Environmental exposures during pregnancy that alter both the maternal gut microbiome and the infant’s risk of allergic disease and asthma include a traditional farm environment and consumption of unpasteurized cow’s milk, antibiotic use, dietary fiber, and psychosocial stress. Multiple mechanisms acting in concert may underpin these associations and prime the infant to acquire immune competence and homeostasis following exposure to the extrauterine environment. Cellular and metabolic products of the maternal gut microbiome can promote the expression of microbial pattern recognition receptors, as well as thymic and bone marrow hematopoiesis relevant to regulatory immunity. At birth, transmission of maternally derived bacteria likely leverages this in utero programming to accelerate postnatal transition from a T_H2- to T_H1- and T_H17-dominant immune phenotype and maturation of regulatory immune mechanisms, which in turn reduce the child’s risk of allergic disease and asthma. Although our understanding of these phenomena is rapidly evolving, the field is relatively nascent, and we are yet to translate existing knowledge into interventions that substantially reduce disease risk in humans. Here, we review evidence that the maternal gut microbiome impacts the offspring’s risk of allergic disease and asthma, discuss challenges and future directions for the field, and propose the hypothesis that maternal carriage of Prevotella copri during pregnancy decreases the offspring’s risk of allergic disease via production of succinate, which in turn promotes bone marrow myelopoiesis of dendritic cell precursors in the fetus.

怀孕期间的环境暴露会改变母体肠道微生物群和婴儿患过敏性疾病和哮喘的风险，包括传统的农场环境和未经高温消毒的牛奶的消费、抗生素的使用、膳食纤维和社会心理压力。协同作用的多种机制可能支持这些关联，并使婴儿在暴露于宫外环境后获得免疫能力和体内平衡。母体肠道微生物组的细胞和代谢产物可以促进微生物模式识别受体的表达，以及与调节免疫相关的胸腺和骨髓造血。在出生时，母源性细菌的传播可能会利用这种在子宫内编程来加速出生后从 T_H 2- 到 T _H 1- 和 T _H 17-显性免疫表型和调节免疫机制的成熟，进而降低儿童患过敏性疾病和哮喘的风险。尽管我们对这些现象的理解正在迅速发展，但该领域还处于起步阶段，我们尚未将现有知识转化为可显着降低人类疾病风险的干预措施。在这里，我们回顾了母体肠道微生物群影响后代过敏性疾病和哮喘风险的证据，讨论该领域的挑战和未来方向，并提出母体携带普氏菌的假设。 怀孕期间通过产生琥珀酸盐降低后代患过敏性疾病的风险，琥珀酸盐反过来促进胎儿树突状细胞前体的骨髓骨髓生成。