Breast Milk: A Source of Functional Compounds with Potential Application in Nutrition and Therapy.

Breast milk is an unbeatable food that covers all the nutritional requirements of an infant in its different stages of growth up to six months after birth. In addition, breastfeeding benefits both maternal and child health. Increasing knowledge has been acquired regarding the composition of breast milk. Epidemiological studies and epigenetics allow us to understand the possible lifelong effects of breastfeeding. In this review we have compiled some of the components with clear functional activity that are present in human milk and the processes through which they promote infant development and maturation as well as modulate immunity. Milk fat globule membrane, proteins, oligosaccharides, growth factors, milk exosomes, or microorganisms are functional components to use in infant formulas, any other food products, nutritional supplements, nutraceuticals, or even for the development of new clinical therapies. The clinical evaluation of these compounds and their commercial exploitation are limited by the difficulty of isolating and producing them on an adequate scale. In this work we focus on the compounds produced using milk components from other species such as bovine, transgenic cattle capable of expressing components of human breast milk or microbial culture engineering.

A polyphenolic extract from green tea leaves activates fat browning in high-fat-diet-induced obese mice.

Fat browning has emerged as an attractive target for the treatment of obesity and related metabolic disorders. Its activation leads to increased energy expenditure and reduced adiposity, thus contributing to a better energy homeostasis. Green tea extracts (GTEs) were shown to attenuate obesity and low-grade inflammation and to induce the lipolytic pathway in the white adipose tissue (WAT) of mice fed a high-fat diet. The aim of the present study was to determine whether the antiobesity effect of an extract from green tea leaves was associated with the activation of browning in the WAT and/or the inhibition of whitening in the brown adipose tissue (BAT) in HF-diet induced obese mice. Mice were fed a control diet or an HF diet supplemented with or without 0.5% polyphenolic GTE for 8 weeks. GTE supplementation significantly reduced HF-induced adiposity (WAT and BAT) and HF-induced inflammation in WAT. Histological analysis revealed that GTE reduced the adipocyte size in the WAT and the lipid droplet size in the BAT. Markers of browning were induced in the WAT upon GTE treatment, whereas markers of HF-induced whitening were reduced in the BAT. These results suggest that browning activation in the WAT and whitening reduction in the BAT by the GTE could participate to the improvement of metabolic and inflammatory disorders mediated by GTE upon HF diet. Our study emphasizes the importance of using GTE as a nutritional tool to activate browning and to decrease fat storage in all adipose tissues, which attenuate obesity.

Hypothalamic lipid-laden astrocytes induce microglia migration and activation.

Obesity-induced hypothalamic inflammation is closely associated with various metabolic complications and neurodegenerative disorders. Astrocytes, the most abundant glial cells in the central nervous system, play a crucial role in pathological hypothalamic inflammatory processes. Here, we demonstrate that hypothalamic astrocytes accumulate lipid droplets under saturated fatty acid-rich conditions, such as obese environment, and that the lipid-laden astrocytes increase astrogliosis markers and inflammatory cytokines (TNFα, IL-1ß, IL-6, MCP-1) at the transcript and/or protein level. Medium conditioned by the lipid-laden astrocytes stimulate microglial chemotactic activity and upregulate transcripts of the microglia activation marker Iba-1 and inflammatory cytokines. These findings indicate that the lipid-laden astrocytes formed in free fatty acid-rich obese condition may participate in obesity-induced hypothalamic inflammation through promoting microglia migration and activation.

Cranberry extract attenuates hepatic inflammation in high-fat-fed obese mice.

Cranberry (Vaccinium macrocarpon) consumption has been associated with health beneficial effects. Nonalcoholic fatty liver disease (NAFLD) is a comorbidity of obesity. In the present study, we investigated the effect of a polyphenol-rich cranberry extract (CBE) on hepatic inflammation in high fat (HF)-fed obese C57BL/6J mice. Following dietary treatment with 0.8% CBE for 10 weeks, we observed no change in body weight or visceral fat mass in CBE-supplemented mice compared to HF-fed control mice. We did observe a significant decrease in plasma alanine aminotransferase (31%) and histological severity of NAFLD (33% decrease in area of involvement, 29% decrease in lipid droplet size) compared to HF-fed controls. Hepatic protein levels of tumor necrosis factor α and C-C chemokine ligand 2 were reduced by 28% and 19%, respectively, following CBE supplementation. CBE significantly decreased hepatic mRNA levels of toll-like receptor 4 (TLR4, 63%) and nuclear factor κB (NFκB, 24%), as well as a number of genes related to the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing 3 inflammasome. In conclusion, CBE reduced NAFLD and hepatic inflammation in HF-fed obese C57BL/6J mice. These effects appear to be related to mitigation of TLR4-NFκB related signaling; however, further studies into the underlying mechanisms of these hepatoprotective effects are needed.