腸内細菌とアレルギー
[Intestine microbiota and allergic diseases]
Abstract
In industrialized countries an increased number of diseases due to immune system disorders including connected with allergy is noted. Allergic diseases generally proceed against the background of various common inflammatory diseases arising in childhood. The role of intestine microflora in its interaction with immune system and defining factors in allergization of children are actively studied. A decrease of risk of allergy development later in life for children who had grown up in the countryside was shown to be possibly related with microorganisms present in food. Thus the positive potential of farms is currently examined as a result of innate immunity activation by using microbial components.
Acinetobacter lwoffii F78 isolated from cowsheds is able to protect mice from experimental allergy by activating Th1-polarization program of dendritic cells. Moreover, an important role in pathogenesis of allergic diseases belongs to mast cells.
Probiotic lactobacilli may weaken activation of mast cells and release of inflammation mediators connected with allergic reactions. The ability of intestine microflora to influence immune response resulted in novel approaches in therapy that use these differences in microbiota for therapy and prophylaxis in allergy patients. And therefore on the basis of "hygiene hypothesis" of allergy emergence, a consideration is expressed that early manipulation with intestinal microbial communities may offer a new strategy of allergic sensibilization prevention.
In the present paper, we discuss the importance of the microbiome in allergic disease. In this review paper, the data from the Medline (PubMed) and search engine of Kirikkale University were systematically searched for all relevant articles in June 15th, 2015 for the past 30 years. The keywords of "microbiome", "dysbiosis", "allergy", "allergic rhinitis", "allergic disease", "mechanisms" and "treatment" were used alone or together. In this paper, microbiomes were presented in terms of "Definition", "Influence of \the human microbiome on health", "The microbiome and allergic diseases", and "Modulation of the gut microbiota in terms of treatment and prevention". Microbiological dysbiosis is also reviewed. The microbiome is the genetic material of all microbes (bacteria, fungi, protozoa, and viruses) that live on or in the human body. Microbes outnumber human cells in a 10:1 ratio. Most microbes live in the gut, particularly the large intestine. Changes in the immune function of the respiratory tract are (at least in theory) linked to the immunomodulatory activity of the gut microbiota via the concept of a "common mucosal response". The gut microbiota shapes systemic immunity, thus affecting the lung mucosa. Alternatively, changes in the gut microbiota may reflect alterations in the oropharyngeal microbiota, which may in turn directly affect the lung microbiota and host immune responses via microaspiration. Dysbiosis is defined as qualitative and quantitative changes in the intestinal flora; and modern diet and lifestyle, antibiotics, psychological and physical stress result in alterations in bacterial metabolism, as well as the overgrowth of potentially pathogenic microorganisms. All immune system components are directly or indirectly regulated by the microbiota. The nature of microbial exposure early in life appears to be important for the development of robust immune regulation; disruption of either the microbiota or the host response can trigger chronic inflammation. Dysbiosis is also an important clinical entity. Antibiotics, psychological and physical stress, and dietary factors contribute to intestinal dysbiosis.
