Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan
Animal Research Center, Sapporo Medical University School of Medicine, Sapporo, Japan.
Appl Environ Microbiol. 2020 Jun 17;86(13). doi: 10.1128/AEM.00405-20.
Immunoglobulin A (IgA) is essential for defense of the intestinal mucosa against harmful pathogens. Previous studies have shown that , the major phylum of gut microbiota together with , impact IgA production. However, the relative abundances of species of responsible for IgA production were not well understood. In the present study, we identified some specific species that were associated with gut IgA induction by -based profiling of species distribution among The levels of IgA and the expression of the gene encoding activation-induced cytidine deaminase (AID) in the large intestine lamina propria, which is crucial for class switch recombination from IgM to IgA, were increased in soluble high-fiber diet (sHFD)-fed mice. We found that was the most abundant species in both sHFD- and normal diet-fed mice. In addition, the gut IgA levels were associated with the relative abundance of group species such as , , and Conversely, the ratio of to other species was reduced in insoluble high-fiber diet fed- and no-fiber diet-fed mice. To investigate whether increases IgA production, we generated monoassociated mice and found increased gut IgA production and AID expression. Collectively, soluble dietary fiber increases the ratio of gut group, such as , and IgA production. This might improve gut immune function, thereby protecting against bowel pathogens and reducing the incidence of inflammatory bowel diseases. Immunoglobulin A (IgA) is essential for defense of the intestinal mucosa against harmful pathogens. Gut microbiota impact IgA production, but the specific species responsible for IgA production remain largely elusive. Previous studies have shown that IgA and , the major phyla of gut microbiota, were increased in soluble high-fiber diet-fed mice. We show here that the levels of IgA in the gut and the expression of activation-induced cytidine deaminase (AID) in the large intestine lamina propria, which is crucial for class switch recombination from IgM to IgA, were correlated with the abundance of group species such as , , and monoassociated mice increased gut IgA production and AID expression. Soluble dietary fiber may improve gut immune function, thereby protecting against bowel pathogens and reducing inflammatory bowel diseases.
免疫球蛋白 A（IgA）对于防御肠道黏膜免受有害病原体的侵害至关重要。先前的研究表明，肠道微生物群落的主要门类与 IgA 的产生有关。然而，负责 IgA 产生的物种的相对丰度尚不清楚。在本研究中，我们通过基于物种分布的 16S rRNA 测序分析，鉴定出一些与基于饮食的 IgA 诱导相关的特定 物种。在可溶性高纤维饮食（sHFD）喂养的小鼠中，回肠固有层 IgA 和编码激活诱导胞苷脱氨酶（AID）的基因的表达增加，这对于从 IgM 到 IgA 的类别转换重组至关重要。我们发现，在 sHFD 和正常饮食喂养的小鼠中， 是最丰富的 物种。此外，肠道 IgA 水平与 组物种的相对丰度相关，如 、 和 。相反，在不溶性高纤维饮食喂养和无纤维饮食喂养的小鼠中， 与其他 物种的比例降低。为了研究 是否增加 IgA 的产生，我们生成了 单定植小鼠，并发现肠道 IgA 的产生和 AID 的表达增加。总之，可溶性膳食纤维增加了肠道 组，如 、 和 IgA 的产生。这可能改善肠道免疫功能，从而保护免受肠道病原体的侵害，并降低炎症性肠病的发病率。
