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.