Carbohydrate-specific antibodies are widespread among all classes of immunoglobulins. Despite their broad occurrence, little is known about their formation and biological significance. Carbohydrate-specific antibodies are often classified as natural antibodies under the assumption that they arise without prior exposure to exogenous antigens. On the other hand, various carbohydrate-specific antibodies, including antibodies to ABO blood group antigens, emerge after the contact of immune cells with the intestinal microbiota, which expresses a vast diversity of carbohydrate antigens. Here we explore the development of carbohydrate-specific antibodies in humans, addressing the definition of natural antibodies and the production of carbohydrate-specific antibodies upon antigen stimulation. We focus on the significance of the intestinal microbiota in shaping carbohydrate-specific antibodies not just in the gut, but also in the blood circulation. The structural similarity between bacterial carbohydrate antigens and surface glycoconjugates of protists, fungi and animals leads to the production of carbohydrate-specific antibodies protective against a broad range of pathogens. Mimicry between bacterial and human glycoconjugates, however, can also lead to the generation of carbohydrate-specific antibodies that cross-react with human antigens, thereby contributing to the development of autoimmune disorders.

碳水化合物特异性抗体广泛存在于所有类型的免疫球蛋白中。尽管它们广泛发生，但对其形成和生物学意义知之甚少。碳水化合物特异性抗体通常在不事先暴露于外源抗原的前提下被归类为天然抗体。另一方面，免疫细胞与肠道菌群接触后，各种碳水化合物特异性抗体（包括抗ABO血型抗原的抗体）出现，这表达了多种碳水化合物抗原。在这里，我们探索了人类中碳水化合物特异性抗体的发展，解决了天然抗体的定义以及抗原刺激后碳水化合物特异性抗体的产生。我们关注肠道微生物群不仅在肠道中而且在血液循环中对形成碳水化合物特异性抗体的重要性。细菌碳水化合物抗原与原生生物，真菌和动物的表面糖缀合物之间的结构相似性导致产生针对多种病原体的碳水化合物特异性抗体。然而，细菌和人糖缀合物之间的模仿也可以导致与人抗原交叉反应的碳水化合物特异性抗体的产生，从而促进自身免疫疾病的发展。真菌和动物导致产生针对多种病原体的碳水化合物特异性抗体。然而，细菌和人糖缀合物之间的模仿也可以导致与人抗原交叉反应的碳水化合物特异性抗体的产生，从而促进自身免疫疾病的发展。真菌和动物导致产生针对多种病原体的碳水化合物特异性抗体。然而，细菌和人糖缀合物之间的模仿也可以导致与人抗原交叉反应的碳水化合物特异性抗体的产生，从而促进自身免疫疾病的发展。