Effect of milk fat globules on growth and metabolism in rats fed an unbalanced diet.

We assessed the effects of supplementing milk fat globules (MFG) on the growth and development of the skeleton in rats fed a Western unbalanced diet (UBD). The UBD is high in sugar and fat, low in protein, fiber, and micronutrients, and negatively impacts health. The MFG-a complex lipid-protein assembly secreted into milk-has a unique structure and composition, which differs significantly from isolated and processed dietary ingredients. Rats consuming the UBD exhibited growth retardation and disrupted bone structural and mechanical parameters; these were improved by supplementation with small MFG. The addition of small MFG increased the efficiency of protein utilization for growth, and improved trabecular and cortical bone parameters. Furthermore, consumption of UBD led to a decreased concentration of saturated fatty acids and increased levels of polyunsaturated fatty acids (PUFA), particularly omega-6 PUFA, in the serum, liver, and adipose tissue. The addition of small MFG restored PUFA concentration and the ratio of omega-6 to omega-3 PUFA in bone marrow and adipose tissue. Finally, large but not small MFG supplementation affected the cecal microbiome in rats. Overall, our results suggest that natural structure MFG supplementation can improve metabolism and bone development in rats fed an UBD, with the effects depending on MFG size. Moreover, the benefits of small MFG to bone development and metabolism were not mediated by the microbiome, as the detrimental effects of an UBD on the microbiome were not mitigated by MFG supplementation.

Dietary pomegranate peel improves milk quality of lactating ewes: Emphasis on milk fat globule membrane properties and antioxidative traits.

Concentrated pomegranate peel extract (CPE) was supplemented to ewes, and milk yield and fat content-fatty acid (FA) and phospholipid (PL) composition-were monitored. CPE-fed ewes had higher milk yield, and fat, protein and lactose contents than controls. Milk PL content-20% higher in the CPE-supplemented group-was regulated by treatment and not by total fat content; milk phosphatidylethanolamine and phosphatidylcholine increased by 22 and 26%, respectively, in CPE-supplemented vs. control ewes. Milk saturated FA concentration was higher, and total polyunsaturated and monounsaturated FA content lower in the CPE vs. control group, regardless of milk total fat content. CPE supplementation increased milk antioxidant capacity, suggesting antioxidant transfer from dietary source to milk, increasing stability and nutritive value. Our study provides first evidence for milk quality improvement in terms of antioxidants and PL enrichment without compromising total milk fat, suggesting strategies to improve dairy animals' milk composition without compromising total production.

Atrazine-induced toxicity in goat spermatozoa is alleviated to some extent by polyphenol-enriched feed.

Atrazine (ATZ) is one of the most extensively used herbicides to control growth of broadleaf and grassy weeds in crops. ATZ and its metabolites have deleterious effect on sperm quality. ATZ is also known for its ability to induce oxidative stress. Pistacia lentiscus (PL) is an evergreen shrub, with a high content of polyphenols in leaf extracts, with a known anti-inflammatory and antioxidant properties. The protective effect of PL or its extracts against ATZ-induced damage have not been yet evaluated. We examined the harmful effects of atrazine (ATZ) exposure on male reproductive system, using goat (Capra hircus) model spermatozoa and the protective effects of PL and PL ethanolic extract (PLE). In in-vivo experiments, male goats were fed a standard ration or one supplemented with 15 mg ATZ/kg body weight daily, for 6 months. Exposure to ATZ impaired the spermatozoa's morphology, viability, mitochondrial membrane potential and cell lipid composition. These alterations may in turn lead to reduced fertilization competence of the exposed spermatozoa. In an ex-vivo experiment, spermatozoa from male goats fed a standard ration or one supplemented with PL or PLE for 90 days and then were exposed to 1 µM ATZ or 10 µM of its major metabolite diaminochlorotriazine (DACT) through in-vitro capacitation. Prefeeding with PL or PLE partially attenuated the harmful effects of ATZ and DACT. Dietary supplementation with polyphenol-enriched feed can protect, to a certain extent, spermatozoa in males exposed to environmental toxicants.

