant milk fat production and composition to improve nutritional quality for consumers. Certain starch‐rich diets supplemented with polyunsaturated fatty acids (PUFA)‐rich vegetable oils and diets supplemented with marine products (long‐chain PUFA) reduce milk fat secretion and modify the milk fatty acid (FA) profile in cows, but not—or less so—in goats. Advanced analysis of both the TAG and PL fractions of milk fat is required to unravel these differences in lipid metabolism between cows and goats fed various lipid‐supplemented diets. This study brings new insight on using nutritional strategies to control milk lipid composition according to ruminant species.

Digestion and Absorption of Milk Phospholipids in Newborns and Adults.

Milk polar lipids provide choline, ethanolamine, and polyunsaturated fatty acids, which are needed for the growth and plasticity of the tissues in a suckling child. They may also inhibit cholesterol absorption by interacting with cholesterol during micelle formation. They may also have beneficial luminal, mucosal, and metabolic effects in both the neonate and the adult. The milk fat globule membrane contains large proportions of sphingomyelin (SM), phosphatidylcholine (PC), and phosphatidylethanolamine (PE), and some phosphatidylserine (PS), phosphatidylinositol (PI), and glycosphingolipids. Large-scale technical procedures are available for the enrichment of milk fat globule membrane (MFGM) in milk replacement formulations and food additives. Pancreatic phospholipase A2 (PLA2) and mucosal phospholipase B digest glycero-phospholipids in the adult. In the neonate, where these enzymes may be poorly expressed, pancreatic lipase-related protein 2 probably has a more important role. Mucosal alkaline SM-ase and ceramidase catalyze the digestion of SM in both the neonate and the adult. In the mucosa, the sphingosine is converted into sphingosine-1-phosphate, which is both an intermediate in the conversion to palmitic acid and a signaling molecule. This reaction sequence also generates ethanolamine. Here, we summarize the pathways by which digestion and absorption may be linked to the biological effects of milk polar lipids. In addition to the inhibition of cholesterol absorption and the generation of lipid signals in the gut, the utilization of absorbed choline and ethanolamine for mucosal and hepatic phospholipid synthesis and the acylation of absorbed lyso-PC with polyunsaturated fatty acids to chylomicron and mucosal phospholipids are important.

Milk Polar Lipids Supplementation to Obese Rats During Pregnancy and Lactation Benefited Skeletal Outcomes of Male Offspring.

Dietary intervention to obese dams during pregnancy and lactation period provides avenues for improving metabolic profiles of the offspring. In the current study, the effects of polar lipids-enriched milk fat globule membrane (MFGM-PL) supplementation to obese dams during pregnancy and lactation on the skeletal outcomes of male offspring are investigated. MFGM-PL is supplemented to obese rats induced by high-fat diet during pregnancy and lactation at a dose of 400mg kg-1 body weight. Results show that maternal MFGM-PL supplementation significantly ameliorates the stunted skeletal growth of male offspring at weaning. In adulthood offspring, maternal MFGM-PL supplementation protects against high-fat diet (HFD)-induced bone microstructure degeneration and bone marrow adipocyte accumulation. Further investigation shows that maternal supplementation of MFGM-PL significantly ameliorates insulin resistance and increases the mRNA expression of growth hormone releasing hormone (GHRH) in the hypothalamus of HFD offspring. The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis is subsequently enhanced in MFGM-PL + HFD offspring, contributing to the beneficial skeletal outcomes. The findings suggest that maternal MFGM-PL supplementation of HFD dam during pregnancy and lactation shows desirable effects on fetal skeletal development, with lasting beneficial programming impacts on skeletal outcomes of offspring.

Optimization of Encapsulation Using Milk Polar Lipid Liposomes with S-Layer Protein and Transport Study of the ACE-Inhibitory Peptide RLSFNP.

The purpose of this study is to develop a new type of nanodrug delivery material by modifying milk polar lipid (MPL) liposomes with the S-layer protein. LIP-RLSFNP (MPL liposomes encapsulating RLSFNP (Arg-Leu-Ser-Phe-Asn-Pro)) and SLP-LIP-RLSFNP (S-layer protein-modified LIP-RLSFNP) were prepared and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, confocal laser scanning microscopy, surface plasmon resonance, and mastersizer dynamic light scattering measurements. The results showed that the S-layer protein could modify the surface of MPL liposomes, stabilize the shape of the vesicles, and improve the resistance to external interference. Furthermore, SLP-LIP-RLSFNP showed better performance in in vitro and in vivo experiments compared with LIP-RLSFNP in terms of promoting absorption and delayed release. The findings suggested that MPL liposomes modified with the S-layer protein have potential for use as an effective delivery system for therapeutic proteins and peptides.

Milk polar lipids favorably alter circulating and intestinal ceramide and sphingomyelin species in postmenopausal women.

BACKGROUNDHigh circulating levels of ceramides (Cer) and sphingomyelins (SM) are associated with cardiometabolic diseases. The consumption of whole fat dairy products, naturally containing such polar lipids (PL), is associated with health benefits, but the impact on sphingolipidome remains unknown.METHODSIn a 4-week randomized controlled trial, 58 postmenopausal women daily consumed milk PL-enriched cream cheese (0, 3, or 5 g of milk PL). Postprandial metabolic explorations were performed before and after supplementation. Analyses included SM and Cer species in serum, chylomicrons, and feces. The ileal contents of 4 ileostomy patients were also explored after acute milk PL intake.RESULTSMilk PL decreased serum atherogenic C24:1 Cer, C16:1 SM, and C18:1 SM species (Pgroup < 0.05). Changes in serum C16+18 SM species were positively correlated with the reduction of cholesterol (r = 0.706), LDL-C (r = 0.666), and ApoB (r = 0.705) (P < 0.001). Milk PL decreased chylomicron content in total SM and C24:1 Cer (Pgroup < 0.001), parallel to a marked increase in total Cer in feces (Pgroup < 0.001). Milk PL modulated some specific SM and Cer species in both ileal efflux and feces, suggesting differential absorption and metabolization processes in the gut.CONCLUSIONMilk PL supplementation decreased atherogenic SM and Cer species associated with the improvement of cardiovascular risk markers. Our findings bring insights on sphingolipid metabolism in the gut, especially Cer, as signaling molecules potentially participating in the beneficial effects of milk PL.TRIAL REGISTRATIONClinicalTrials.gov, NCT02099032, NCT02146339.FUNDINGANR-11-ALID-007-01; PHRCI-2014: VALOBAB, no. 14-007; CNIEL; GLN 2018-11-07; HCL (sponsor).