Effect of infant's gender and lactation period on biochemical and energy breast milk composition of lactating mothers from Algeria

In this research, we reported the effect of infant's gender on the calorie and biochemical composition of human breast milk during different lactation periods including colostrum, transitional, and mature milk, and to evaluate the difference of total fat, cholesterol, carbohydrate, lactose, glucose, total proteins, whey proteins, casein and energy between human breast milk for male (HBMM) and for female HBMF). In total, 125 HBM samples were analyzed; 72 samples for male infants and 53 with female infants. The main findings were: (1) the mature fat content in HBM for male infants was significantly higher than for female infants (p = 0.017), and (p < 0.001) for both sexes during all lactation periods. Moreover, no significant difference (p > 0.05) was recorded in cholesterol concentrations at all lactation periods between the milk for the different sexes; (2) the concentration of carbohydrate and lactose in colostrum and mature HBMF was higher than in HBMM. At all lactation periods, there was no significant differences in carbohydrate female BM (P = 0.05). By contrast, there were significant differences in males BM (p = 0.03); the lactose content between HBMF and HBMM differed significantly (p < 0.001). The highest glucose concentration was observed in mature HBMF (0.18 ± 0.11 g/L) compared to HBMM (0.13 ± 0.08 g/L) at a statistical significance of p = 0.032. Furthermore, highly significant differences in HBMF glucose concentrations (p < 0.01) were noticed compared with HBMM (p = 0.08) at all lactation periods; and (3) concerning total protein, whey protein and casein, no significant differences between HBMM and HBMF (p > 0.05) were observed in each period of lactation. The results of the current study highlighted that milk energy density was higher in male HBM than in female HBM at stages of lactation with highly significant (p < 0.001) and confirms that biochemical and energy contents, in HBM of lactating mothers from all lactation periods, were affected by the sex of infants.