Therapeutic effect of probiotics on metabolic indices and clinical signs in age-related macular degeneration.

Probiotics positively influence age-related macular degeneration (ARMD) given their propensity to attenuate oxidative and inflammatory stress. We addressed the impact of probiotics on metabolic profiles, clinical indices, inflammatory and oxidative stress parameters in ARMD patients. We performed a randomized, double-blind, placebo-controlled trial analyzing 57 subjects with ARMD aged between 50 and 85 years. Subjects were randomized into two groups, and received daily for 8 weeks either probiotic capsule or placebo. Fasting blood samples were obtained at baseline and after the 8-week intervention for the determination of metabolic profiles and oxidative stress biomarkers. After the 8-week intervention, compared with the placebo, probiotic supplementation significantly increased means HDL-cholesterol (Probiotic group: +3.86±4.42 vs. Placebo group: -0.55±4.93 mg/dL, P = .001), plasma total antioxidant capacity (TAC) (Probiotic group: +77.43±168.30 vs. Placebo group: -23.12±169.22 mmol/L, P = .02) and significantly decreased malondialdehyde (MDA) levels (Probiotic group: -0.18±0.46 vs. Placebo group: +0.18±0.25 µmol/L, P = .001). There was no significant effect of probiotic administration on other metabolic profiles and clinical symptoms. Overall, an eight-week probiotic administration among ARMD patients had beneficial effects on TAC, MDA and HDL-cholesterol levels; however, it did not affect clinical signs and other metabolic profiles.

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 Lactobacillus acidophilus, Bifidobacterium bifidum, Bifidobacterium langum, Bifidobacterium lactis daily (2 × 109 CFU/each strain) (n = 36) or placebo (starch) (n = 36) and were instructed to take one capsule daily for 12 weeks. Finally, 55 participants [probiotic group (n = 30) and placebo group (n = 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, Ptime×group<0.001), homeostatic model assessment for insulin resistance (Probiotic group: -2.5 ± 3.8 vs. Placebo group: 1.1 ± 2.7, Ptime×group<0.001) and hemoglobin A1c (HbA1C) (Probiotic group: -0.4 ± 0.7 vs. Placebo group: -0.02 ± 0.2%, Ptime×group=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, Ptime×group<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.