European Journal of Nutrition: Breast Milk Composition May Be Linked to Early Nervous System Development

The findings were published in the European Journal of Nutrition. An international research team led by Professor Gao Ying of the Shanghai Institute of Nutrition and Health analyzed data from 120 mother-infant pairs.

The researchers measured levels of odd- and branched-chain fatty acids (OBCFAs) in breast milk samples collected 42 days and eight months after childbirth. These compounds are produced through the activity of microorganisms. Their dietary sources include dairy products, meat from ruminant animals and fermented plant-based foods.

The children's development was assessed at eight months of age using standardized tests of cognitive and motor skills. The researchers found that higher concentrations of certain fatty acids, including C15:0 and C17:0, as well as higher overall OBCFA levels in breast milk, were associated with lower motor development scores. The association remained even after accounting for several other factors.

The association was more pronounced among children born by cesarean section, infants of mothers younger than 31, and women who experienced excessive weight gain during pregnancy.

The researchers suggest that a possible explanation may involve interactions between the gut microbiota and the brain. Fatty acids may influence the composition of gut microorganisms, which in turn play a role in early nervous system development. However, this mechanism has not yet been established.

The authors emphasize that the findings need to be verified in larger groups of children with longer follow-up periods. The study cannot establish a cause-and-effect relationship and does not provide grounds for recommending that mothers change their diets or stop breastfeeding.