Mom's pregnancy diet may help protect babies against food allergy: study

Source: Xinhua| 2017-11-21 03:53:51|Editor: pengying
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WASHINGTON, Nov. 20 (Xinhua) -- Breastfeeding mothers who ate allergenic foods during pregnancy may protect their babies against food allergies, a new study suggested Monday.

Conducted by researchers at Boston Children's Hospital and Harvard Medical School, the study showed that pregnant mice that consumed allergy-provoking foods such as eggs and peanuts transferred protective antibodies to their offspring through breast milk.

The antibodies caused the baby mice to produce allergen-specific regulatory T immune cells, which made them tolerate the allergenic foods, said the study in the Journal of Experimental Medicine.

The findings supported recent allergy-prevention guidelines, which rejected prior advice urging mothers to avoid highly allergenic foods during pregnancy or while breastfeeding.

"Whether mothers should eat allergenic foods during pregnancy or avoid them has been controversial," said Michiko Oyoshi of Boston Children's Division of Allergy and Immunology, who led the study in collaboration with her co-senior author Richard Blumberg of Brigham and Women's Hospital.

"Different studies have found different results, in part because it's hard in human studies to know when mothers and babies first encountered a specific food. But in a mouse model, we can control exposure to food."

The study showed that breast milk from mothers who consumed allergenic foods prevented anaphylaxis as well as production of immunoglobulin E and expansion of mast cells, both hallmarks of an allergic response.

Breast milk was protective even when fed to unrelated offspring not exposed to food allergens in utero.

In other experiments, mothers who had never consumed allergenic foods were given food-specific antibodies from other mothers and this also protected their breastfed offspring.

Human breast milk, fed to mice with humanized immune systems was also protective, suggesting that the mouse findings may translate to human infants.

Finally, Oyoshi and colleagues had mice born to allergen-exposed mothers nurse from mothers that had never consumed allergenic foods.

"We still saw protection from the in-utero exposure, but the protection was better when the mice were also exposed through breastfeeding," said Oyoshi, who is also an assistant professor of pediatrics at Harvard Medical School.

"If you combine both in utero and breastfeeding exposure, you have optimal induction of food tolerance."

Oyoshi's research team is now enrolling human mothers in a study that will compare breastmilk from mothers of children at low risk or high risk for food allergy and will examine the contents of breastmilk before and after the nursing mother eats peanuts.