The effects of probiotics on mental health and hypothalamic-pituitary-adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers.

OBJECTIVE: The aim of this study was to determine effects of probiotic yogurt and multispecies probiotic capsule supplementation on mental health and hypothalamic-pituitary-adrenal axis in petrochemical workers. METHODS: The present randomized double-blind, placebo-controlled trial was conducted on 70 petrochemical workers. Subjects were randomly divided into three groups to receive 100 g/day probiotic yogurt + one placebo capsule (n = 25) or one probiotic capsule daily + 100 g/day conventional yogurt (n = 25) or 100 g/day conventional yogurt + one placebo capsule (n = 20) for 6 weeks. Mental health parameters including general health questionnaire (GHQ) and depression anxiety and stress scale (DASS) scores were measured. Fasting blood samples were obtained at the beginning and 6 weeks after the intervention to quantify hypothalamic-pituitary-adrenal axis. RESULTS: After 6 weeks of intervention, a significant improvement of GHQ was observed in the probiotic yogurt (18.0 ± 1.5 vs. 13.5 ± 1.9, P = 0.007) and in the probiotic capsule group (16.9 ± 1.8 vs. 9.8 ± 1.9, P = 0.001), as well as a significant improvement in DASS scores in the probiotic yogurt (23.3 ± 3.7 vs. 13.0 ± 3.7, P = 0.02) and the probiotic capsule group (18.9 ± 3.2 vs. 9.4 ± 4.0, P = 0.006). However, there was no significant improvement in the conventional yogurt group (P = 0.05 for GHQ and P = 0.08 for DASS). DISCUSSION: The consumption of probiotic yogurt or a multispecies probiotic capsule had beneficial effects on mental health parameters in petrochemical workers.

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.