Human milk oligosaccharide 2’-fucosyllactose links feedings at 1 month to cognitive development at 24 months in infants of normal and overweight mothers

BACKGROUND: Infant cognitive development is influenced by maternal factors that range from obesity to early feeding and breast milk composition. Animal studies suggest a role for human milk oligosaccharide (HMO), 2’-fucosyllactose (2’FL), on learning and memory, yet no human studies have examined its impact on infant cognitive development relative to other HMOs and maternal factors. OBJECTIVE: To determine the impact of 2’FL from breast milk feeding on infant cognitive development at 24 months of age relative to maternal obesity and breast milk feeding frequency. METHODS AND MATERIALS: Hispanic mother-infant pairs (N = 50) were recruited across the spectrum of pre-pregnancy BMI. Breast milk was collected at 1 and 6 months, and feedings/day were reported. Nineteen HMOs were analyzed using high-performance liquid chromatography, with initial interest in 2’FL. Infant cognitive development score was assessed with the Bayley-III Scale at 24 months. Linear regressions were used for prediction, and bootstrapping to determine mediation by 2’FL. RESULTS: Maternal pre-pregnancy BMI was not related to feedings/day or HMOs, but predicted poorer infant cognitive development (β = -0.31, P = 0.03). Feedings/day (β = 0.34) and 2’FL (β = 0.59) at 1 month predicted better infant cognitive development (both P≤ 0.01). The association of feedings/day with infant cognitive development was no longer significant after further adjustment for 2’FL (estimated mediation effect = 0.13, P = 0.04). There were no associations of feedings/day and 2’FL at 6 months with infant cognitive development. CONCLUSIONS: Our findings suggest that maternal factors influence infant cognitive development through multiple means. Though maternal obesity may be a separate negative influence, greater frequency of breast milk feeding at 1 month contributed to infant cognitive development through greater exposure to 2’FL relative to other HMOs. The influence of 2’FL was not significant at 6 months, indicating that early exposure to 2’FL may be a critical temporal window for positively influencing infant cognitive development.