Impact of Probiotics on Mucin Production in the Ocular Surface

Abstract

Background: Dry eye disease is a common ocular surface disorder characterized by tear film instability and ocular discomfort, frequently managed using artificial tears with variable effectiveness. Emerging evidence suggests that probiotics may modulate immune and microbial pathways relevant to ocular surface homeostasis and tear film stability. Objective: To compare probiotic therapy with artificial tears in adults presenting with dry eye symptoms, using symptom improvement and tear break-up time (TBUT) as indicators of clinical response. Methods: A comparative two-arm interventional study was conducted in a tertiary care hospital in Lahore, enrolling 384 adults with dry eye symptoms allocated equally to a probiotic group (n=192) and an artificial tear group (n=192). Symptom improvement in dryness, itching, burning sensation, and treatment satisfaction was recorded, and post-intervention TBUT was assessed in seconds. Between-group comparisons were evaluated using appropriate inferential tests, with statistical significance defined at p<0.05. Results: The probiotic group reported high improvement rates in dryness (91.1%), itching (89.1%), burning (93.2%), and overall satisfaction (93.2%), while no improvement was recorded in the artificial tear group (all p<0.001). Post-intervention TBUT was higher in the probiotic group (9 seconds) than in the artificial tear group (6 seconds), reflecting an absolute difference of 3 seconds (p<0.001). Conclusion: Probiotic therapy was associated with substantially greater symptom improvement and improved tear film stability compared with artificial tears among adults with dry eye symptoms. Further randomized trials with validated symptom instruments and objective biomarkers are needed to confirm efficacy and clarify mechanisms.