Human milk cholesterol is associated with lactation stage and maternal plasma cholesterol in Chinese populations

Network analysis of the proteome and peptidome sheds light on human milk as a biological system

Proteins and peptides found in human milk have bioactive potential to benefit the newborn and support healthy development. Research has been carried out on the health benefits of proteins and peptides, but many questions still need to be answered about the nature of these components, how they are formed, and how they end up in the milk. This study explored and elucidated the complexity of the human milk proteome and peptidome. Proteins and peptides were analyzed with non-targeted nanoLC-Orbitrap-MS/MS in a selection of 297 milk samples from the CHILD Cohort Study. Protein and peptide abundances were determined, and a network was inferred using Gaussian graphical modeling (GGM), allowing an investigation of direct associations. This study showed that signatures of (1) specific mechanisms of transport of different groups of proteins, (2) proteolytic degradation by proteases and aminopeptidases, and (3) coagulation and complement activation are present in human milk. These results show the value of an integrated approach in evaluating large-scale omics data sets and provide valuable information for studies that aim to associate protein or peptide profiles from biofluids such as milk with specific physiological characteristics.

Ostrich oil as a fat substitute in milk‐based infant formula

In this study, the possibility of replacing vegetable fats with ostrich oil in infant formula (IF) production was investigated. The fatty acid profile, the positional distribution of fatty acids in the triacylglycerols, the cholesterol content, and the physicochemical properties of ostrich oil were determined and compared with breast milk fat and vegetable oils. In the next step, two infant formulas were produced using ostrich oil and vegetable oils and the physicochemical properties, rheological properties, color parameters, and sensory analysis of the resultant powders were compared. The results showed that the predominant fatty acids in ostrich oil are palmitic acid, oleic acid, and linoleic acid which is similar to breast milk fat and vegetable oils. The presence of appropriate cholesterol content in ostrich oil makes it more similar to breast milk fat compared to vegetable fats. Palmitic acid was located at sn-2 position in 15% triacylglycerol from ostrich fat, which was equal to the amount reported for vegetable fats. The incorporation of ostrich oil in infant formula production showed that there is no statistically significant difference between quality attributes of powder formulated with ostrich oil or vegetable oils. Therefore, ostrich oil can be introduced as a new source of edible oil, and addition of ostrich oil is an effective way to reduce the gap between the composition of breast milk and infant formula.

Human Milk Lipid Profiles around the World: A Systematic Review and Meta-Analysis

Reported breast milk lipid concentrations may vary with geographical region, postnatal age, and year of sample collection. In this review, we summarized data on the concentrations of total fat, total phospholipids, cholesterol, and fatty acids in human milk worldwide and their variation according to lactation stage, study area, and sample collection year. A systematic literature search was performed using the PubMed, Embase, Web of Science, and Medline databases for English-language papers and Wanfang and China National Knowledge Infrastructure databases for Chinese-language papers. A total of 186 studies evaluating the human milk lipid profiles were included. According to random-effects models based on worldwide data, the summarized means (95% CIs) as percentages of total fat were 42.2% (41.1%, 43.3%) for SFAs, 36.6% (35.6%, 37.5%) for MUFAs, and 21.0% (19.3%, 22.7%) for PUFAs. However, the study heterogeneity was high for most types of fatty acids (I2 > 99%). Human milk from Western countries had higher concentrations of MUFAs and 18:1n-9 (ω-9), but lower concentrations of PUFAs, 18:2n-6, 20:4n-6, 18:3n-3, 20:5n-3, 22:6n-3, and total n-6 PUFA compared with those from non-Western countries (P < 0.001-0.011). Significant lactation stage differences were observed for total fat and some individual fatty acids. The concentrations of SFAs and 16:0 were significantly negatively correlated with sampling year (P < 0.001-0.028). In contrast, a significant positive correlation between the concentrations of 18:2n-6 and 18:3n-3 and sampling year was observed (P < 0.001-0.035). Our results suggest that the pooling of data on human milk lipid profiles in different studies should be done with caution due to the high between-study heterogeneity. The concentration of lipids, including total fat, cholesterol, and specific fatty acids, differs in human milk according to lactation stage, geographical region, and year of sample collection.