Influence of gestational diabetes mellitus on fatty acid concentrations in human colostrum.

OBJECTIVE: The aim of this study was to examine differences in fatty acid concentrations in colostrum of women with and without gestational diabetes mellitus (GDM). The effect of GDM on fatty acid composition of colostrum is not fully understood, although rates of GDM are increasing globally. METHODS: A prospective case-control study was conducted of postpartum women with and without GDM. Gas chromatographic analysis was conducted to examine differences in colostral fatty acids of the colostrum samples of 29 women with and 34 without GDM. RESULTS: Analyses of the fatty acid composition revealed significantly higher concentrations of four essential ω-6 polyunsaturated fatty acids-γ-linolenic, eicosatrienoic, arachidonic, and docosatetraenoic-in the colostrum of GDM women compared with non-GDM women. Timing of collection influenced saturated medium chain fatty acid and monounsaturated fatty acid levels. CONCLUSIONS: Differences in concentrations of ω-6 fatty acids but not in dietary linoleic fatty acid or ω-3 fatty acids suggest that altered concentrations are attributed to changes in specific endogenous metabolic pathways. Implications of higher concentrations of ω-6 fatty acids in the colostrum of women with GDM have yet to be determined. Timing of colostrum collection is critical in determining colostral fatty acid and metabolite concentrations.

Human milk fatty acids composition is affected by maternal age.

Human colostrums and transition milk were collected from women under the age of 37 years and women aged 37 years and older. Transition milk of the younger group had lower fat content and 10-fold higher concentrations of omega 6 FA, eicosadecanoic, and arachdonic acids. Gestational age affected the colostrum concentration of total fat and omega 3 and omega 6 FA composition only in the older group. We concluded that age may be a factor in the FA composition of human milk. This should be taken into account when planning diets for pregnant women of different ages.

Fatty acids composition of human milk fed to small for gestational age infants.

OBJECTIVES: To test the null hypothesis that mothers of asymmetric small for gestational age (SGA) infants produce milk with fatty acids composition similar to that of lactating mothers of appropriate-for-gestational-age (AGA) infants. METHODS: We obtained human milk (HM) from 2 groups of lactating volunteers that gave birth to asymmetric SGA (study group) or AGA infants (control group). Each mother was asked to contribute by manual expression at least one of 3 samples: first 72 hours after labor (colostrum), day 2-7 postpartum (transitional milk) and 14 days post partum (mature milk). After lipid extraction using Folch's cold-extraction procedure fatty acids were analyzed using gas chromatography. RESULTS: A total of 108 samples were obtained in 60 women. In univariate analysis, there were no significant differences in any of the fatty acids concentrations examined between groups. This remained true when timing of the sample (colostrum, transitional or mature milk) or gestational age were introduced as confounders in analysis of variance (general linear model). CONCLUSION: Fatty acid composition of human milk is not affected by whether or not the infant was fetal growth restricted. We suggest that mothers of SGA infants may be reassured about the fat quality of their milk.

The relationship between size and lipid composition of the bovine milk fat globule is modulated by lactation stage.

The effect of lactation stage and size on the lipid composition of bovine milk fat globules (MFG) and their membranes (MFGM) was investigated. MFG were separated into six size groups (1-3 µm) from samples collected in early, mid and late lactation stages (10-250 days postpartum). Fatty acid and polar lipid composition was determined in each size group, at each lactation stage. PUFA concentration was affected by lactation stage but not MFG size. Saturated fatty acid concentration at 60 days postpartum was 10% higher in small vs. large globules. Phosphatidylcholine and cholesterol followed the same concentration pattern throughout lactation in all MFG size groups. From day 100 postpartum on, phosphatidylethanolamine concentration was constant in the large MFG, but dropped twofold in the small MFG. Results suggest distinct compositional regulation for large and small MFG at different lactation stages. Such interactions between structure, composition and lactation stage may be exploited for human milk and dairy product consumption.