Abstract
Purpose :
To investigate effects of oral administration of probiotics on dry eyes in a Sjögren mouse model
Methods :
12-weeks-old NOD.B10.H2b mice were used as an autoimmune dry eye model. Probiotic IRT5 powders contain 2 × 108 colony forming units (CFU)/g of 5 commensal strains (Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus reuteri, Bifidobacterium bifidum, and Streptococcus thermophilus). The total amounts of IRT5 probiotics were 1x109 CFU in 300µL PBS per mice for an oral gavage feeding. Either IRT5 probiotics or phosphate buffered saline (PBS) were administered orally for 3 weeks after pre-treatment of antibiotics for 5 days. Clinical manifestations were evaluated with phenol red thread test and corneal dye staining with 3% lissamine green B. The changes of T cells were evaluated in drainage lymph nodes using fluorescence-activated cell sorting. Reverse transcription PCR (RT-PCR) for cornea, conjunctiva, and lacrimal glands, and fluorescence-activated cell sorting for drainage lymph nodes were performed. The feces before and after treatment with IRT5 or PBS were collected and analyzed for microorganisms.
Results :
Ocular staining score was significantly decreased in IRT5 treated mice compared with the score of both pretreatment status (p=0.0083, Wilcoxon signed rank test) and PBS administered mice (p=0.0005, Mann Whitney test). Phenol red thread test also showed a significant increase of tear secretion in IRT5 treated mice after 3 weeks treatment (p=0.0039, Wilcoxon signed rank test). In the submandibular lymph node, the percentage of CD4+ T cells and IFNγ-secreting CD8 T cells were significantly decreased after treatment (p=0.0317 and 0.0362, Mann Whitney test), but regulatory T (Treg) cells were significantly increased after treatment (p=0.0317, Mann Whitney test). In the mesenteric lymph node, the percentage of Th17 cells decreased (p=0.0317, Mann Whitney test). RT-PCR showed no significant differences in GM-CSF, IL-23, IL-10, IL-17 in cornea, conjunctiva, and lacrimal gland. In the fecal analysis, microbial diversity was increased, and the butyrate-producing strain, Lachnospiraceae, was more abundant in the IRT5 treated group.
Conclusions :
This suggests that the administration of IRT5 probiotics may improve the clinical manifestations of ocular dryness syndrome through immune regulation by changes in the composition of gut microbiota.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.