结直肠癌（CRC）是全球癌症死亡的第三大原因，也是埃及和美国报告的最常见癌症类型之一。益生菌作为一种膳食疗法的使用正在增加，不论是作为预防还是作为CRC的治疗。乳酸菌寡糖作为生物活性物质的广泛接受推动了利用发酵技术进行大规模生产LAB寡糖的需求增加。因此，在当前研究中，我们采用了Plackett-Burman设计（PBD）方法，进行了十六次实验试验，以优化从酸ophilus乳酸菌中生产目标寡糖LA-EPS-20079的方法。葡萄糖、酵母提取物和三水合乙酸钠是影响LA-EPS生产的前三个显著变量。酸ophilus乳酸菌达到的LA-EPS-20079的最大浓度为526.79 μg/ml。此外，采用响应面法中的Box-Behnken设计（BBD）来完成优化过程。所选变量的最佳水平为30.0 g/l葡萄糖、5 g/l酵母提取物和10.0 g/l三水合乙酸钠，预测的LA-EPS-20079浓度为794.82 μg/ml。通过验证结果，模型的有效性达到了99.93%。两个优化试验都对结肠癌细胞系（CaCo-2）显示出强大的细胞毒性效应，抑制百分比范围从64.6%到81.9%不等。此外，BCL2和Survivin基因的表达水平下调，折叠变化分别为3.377和21.38。最后，我们得出结论，经优化的LA-EPS-20079保持了对CaCo-2细胞系的抗癌作用，这是我们研究组先前报道的。© 2023. BioMed Central Ltd., part of Springer Nature.

Colorectal cancer (CRC) is the third cause of death by cancers worldwide and is one of the most common cancer types reported in both Egypt and the United States. The use of probiotics as a dietary therapy is increasing either as a prevention or as a treatment for many diseases, particularly, in the case of CRC. The increasing acceptance of lactic acid bacterial (LAB) oligosaccharides as bioactive agents has led to an increase in the demand for the large-scale production of LAB-oligosaccharides using fermentation technology. Therefore, in the current study, we are using the Plackett- Burman design (PBD) approach, where sixteen experimental trials were applied to optimize the production of the target oligosaccharide LA-EPS-20079 from Lactobacillus acidophilus. Glucose, yeast extract and sodium acetate trihydrate were the top three significant variables influencing LA-EPS production. The maximum concentration of LA-EPS-20079 achieved by L. acidophilus was 526.79 μg/ml. Furthermore, Box-Behnken design (BBD) as response surface methodology (RSM) was used to complete the optimization procedure. The optimal levels of the chosen variables which were 30.0 g/l, glucose; 5 g/l, yeast extract and 10.0 g/l sodium acetate trihydrate with the predicted LA-EPS-20079 concentration of 794.82 μg/ml. Model validity reached 99.93% when the results were verified. Both optimized trials showed great cytotoxic effects against colon cancer line (CaCo-2) with inhibition percentages ranging from 64.6 to 81.9%. Moreover, downregulation in the expression level of BCL2 and Survivin genes was found with a fold change of 3.377 and 21.38, respectively. Finally, we concluded that the optimized LA-EPS-20079 has maintained its anticancer effect against the CaCo-2 cell line that was previously reported by our research group.© 2023. BioMed Central Ltd., part of Springer Nature.