Weight variation during the experiment. Mice from the Control + Sb and Mucositis + Sb groups were pre-treated with 108 CFU of S. boulardii by gavage for 10 days; other groups received saline by gavage. On day 11 of the experiment, mice from the Mucositis group received an intraperitoneal injection of 300 mg/kg of 5-FU. The weights were monitored daily until day 13 (A), and weight losses represent the difference between the weight on day 11 and day 13 (B). (*) Indicates statistically significant differences (p < 0.05), n = 7; data are representative of three different experiments.