Compostos bioativos no leite humano e sua relação com parâmetros antropométricos maternos e de lactentes

Abstract

Breast milk is widely recognized as the ideal source of nutrition for newborns, offering not only the nutrients necessary for their development, but also protection against infections and diseases. In addition to the benefits for the infant, breastfeeding brings significant advantages for women, such as reducing the risk of metabolic diseases, cancers and helping with postpartum weight loss. The composition of breast milk adapts to the baby's nutritional and immunological needs over time, and contains bioactive compounds, such as oligosaccharides, immunoglobulins, growth factors and hormones, which play vital roles in the development and protection of the newborn (NB). Among the hormones present, ghrelin and leptin stand out, which influence the regulation of appetite and body weight, also affecting breastfeeding women. Furthermore, it is known that maternal obesity can also interfere with breastfeeding, hindering the hormonal response necessary for milk production. This study therefore aims to analyze the relationship between ghrelin and leptin levels in breast milk and the nutritional status of postpartum women and their infants. This is a cross-sectional quantitative study carried out with women in the immediate postpartum period (24 to 48 hours after birth) up to six months of birth. The inclusion criteria were: age over 18 years old; healthy pregnancy; healthy baby born between 37 and 41 weeks of gestation and weighing more than 2,500kg. Postpartum women who had any maternal health problem that could affect breastfeeding, such as hypogalactesia, HIV positive, among others, were excluded; nursing mothers who reported smoking or alcohol consumption; multiple pregnancy; low birth weight of the newborn (< 2,500kg) and history of pre-eclampsia or gestational diabetes during pregnancy. Nutritional status was classified by Body Mass Index (BMI). Breast milk was collected from 74 women and the hormones ghrelin and leptin present in milk were analyzed, considering the relationship with nutritional status and milk phase. Hormonal analyzes of leptin and ghrelin were performed using an immunoenzymatic ELISA assay, using specific commercial kits. The data were analyzed with the SPSS version 20.0 program, using multiple linear regression to control confounding variables. The average levels of ghrelin and leptin in breast milk in this study were 268.38 ng/mL and 54.52 ng/mL, respectively. Ghrelin varied with pre-pregnancy nutritional status (higher in overweight/obesity) and late postpartum period (11-45 days). Leptin was influenced by current nutritional status, type of milk (transition, 4-20 days) and skin-to-skin contact at birth. The regression models also showed that pre-gestational weight and lactation time predict ghrelin, with ghrelin decreasing by 0,004 mg/mL per day of breastfeeding, while leptin is influenced by gestational age and birth weight. The findings can contribute to the promotion of interventions that improve the quality of life of the mother-baby binomial, aiming to highlight the benefits of breastfeeding for both.