Allergies, including asthma, food allergy and atopic dermatitis, are increasing in prevalence, particularly in westernized countries. Although a detailed mechanistic explanation for this increase is lacking, recent evidence indicates that, in addition to genetic predisposition, lifestyle changes owing to modernization have an important role. Such changes include increased rates of birth by caesarean delivery, increased early use of antibiotics, a westernized diet and the associated development of obesity, and changes in indoor and outdoor lifestyle and activity patterns. Most of these factors directly and indirectly impact the formation of a diverse microbiota, which includes bacterial, viral and fungal components; the microbiota has a leading role in shaping (early) immune responses. This default programme is markedly disturbed under the influence of environmental and lifestyle risk factors. Here, we review the most important allergy risk factors associated with changes in our exposure to the microbial world and the application of this knowledge to allergy prevention strategies.

过敏症，包括哮喘、食物过敏和特应性皮炎，患病率正在增加，特别是在西方国家。尽管缺乏对这种增加的详细机制解释，但最近的证据表明，除了遗传易感性之外，现代化导致的生活方式改变也起着重要作用。这些变化包括剖腹产的出生率增加、抗生素的早期使用增加、西化饮食和肥胖的相关发展，以及室内和室外生活方式和活动模式的变化。这些因素中的大多数直接或间接地影响了多样化微生物群的形成，其中包括细菌、病毒和真菌成分；微生物群在塑造（早期）免疫反应方面起主导作用。该默认程序在环境和生活方式风险因素的影响下受到明显干扰。在这里，我们回顾了与我们接触微生物世界的变化相关的最重要的过敏风险因素，以及这些知识在过敏预防策略中的应用。