Morphometrical analyses of small intestine slices from mice pre-treated or not with S. boulardii and subjected to mucositis induction. 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 the 11th day of the experiment, mice from the Mucositis group received an intraperitoneal injection of 300 mg/kg of 5-FU. A) villus mean height (μm), B) Lieberkün crypt mean height (μm), C) villus mean thickness (μm) and D) ratio between villus and crypt mean height. (*) Indicates statistically significant differences (p < 0.05), n = 3.