The effects of probiotics supplements on metabolic indices and clinical signs in patients with diabetic retinopathy, a randomized double blind clinical trial.

Purpose: This study was carried out to evaluate the effects of probiotics administration on clinical status and metabolic profiles in diabetic retinopathy (DR) patients.

Methods: This randomized, double-blind, placebo-controlled trial was conducted among 72 DR patients. Subjects received probiotics including , , , daily (2 × 10 CFU/each strain) ( = 36) or placebo (starch) ( = 36) and were instructed to take one capsule daily for 12 weeks. Finally, 55 participants [probiotic group ( = 30) and placebo group ( = 25)] completed the study. Fasting blood samples were obtained at baseline and after the 12-week intervention to determine metabolic profiles. To determine the effects of probiotic supplementation on clinical symptoms and biochemical variables, we used one-way repeated measures analysis of variance.

Results: After the 12-week intervention, compared with the placebo, probiotic supplementation significantly decreased means serum insulin concentrations (Probiotic group: -4.9 ± 6.5vs. Placebo group: 3.0 ± 7.7 µIU/mL, P<0.001), homeostatic model assessment for insulin resistance (Probiotic group: -2.5 ± 3.8 vs. Placebo group: 1.1 ± 2.7, P<0.001) and hemoglobin A1c (HbA1C) (Probiotic group: -0.4 ± 0.7 vs. Placebo group: -0.02 ± 0.2%, P=0.01), and significantly increased the quantitative insulin sensitivity check index (QUICKI) (Probiotic group: 0.02 ± 0.03 vs. Placebo group: -0.03 ± 0.04, P<0.001). There was no significant effect of probiotic administration on other metabolic profiles and clinical symptoms.

Conclusions: Overall, probiotic supplementation after 12 weeks in DR patients had beneficial effects on few metabolic profiles. This study was registered under the Iranian website for clinical trials as http://www.irct.ir: IRCT20130211012438N29.