Many children outgrow their food allergies as they reach their teenage or adult years. A food that used to cause a reaction by the immune system in a negative way is now neutral; the food is tolerated.
A new study published in the January 28, 2016, online issue of Science by La Jolla Institute for Allergy and Immunology (LJI) may explain how children might develop tolerance to foods over time. It also provides important clues as to why they are more prone to food allergies than adults in the first place.
When a new food enters the body for the first time, the immune system should identify the food protein as a “friend”. Identifying the food as a “friend” releases a certain type of immunosuppressive cell called “Treg” cells, which allow the body to use the food as nutrient and safely consume it. This study showed that eating a “normal diet,” one with a variety of unique foods, stimulates the production of Treg cells.
Using germ-free mice raised and bred on an elemental diet, researchers were able to represent an “immunological blank state” to test whether these special mice would produce Tregs. Researchers found that these mice were depleted of Tregs in the small intestine whereas a large number were found in mice fed a “normal” diet. The “normal” food proteins in the diet and the beneficial bacteria in the intestine generated a defensive army of Tregs, primed to stop an inflammatory response to food.
Study results suggest that the consumption of different types of foods in the diet stimulates cells in the gut that suppress rejection of food by the immune system.
A press release from LJI states, “Knowing this could explain why children, who have more limited exposure to novel foods than adults, are more susceptible to food allergies. It also suggests what happens on a cellular basis as some outgrow it: namely, they may be expanding their repertoire of Tregs that recognize new foods as ‘safe’.”
Please note that these mouse-model results need to be verified in humans before conclusions can be drawn.
For an in-depth look at this study, read a press release from LJI.