Lactobacillus casei's Antitumor Potential in Colorectal Cancer: Exploring Mechanisms-A Systematic Review

Colorectal cancer (CRC) is the third most common cancer worldwide. Around 1.8 million people were diagnosed with CRC in 2018, and 881,000 died. The limitations of chemotherapy and radiotherapy, as well as the uncertainty of CRC-specific therapies, encourage the development of alternative CRC prevention, treatment, and control measures. Probiotics are being studied as a strategy for preventing and treating CRC due to their potential health benefits. Lactobacillus casei (L. casei) shows promise in reducing tumor growth and cancer cell survival in CRC, according to recent studies. Due to the varying efficiency of probiotics depending on the specific strain, substantial research has been conducted on the L. casei strains to explore their potential anticancer effects in CRC. In this study, we aimed to conduct a systematic review of exploring the various mechanisms of L. casei strains to facilitate the development of effective probiotic supplements to complement standard CRC therapy. We conducted a meticulous search on Scopus, PubMed, Embase, and Web of Science. Initial research resulted in 433 records, from which 412 papers were excluded by reason. The remaining 21 papers were categorized into four topics. These papers discuss several mechanisms involved in anticancer properties against CRC, including apoptosis induction and antiproliferation activity, immunomodulation, gut microbiome, intestinal barrier function modulation, and detoxifying carcinogens. Our findings suggest that using the potential strains of L. casei in combination therapy and targeted therapy, along with conventional drugs, could be a promising approach against CRC.