Multivariate analysis of nutritional profile of human milk compared with milk from 6 farm species

Milk is the first food for humans (and mammals). More than 80% of the global milk production derives from cattle, the remaining is provided by buffaloes, goats, sheep, camels, equids, and few other species. The present study aimed to explore and compare the nutritional profile of human milk in comparison with milk from 6 farm species (cows, buffaloes, sheep, goats, dromedary camels, donkeys). Samples of bulk milk from different farms (≥10 samples/species) were collected from different herds located in Italy, and from two different Algerian areas for individual camel milk samples. Ten individual human milk samples were donated by the human milk bank (BLUD of Vicenza, Italy). A complete macronutrient profile of these samples was obtained through gold standard ISO-IDF procedures and a detailed mineral profile was obtained using ICP-OES instrumentation. The data were analysed using multivariate analysis: principal component (PCA), factor (FA), and cluster analysis. About the PCA, the first PC explained more than 50% of the total variance and the second PC only 11%. Both showed that lactose had an opposite direction compared to all the other macronutrients and minerals (in particular K and Fe). The FA showed that 3 latent explanatory variables controlled 70% of the total variance. In particular, the first factor ‘concentration of milk’ discriminated milk with high or low content of the major macronutrients, except lactose, and some minerals linked to them. The second ‘lactose vs K, Na, ash’ was related to the osmotic pressure of milk. The third factor ‘micro-minerals’ was mainly related to milk Fe, Al, and Si. Finally, the dendrogram obtained from the cluster analysis showed that human milk was very close to donkey milk. Goat milk clustered together with cow milk and they were close to the camel milk. Sheep and buffalo milk were close to each other and most distant from human and donkey milk. Further analyses are scheduled to explore possible effects on human nutrition