The effect of probiotics supplementation on the side effects of chemo radiotherapy for colorectal cancer: A literature review

Colorectal Cancer (CRC) is fourth leading cause of cancer-related deaths (8.5%) and ranks as the second most common cancer among women (9.2%) and the third among men (10.0%) worldwide. The main treatments modalities for CRC as all the different types of cancer are surgery, radiation therapy, and chemotherapy. However, such treatments (mainly radio and chemotherapy) have several side effects which cannot be ignored and mainly presented as gastrointestinal toxicity that include infections, mucositis, enteritis, diarrhoea, nausea and vomiting. Probiotics are one of Biological Radio protectors (BRPs) that have been reported to preserve gastrointestinal tract in patients treated with radiotherapy and/or chemotherapy. The main use of probiotics as BRPs is treatment of intestinal toxicity and inflammation induced by radiotherapy, chemotherapy or surgical interventions. These effects may explain by different abilities of the probiotics such as synergistic activity, toxin neutralization, antioxidant property, antagonistic activity, and immune system stimulation. Moreover, the probiotic effect on reducing the side effects during radio- chemotherapy may improve the quality of life in CRC patients during and after the treatment. Further studies on uses of probiotic to improve immune system, inflammatory response and the exact doses with optimum combination of strains to reduce or prevent the side effects occur during treating CRC is needed.