This prospective clinical study investigates whether a dietary supplement product can modulate the gut microbiota and improve ocular surface outcomes in patients with dry eye disease. Participants will be recruited from Istanbul Medipol University Hospital (Department of Ophthalmology) and Liv Hospitals (Vadi Istanbul and Ulus). Each participant will receive the dietary supplement product for 8 weeks. Gut microbiota analyses will be conducted at baseline and week 8. Ocular surface assessments including Schirmer test and invasive tear breakup time (TBUT) will be performed at baseline and week 8.