The trillions of microbes that constitutively colonize the intestine (the gut microbiota) impact diverse aspects of human physiology in health and disease. Immunoglobulin A (IgA) is the most abundant antibody isotype produced at mucosal surfaces, and nearly two grams of IgA is secreted into the intestine every day. Secretory IgA (SIgA) provides critical protection against pathogens and toxins, but can also directly bind to and 'coat' commensal bacteria in the gut. Commensal targeting by SIgA shapes gut microbiota composition, modulates bacterial behaviors, and enforces host-microbiota homeostasis in both mice and humans.

中文翻译：

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免疫球蛋白 A 和微生物组。

在肠道内定殖的数以万亿计的微生物（肠道微生物群）影响着人类健康和疾病生理机能的各个方面。免疫球蛋白 A (IgA) 是黏膜表面产生的最丰富的抗体同种型，每天有近 2 克 IgA 分泌到肠道中。分泌型 IgA (SIgA) 提供针对病原体和毒素的关键保护，但也可以直接结合并“包裹”肠道中的共生细菌。SIgA 的共生靶向塑造肠道微生物群组成，调节细菌行为，并在小鼠和人类中强制宿主微生物群的稳态。