The impact of food antigens on the immune system of the organism is undisputable. The alimentary tract (GALT) is one of the most significant elements in the immune defence barrier of the organism. This is caused by a considerable role of the immune system related with the gastro-alimentary tract in the functioning of the whole immune system of the organism also in food allergy. Due to many synergising health, genetic and environmental factors, the problem of food allergy has been arising an increasing interest. In the last two decades in Europe the number of allergic persons has doubled. The problem is becoming one of the most significant epidemiological and economic issues. The above-mentioned threats cause that precise and sensitive methods appear to be more important in monitoring food components, which can induce the allergenic response. In this work, the possibilities of application of immunometric methods for the examination of immunoreactive properties of foods, and their changes as a result of the processing employed as well as immunomodulative properties of selected food components (probiotics) were presented on the basis of the results obtained in an own research.