结直肠癌（CRC）是最常见且具有较高患病率和死亡率的癌症之一。通过给予益生元和益生菌来调节肠道健康可能是减少CRC风险的可行替代方法。本研究旨在评估牛蒡和酸奶的功能效果，单独或联合应用于结直肠癌大鼠中。成年Wistar大鼠被分为五组（n = 8）：健康对照组（HC，摄取AIN-93M饲料）、癌组（CC，摄取CCR + AIN-93M饲料）、牛蒡组（Y，摄取CCR + AIN-93M + 牛蒡饲料）、酸奶组（K，摄取CCR + AIN-93M + 酸奶饲料）和牛蒡+酸奶组（YK，摄取CCR + AIN-93M + 牛蒡 + 酸奶饲料）。通过亚甲基双肼（55 mg kg-1，皮下注射）诱导CC、Y、K和YK组发生结直肠癌，持续5周。从第6周开始，实验组饮用相应饲料。在第15周，收集尿液以进行肠道渗透性分析，然后处死动物。牛蒡增加了醋酸盐水平、降低了pH和致癌肿瘤病变，并增加了与未消化碳水化合物发酵相关的细菌（如Dorea属、Collinsela属和双歧杆菌）的丰度。另一方面，酸奶增加了肉眼可见的肿瘤病变，并增加了厚壁菌门和梭菌的丰度。牛蒡 + 酸奶的联合应用增加了致癌病变的数量，尽管pH值降低，并且有益菌的丰度降低。因此，可以得出结论，牛蒡，与酸奶不同，是减轻实验大鼠癌变表现的有希望的替代方法。

Colorectal cancer (CRC) is one of the most common cancers with high morbidity and mortality. The modulation of intestinal health through the administration of pro- and prebiotics may be a viable alternative to reduce the risk of CRC. This study aimed to evaluate the functional effects of yacon and kefir, isolated or associated, in rats with colorectal cancer. Adult Wistar rats were divided into five groups (n = 8): HC (healthy control AIN-93M diet), CC (CCR + AIN-93M diet), Y (CCR + AIN-93 M + yacon diet), K (CCR + AIN-93-M + kefir diet) and YK (CCR + AIN-93 M + yacon + kefir diet). Colorectal carcinogenesis was induced in groups CC, Y, K, and YK with 1,2-dimethylhydrazine (55 mg kg-1, subcutaneously) for 5 weeks. From the 6th week onwards, the experimental groups were fed the respective diets. In the 15th week, urine was collected for analysis of intestinal permeability and then the animals were euthanized. Yacon increased acetate levels, reduced pH and carcinogenic neoplastic lesions, and increased the abundance of bacteria related to the fermentation of non-digestible carbohydrates, such as the genera Dorea, Collinsela, and Bifidobacteria. On the other hand, kefir increased macroscopic neoplastic lesions and increased the abundance of Firmicutes and Clostridium. The association of yacon + kefir increased the number of carcinogenic lesions, despite a reduction in pH and beneficial bacteria prevalence. Thus, it is concluded that yacon, unlikely kefir, is a promising alternative to mitigate the manifestations of induced carcinogenesis in rats.