Fuccio, L., Guido, A., Eusebi, L. H., Laterza, L., Grilli, D., Cennamo, V., … Bazzoli, F. (2009). Effects of probiotics for the prevention and treatment of radiation-induced diarrhea. Journal of Clinical Gastroenterology, 43(6), 506–513.

To evaluate the effectiveness of probiotic supplementation for the prevention and treatment of radiation-induced diarrhea

Databases searched were PubMed, EMBASE, Cochrane Library, Google Scholar, and online clinical trials registers (Cochrane Central Register of Conrolled Trials, metaRegister of Controlled Trials, National Institutes of Health) until January 2009. Other relevant trials were identified from the reference list of selected articles. Abstracts presented up to 2008 at the United European Gastroenterology Week meetings, American Society for Therapeutic Radiology and Oncology Annual Meetings, and American Gastroenterological Association Digestive Disease Week were searched manually.

Search keywords were diarrhea, probiotics, radiotherapy, radiation therapy, Lactobacilli, Bifidobacteria, Enterococci, VSL no. 3, pelvic tumors, and abdominal tumors.

Studies were included in the review if they were randomized, controlled trials with at least two parallel groups that evaluated the effectiveness of probiotic supplementation to prevent or treat radiation-induced diarrhea.

Studies were excluded if they were review articles, involved nonradiation-induced diarrhea, or covered radiation-induced gastrointestinal (GI) symptoms other than diarrhea.

The abstracts of 58 articles were reviewed. Fifty evaluated the effects of probiotic supplementation for conditions other than radiation therapy and were eliminated. Of the remaining eight, three were duplicate reports and one studied radiation-induced chronic bowel discomfort rather than diarrhea.

The remaining four studies were selected for this review. Three were randomized controlled trials evaluating probiotic supplementation for the prevention of radiation-induced diarrhea, and one trial evaluated probiotic supplementation for the treatment of radiation-induced diarrhea.

Three studies evaluated the use of probiotic supplementation to prevent radiation-induced diarrhea. A total of 632 individuals initially were randomized to the studies; the final sample sizes were 21, 85, and 482. The study using probiotic supplementation to treat radiation-induced diarrhea had a sample size of 205 patients, with 102 receiving the intervention and 103 receiving a placebo.

• Probiotic supplementation was well-tolerated in the prevention and treatment trials.
• The three trials addressing probiotic supplementation for the prevention of radiation-induced diarrhea did not collectively show significant differences between the intervention and control groups.
• The study addressing treatment also did not show significant differences between the intervention and placebo groups.

The few available studies on the use of probiotics to prevent or treat radiation-induced diarrhea do not allow for firm conclusions to be drawn regarding the benefits of this intervention.

The studies included in the systematic review and meta-analysis used different single strains and different doses of probiotics.

More studies using preparations containing several strains of probiotics and studies looking at comparisons between different probiotics are needed.