BackgroundThe antimetabolite chemotherapy 5-Fluorouracil is one of the most commonly prescribed drugs in clinical cancer treatment. Although this drug is not specific for cancer cells and also acts on healthy cells, it can cause mucositis, a common collateral effect. Dysbiosis has also been described in 5-fluorouracil-induced mucositis and is likely to contribute to the overall development of mucositis. In light of this theory, the use of probiotics could be a helpful strategy to alleviate mucositis. So the aim of this study was evaluate the impact of the probiotic Saccharomyces boulardii in a model of mucositis.ResultsAfter induced of mucositis, mice from the Mucositis groups showed a decrease in food consumption (p < 0.05) and therefore had a greater weight loss (p < 0.05). The treatment with Saccharomyces boulardii did not reverse this effect (p > 0.05). Mucositis induced an increase in intestinal permeability and intestinal inflammation (p < 0.05). There were no differences in mucosal lesions, intestinal permeability and sIgA secretion (p > 0.05) in mice pretreated with S. boulardii.ConclusionsS. boulardii was not able to prevent the effects of experimental mucositis induced by 5- Fluorouracil.