The immunology of the hygiene hypothesis of allergy is complex and involves the loss of cellular and humoral immunoregulatory pathways as a result of the adoption of a Western lifestyle and the disappearance of chronic infectious diseases. The influence of diet and reduced microbiome diversity now forms the foundation of scientific thinking on how the allergy epidemic occurred, although clear mechanistic insights into the process in humans are still lacking. Here we propose that barrier epithelial cells are heavily influenced by environmental factors and by microbiome-derived danger signals and metabolites, and thus act as important rheostats for immunoregulation, particularly during early postnatal development. Preventive strategies based on this new knowledge could exploit the diversity of the microbial world and the way humans react to it, and possibly restore old symbiotic relationships that have been lost in recent times, without causing disease or requiring a return to an unhygienic life style.

中文翻译：

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过敏性流行病的免疫学和卫生学假设。

过敏的卫生假说的免疫学很复杂，并且由于采用西方生活方式和慢性传染病的消失而导致细胞和体液免疫调节通路的丧失。饮食的影响和减少的微生物组多样性现在构成了关于过敏性流行如何发生的科学思考的基础，尽管仍然缺乏对人类过程的清晰机械学见解。在这里，我们提出屏障上皮细胞受到环境因素以及微生物组危险信号和代谢产物的严重影响，因此，它们是免疫调节的重要变阻剂，特别是在出生后早期。基于这种新知识的预防策略可以利用微生物世界的多样性以及人类对其的反应方式，