ALL STEM CELLS

When scientists observed the frequency of colon cancer in the human population, they found that the consumption of fermented dairy products, mainly yogurt, may reduce the risk of colon cancer.
This epidemiological observation suggests that there could be a link between consuming probiotics and a low risk of colon cancer. The first time probiotics were thought to help prevent colon cancer was seen when different populations of people were compared and a difference in colon bacteria appeared to influence the risk of colon cancer. When Japanese-Hawaiians, North American Caucasians, native rural Japanese and rural native Africans patients who recently had a colon polyp removed were compared, the populations whose colons contained Lactobacillus species and Eubacterium aerofaciens had a lower risk of colon cancer. People whose colons contained bad microbes were found to have a higher risk of colon cancer. Thus it would appear that colons with lactic acid–producing bacteria (e.g.,Lactobacillus species) have a lower risk of colon cancer. Th ese good microbes must be causing positive health effects in the colon. Probiotics keep the colon healthy.

What influences the species in the colon microflora? A healthy colon contains a variety of probiotics, particularly Bifi dobacterium. However, changes in intestinal microflora from eating a diet high in meat, high in fat and low in fiber; suffering from stress; or using antibiotics can result in increasing levels of bad microbes (e.g., Bacteriodes and Clostridium) and a decrease in the levels of Bifi dobacterium.

Such a change to the microbes in your intestines results in an increase in enzymes that can turn pro-carcinogens into carcinogens, such as beta-glucuronidase, azoreductase, urease and nitroreductase. This creation of carcinogens increases the risk of colorectal cancer developing. Thus, theoretically by reducing the production of these enzymes by reducing the number of bad microbes in your colon, you can reduce the risk of cancer. In fact, animal studies have found that reducing the activity of these enzymes does reduce the incidence of tumors (cancer). Probiotics may be a way to reduce the presence and activity of these cancer-promoting enzymes in the colon. Bifi dobacteria probiotics may support colon health and prevent cancer development in another way. Bifi dobacteria participate in the metabolism of various compounds including the omega-6 fatty acid, conjugated linoleic acid (CLA). CLA is thought to have anti-cancer effects. By helping the body work with CLA, probiotics can indirectly help reduce the risk of colorectal cancer.

Are there specific probiotic strains that are known to have anticancer effects in the colon? No, there are no known anti-cancer probiotic strains. However, specific probiotic strains have been identified in animal studies as having the ability to reduce the risk of developing colorectal cancer. B. longum and B. breve have been shown to prevent DNA damage by carcinogens. In addition, both B. longum and B. animalis can decrease the formation of lesions in the colon that commonly develop into cancer. B. longum may also have anti-tumor activity making it a great probiotic for defending against colorectal cancer. How exactly Bifi dobacteria prevents colon (colorectal) cancer is not yet known. Long-term, extensive studies are required and eagerly anticipated.

Prebiotics may also help in the colon cancer battle. In the presence of the prebiotic inulin, B. longum appears to off er greater anti-cancer effects in the colon. Studies in rats have shown that when combined, B. longum and insulin reduced the formation of pre-cancerous lesions in the colon. In fact, the probiotic-prebiotic combination worked better than either one alone. Perhaps the more prebiotics and probiotics the better? An animal study found that the probiotic-prebiotic combination of insulin, oligofructose, Lactobacilli rhamnosus and Bifi dobacterium lactis(Bb12) resulted in a significantly lower number of colon tumors than in the animals not receiving the combination. It appears that a healthy population of colon microflora in the presence of prebiotics is a potentially effective way to prevent colon cancer. The symbiotic relationship between probiotics and prebiotics in the colon is well supported throughout research. Ensuring your diet offers your intestinal microflora sufficient prebiotics likely plays a very important role in human health.

Can probiotics reduce cancer risk in humans? Experts are not certain. A prospective trial which is ongoing in Europe is called the European SYNCAN project. It is investigating the effect of L. rhamnosus GG and B. lactis Lb12 on colon cancer and may off er some new information as to how effective probiotics are against colon cancer. Evidence to date suggests that probiotics have protective properties against cancer. Studies have found that probiotics prevent DNA damage, which is an initiator of cancer. Some epidemiological studies suggest that consumption of fermented dairy products, which are good dietary sources of probiotics, might have protective effects against colon cancer. Th us, it is possible that using probiotics may be a natural way to decrease the risk of colon cancer.