This study aimed to investigate the effects of colloidal silica nanoparticles Aerosil 200 (A200) on intestinal barrier and mucosal immunity in childhood mice. Three-week-old BALB/c mice were administered A200 (20, 50, 200 mg·kg-1) via gavage for 7 days. Intestinal morphology, barrier function, immune cell phenotypes, and oral tolerance were systematically evaluated. Histopathological analysis of intestinal morphology revealed that no obvious pathological damage in the intestine. However, 200 mg·kg-1 A200 increased ileal villus length, reduced crypt depth. Functional assessments of the intestinal barrier demonstrated that 200 mg·kg-1 A200 upregulated ZO-1 in the ileum but downregulated it in the colon; The intestinal stem cell marker Lgr5 remained unchanged, while Mucin-2 increased and lysozyme decreased in the ileum. Analysis of immune cell phenotypes revealed that the 200 mg·kg-1 group exhibited elevated proportions of Treg and Th2 cells in the mesenteric lymph nodes, while serum and intestinal levels of TNF-α and IL-6 remained unaffected. Oral tolerance assays revealed no alteration in OVA-specific IgG, IgG1, or IgG2a antibody levels. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Peking University Health Science Center (Approval No.: BCJB0076). In conclusion, A200 is generally safe for childhood mice but may modulate epithelial barrier proteins and immune cell phenotypes at high doses, which may provide insights into its pediatric application.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |