Study of the potential radioprotective effects of probiotic bacteria to mitigate gastrointestinal complications after conventional radiotherapy

Intervention 1: Intervention group: 1-Patients will take two capsules (daily) containing several probiotic strains from one week before the start of treatment until 10 days after the end of radiotherapy. Intervention 2: Intervention group: 2-Patients will take two capsules (daily) containing several probiotic strains from one week after the start of treatment to 10 days after the end of radiotherapy. Intervention 3: Control group: Two placebo capsules daily for ten days after the end of radiotherapy.
Primary outcome(s): Quality of life. Timepoint: At the beginning of the study and 8 weeks after the intervention. Method of measurement: Questionnaire.;Gastrointestinal disorders. Timepoint: At the beginning of the study and 6 months after the intervention. Method of measurement: Clinical examination by an oncologist.
Study Design: Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Other design features: Participants will take probiotics for up to ten days after completing radiotherapy, Randomization description: Participants are randomly assigned to three groups to receive probiotics one week before the start of radiotherapy (n = 20), one week after the start of radiotherapy (n = 20) or placebo (n = 20), Blinding description: Randomization will be hidden from researchers and participants until the statistical analysis is completed.Another person who has no role in this clinical trial and is not aware of random allocation gives the capsules to participants.