Urbancsek, H., Kazar, T., Mezes, I., & Neumann, K. (2001). Results of a double-blind, randomized study to evaluate the efficacy and safety of Antibiophilus in patients with radiation-induced diarrhoea. European Journal of Gastroenterology and Hepatology, 13(4), 391–396.

To determine the efficacy and tolerability of Lactobacillus rhamnosus (marketed as Antibiophilus) in treating radiation-induced diarrhea

Patients in the treatment group were instructed to use Antibiophilus sachets containing 1.5 grams of Lactobacillus rhamnosus. Patients in the control group used identically appearing placebo sachets containing 700 mg corn starch, 797 mg microcrystalline cellulose, 1.37 mg iron oxide, 1.13 mg orange coloring agent, and 1 mg caramel aroma. Both groups used the sachets three times per day and were asked to document the date and time of any rescue medication.

Patients were between 19–75 years old and had developed diarrhea within 4 weeks of receiving radiation therapy to the abdomen. The experimental group contained 102 patients, and the control group contained 103 patients.

This was a randomized, double-blind, parallel group study.

• The primary endpoint to assess efficacy was the time to and frequency of rescue medication for diarrhea. 
• Secondary endpoints were the number of bowel movements and diarrhea grading (0 for no diarrhea, 1 for mild, 2 for moderate, and 3 for severe).

• A greater percentage of patients in the control group (48%) required rescue medication compared to the experimental group (35%), but the difference was not statistically significant (p = 0.064).
• The control group experienced a greater average number of bowel movements per day (3.2) compared to the experimental group (2.4), but the difference was not statistically significant (p < 0.10).
• Diarrhea was graded at a higher severity for the control group (1) compared to the experimental group (0.7), but the difference was not statistically significant.
• Although the results suggested a superior efficacy for diarrhea treatment in the experimental group, the results failed to show a statistically significant difference for any of the measured variables. Despite this lack of statistically significant differences, the authors concluded that antibiophilus therapy yielded a favorable benefit-to-risk ratio.

• The study population was limited to patients who were already experiencing diarrhea. The study did not provide any data regarding prevention of diarrhea.
• The endpoints were based on patients' subjective reports.

This study involved a large sample. Although the results suggested a superior efficacy for diarrhea treatment in the experimental group, the results failed to show a statistically significant difference for any of the measured variables.