A report in Nutrition Action Health Letter notes that, “If you’re not a smoker, the cancer that’s most likely to kill you—other than breast or prostate—is cancer of the colon or rectum. In 1999, an estimated 94,700 Americans were diagnosed with colon cancer and 34,700 with rectal cancer. Within ten years, 55 percent of them will die.”
But we have reason to be optimistic. We can prevent or markedly reduce our risk for colon cancers through our dietary habits. It is in the area of prevention of one of our most deadly cancers, that of the colon, that probiotics offer stellar benefits. We don’t think of the friendly bacteria in our gastrointestinal tract as important components of cancer prevention. Yet, healthy populations of friendly bacteria play many important roles in our body’s quest to defend itself against malignant disease.
“One of the most promising areas for the development of functional foods lies in modification of the activity of the gastrointestinal tract by use of probiotics, prebiotics and synbiotics,” notes a 2002 report in the British Journal of Nutrition. “While a myriad of healthful effects have been attributed to the probiotic bacteria, perhaps the most controversial remains that of anticancer activity.”
Yogurt, and lactic acid-producing bacteria have received much attention as potential cancer-preventing agents in the diet, note researchers at Northern Ireland Centre for Diet and Health, School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland. “It is usually considered that the mechanism of the action is by increasing the numbers of [lactic acid-producing bacteria] in the colon, which modifies the ability of the microflora to produce carcinogens. Prebiotics such as non-digestible oligosaccharides appear to have similar effects on the microflora by selectively stimulating the growth of lactic acid-producing bacteria in the colon.” Evidence for cancer-preventing properties of pro- and prebiotics is derived from studies on fecal enzyme activity in animals and humans, inhibition of genotoxicity of known carcinogens in vitro and in vivo, suppression of carcinogen-induced preneoplastic lesions and tumours in laboratory animals.
In the February 1980 issue of the Journal of the National Cancer Institute, the effect of diet and Lactobacillus acidophilus supplements on fecal microflora enzyme activity was studied in humans.Compared to vegetarians, omnivores eating a Western-type diet had higher levels of beta-glucuronidase, nitroreductase, azoreductase, and steroid 7-alpha-dehydroxylase in their fecal microflora. Removal of red meat or addition of fiber in the form of bran or wheat germ to the diet of omnivores for 30 days had no effect on beta-glucuronidase, nitroreductase, or azoreductase activity. However, the addition of viable Lactobacillus acidophilus supplements to the diet of omnivores significantly decreased fecal bacterial beta-glucuronidase and nitroreductase activities. Thirty days after lactobacillus supplements were curtailed, fecal enzyme levels returned to normal base-line activities. “These findings suggested that the metabolic activity of the fecal microflora was influenced by diet and could be altered by lactobacillus supplements and to a lesser extent by dietary fiber.”
Some of these studies indicate that combinations of pro and prebiotics (synbiotics) are more effective. Epidemiological studies provide some, although limited, evidence for protective effects of products containing probiotics in humans.
Take for example, beta glucuronidase, an enzyme that disrupts our ability to detoxify environmental chemicals and hormones, such as estrogen, that the body naturally produces. High levels of beta glucuronidase in the body appear to put people at risk for both breast and colon cancer.
However, a healthy flourishing population of friendly bacteria helps to displace unfriendly bacteria responsible for producing this enzyme. Your protection against two prevalent, often deadly cancers is thereby enhanced.
Very recent research from the American Health Foundation, Valhalla, New York, indicates that FOS has a significant chemopreventive potential and can prevent formation of precancerous lesions (i.e., polyps) in the colon, markedly delaying the cancer process.
We don’t know precisely how probiotics exert their anti-cancer benefits but believe that by enhancing populations of bifidobacteria, this may result in direct removal of procarcinogens, indirect removal of procarcinogens, or activation of the body’s immune system. In one experimental study, it was shown that a particular strain of L.acidophilus could prevent tumor formation in rats challenged by a chemical carcinogen. The researchers involved in the study postulate that the inhibition of cancer “may involve (a) inhibiting the growth of putrefactive bacteria and in turn reducing the production N-nitroso compounds; (b) direct reduction of secondary nitrites and bile salts . . . and (c) stimulation of intraperitoneal macrophages and their enzymes which may play a role in the antitumor effect . . .”
Tumor suppression via the body’s immune response system may also be affected by the presence of bifidobacteria. Cell wall fractions of Bifidobacterium infantis are known to contain active anti-tumor constituents. Meanwhile, healthy populations of beneficial bacteria activate the immune system’s macrophages and they become more alert on the job.
Bolstering the body’s balance of Lactobacillus acidophilus may truly prevent colon cancer. In an experimental crossover study, 21 healthy subjects were given either milk with viable lactobacillus cultures or milk without the cultures. The fecal concentration of bacterial enzymes that convert procarcinogens into full-fledged carcinogens was significantly reduced within one month in persons receiving the lactobacillus cultures but not in the group receiving the placebo.
In another study, the authors noted that the link between diet and colon cancer is explained, in part, by the alteration of fecal bacterial enzyme activity caused by the Western-style diet, which is high in meat and saturated fat, and low in fiber.
In an in vivo study, using probiotic Lactobacilli “was associated with reduced prevalence of colon cancer and mucosal inflammatory activity,” say researchers from the Department of Microbiology, University College Cork, Ireland.
Breast Cancer
Breast cancer is the cause of over six-hundred-thousand deaths worldwide every year, and forty-six thousand in the United States. The majority of these were among postmenopausal women under seventy: premature death sentences, robbing them of fifteen to twenty years of life. According to a renowned international authority: “It is the leading cause of cancer death in women throughout the industrialized world and in many developing countries.”
Fortunately, breast cancer is another malignant disease that friendly bacteria may protect against. For example, in one experimental study, “the growth of both tumor lines was significantly inhibited by supplementing the diet with nondigestible carbohydrates [i.e., FOS]. Such nontoxic dietary treatment appears to be easy and risk free for patients, applicable as an adjuvant factor in the classical protocols of human cancer therapy.”
Lactobacillus inhibits beta-glucuronidase, the fecal bacterial enzyme that prevents the body from detoxifying more potent forms of estrogen (such as estradiol) into nontoxic forms (e.g., estriol). Toxic forms of estrogen increase women’s risk of breast cancer, but the more benign forms reduce risk. Thus, probiotics may play an important role in normalizing the gut flora that would help to defuse toxic estrogen.
Liver Cancer
Aflatoxins have been shown by studies to be acute toxicants and liver carcinogens. They are found in many food items, especially poor quality peanut butter. In a study that examined the ability of lactobacilli to bind to and kill foodborne carcinogens, this strain of probiotic showed potential in the detoxification of aflatoxin B1, aflatoxin B2, and aflatoxin G1. Binding activity was both time and concentration dependent.
How to Use Probiotics to Lower Your Cancer Risk
Do not consider probiotic supplements as the cancer cure. Consult your physician for your cancer treatment. Take a probiotic supplement containing lactobacilli and bifidus with FOS to supplement your doctor recommended program.