Modulating gut microbiota with probiotics Lacticaseibacillus rhamnosus Probio-M9 and Bifidobacterium animalis subsp. lactis V9 to augment the efficacy of colon cancer chemotherapy

We investigated the effects of combined probiotics (Lacticaseibacillus rhamnosus Probio-M9 & Bifidobacterium animalis subsp. lactis V9) for chemotherapy, the most common treatment, in a CRC mouse model. The results showed that combining probiotics with chemotherapy had significantly more decrease in tumor volume compared to chemotherapy-only group receiving 5-FU/Oxp. Flow cytometry analyses revealed increased CD4+ T cells and decreased CD8+ T cells in probiotic supplement group, suggesting that probiotics take effect immune regulation. Furthermore, metagenomic sequencing of fecal samples indicated that probiotic supplementation modulated gut microbiota diversity and structure, and changed gut microbiota functional pathways, suggesting an auxiliary effect on chemotherapy. Overall, our proof-of-concept study suggests that probiotics enhance the therapeutic effect of chemotherapy in CRC, providing evidence for future studies on probiotic intervention in cancer treatment.