Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan.
Nutrients. 2024 Aug 23;16(17):2824. doi: 10.3390/nu16172824.
Immunoglobulin A (IgA) is a major gut antibody that coats commensal gut bacteria and contributes to shaping a stable gut bacterial composition. Although previous studies have shown that cyclic oligosaccharides, including cyclic nigerosyl-1,6-nigerose (CNN) and cyclodextrins (CDs, including αCD, βCD, and γCD), alter the gut bacterial composition, it remains unclear whether cyclic oligosaccharides modify the IgA coating of gut bacteria, which relates to cyclic oligosaccharide-induced alteration of the gut bacterial composition. To address this issue, mice were maintained for 12 weeks on diets containing CNN, αCD, βCD, or γCD; the animals' feces were evaluated for their bacterial composition and the IgA coating index (ICI), a measure of the degree of IgA coating of bacteria. We observed that the intake of each cyclic oligosaccharide altered the gut bacterial composition, with changes in the ICI found at both the phylum and genus levels. The ICI for Bacillota, Lachnospiraceae NK4A136 group, UC Lachnospiraceae, and were significantly and positively correlated with the relative abundance (RA) in total bacteria for these bacteria; in contrast, significant correlations were not seen for other phyla and genera. Our observations suggest that cyclic oligosaccharide-induced modulation of the IgA coating of gut bacteria may partly relate to changes in the community structure of the gut bacteria.
免疫球蛋白 A（IgA）是一种主要的肠道抗体，它覆盖共生肠道细菌，并有助于塑造稳定的肠道细菌组成。尽管先前的研究表明，包括环状奈格尔糖-1,6-奈格尔糖（CNN）和环糊精（CD，包括αCD、βCD 和 γCD）在内的环状寡糖会改变肠道细菌组成，但目前尚不清楚环状寡糖是否会改变肠道细菌的 IgA 覆盖，这与环状寡糖诱导的肠道细菌组成改变有关。为了解决这个问题，我们将小鼠维持在含有 CNN、αCD、βCD 或 γCD 的饮食中 12 周；评估动物粪便的细菌组成和 IgA 覆盖指数（ICI），这是衡量细菌 IgA 覆盖程度的指标。我们观察到，每种环状寡糖的摄入都会改变肠道细菌组成，在门和属水平上都发现了 ICI 的变化。厚壁菌门、Lachnospiraceae NK4A136 组、UC Lachnospiraceae 和 的 ICI 与这些细菌的总细菌相对丰度（RA）呈显著正相关；相比之下，其他门和属则没有显著相关性。我们的观察表明，环状寡糖诱导的肠道细菌 IgA 覆盖的调节可能部分与肠道细菌群落结构的变化有关。
