Mechanisms for the interaction of the milk fat globule membrane with the plasma membrane of gut epithelial cells

Cow's Milk Bioactive Molecules in the Regulation of Glucose Homeostasis in Human and Animal Studies

Obesity disrupts glucose metabolism, leading to insulin resistance (IR) and cardiometabolic diseases. Consumption of cow's milk and other dairy products may influence glucose metabolism. Within the complex matrix of cow's milk, various carbohydrates, lipids, and peptides act as bioactive molecules to alter human metabolism. Here, we summarize data from human studies and rodent experiments illustrating how these bioactive molecules regulate insulin and glucose homeostasis, supplemented with in vitro studies of the mechanisms behind their effects. Bioactive carbohydrates, including lactose, galactose, and oligosaccharides, generally reduce hyperglycemia, possibly by preventing gut microbiota dysbiosis. Milk-derived lipids of the milk fat globular membrane improve activation of insulin signaling pathways in animal trials but seem to have little impact on glycemia in human studies. However, other lipids produced by ruminants, including polar lipids, odd-chain, trans-, and branched-chain fatty acids, produce neutral or contradictory effects on glucose metabolism. Bioactive peptides derived from whey and casein may exert their effects both directly through their insulinotropic effects or renin-angiotensin-aldosterone system inhibition and indirectly by the regulation of incretin hormones. Overall, the results bolster many observational studies in humans and suggest that cow's milk intake reduces the risk of, and can perhaps be used in treating, metabolic disorders. However, the mechanisms of action for most bioactive compounds in milk are still largely undiscovered.

The Role of Food Matrices Supplemented with Milk Fat Globule Membrane in the Bioaccessibility of Lipid Components and Adaptation of Cellular Lipid Metabolism of Caco-2 Cells

This study aimed to evaluate the digestive efficiency of food matrices supplemented with milk fat globule membrane isolated from buttermilk (BM-MFGM), using the INFOGEST in vitro digestion protocol hyphenated with the assessment of the digested material on the lipid profile of the Caco-2 cell culture model. First, we examined lipid profiles in food matrices supplemented with BM-MFGM and their subsequent digestion. The results showed distinct lipid profiles in different food matrices and micellar fractions. The presence of BM-MFGM lipids changed the cellular lipid profiles in Caco-2 cell cultures, with diverging contents in cholesteryl esters, triacylglycerides, and neutral lipids depending on the micellar food matrix factor. Hierarchical clustering analysis revealed patterns in cellular lipid responses to micellar stimuli, while volcano plots highlighted significant changes in cellular lipid profiles post-treatment. Thus, this study underscores the importance of in vitro digestion protocols in guiding food matrix selection for bioactive ingredient supplementation, elucidating intestinal epithelium responses to digested food stimuli.

Preparation of milk fat globule membrane ingredients enriched in polar lipids: Composition characterization and digestive properties

In this study, milk fat globule membrane (MFGM) ingredients enriched in polar lipids were prepared using membrane filtration, including microfiltration, diafiltration, and ultrafiltration from butter serum powder. Polar lipids (phospholipids, sterols, and gangliosides) in prepared MFGM ingredients were analyzed by 31P nuclear magnetic resonance spectroscopy, GC-MS, and ultra-performance liquid chromatography (UPLC)-MS/MS, respectively. The lipolysis degree and microstructure of MFGM ingredient and soybean lecithin (SL) emulsions during in vitro digestion were also analyzed. Microfiltration showed higher concentration efficiency than ultrafiltration, which increased by 2.16% and 2.73% in phospholipids, respectively. Moreover, diafiltration concentrated more polar lipids (6.39% of phospholipids) than microfiltration. Milk fat globule membrane ingredients had high levels of sphingomyelin (1.27%-1.36%) and ratio of GD3 to GM3 is 9.25- to 9.88-fold. The different lipolysis behaviors between MFGM ingredient emulsions and SL emulsions were correlated with their different polar lipid compositions. Phospholipids from both MFGM ingredients and SL could help maintain the initial structure during the gastric digestion. These results could provide a scientific basis for developing high-polar-lipids food, particularly infant formulas and special functional foods.

Milk fat globule membrane and its polar lipids: reviewing preclinical and clinical trials on cognition

In most parts of the world, life expectancy is increasing thanks to improved healthcare, public health policies, nutrition, and treatment. This increase in lifespan is often not accompanied by an increase in health span, which severely affects people as they age. One notable consequence of this is the increasing prevalence of neurodegenerative diseases such as mild cognitive impairment, dementia, and Alzheimer's disease. Therefore, dietary and pharmaceutical measures must be taken to reduce the burden of such pathologies. Among the different types of nutrients found in the diet, lipids and especially polar lipids are very important for cognition due to their abundance in the brain. Amid the most studied sources of polar lipids, milk fat globule membrane (MFGM) stands out as it is abundant in industrial by-products such as buttermilk. In this narrative review, we discuss the latest, i.e. less than five years old, scientific evidence on the use of MFGM and its polar lipids in cognitive neurodevelopment in early life and their potential effect in preventing neurodegeneration in old age. We conclude that MFGM is an interesting, abundant and exploitable source of relatively inexpensive bioactive molecules that could be properly formulated and utilized in the areas of neurodevelopment and cognitive decline. Sufficiently large randomized controlled trials are required before health-related statements can be made. However, research in this area is progressing rapidly and the evidence gathered points to biological, health-promoting effects.