目的：研究特异乳酸菌（Lb-f）对环磷酰胺（CTX）体内外抗人大肠癌HCT116 细胞作用的影响。方法：体外培养HCT116

细胞，MTT法考察4、2、1 μg/ml CTX与加入10 μg/ml Lb-f 联用后对HCT116 细胞存活率的影响。复制HCT116 细胞异种移植瘤裸

鼠模型，考察100、50、25 mg/kg CTX与加入180 mg/kg Lb-f 联用后对荷瘤鼠瘤体积、瘤质量及二者相对抑瘤率、化疗增敏效果（以q

值表示）、外周血白细胞及血小板数量的影响。结果：与单用CTX比较，CTX联用Lb-f 对HCT116 细胞的存活率，对荷瘤裸鼠瘤体

积相对抑瘤率、瘤质量相对抑瘤率和q 值均无明显影响（P＞0.05），能增加外周血白细胞及血小板数量（P＜0.05）。结论：Lb-f 对

CTX体内外HCT116 细胞的抑制生长作用未见协同效应；对CTX引起的HCT116 细胞异种移植瘤裸小鼠外周血白细胞及血小板

减少具有抑制作用。

OBJECTIVE：To study the effects of Lactobacillus fermentum（Lb-f）on inhibition of cytoxan（CTX） on HCT116

cells of human colorectal cancer in vitro and in vivo. METHODS：HCT116 cells were cultured in vitro. MTT assay was used to investigate

the effects of 4，2，1 μg/ml CTX and combined with 10 μg/ml Lb-f on the survival rate of HCT116 cells. HCT116 cell xenograft

tumor nude mice model was induced to investigate the effects of 100，50，25 mg/kg CTX and combined with 180 mg/kg

Lb-f on tumor volume，tumor weight，relative tumor inhibition rate，the sensitization effect of chemotherapy（by q value），the

number of peripheral blood leucocyte and platelet. RESULTS：Compared with CTX alone，CTX combined with Lb-f had no significant

effect on survival rate of HCT116，relative inhibition rate of tumor volume in nude mice， relative inhibition rate of tumor

weight and q value（P＞0.05），but increased the number of peripheral blood leucocyte and platelet（P＜0.05）. CONCLUSIONS：

No synergistic effects of Lb-f is found on the inhibition of CTX on the growth of HCT116 in vitro and in vivo；Lb-f can inhibit the

decrease of peripheral blood leucocyte and platelet of HCT116 cell xenograft tumor nude mice induced by CTX.