Efeito do estado nutricional materno sobre a concentração de compostos bioativos do colostro

Abstract

Obesity is currently configured as a serious global public health problem, increasingly common in women of childbearing age. Excess weight during pregnancy is associated with a higher relative risk of variation in human milk components. The presence of bioactive compounds with non-nutritional functions in child health and their dynamic concentration in human milk may vary due to several factors, including maternal nutritional status. Therefore, this study aims to evaluate the effect of maternal BMI on the concentration of bioactive compounds in colostrum. To achieve this, a crosssectional study was carried out, with postpartum women hospitalized in a public maternity hospital, aimed at assisting women with low and medium obstetric risk, with 100% assistance provided by the SUS. The sample consisted of 80 mothers, 20 of whom had recently given birth for each category of BMI, considering the following inclusion criteria: age group of 20 – 40 years, pregnancy with a single live fetus, gestational age of the conceptus ≥ 37 weeks, absence of infectious diseases or gestational clinical complications and with a record of gestational weight in the maternity medical record or on the pregnant woman's card, as long as it is dated up to 30 days before delivery. Colostrum collection was performed by manual milking at the bedside, between 24-48 hours after delivery, by the patient herself, supervised by a qualified researcher. Afterwards, the colostrum was immediately refrigerated (-20°C) and transported for storage in an ultrafreezer (-80°C), until the moment of analysis of its components by nuclear magnetic resonance (NMR). The identification of groups of milk samples and biomarkers corresponding to the metabolic profile of the mothers (bioactive compounds in breast milk) were evaluated by principal component analysis (PCA) and by orthogonal discriminant analysis by partial least squares (OPLS-DA), considering the four different categories of maternal BMI (Low weight (B), normal weight (E), overweight (S) and obesity (O). Analyzes were performed using the SIMCA-P software (version 14.0, Umetrics, Umeå, Sweden). A total of 22 metabolites were found in breast milk samples, 12 of which were quantified in the aqueous phase (amino acids and sugars). The results of the 6 paired series OPLS-DA (O versus group S (OxS); group O versus group B (OxB); group O versus group E (OxE); group S versus group B (SxB); group S versus group E (SxE) and group B versus group E (SxE) in relation to each metabolite, showed that there were no differences significant among breast milk samples, CV-ANOVA p > 0.05. Thus, the paired t-test (p < 0.05) was applied to verify possible significant differences between the pairing of groups (BxExSxO) in relation to each metabolite. In our study, N- cetylneuraminic Acid (Neu5AC) had higher levels in obese mothers when compared to underweight mothers (p = 0.019) and eutrophic mothers (p = 0.015). The levels of N-Acetyl-L-Glutamine showed a significant difference in the comparison between low weight mothers and eutrophic mothers (BxE, p = 0.021), with low weight mothers having a greater amount of this metabolite. A similar result was observed for fucosis, which was shown to be elevated in low weight mothers compared to eutrophic mothers (BxE, p = 0.044). Because the above findings are influenced by some factors related to the mother-child binomial, further studies are needed to elucidate the possible influence of maternal nutritional status on the concentration of metabolites that make up fucosylated and sialylated Human Milk Oligosaccharides (HLL). These findings encourage further investigations into the impact of these bioactive factors on child health.