In addition to making babies smarter, expectant moms who consume a diet based on fish and walnut oils may also be kickstarting their babies' immune systems and warding off future allergies, scientists say.

The French study, published in this months's Journal of Physiology, claims to have found that a group of polyunsaturated fatty acids -- also known as n-3PUFAsu00a0 -- helps the baby develop a more 'permeable' gut.