Probiotics protect cancer patients from radiation effects
Scientists at Washington University School of Medicine in St. Louis have shown that taking a probiotic before radiation therapy can protect the intestine from damage — at least in mice.
The new study suggests that taking a probiotic also may help cancer patients avoid intestinal injury, a common problem in those receiving radiation therapy for abdominal cancers. The research is published online in the journal Gut.
Radiation therapy often is used to treat prostate, cervical, bladder, endometrial and other abdominal cancers. But the therapy can kill both cancer cells and healthy ones, leading to severe bouts of diarrhea if the lining of the intestine gets damaged.
“For many patients, this means radiation therapy must be discontinued, or the radiation dose reduced, while the intestine heals,” says senior investigator William F. Stenson, MD, the Dr. Nicholas V. Costrini Professor in Gastroenterology & Inflammatory Bowel Disease at Washington University. “Probiotics may provide a way to protect the lining of the small intestine from some of that damage.”
“The lining of the intestine is only one cell-layer thick,” Stenson says. “This layer of epithelial cells separates the rest of the body from what’s inside the intestine. If the epithelium breaks down as the result of radiation, the bacteria that normally reside in the intestine can be released, travel through the body and cause serious problems such as sepsis.”
The researchers found that the probiotic was effective only if given to mice before radiation exposure.
Because the probiotic protected intestinal cells in mice exposed, the investigators believe it may be time to study probiotic use in patients receiving radiation therapy for abdominal cancers.
“In earlier human studies, patients usually took a probiotic after diarrhea developed when the cells in the intestine already were injured,” says first author Matthew A. Ciorba, MD, assistant professor of medicine in the Division of Gastroenterology. “Our study suggests we should give the probiotic prior to the onset of symptoms, or even before the initiation of radiation because, at least in this scenario, the key function of the probiotic seems to be preventing damage, rather than facilitating repair.”