Effect of the IRT5 treatment without antibiotics pretreatment in an autoimmune dry eye mouse model. (A) Ocular staining score was significantly lower in the IRT5-treated group (n = 5, 10 eyes) than in the PBS-treated group (n = 4, 8 eyes). However, the phenol red thread test results were not significantly changed after IRT5 treatment. (B) In the conjunctiva and cornea of the IRT5-treated group, IL-1β was significantly lower (P = 0.0434) and IL-10 was significantly higher (P = 0.0343) than in the PBS-treated group. (C) Average taxonomic composition at the family level before and after the PBS (n = 4) and IRT5 (n = 5) treatment is shown. (D) The Firmicutes to Bacteroidetes ratio and alpha diversity analyzed using the Chao1 index were not significantly different between the two groups. (E) Compared to the PBS-treated group, Lactobacillus intestinalis was lower, and the Lactobacillus helveticus group, Lactobacillus hamsteri, and the Staphylococcus saprophyticus group were higher in the IRT5-treated group.