Probiotics, or "friendly" bacteria, have been steadily gaining popularity in the United States since the mid-1990s. According to the National Center for Complementary and Alternative Medicine, sales of probiotics nearly tripled in the United States between 1994 and 2003. Lactobacillus acidophilus, the most popular form of probiotic, has been investigated as a treatment for dozens of conditions, ranging from asthma to liver disease. Emerging evidence suggests that this popular supplement may also offer benefits for the prevention or treatment of colon cancer.
Function
Acidophilus and other lactobacillus probiotics imitate the actions of friendly bacteria that live naturally in the human colon. The live organisms protect the colon from pathogenic bacteria and help to regulate digestion. Like naturally occurring probiotics, acidophilus organisms produce lactic acid, a compound that helps digest sugar compounds such as lactose. In theory, these protective actions may prevent the forms of cellular damage that lead to colon cancer.
Effects
According to the American Cancer Society, acidophilus supplements may act in several ways to prevent colon cancer and other malignancies. In laboratory environments, milk containing acidophilus appears to stop or slow the growth cancerous colon cells. Additionally, rats taking acidophilus supplements experience less DNA damage after ingesting compounds known to cause cancer. The cancer society notes that this preliminary evidence is far from conclusive. No large-scale human studies have evaluated acidophilus' ability to prevent or fight cancer cells.
Benefits
Acidophilus supplements may offer benefits to people with pre-existing colon cancer and those who are undergoing treatment for the condition. According to the American Cancer Society, acidophilus may reduce the severity of diarrhea in patients receiving chemotherapy for colon cancer. The U.S. National Institutes of Health acknowledges acidophilus' theoretical ability to prevent E. coli and other infections in chemotherapy patients. However, large-scale studies have not yet evaluated the safety or effectiveness of acidophilus as a complementary treatment for chemotherapy patients.
Considerations
Some evidence casts doubt on acidophilus' purported ability to prevent or treat colon cancer. The American Cancer Society notes that a related probiotic, Lactobacillus casei, failed to reduce colon cancer recurrence in cancer survivors. The cancer society also notes that acidophilus does not appear to prevent breast cancer or skin cancer in animals. Like many other forms of complementary medicine, acidophilus lacks solid scientific evidence as a colon cancer treatment option.
Warning
According to the University of Maryland Medical Center (UMMC), acidophilus supplements are safe for the vast majority of people. However, certain individuals, including cancer patients, must take special precautions to reduce the likelihood of rare but serious side effects. People who are not taking medication may experience diarrhea after taking more than 2 billion units of acidophilus in a day. High doses of acidophilus can also cause systemic infections in people with severely compromised immune systems. UMMC warns that people taking immune-compromising drugs, including chemotherapy, should consult a health-care provider for dosing guidelines.
