Lactobacillus paracasei subsp. paracasei NTU 101-fermented skim milk as an adjuvant to uracil-tegafur reduces tumor growth and improves chemotherapy side effects in an orthotopic mouse model of colorectal cancer

Colorectal cancer (CRC) is a major cause of cancer-related deaths worldwide. Chemotherapy is the usual treatment, but entails side effects. Although lactic acid bacteria (LAB) ameliorate CRC, the effects of LAB-fermented skim milk are unknown. Thus, we investigated the effect of Lactobacillus paracasei subsp. paracasei NTU 101-fermented skim milk (NTU 101FM) in combination with chemotherapy on CRC, and its effect on chemotherapeutic side effects in vivo. NTU 101FM + chemotherapy treatment significantly suppressed tumor growth and metastasis compared to chemotherapy alone via regulating vascular endothelial growth factor, matrix metalloprotein-9, and tissue inhibitor of matrix metalloproteinase-1 levels. Pro-inflammatory cytokines and oxidative stress in the tumor, intestine, and serum were significantly controlled by NTU 101FM compared to chemotherapy alone. In CRC mice, NTU 101FM significantly suppressed increases in spleen weight and inflammation-related factors induced by chemotherapy. These findings indicate that NTU 101FM potentially improves the side effects and efficiency of chemotherapy.