Pregnant women who eat a diet rich in fatty acids such as those found in fish, walnuts and flaxseed can reduce the baby's chances of developing food allergies, researchers say.
The research found that if a mother's diet contains a certain group of polyunsaturated fatty acids (PUFAs), the baby's gut develops differently.
The PUFAs are thought to improve how gut immune cells respond to bacteria and foreign substances, making the baby less likely to suffer from allergies.
"There is intense research interest in maternal diet during pregnancy. In the western diet, the group of polyunsaturated fatty acids that we have shown to help gut function are actually disappearing - our dietary intake of fish and nut oils is being replaced by corn oils which contain a different kind of fatty acid". Said Dr Gaelle Boudry, of the INRA research institute in Rennes, France.
"Our study identifies that a certain group of polyunsaturated fatty acids - known as n-3PUFAs - causes a change in how a baby's gut develops, which in turn might change how the gut immune system develops. These changes are likely to reduce the risk of developing allergies in later life."
The team found that supplementing a mother's diet with n-3PUFA caused the newborn's gut to become more permeable. A more permeable gut enables bacteria and new substances to pass through the lining of the gut into the bloodstream more easily. These new substances then trigger the baby's immune response and the production of antibodies.
"The end result is that the baby's immune system may develop and mature faster - leading to better immune function and less likelihood of suffering allergies," added Dr Boudry.
The study has been published in The Journal of Physiology.