Cyclic Oligosaccharide-Induced Modulation of Immunoglobulin A Reactivity to Gut Bacteria Contributes to Alterations in the Bacterial Community Structure.

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.

Cyclic Nigerosylnigerose Attenuates High-Fat Diet-Induced Fat Deposition, Colonic Inflammation, and Abnormal Glucose Metabolism and Modifies Gut Immunoglobulin a Reactivity to Commensal Bacteria.

Scope: High-fat diet (HFD) intake induces gut dysbiosis, inflammation in the peripheral tissues, and a reduction in immunoglobulin A (IgA) coating of gut bacteria, which is related to HFD-induced insulin resistance (IR). This study evaluates the effect of cyclic nigerosylnigerose (CNN), a dietary fiber that prevents gut inflammation and promotes IgA coating of gut bacteria, on the above-mentioned HFD-induced disorders.

Methods And Results: Balb/c mice are fed an HFD and administered CNN for 20 weeks.