Associations between human milk oligosaccharides and infant body composition in the first 6 mo of life

Background: Evidence linking breastfeeding to reduced risk of developing childhood obesity is inconclusive, yet previous studies have not considered variation in specific components of breast milk that may affect early development. Objective: We examined whether differences in the composition of human milk oligosaccharides (HMOs) correlate with infant growth and body composition at 1 and 6 mo of age. Design: Twenty-five mother-infant dyads were recruited from the University Hospital at the University of Oklahoma Health Sciences Center. Infants were breastfed for 6 mo. Breast-milk and infant measures were obtained at 1 and 6 mo of infant age. HMO composition was analyzed by high-pressure liquid chromatography, and infant growth (length and weight) and body composition (percentage fat, total fat, lean mass) were measured by dual-energy X-ray absorptiometry. Relations between HMOs and infant growth and body composition were examined by using multiple linear regression. A priori covariates included maternal prepregnancy body mass index, pregnancy weight gain, and infant age and sex. Results: Higher HMO diversity and evenness at 1 mo were associated with lower total and percentage fat mass at 1 mo. At 1 mo, each 1-mu g/mL increase in lacto-N-fucopentaose (LNFP) I was associated with a 0.40-kg lower infant weight (P = 0.03). At 6 mo, each 1-mu g/mL increase in LNFPI was associated with a 1.11-kg lower weight (P = 0.03) and a 0.85-g lower lean mass (P = 0.01). At 6 mo, each 1-mu g/mL increase in LNFPI was associated with a 0.79-g lower fat mass (P = 0.02), whereas disialyl-lacto-N-tetraose and LNFPII were associated with a 1.92-g (P = 0.02) and 0.42-g (P = 0.02) greater fat mass, respectively. At 6 mo, each 1-mu g/mL increase in fucosyl-disialyl-lacto-N-hexaose and lacto-N-neotetraose was associated with 0.04% higher (P = 0.03) and 0.03% lower (P, 0.01) body fat, respectively. Conclusion: These findings support the hypothesis that differences in HMO composition in mother's milk are associated with infant growth and body composition.