Soluble Dietary Fiber from Polygonatum cyrtonema Hua Attenuates Cyclophosphamide-Induced Intestinal Injury in Mice

This study aimed to evaluate the protective effects of soluble dietary fiber (SDF) derived from Polygonatum cyrtonema Hua residues on cyclophosphamide (CTX)-induced intestinal injury in mice. A total of 60 C57BL/6 mice (6–8 weeks old; body weight, 23.8 ± 0.5 g) were randomly allocated to six groups (n = 10 per group): a control group (CON), a CTX model group (CTX), a levamisole-treated positive control group (PC), and low-, medium-, and high-dose SDF groups (125, 250, and 500 mg/kg body weight, respectively). Mice received oral administration of SDF or an equal volume of water for 21 consecutive days and were intraperitoneally injected with CTX (80 mg/kg body weight) on days 19–21 to induce intestinal injury. The results demonstrate that SDF possessed a porous, sponge-like network structure and comprised multiple monosaccharides. SDF intervention, particularly at medium and high doses, significantly attenuated CTX-induced body weight loss and immune organ atrophy; restored villus height and the villus-to-crypt ratio; increased the numbers of goblet cells and intraepithelial lymphocytes; elevated intestinal levels of sIgA, β-defensins, and lysozyme; and reduced serum levels of LPS, D-lactic acid, and DAO (p < 0.05). In conclusion, SDF derived from Polygonatum cyrtonema effectively mitigates CTX-