Jiang C, et al. - In 99 eligible patients who were on concurrent radiochemotherapy (CCRT) for locally advanced nasopharyngeal carcinoma, researchers assessed the severity of oral mucositis (OM, a frequently seen, unpreventable complication of radiochemotherapy). During radiochemotherapy, a probiotic combination or placebo was randomly administered to these patients, and the incidence of severe OM (grade 3 or higher) was assessed. In the placebo group, the incidences of grade 0, 1, 2, and 3 OM were 0%, 0%, 54.29, and 45.71%, respectively, and in the probiotic combination group, these were 12.07%, 55.17%, 17.24%, and 15.52%, respectively. By changing gut microbiota, a probiotic combination caused significant improvement in the immune response of patients and attenuation in the OM severity.