Mucositis is one of the most strenuous side effects caused by chemotherapy drugs, such as 5-fluorouracil (5-FU), during the treatment of several types of cancers. The disease is so prevalent and aggressive that many patients cannot resist such symptoms. However, despite its frequency and clinical significance, there is no effective treatment to prevent or treat mucositis. Thus, the use of probiotics as an adjuvant for the treatment has gained prominence. In the present study, we evaluated the effectiveness of oral administration of the Antarctic strain of Rhodotorula mucilaginosa UFMGCB 18,377 as an alternative to minimize side effects of 5-FU-induced mucositis in mice. Body weight, food consumption, stool consistency, and presence of blood in the feces were assessed daily in mice orally treated or not with the yeast and submitted or not to experimental mucositis. Blood, bones, and intestinal tissues and fluid were used to determine intestinal permeability and immunological, microbiological, and histopathological parameters. Treatment with R. mucilaginosa UFMGCB 18,377 was able to decrease clinical signs of the disease, such as reduction of food intake and body weight loss, and also decreased the number of intestinal enterobacteria and intestinal length shortening. Additionally, treatment was able to decrease the levels of MPO and EPO activities and inflammatory infiltrates, as well as the histopathological lesions characteristic of mucositis in the jejunum and ileum. Results of the present study showed that the oral administration of R. mucilaginosa UFMGCB 18,377 protected mice against mucositis induced by 5-FU.

粘膜炎是化疗药物（如 5-氟尿嘧啶 (5-FU)）在治疗多种癌症期间引起的最严重的副作用之一。这种疾病是如此普遍和具有侵略性，以至于许多患者无法抵抗这些症状。然而，尽管其频率和临床意义，没有有效的治疗方法来预防或治疗粘膜炎。因此，使用益生菌作为治疗的佐剂已获得突出地位。在本研究中，我们评估了口服粘液红酵母南极菌株的有效性UFMGCB 18,377 作为替代品，可最大限度地减少 5-FU 诱导的小鼠粘膜炎的副作用。每天对口服或未用酵母菌处理的小鼠进行体重、食物消耗、粪便稠度和粪便中是否存在血液，以及是否患有实验性粘膜炎。血液、骨骼和肠道组织和液体用于确定肠道通透性和免疫学、微生物学和组织病理学参数。用R. mucilaginosa治疗UFMGCB 18,377 能够减少该疾病的临床症状，例如减少食物摄入和体重减轻，还可以减少肠道肠杆菌的数量和肠道长度缩短。此外，治疗能够降低 MPO 和 EPO 活性水平和炎症浸润，以及空肠和回肠粘膜炎的组织病理学病变特征。本研究结果表明，口服R. mucilaginosa UFMGCB 18,377 可保护小鼠免受 5-FU 诱导的粘膜炎。