Gut Guardians: How Lactic Acid Bacteria in Foods Could Help Lower Colorectal Cancer Risk

Cancer remains one of the most pressing global health challenges, with millions of new diagnoses each year and an ever-increasing burden on healthcare systems worldwide. Despite significant advancements in the understanding of cancer biology and the development of various treatment strategies, many cancers remain difficult to treat effectively, especially in their later stages. Therapeutic options for cancer generally fall into a few major categories: surgery, radiation therapy, chemotherapy, targeted therapy, immunotherapy, and emerging treatments like gene therapy and personalized medicine. Traditional surgical treatment, supplemented by chemotherapy and radiotherapy, has obvious side effects on patients. Immunotherapy may lead to some unpredictable complications. Low introduction rate and high cost are some of the problems of gene therapy, so finding a safe, reliable and least toxic treatment method is extremely crucial.

Colorectal cancer, which includes cancers of the colon and rectum, is one of the most common and deadly cancers worldwide. Affecting both men and women, it often develops slowly over several years, sometimes without noticeable symptoms in its early stages. As the second-leading cause of cancer-related deaths globally, colorectal cancer presents significant challenges in both early detection and effective treatment. Risk factors such as age, family history, lifestyle choices, and certain genetic conditions contribute to the rising incidence of this cancer. While treatments like surgery, chemotherapy, and radiation have traditionally been used to manage colorectal cancer, newer approaches, such as targeted therapies and immunotherapies, are providing fresh hope. However, despite advancements, many patients still face poor prognoses, particularly when diagnosed at an advanced stage.

Lactic acid bacteria (LAB) are a diverse group of beneficial microbes commonly found in fermented foods like yogurt, kefir, probiotic drinks and sauerkraut. Lactic acid bacteria and their metabolites are widely used in functional foods or as adjuvant therapies for various diseases because they are safe to eat and have no adverse reactions.

A study was carried out to investigate the anti-colorectal cancer properties of Lactic acid bacteria. Ten strains of lactic acid bacteria were isolated from traditional fermented foods such as fermented soya bean, fermented goat milk cheese, fermented bean curd and sauerkraut. The HT-29 Colorectal cancer cell line was treated upon. Out of these ten strains, the strain obtained from fermented goat milk cheese (Lb. plantarum AY01), showed high anti-cancer properties. Flow cytometry was carried out to detect apoptosis (programmed cell death) and cell-cycle arrest. Lb. plantarum AY01 blocked the cell proliferation at S-phase, by inducing apoptosis. Apoptosis was induced by activating the p38 MAPK pathway. Active substances present in Lb. plantarum AY01 were separated, purified, and subjected to LC-MS and HPLC, to identify the compounds present in its final separated components. It was detected that 2’-Deoxyinosine was the anti-colorectal cancer active substance present in Lb. plantarum AY01.

It can be concluded that Lactic acid bacteria (LAB) play an auxiliary therapeutic role in colorectal cancer mainly by improving the intestinal flora composition, inhibiting the growth of pathogenic bacteria and inhibiting the proliferation of cancer cells. Regular consumption of foods consisting LAB can prove beneficial to our gut-health, in the long run.

 

REFERENCES:

1. Zhao SH, Zhang SM, Yang JW, Liu CJ, Zeng XQ, Zhang YL, et al. Preliminary study on the active substances and cellular pathways of lactic acid bacteria for colorectal cancer treatment. Journal of Cancer. 2024;15(15):4902–21.

‌