A new study just published may demonstrate how food allergies develop, and why. They key may be in gut reactions to "novel" foods and would also explain why many children with food allergies eventually "outgrow" them.
The study, published in the January 28, 2016 online issue of Science, was conducted by Charles Surh, PhD, a researcher at the La Jolla Institute for Allergy and Immunology in California. Using "antigen-free" mice, molecular analysis of cells in the digestive tract, and different dietary models, Surh found interesting results.
His theory is that children are less likely to be exposed to "foreign" (or novel) foods than are adults. Because they are more sensitive to some stimulus, such as spices and heat, and because children are less likely to want to try unusual foods, they are also less likely to have their gut bacteria and immune systems stimulated by them than are adults. This would help explain why children are more susceptible to food allergies than are adults.
The idea is that nutrients and the foods we get them from are "foreign" to our bodies and are thus treated like any other foreign matter which enters them.
Our immune systems react to things ingested with a combination of defenses meant to ward off potential pathogens. If our digestive systems are not stimulated enough in youth, they may not develop a proper balance of immuno-response, which could lead to food allergies.
Measuring the T regulators (Tregs) in the mice, Surh and his team were able to show that allergen-free mice raised on certain diets had far fewer Tregs. The Tregs are suppresive to immunological responses in the gut, lessening reactions to certain types of proteins.
The study could set the groundwork for further research into the role of early diets and childhood food allergies.