目的 运用微生物组学、代谢组学探究乌梅丸延缓结肠炎癌转化的作用机制。方法 采用偶氮甲烷（azoxymethane，AOM）/葡聚糖硫酸钠（dextran sulfate sodium，DSS）构建结肠炎癌转化动物模型，将32只C57BL/6J小鼠随机分为对照组、模型组和乌梅丸低、高剂量（11.18、22.36 g/kg）组。通过肠道内窥镜观察、大体标本评估和苏木素-伊红（hematoxylin-eosin，HE）染色评价结肠肿瘤进展与组织病理学变化；ELISA检测血清中白细胞介素-6（interleukin-6，IL-6）、肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α），以及血清与粪便中总胆汁酸（total bile acids，TBA）、胆酸（cholic acid，CA）、脱氧胆酸（deoxycholic acid，DCA）、石胆酸（lithocholic acid，LCA）水平；16S rRNA基因测序技术检测肠道微生物多样性及物种丰度；非靶向代谢组学技术评估代谢物丰度；qRT-PCR法验证裂解梭菌（Clostridium scindens，C. scindens）、海氏梭菌（Clostridium hylemonae，C. hylemonae）、洪氏梭菌（Clostridium hiranonis，C. hiranonis）以及辅酶A转移酶编码基因BaiF表达。结果 与模型组比较，乌梅丸干预能够阻延结肠炎癌转化，且乌梅丸低剂量的疗效更佳。低剂量的乌梅丸可显著减少结肠肿瘤数量（P＜0.001），降低结肠炎症评分与肿瘤病理学评分（P＜0.05、0.01），降低血清IL-6、TNF-α水平（P＜0.01、0.001）。微生物组学结果显示，乌梅丸可改善肠道菌群结构，减少梭菌属Clostridium等机会致病菌丰度，同时增加乳酸杆菌属Lactobacillus、罗氏菌属Roseburia等益生菌丰度。非靶向代谢组学结果表明，乌梅丸低剂量组与模型组之间存在82种差异代谢物，显著富集于次级胆汁酸代谢通路。乌梅丸可显著降低血清及粪便中TBA、CA及DCA水平（P＜0.05、0.01、0.001）。qRT-PCR结果进一步证实乌梅丸可抑制C. scindens和C. hylemonae等参与DCA合成的细菌（P＜0.05），并导致BaiF基因表达水平降低（P＜0.001）。结论 乌梅丸可通过调复肠道菌群介导的胆汁酸稳态，降低C. scindens等细菌丰度及其脱羟基化功能，减少DCA的生成，从而缓解结肠炎症并延缓炎癌转化进程。

Objective To investigate the mechanism of Wumei Pill (乌梅丸) in delaying the transformation of colitis cancer using microbiome and metabolomics. Methods A colitis cancer transformation animal model was constructed using azoxymethane (AOM)/dextran sulfate sodium (DSS). A total of 32 C57BL/6J mice were randomly divided into control group, model group, and Wumei Pill low-, high-dose (11.18, 22.36 g/kg) groups. Colonic tumor progression and histopathological changes were evaluated by intestinal endoscopic observation, macroscopic specimen assessment and hematoxylin-eosin (HE) staining. Levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) in serum, and levels of total bile acids (TBA), cholic acid (CA), deoxycholic acid (DCA), lithocholic acid (LCA) in serum and in feces were measured by ELISA. 16S rRNA sequencing technology was used to analyze gut microbial diversity and species abundance. The abundance of metabolites was assessed by non-targeted metabolomics analysis. qRT-PCR was used to verify the expression changes of Clostridium scindens (C. scindens), Clostridium hylemonae (C. hylemonae), Clostridium hiranonis (C. hiranonis) and the coenzyme A transferase encoding gene BaiF. Results Compared with model group, the intervention of Wumei Pill could delay the transformation of colitis cancer, and the therapeutic effect was better at low dose of Wumei Pill. Low dose Wumei Pill could significantly reduce the number of colon tumors (P < 0.001), lower colitis and tumor pathology scores (P < 0.05, 0.01), and lower levels of IL-6 and TNF-α in serum (P < 0.01, 0.001). The microbiological results showed that Wumei Pill could improve the structure of intestinal microbiota, reduce the abundance of opportunistic pathogenic bacteria such as Clostridium, and increase the abundance of probiotics such as Lactobacillus and Roseburia. The non-targeted metabolomics results showed that there were 82 differential metabolites between Wumei Pill low-dose group and model group, significantly enriched in secondary bile acid metabolism pathway. Wumei Pill could significantly reduce the levels of TBA, CA,and DCA in serum and feces (P < 0.05, 0.01, 0.001). qRT PCR results further confirmed that Wumei Pill could inhibit bacteria involved in DCA synthesis such as C. scindens and C. hylmonae (P < 0.05), and lead to a decrease in BaiF gene expression level (P < 0.001). Conclusion Wumei Pill could alleviate colitis and delay the progression of inflammatory cancer by modulating the bile acid homeostasis mediated by gut microbiota, reducing the abundance and dehydroxylation function of bacteria such as C. scindens, and decreasing the production of DCA.

R285.5

国家自然科学基金资助项目（82505494）；委校联合创新基金项目（WXLH202403144）