Three genes have been identified that may influence a woman’s milk supply when she is trying to breastfeed, researchers say.
While the precise role of the genes isn’t clear yet, the findings “will pave the way for more research in the area of milk production… and future studies will assist in our understanding, diagnosis, and treatment of breastfeeding difficulties,” they wrote in a report published in Science Advances.
In fresh breast milk samples donated by nine lactating people with low milk production, seven with high milk production, and 14 with normal milk production, the researchers analyzed the genetic makeup of milk fat globules and of cells that had come from the lining of the milk duct.
Low and high milk producers had differences in cell types and in levels of three genes called GLP1R, PLIN4, KLF10.
Because breastmilk delivers the mother's beneficial bacteria to the infant's intestines, the researchers also wanted to know whether genes affecting milk volume would also affect the health and variety of the baby's gut bacteria, which play a key role in immune, metabolic, and nervous system functions.
Mothers’ milk supply levels did not impact the babies’ intestinal bacteria, or microbiome, they found.
“These findings further support the messaging that individuals with low milk supply should be encouraged to continue partial breastfeeding to support healthy infant microbiome development,” the researchers said.