College of Food Science and Nutritional Engineering, Beijing Key Laboratory of Viticulture and Enology, China Agricultural University, Beijing, China.
Obes Rev. 2021 Apr;22(4):e13155. doi: 10.1111/obr.13155. Epub 2020 Nov 4.
Immunoglobulin A (IgA) is the most abundant immunoglobulin isotype secreted into the mucosal tissues, mainly intestinal mucus. Humans can produce several grams of IgA every day, accounting for three quarters of the body's total immunoglobulin content. IgA, together with mucus and antimicrobial peptides, forms the first line of defence for intestinal epithelial cells, protecting them from a significant number of intestinal antigens. IgA also plays a principal role in controlling the gut microbiota (GM), and disruption in IgA can result in dysbiosis, such as the enrichment of Proteobacteria, which are generally bound by IgA. Proteobacteria overexpansion is also usually seen in obesity and colitis. Consistent with this, IgA dysfunction frequently results in metabolic syndrome (MetS), including conditions such as obesity, adiposity, insulin resistance, and inflammation. In contrast, enhanced IgA function can improve, and even prevent, MetS. Interactions among IgA, GM, and metabolism provide a promising avenue to combat MetS.
免疫球蛋白 A（IgA）是分泌到黏膜组织中的最丰富的免疫球蛋白类型，主要是肠道黏液。人类每天可以产生数克 IgA，占全身总免疫球蛋白含量的四分之三。IgA 与黏液和抗菌肽一起，形成肠上皮细胞的第一道防线，保护它们免受大量肠道抗原的侵害。IgA 还在控制肠道微生物群（GM）方面发挥主要作用，IgA 的紊乱会导致菌群失调，例如 Proteobacteria 的富集，通常由 IgA 结合。Proteobacteria 的过度扩张也常见于肥胖和结肠炎。与此一致的是，IgA 功能障碍经常导致代谢综合征（MetS），包括肥胖、肥胖、胰岛素抵抗和炎症等情况。相比之下，增强 IgA 功能可以改善甚至预防 MetS。IgA、GM 和代谢之间的相互作用为对抗 MetS 提供了一个有前途的途径。
