Effects of Probiotics on Biomarkers of Oxidative Stress and Inflammatory Factors in Petrochemical Workers: A Randomized, Double-blind, Placebo-controlled Trial

BACKGROUND The aim of the current study was to determine effects of probiotic yoghurt and multispecies probiotic capsule supplementation on biomarkers of oxidative stress and inflammatory factors in petrochemical workers. METHODS This randomized, double-blind, placebo-controlled trial was done among petrochemical workers. Subjects were randomly divided into three groups to receive 100 g/day probiotic yogurt (n = 12) or one probiotic capsule daily (n = 13) or 100 g/day conventional yogurt (n = 10) for 6 weeks. The probiotic yoghurt was containing two strains of Lactobacillus acidophilus and Bifidobacterium lactis with a total of min 1 × 10(7) CFU. Multispecies probiotic capsule contains seven probiotic bacteria spices Actobacillus casei 3 × 10(3), L. acidophilus 3 × 10(7), Lactobacillus rhamnosus 7 × 10(9), Lactobacillus bulgaricus 5 × 10(8), Bifidobacterium breve 2 × 10(10), Bifidobacterium longum 1 × 10(9) and Streptococcus thermophilus 3 × 10(8) CFU/g. Fasting blood samples were obtained at the beginning and end of the trial to quantify biomarkers of oxidative stress and inflammatory factors. RESULTS Although a significant within-group decrease in plasma protein carbonyl levels was seen in the probiotic capsule group (326.0 ± 308.9 vs. 251.0 ± 176.3 ng/mL, P = 0.02), the changes were similar among the three groups. In addition, significant within-group decreases in plasma iso prostaglandin were observed in the probiotic supplements group (111.9 ± 85.4 vs. 88.0 ± 71.0 pg/mL, P = 0.003) and in the probiotic yogurt group (116.3 ± 93.0 vs. 92.0 ± 66.0 pg/mL, P = 0.02), nevertheless there were no significant change among the three groups. CONCLUSIONS Taken together, consumption of probiotic yogurt or multispecies probiotic capsule had beneficial effects on biomarkers of oxidative stress in petrochemical workers.